Vorshlag BRZ Project Build Thread (aka: the Miata Coupe?!)

[Fair!]

So I know this isn't exactly a Miata build, but this chassis damn close to a Miata, and many Miata owners are buying or at least considering the FR-S and BRZ. Hope putting this here doesn't upset Miata purists. :)

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BRZ Project Introduction - August 28, 2012: We here at Vorshlag have had a cautiously optimistic view of the FT-86 Subaru/Toyota RWD joint venture starting 3+ years ago when the car was first announced. As soon as the pre-production cars started circulating the USA (January-February 2012), we went to a local Subaru dealer and measured all sorts of things (which you can read about in my February 2012 post here).

We noticed several things about the pre-production car pretty quickly, such as the many similarities with production Subaru model parts and some notable exceptions. The placement of the engine was uncharacteristically far back for a Subaru, which helps explain its more ideal 56% front weight bias.



The basics looked good, but as with any production built car, it looked to have some compromises that we felt we can improve on. We had a quick pow-wow and came up with some plans, then the same weekend we took measurements on the blue pre-production BRZ, Matt here at Vorshlag placed an order for a 2013 Subaru BRZ Limited in the same World Rally Blue.



Months went by with his Dallas based dealer without any ETA for his order, while other BRZs were arriving for weeks at this same dealership. He lost patience with this process, cancelled his order, and found an identical car sitting on a lot in the state of Connecticut. His car finally arrived on July 18th and he began daily driving it while we worked on a Subaru build for Pikes Peak. Once that STi project was finished and the race was over, we finally got a chance to get his BRZ into the shop to corner weigh it, remove a few parts and scale them, and measure the suspension in more detail.

Purpose & Goals

Like we often do when a new chassis comes out, this particular BRZ is going to be a test mule for new Vorshlag parts. It will be primarily a daily driven street car, but also set-up to run in the SCCA autocross class called "STR" (until the Solo Events Board wises up and moves it to the STX class, where I think it belongs). The rules for that class limit the tire width to 255mm and the wheel width to a maximum of 9" wide. The suspension options are fairly open so we can do springs, coilover shocks, camber plates, bushings, some control arms, swaybars, and more - so long as we don't move any of the suspension pick-up points. Engine mods are pretty restricted, but full length headers are legal (with cat placement rules) as well as a lightweight cat-back exhaust, a cold air intake and engine tuning. We will either make these items or source them from other vendors.


Vorshlag camber plates for use with OEM springs require a new upper spring perch made with a modified stock or CNC aluminum perch

One of the first parts that we will test are our FT86 camber plates (which we've already sold for many coilover equipped FR-S and BRZ models). This car's front spring diameter is unique for Subaru and will require a new upper spring perch design to work with the FT86 chassis OEM front springs or OEM-style lowering springs. All of our camber plates include a new upper spring perch with a sealed radial bearing inside. Swift Springs has new Sport lowering springs coming from Japan that we will install as soon as they arrive. Whiteline has some bushings and bars that will be added to the car when they are available, too.


This weighing still had all of the "trunk junk", 3/4 tank of gas, and came in at 2775 lbs.

We don't plan on making this into a gut-crushing race car, but a better handling, fun street car and hopefully faster for autocross and track use. We had originally planned on testing the first pre-production AST 4150 monotube coilovers for the FT86 chassis, but they were sent to another dealer, so we're waiting for the second test set. As soon as we get coilovers on the car we will post in this thread with our impressions. The corner weight shown above shows 55.9% weight over the front axles, which is exceptional for any Subaru we've ever weighed. Many times their FWD or AWD models approach 60/40 weight bias, but the lack of AWD allowed the engineers to move the engine and transmission back (and low) for a better F/R bias and lower Center of Gravity (CG). We plan to lower that 2775 pound initial weight and will show the weight loss for each part we replace.

First Mod: Better Wheels & Tires


Look how narrow and "tucked" inboard the factory wheels and tires look on this wide sports coupe.

The first upgrade for Matt's car was a wheel and tire change, since any kind of competition on the factory rolling stock was going to be an exercise in frustration. This is a great handling car from the factory, for sure, but the one major deficiency of this car that almost all car magazines have agreed upon is the factory tires. The relatively narrow 215/45/17 Michelin Primacy HP tires are what come on the European model Toyota Prius, which tells you it is about as far from a performance tire as they come. This is a low rolling resistance tire, first and foremost.

(continued below)

[Fair!]

I got a lot of grief earlier this year for calling the factory BRZ tires "Prius tires" (even though that's exactly what they were), and at the time it was from people who had never seen or driven these cars. I suspected at the time that these skinny, low grip tires would make the cars test poorly by the car mags (it did) and be a significant hindrance to the on-track performance of this new model. Once Car&Driver (article) got their hands on the car, they felt the same way and simply swapped the Prius tires for an identically-sized Dunlup Direzza Star Spec. They dropped over 2.3 seconds on their one minute and thirty second test course (article). These Primacy tires will help you eek out another ~1/2 mpg better on the highway than a wider performance tire, if you are a Hyper Miler. If you are an automotive performance enthusiast, you will very likely want to make a wheel and tire upgrade a high priority.



I've already seen dozens of BRZ and FR-S owners upgrading to 7.5" and 8" wide wheels, but we at Vorshlag have never been shy about stuffing as much wheel width under a car as possible. A larger wheel can support a larger tire and with a larger tire you can get more grip! Tire heights do have to be considered, but a taller tire can have an advantage in autocross situations where an extra 1-3mph in 2nd gear can make all the difference. I only stop adding wheel width when we get tire rub, and even then I'll roll a fender and try to get more if we can. After some early measurements before Matt's car arrived, then a bit of a gamble, we went with a 17x9" aluminum wheel that has an +42mm offset front and rear. These bolted on with perfect inboard clearance. The rear can take more wheel width, but the front is pretty maxed out until we can get some more negative camber with our camber plates. This is definitely a car where a "square" wheel set-up will be best for street/competition usage (same width front and rear).

Now I will point out that going from the stock 17" wheel diameter up to 18" wheel diameter gains you nothing performance wise but higher cost & weight on both the wheel and tire. If you keep the same tire diameter (to not alter gearing or speedometer) this +1 wheel diameter change would result in a shorter sidewall height, making the ride quality worse and the additional weight can adversely affect handling. That was failure number one in Car&Driver's article when they started messing with wheels and tires beyond just slapping better tires on the stock wheels. They used an 18x7.5" wheel (still too narrow) and a tall 235/40/18 Dunlop tire (almost a full inch taller in diameter) and slowed down 0.7 seconds from the 215/45/17 Dunlop tires on that same road course. Classic mistake where upping wheel diameter for no reason other than style bit them in the ass. Don't fall for the "+1" trap, just stick with 17" wheels on your BRZ or FR-S for the best performance. Competition racers might even look at 16" wheel diameters, which should easily clear the small-ish brake rotors, but trying to find wide performance tires in 16" wheel diameter is just about impossible these days, so back to 17's you go.



The tires installed were 245/40/17 Michelin Pilot Super Sport's. Personally, I would have used a 255/40/17 tire from Hankook (RS-3) or Dunlop (Direzza Star Spec), but Matt wanted to test this new PSS model. Since Michelin doesn't make a 255/40/17 in the new PSS yet, he bought the widest he could find in the right diameter (to not alter gearing), which was 245/40/17.

This 17x9 wheel is a big performance boost, being a full two inches wider than the somewhat heavy 17x7" stock wheels (20.4 lbs). The addition of wider aftermarket wheels and 30mm wider 245/40/17 tires was still a total wash with regards to weight: the original equipment 17x7" wheel and 215/45/17 tire was was 41.3 lbs, while the 17x9" wheel and 245mm PSS tire weighed 41.4 lbs. I've seen this same sized 17x9" wheel weigh as much as 2 pounds lighter per corner, so there could still be weight loss to be had here if someone makes an uber-light fitment for this car. This particular 17x9" is not a wheel we can sell (it is exclusive to another wheel dealer), so we will evaluate this sample set and come up with an alternative that we can market and sell, soon. From our search of many wheel catalogs there are barely any quality 17x9" wheels right now that fit this car (5x100mm bolt pattern is the tough variable), but I'm sure there will be if this car stays as popular as it is now.



I drove this car last week on the new rubber, which was the first time I have driven any car on the Michelin PSS, and I was impressed. They were MUCH quieter than Hankook RS3's or Dunlop Star Spec's (which end up being on about 80% of our customers' cars). Lots of dry grip, responsive as hell (it helped that these were 245mm tires on 17x9" wheel) and the ride was excellent. Matt didn't want to go with the RS3 or Dunlop in 255/40/17, because he's owned and driven on both of those tires and was tired with the noise and poorer street ride they tend to provide. However, for a "street tire" autocross class or track use I would use one of those other two models in a heartbeat.

The 2700 Calorie BRZ Diet

As usual, this car came in significantly heavier than the earlier claims made by the manufacturer, forum fan boys and magazine speculation. I'm not picking on this car in particular because this ALWAYS happens. Before the Honda S2000 was released many people bragged that it would only weigh 2400 pounds, but it came out at over 2850. It's an old story - the promise of a fly weight car that ends up being heavier when the actual production model hits the showrooms. Crash standards, luxury options, and emissions equipment all conspire to add pounds.

The FT86 chassis was supposed to be 2500-2600 pounds and it's nearly 2800, so we will focus some of our efforts on lowering that number. Each time we remove a factory part we will show the weight, as well as whatever goes on to replace it. Lower weight means more performance in every vector, be it cornering, braking or forward acceleration. 5 pounds here, 10 pounds there - it will add up.



Matt left his BRZ unattended when he went to lunch one day last week. It was on the lift so we could measure some things, so I pulled the exhaust off for a quick check (then sent him a text with pictures of his car in pieces - hehe!). The muffler was surprisingly light, as was the entire after-cat system. At a hair over 38 pounds, the after-cat exhaust is not a place where we are going to find a big weight loss. A typical exhaust on BMWs we work on can exceed 90 pounds, and dropping 30-40 out with a lightweight racing style exhaust and muffler on those is common... but that will not be the case here.



That suitcase-sized rear muffler is the heaviest part of the system, of course, but must not have much "heavy" inside. I was pretty bummed, thinking this was be a good place to lose weight. Most of the aftermarket mufflers we use are still 8-13 lbs, so there are still some weight savings to be had. The stock exhaust is quiet and could be restrictive - we shall see.

We did see a lot of steel in the control arms and such, which could be replaced with aluminum by the aftermarket or maybe a future, rumored "STI" model, like the STI model Imprezas often do. We will check what this stuff weighs and see what we can do. The factory exhaust manifolds might hold some pounds we can drop, so when we get a chance to pull those off we will get a weight and think about a custom header. Might unleash some power, too.

Initial Impressions

I have owned and driven a wide variety of sports coupes and roadsters and the BRZ does not disappoint. The normal complaint with a Miata that I run into with my height is a general lack of headroom, but that is not a problem on the FT86 chassis. The interior is roomy and the greenhouse has excellent visibility, with the exception of the B-pillar creating a bit of a blind spot on the left side (this can be mitigated with proper side mirror set-up). The chassis feels tight and has none of the cowl shake and rattle I always feel in a Miata or other roadsters. The car rides well and handles like a Miata (except less roll), with instant steering response and very neutral handling - especially on the 245 Michelins stretched out on the 17x9" wheels.

The interior quality is exceptional for a car in this market niche, and the radio sounds really good. The pedals, steering wheel and shifter are all placed perfectly, other than an unusual angle of the wheel relative to the dash when I have it adjusted so that I can see the gauges. It just looks a little off, but I don't notice it once I start driving. Exceptionally good seats that I would not be in any rush to replace, which is rare. The back seat area is more of a package shelf than room for even tiny humans, but this still makes the car more useful around town than something like a Miata. I like the fact that it has a trunk and not a hatch back, too.


We know nothing about this turbo kit, so please contact Dynosty with any questions! This is simply a reference for the stock power level.

Having driven it hard on the street I can say that I do like it, but of course I wish it had more power. The 200 horses that this motor is rated at are all up top, and you have to wind it up to get it really going. It doesn't help that my daily driver has nearly three times the horsepower, so I guess I am a bit biased when you hand me a car that makes around 155 whp. Drive it hard enough and around several corners on some grippy tires and you forget all about the lack of power, because horsepower was never what this car was about. It is a true driver's car, with a quick steering feel, easily darting around back roads or carving corners on a purpose built road course. Low(ish) weight and lower cost consumables, great controls with proper manual gearbox shift feel.



This car really is a blast to drive as long as you don't have a Viper or Z06 sitting in your garage, and I think Subaru and Toyota have a hit on their hands. The look and performance of the FT86 appeals to a fairly diverse audience and will likely turns heads for quite a while. After my very first drive in this car, I parked at a restaurant and had two random older gentlemen walk up and ask me "well, how is it!?" They couldn't take their eyes off the car and knew a lot about it, which was odd for "non-car-guys".

Some of the deficiencies I point to in my post exist because they have to sell it to just about anyone, from a grandmother to a teenager, so I get why it has the compromises it has. I am fairly confident we can improve upon the various performance aspects of this car for the true car enthusiasts that want to buy this car: to make it lighter, handle better, generate more grip, and maybe even accelerate harder.

Stay tuned and let's see what we can do.

Cheers,

Terry Fair @ Vorshlag Motorsports

[Sharpie]

Thanks for sharing. I'm super impressed with what your shop is pulling off these days.

[altiain]

Before the Honda S2000 was released many people bragged that it would only weigh 2400 pounds, but it came out at over 2850.

What S2000 weighs over 2850 pounds? A stock AP1 or CR with a full tank of fuel is closer to 2750 pounds, and it includes a steelie donut spare, unlike most currect production cars. STR-prepped S2000s can quite easily get below 2600 pounds.

[slowchildmiata]

Quoted from Honda... 2864lbs

http://automobiles.honda.com/certifi...fications.aspx

[OZMDD]

Wow. Thats nearly 500 lbs more than mine, 400lbs for a zero-option CR w/o the HT. No wonder the NC can hang with the S2K in most situations other than straight lines.

[Fair!]

What S2000 weighs over 2850 pounds? A stock AP1 or CR with a full tank of fuel is closer to 2750 pounds, and it includes a steelie donut spare, unlike most currect production cars. STR-prepped S2000s can quite easily get below 2600 pounds.

Well... I think some folks can get pretty fast and loose with weight facts on the internets. Not saying you are, just that maybe weight numbers posted on some forums are optimistic sometimes. I believe what I can see and measure for myself. That seems awfully fishy that a "bone stock AP1" weighs under 2800 with a full tank of fuel. I'd have to see it myself.

I have weighed hundreds of cars at our shop and while working impound dozens of times at various National Solo events. Real, stock, non-CR S2000s are over 2800 pounds. Here is an S2000 CR with weight pics we took. This car that was heavily prepped for AStock and all the normal trunk junk was removed and the exhaust system was cut off behind the resonator, but with the hard top installed.



Picture at left (2928 lbs) is with driver, picture at right is without. At 2788 lbs without an exhaust after the cat and without any trunk junk/spare tire that is still pretty darn light, but its heavier than a bone stock BRZ with trunk junk and more than 1/2 tank of fuel. I don't know what the hard top weighs. With lightweight race wheels and Hoosiers that S2000 CR would drop another 20-30 lbs, but another 190 pounds? I just don't see how this car could get down to 2600 even in STR form, but if you show us an STR CR car on the scales with the weights I could potentially eat some crow. Maybe the stock seats are 95 pounds each?

That link to the bench racing S2K forum thread where someone calculates every pound from published data... well, that's exactly what is wrong with many internet forums.


note the exhaust system was gone behind the resonator



Bone stock RX8 at 2862 lbs

The RX8 is another lightweight car, especially considering it has 4 doors and a usable back seat. Mazda has always been a bit more frugal with the pounds. Subaru and Toyota did a pretty good job on the BRZ, but it still missed the weight target they were aiming for (within 100 pounds of the NC MX5).

Thanks,

[Nails]

It doesn't get too hot for the zip ties?

[miataspeedracer]

Great write-up!

In my head, I'm doing mental math on a new BRZ vs. a well-prepped NC with suspension bits, I/H/E, better wheels/tires, hard top, etc. I think you could build an awesome NC for $28K that would run with a BRZ on the track.

[altiain]

Terry,

A couple of things to note – the S2k hard top weighs about 45 pounds. You also don’t note whether that CR has A/C and/or a radio (both available as factory delete options). A CR without hardtop, A/C, or radio is only 20-30 pounds lighter than an AP1.

Non CR AP2s are heavy. Like 80+ pounds heavier than AP1s, and just got heavier as the model years went on. The CR starts with an AP2 chassis (and all the additional steel and bracing that was added over time), Adds quite a bit of body cladding (front bumper extension, rear wing, cowls behind the seats), then drops weight by deleting the soft top, radio, and A/C.

At the Colorado ProSolo last year, three well prepared STR S2000s were weighed. Thorne’s CR was 2579 pounds, Robert Carpenter’s AP2 was 2666 pounds, and Melchior’s AP1 was 2588 pounds. Note the AP1 is within 10 pounds of a "semi-delete" CR (no radio, no hardtop, partial A/C removal).

[OZMDD]

2370 ftw! :d

[slowchildmiata]

2370 ftw! :d

Cheater car!

[Fair!]

Forgot to update this thread after it got a bit derailed in S2000 weight arguments. And since I can only do 10 pics per post these updates will be broken up a lot...

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Project Update for October 2, 2012: Well a lot has happened in the last four weeks since my first BRZ post. We've been super busy with some big race weekends, and have been working on several LS1 swaps in-house among other cars. Still, we have made some strides on this FT-86 project. First, the SCCA classing news.

FT-86 Twins Classed In STX!

If you are interested in SCCA autocrossing this FT86 chassis, there were some notable things said and seen at the 2012 SCCA Solo Nationals. We noticed a number of FR-S/BRZ cars entered in C Stock and a few in Road Tire, but the car was not classed in Street Touring category for this years Nationals, which was held last month in Lincoln, Nebraska.


Left: We saw seven FT86 cars at Nationals in CStock and RTR. Right: Our ESP Mustang did all right with four months of ESP development

I went to the SCCA Town Hall Meeting and it was said there that the FT86 twins would be classed in Street Touring soon after Nationals. It was inferred to me personally that the twins would go to STR, racing against the S2000, 3rd Gen MX5, and the other roadsters in that class. I felt this was a bad idea and that it belonged in a slower class, STX, which is made up of heavier 4 seat cars like the FT86 chassis. Behind the scenes the SEB and STAC (the two groups that class cars in ST) were split down the middle, and I "read the tea leaves" as they would be conservative and put this car in the faster class.


There's two things you don't find in Nebraska: good Mexican food and predictable weather

I made predictions soon after Nationals that the twins would go to STR, but was thankfully wrong, as this October 2012 FasTrack notification a couple of weeks ago placed the BRZ and FR-S into STX class. There are very few preparation differences between STR and STX classes, with X having a 265mm tire width maximum and R being 255, but both are limited to a maximum of a 9" wide wheel. The rest of the rules are identical - header-back exhaust, high flow cat, cold air intake is somewhat unrestricted, outer fender contours cannot be changed, but suspension has lots of allowances. You can't use metal bushings or move pick-up points (avoid those silly "anti-lift kits"!) but you can use coilovers, camber plates, poly/plastic bushings, and more. Great classing choice b the SEB and STAC, and I commend both on their choice and apologize for ever doubting their wisdom.


These are your typical STR (S2000, left) and STX (325 & 328 E36, right) front running car models

I made some statements on roadraceautox forum (aka: The Sandbox) that, if I was wrong about these cars going to STR, I would eat crow, dance a jig and prep Matt's car for STX. Ran out of time today and didn't get to take a video of me "dancing a jig" but we will do it this weekend at the NASA event. I have never been happier to be wrong, too. The SEB still has a 12 month window to change their mind when they first class a car, so if the FR-S or BRZ proves to be dominant in STX they said that they will move it to STR, potentially before the 2013 Solo Nationals. So if you prepare your car for STX just... be careful not to go TOO fast at a National Tour or ProSolo. :P

This STX classing for the twin has already made a big impact on racers - just today a long-time SCCA Solo racer called me and said "As soon as I saw the STX classing I bought a car that week!" Again, I don't feel the FT86 twins will be a threat to STX, but they should at least be competitive here, unlike in STR, where they would have been cannon fodder.

Whiteline FT86 Parts Going On

We at Vorshlag were already an Energy Suspension and Powerflex bushing dealer, but picked up Whiteline products last month as well. This was because they had some new bushings, Watts Link kit, control arms and relocation brackets for our twin 2011 & 2013 Mustang GTs that we needed. We put them to the test at the Solo Nationals and Global Time Attack events last month and did very well at both. When one of their reps came to our shop before the GTA event, he saw that we had a BRZ project and offered up some new goodies to test straight away. The early FT86 items from Whiteline available right away were two of the WRX/STi holdover parts that made it to the FT86 unaltered.



The first thing we installed was the Whiteline transmission mount bushing insert, part number KDT926, shown above. We have these ready to sell, of course. This kit is a polyurethane shifter bushing insert that fills a massive void in the OEM transmission bushing. Installing this bushing took minutes from underneath and it really tightened up the shift feel, but added a tiny bit of NVH in the process (noise/vibration/harshness).



You can see the gap in the OEM bushing above left and the Whiteline insert installed above, right. The main bolt from the bottom secures the insert in place. Very easy install and very worthwhile for anyone wanting a better shift feel or anyone doing competition events where this is allowed. Matt says it has a little extra vibration at 750-800 rpm and a little more engine noise at 2500-3500 rpm. It isn't too harsh and I barely noticed it myself, but just wanted to warn anyone. He says it has become less noticeable since he has been driving it for the past week.

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[Fair!]

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Next up was the Whiteline polyurethane rear crossmember bushing insert kit, part number KDT922. We also have this ready to sell in our FT86 model section. This kit has two-piece polyurethane inserts for the rear crossmember bushings, which are made of rubber and also have BIG voids in them to make it all squishy and sloppy. Again, the OEM has to make these cars 100% smooth for every single type of driver on the road, but enthusiasts and competitors are going to want firmer bushings in several places.


Left: Stock bushing installed. Right: Whiteline KDT922 kit installed

This rear crossmember insert kit prevents the rear differential housing from having to "wind up" against those big, open rubber bushings. They are easy to install (and easy to remove later, if the car gets sold) and tighten up the reaction time from when you mash the throttle to the car accelerating forward. Once the car was in the air, the rear subframe was lowered an inch or so and these inserts were bolted above and below the rubber bushings, removing the gap and firming them up. It took about 45 minutes.


Here is a animated GIF showing the installation of the KDT922 kit

Swift Lowering Springs, Test 1


Left: OEM ride height reality. 15" from fender lip to center of wheel, F&R. Right: Photoshopped ride height goal, about 1.5" lower?

One of the most visually irritating things about this car, after we replaced the OEM skinny wheels and tires, was the tall stance. Again - Subaru and Toyota had to make the FT86 twins work on almost any sort of road or weather condition (think: heavy snow drifts), so they made it sit up tall and have relatively soft springs. We measured Matt's BRZ at 15" from center of wheel to fender lip on all four corners. Measuring this way will not change with tire height changes, so it's how we measure all cars that have unaltered fender lips.

One of the first and most popular suspension upgrades on many sports cars is a change to "aftermarket lowering springs". These usually lower a car 1 to 1.5 inches and stiffen up the rates 10-30%. There are several brands and options for the FT86 and we carry both Eibach and Swift. Most lowering springs have a variable rate design, where the first inch or so of travel is OEM soft, but then the coil spacing changes and they get stiffer after that amount of displacement.


Left: OEM rear spring next to Swift Lowering Spring. Right: OEM rear shock and Swift spring.

Swift heard about our BRZ build and sent us a prototype set of lowering springs for the FT86. Well, it was more like we begged them to send us their first set (after they had done their in-house testing on them) so we could at least show something going on with this car (because our coilover shocks are very late). They warned us that this set of Swifts was not the final production version and that the ride heights were not what they targeted, so I'm not giving any stats or impressions on these just yet. We were just happy to get the first test set on Matt's car and will revisit this when the revised production springs are available.

more below

[Fair!]

more from above


Left: Front Swift spring on OEM strut. Right: Rear OEM shock and Swift spring.

The ride height is a bit lower, but it is not dramatic. I suspect that the production kit will be closer to 1" - 1.5" below the stock 15" number. We raised the front a tick with our prototype camber plate + OEM perch solution, which I will explain below.

Vorshlag Camber Plates for OEM Spring Prototypes

We have already been selling camber plates for the FT86 for a few months, but so far we only support the coilover offerings that use a 2.25", 60mm, or 2.5" ID linear springs. This is because our Vorshlag camber plates always come with a new upper spring perch with an integral sealed radial bearing inside - it is a long story, but this is why our plates don't wear out or make noise or have funky steering feedback. Whenever we make a new camber plate design it gets the coilover perch first, then we tackle the OEM perch second. The FT86 uses many Subaru GD chassis parts and our high caster Vorshlag camber plates work perfectly on this car. But the Impreza GD's front OEM spring diameter is very different than the FT86's spring diameter, so we had to make something custom.



Making the OEM perch for our camber plates is a lot more involved than just fitting it to the factory diameter spring (which aftermarket lowering springs all match). To do it correctly it requires a lot of calculations, modeling and some testing to get the final camber plate + perch assembly to match the factory ride height. What we don't want to ever do is raise or lower the ride height in the new camber plate + perch assembly for an OEM/aftermarket lowering spring application. For a coilover car we actually try to minimize the stack-up height, to increase total stroke; ride height can be adjusted with the adjustable spring perches inherent to coilovers.



We took Matt's car apart a couple of weeks ago and measured the factory spring diameter and modeled the OEM top mount and upper perch, but have not had time to do the full 3D design work necessary to make an all new upper perch explicitly for this chassis/spring. But we had just finished all of this design work + prototypes + testing phase for the BMW 1M OEM perch and had an extra pair of early 1M prototypes sitting on the build table when the BRZ Swift lowering springs arrived. Lo and behold, they were almost perfect fit to the FT86 front spring diameter!



So when we did the Swift spring install on Matt's car we machined a custom set of BRZ upper perches in the lathe from a 1M prototype set and - viola! - we had our first BRZ OEM spring perch solution. After installing them it looks like it needs some more tweaking to be the perfect solution for the FT86, but for now it allowed Matt's BRZ to get up to -3.0° of negative camber in the front! His BRZ started out with -0.2 to -0.4° on the front end (and we verified this OEM camber setting range on a friend's FR-S also) so that is a big gain, and it can go right back to the stock setting (and a little beyond) for a big range of adjustment.


Here's how it sits with our prototype camber plate + OEM perch and prototype Swifts.

Again, please ignore the ride height of this car in the picture above. This has both prototype Swift springs and prototype Vorshlag plates with OEM perches. Both designs are not quite 100% yet - we still need to tweak the front OEM style Vorshlag perches a bit, and the lowering springs are not production lengths either. The raised front relative to the rear is from our camber plate, not the Swift springs, too. We will readdress this in a future post when both production parts are ready. Should be a matter of weeks. These Vorshlag OEM style upper perch + Camber Plates are not for sale at this time; we are only supporting coilover spring diameters for our FT86 plates right now.

last one below

[Fair!]

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Issues With The Car

Matt's BRZ has logged a tick over three thousands miles on the odometer now and two small issues have cropped up. First thing we noticed visually was the right rear taillight housing is showing water inside. This is likely from a crack in the foam rubber seal between the outer lens and the tailing housing itself, and condensation has entered. My brand new Mazda RX8 did this when it was about the same age (two months old). Matt will have the Subaru dealer replace the leaking housing under warranty.


We over-filled the blinker fluid!

The second issue is the 3rd gear synchronizer seems to be shot, and it hasn't been abused. This started happening weeks before the Whiteline transmission bushing insert was installed, which had nothing to do with the synchro failure. I drove the car when it was a week old and it shifted smoothly into each gear, with fast or slow gear changes. Matt has only been daily driving this car to work and on a couple of trips, he doesn't speed shift or drive like a maniac, and almost every car he has ever owned was a manual. I don't think it is user error. But today when I drove it with 3000 miles the synchro is snicking badly unless you shift 2-3 like a grandma. It takes a "1....2....3..." count to get it onto 3rd without crashing. It doesn't seem to occur below about 4k RPM, but above that it will grind even with the most gingerly shift. Again, I just saw this first hand and was shocked. This will be another thing to mention to the dealer for repair under warranty.

Not trying to spook anyone - these are not necessarily unexpected issues with a brand new design like this. And also I had a then brand new model 2005 RX8 showing more issues than this - a blown strut, end link fell apart, taillight housing was full of water, and it got horrible gas mileage - so just be ready if these issues pop up. We are seeing a sample set of one here, so these two problems do not necessarily mean this is a trend.

What's Next?

We have more production FT86 Whiteline parts coming right after the SEMA show next month, hopefully. We have a three track events at Eagles Canyon Raceway coming up int he next 6 weeks (NASA Oct 6-7, SCCA PDX Oct 13-14, Five Star Ford Open Track day Nov 17) but Matt is out of town for two of those. Hopefully we can get it on ECR (our main test track here in town) at the November event and get some baseline test laps in.

Thanks,

[Fair!]

Project Update for December 28th, 2012: Well, we made it past the Mayan Apocalypse so I guess I can finally post up the work we've been up to for the past three months on various Subaru BRZ and Scion FR-S cars. We have done a bit with Matt's BRZ, drove it at two track days, installed various Whiteline parts and springs into multiple FT86s, and more. I worked on this update for two solid days, so it got pretty long. Let's get started. :)

BRZ Baseline Dyno Testing

Vorshlag isn't a "engine tuner" shop in any shape or fashion - we don't own a chassis dyno and likely never will. The only things we do to add horsepower are custom fabricated exhaust systems and LS1 V8 swaps, but we don't do any on-site engine building or tuning. So to do any power testing, we have to go to a few local shops that have chassis dynos. Back in mid-October, we took three of our shop cars to a local speed shop we use for tuning our Mustangs (True Street Motorsports) and got 2-3 baseline chassis dyno pulls on each. The BRZ was one of these cars, as was our brand new and bone stock 2013 GT (378 whp) and our headers/cold air equipped 2011 GT (424 whp).



Not only do we have dyno pulls done on our cars to see baseline stock numbers we are starting with, we do it after each power upgrade to verify results as well as sort of "regular engine health check-up". Kind of like an annual physical at your doctor, an annual dyno pull is a good test to make sure all systems are performing how they should. If you see big changes from the same tune/set of parts, it is worth investigating. You do this not only by looking at the peak dyno numbers but also checking the shape of the torque and hp curves (looking for irregular humps, drops or spikes) and also checking the air:fuel ratio (any decent shop that has a dyno will have a wide band O2 sensor reading as well).

Everything looked fine on all three cars and the baseline numbers on the BRZ were right about what we figured they would be. We have one dyno chart showing all 3 cars, and you can see the BRZ plot way down at the bottom. Hey, it is not a horsepower killer!



So there it is - the 167 whp BRZ monster dyno pull. This will be the baseline for hopefully some power improvements. Looking at the shape of the curve told us how the motor pulled through the rev range, with most of the power concentrated from 5000-7000 rpm. With the 6-spd gearbox, the ratios are pretty tight, which meant we knew that shifting at 7000 rpm was probably best, as the power fell off a cliff above 7K. When I was at a track day instructing with someone in an FT86 recently, who was shifting every gear on every lap at the 7500 rpm redline, you could feel the engine power falling off hard at the higher revs. I told him about the shape of the dyno curve above and asked him to shift at 7000 rpm instead. Lap times immediately dropped a full second and engine wear went down considerably (friction goes up with RPM nearly exponentially). Knowledge is power... in this case, literally.

From research done by looking at results from tuner shops, most bolt-on mods that add power to other cars are not showing significant gains on these FT86 cars. We have seen beautifully made, custom mandrel bent exhausts lose power on an FT86. Cold air kits that make the engines run poorly. It all boils down to the ability to add a custom tune - which is proving elusive to the various tuner shops, for now. Once the Toyota/Subaru engine management code is cracked, there could be potential gains to be had. For now we recommend concentrating on handling - tires, brakes and suspension - where we have seen SIGNIFICANT improvements with the right choice of parts.

Wheel & Tire Improvements - EVEN BIGGER!

Obviously we have been big supporters of ditching the factory FT86 17x7" wheel and 215mm all-weather Prius tires. The stock rubber is so very, very bad for performance, the OEM wheels are somewhat heavy, and all of it is too narrow for this 71" wide car (that is WIDE!). We've been preaching the evils of the factory rubber since before the car came out, and I got a lot of flak for the negative review of these skinny stock tires. But we didn't back down, and our theories proved correct - these cars respond immediately to wider tire and wheel upgrades with big grip increases.



A decent wheel and tire upgrade makes huge, HUGE gains in lateral grip on this chassis. Early on we went to a light-ish 17x9" alloy wheel on Matt's BRZ and have used two different performance street tires on them now. First was the 245/40/17 Michelin Pilot Super Sports on the 17x9" wheels, shown below. These tires fit these ET42 offset 17x9" wheels with just a little extra camber up front. No fender rolling or spacers were needed. Excellent street tire, quiet and grippy, and could even double as a good autocross or track tire.


Left: The 245/40/17 Michelin on the 17x9" wheel dwarfs the stock 215mm tire on the 17x7" wheel. Right: 245s installed.

Before his first track event, Matt decided to upgrade to some more track proven EPS (Extreme Performance Summer) tires, the Hankook R-S3, in a slightly wider 255/40/17 size. We ordered these through our TireRack account, then mounted and balanced them here at Vorshlag on the same wheels.



These 255 tires are big and actually fit the 17x9" wheels a bit better, but proved tricky fitting on the front of the car. The 10mm wider tire was touching the lower spring perch, with the large diameter OEM style springs. Just touching, but that's enough to necessitate a spacer.



We had to slip in a 5mm spacer up front to clear the strut, but o make that work we had to add longer wheel studs to the front hubs. You can read about that process below (luckily we stock and sell 65mm press in Subaru studs!). Ain't it fun modding cars? Sometimes it can snowball... one change (tires) can sometimes involve two more (spacers and wheel studs), but the results can sometimes be worth it (crazy grip!). The 5mm spacer proved to be the perfect amount of tire to strut clearance needed up front, with no rubbing on the strut or front fenders (with additional negative camber). The rear bolted on with no adjustments - we could easily get a 9.5" if not a 10" wide wheel out back (but why?).

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Notice how we did NOT go to 18" wheels on the BRZ for his track tire? This was no accident. The FT86 chassis is light and nimble, and the stock brake rotors are relatively small in diameter. The only performance reason to increase wheel diameter is to clear larger rotor sizes, period. Everything else is done for STYLE. Big ballin' wheels look cool and cool cars are fast - or that's at least what we've been taught. If you can turn off that instinct and go with what is actually better for handling, you will stay with 17" wheels on these cars. As you can see below, even with +30mm more tire width (that is huge!) and +1" of wheel width, the 17x9" combo is very similar in weight to the 18x8" combo shown (and this 17" wheel isn't particularly light).


Compare the weights of a somewhat heavy 18x8" wheel and 225mm tire to a light-ish 17x9" wheel and 255mm tire.

Technically the FT86 could even use 16" wheels and still clear the stock brakes with ease, but then your tire choices shrink to almost nothing. This stems from a problem of tire size availability in smaller diameters. The tire manufacturers have catered their offerings to the car manufacturers' ever larger wheel diameter fascination, and now to get any decent widths in performance tires you have to go to 17". Well 17" diameter tires tend to top out at 255mm (some 17" tires go to 265mm) width, so if you want wider you have to go up to 18". Each step up in wheel diameter shortens the sidewall height (bad for ride and handling), ups the weight (bad), and ups the cost (bad). It just becomes a whole big bag of bad, so if you are chasing ever wider tires you end up in 18" wheels - but on big heavy cars you have to do that. We feel that the 255mm tire fits the lighter weight and overall performance of this car very nicely, so 17" wheels will work the best. For a street-only "fun" set of wheels... sure, go crazy 18", but just know that it will be heavier, ride worse, and tires will cost more than a similar 17" wheel set-up would.


This BRZ on the 17x9" wheels and 255/40/17 R-S3 Hankook tires is 71" wide, and the big track width is great.

Better Brakes for the BRZ?

Matt's car has also had some brake system upgrades to get it ready for the track. We left the rotors and calipers alone, because we wanted to see how well the car could do on track with just upgraded pads, lines and fluid. And the results are that it does VERY well with those upgrades alone. Incredible braking performance, no noticeable fade, and no need for more brake torque. So a "Big Brake Kit" (BBK) upgrade is not on the short list for mods, or even the long term wish list, until the car gains a lot more horsepower.



We took a gamble and went with a pad brand that several racers recommended - Carbotech. The XP12 compound were used up front and XP8 in the rear. This seemed like the best "track pad" for the size brakes the car had, according to Carbotech. And they were right - it was spot on perfect. They did recommend the XP10 compound for the front as well, but it wasn't available in time for the first event. Sure, they dust and make lots of noise, but we didn't want a compromised dual-purpose pad. These are used for track events only and after tracking with them twice, we think they were the right choice (and they still look great!). We swap back to the OEM pads and rotors for street and autocross use, which are quiet, work better cold and make a lot less dust.



While the pads were going in, we had custom stainless braided Teflon lined brake flex lines built to order. These are made by a friend of ours using high quality BrakeQuip brand parts, and all ends are crimped on a DOT numbered machine, for the best possible quality and street legality. We made them exactly like the OEM brake lines, with all of the goofy Subaru style banjos and FT86 specific ends and brackets, unlike the lower cost brake line kits we've seen popping up for the "FT86" chassis. Most of those are somewhat generic Subaru WRX kits, with many of the brackets missing and none of the locating tabs.



This makes our Vorshlag FT86 brake line kit cost nearly fifty or more dollars than the other braided brake hose kits out there, but our lines actually fit the FT86 exactly like the original Subaru lines. The lines attach to the struts just like the stock ones, and aren't held in place with a zip-tie. The ends are clocked properly and point in the right directions, for a kink-free installation. Our motto is Do It Right The First Time. The details are too numerous to go over here - check out the product page linked here to see the differences in our lines vs cheaper ones. Our kit will never be the cheapest out there, not by a long shot. Making the lines to fit and function exactly like stock lines is harder and costs more. These are DOT approved stainless braided lines, so they don't have the expansion/flex of the stock rubber lines. Better brake feel and the utmost in safety.

We also flushed the old factory brake fluid out and went with a full bleed using Motul RBF600. The much higher boiling point of the Motul brake fluid means less chance of boiling on track and going all to mush. We didn't do this on my 2013 GT for the October NASA event and I lost the pedal about halfway through my first sessions and drove right off the track! Huge mistake - never skimp on proper brake fluid for any car you take on track. At the bare minimum the brake fluid should be replaced with high quality, high boiling point DOT4 fluid.

Does the car need brake ducting? Surprisingly it didn't. After I took several hot laps in the car, abusing the brakes like I tend to do, Matt's BRZ with these pads/lines/fluid made lap after lap topping 1.4-1.5g under braking. Hey, at least that's what the AIM Solo data shows, and we were out-braking all sorts of cars. I was amazed that I couldn't overheat the brakes, but maybe I could on a hot Texas day taking a full 20 minute session of abuse. I could overheat the 255mm tires before the brakes would fade, so who knows? If we see the brakes fading with more suspension mods and lower lap times, we will come back and look at adding brake ducting to the front. But for now it seemed fine without it - a rare thing in modern sports cars.

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Other FT86 Track & Autocross Preparation Work

We have worked on a number of local FT86 owner's cars, getting them ready for track and/or autocross use. Britney's FR-S was already modded with a custom exhaust and some aftermarket 17x7" wheels and 215mm Hankook R-S3 tires when it came to Vorshlag for some front camber help.



Looking at other Subaru modders online, they went with the smaller shank diameter Subaru "crash bolts" at the upper front strut to spindle bolt location. Normally the FT86 (similar to the Impreza which the suspension is based off of) has the "enlarged shank" 16mm bolt in the upper spindle mount holes and the 14mm bolt in the lower holes. This "crash mod" entails swapping out the fatter upper spindle bolt with the slimmer 14mm bolts, so now there is slop in the mounting holes and you can tweak the strut inboard a bit more without slotting any holes. It... is not the ideal way to gain camber, but it is a simple and inexpensive way to gain about a degree.

So Britney's FR-S and it had -.2° and -.4° deg camber up front from the factory. We spent a whopping 30 minutes installing these bolts and got the front camber to -1.7° on both sides. Not bad for the stock ride height, and anything is better than the stock setting for track use. Personally I like to see -2.5° or more for track but hey, for as cheap as these bolts are it isn't half bad.

Next up was Mark's FR-S, which got the first production Swift lowering springs we've installed as well as Whiteline's front and rear camber kits. The front kit is similar to the crash bolt fix, but uses nicer bolts and other specific hardware (see below for further details). The rear kit includes a pair of offset and adjustable elastomer bushings for the upper control arms. Mark already had some 18x8" ET48 "Sparco" wheels, which were pretty and at least an inch wider than stock. However, since the costs were low and they were 18" diameter, they were also fairly heavy. Still, almost anything is an upgrade over the skinny stock 17x7" wheels. For tires he had 225/40/18 Michelin PS2s.

We started by checking his ride height, toe and camber settings at all four corners.


Before and after ride height checks shown on the RF corner (from 14.5" down to 13.5").

Then we pulled his OEM springs and rated them on our digital spring rater. And we rated Matt's OEM BRZ springs as well. Yes, they are indeed different...



Here are the FR-S and BRZ OEM spring rate charts. Kind of big, but they need to be to be legible.


FR-S and BRZ OEM spring rates, as tested by Vorshlag. Click above to enlarge.

As you can see, the stock FR-S rates are pretty soft, but fairly linear both front and rear. The BRZ's OEM springs are stiffer up front (+63 lbs/in) and softer in the rear (-20 lbs/in). In the grand scheme of things that isn't a lot of stiffness, but the balance difference is probably noticeable if you drive the two cars in stock form back to back on track. But who wants to keep these soft stock rates and 4x4 ride heights? Most of you reading this won't.

After rating Mark's FR-S springs, we installed the Swift BRZ lowering springs, p/n 4F912, which we also tested for rate.


Click the Swift spring rate chart above to enlarge.

The overall drop when we installed these Swift springs onto Mark's FR-S was almost exactly 1" at all four corners. We shortened the bump stops as well. We took about 1/3rd of the OEM bump stop off from each corner.

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Once the springs were installed, it was onto the Whiteline rear UCA bushings. These were tricky to install, mostly due to the hassle of cutting apart one of the OEM bushings to be able to press it out of the control arm. We figured out some tricks and with our bushing installation rig we were able to get the old ones out and the new Whiteline bushings installed. Kind of a mess, but once the "flange" was cut off the OEM rubber bushings they could be pressed out. This is a job probably best left to "advanced" modders or your local suspension shop.



Now the rear camber can finally be adjusted (which the stock rear suspension is otherwise lacking) and a pair of OEM rubber bushings are gone, so this point will no longer deform under heavy lateral loading (track/autocross use). We like this kit and will be picking up a set for Matt's BRZ as well as some sets to stock and sell.


Whiteline's eccentric camber bolt kit as installed on the front strut of an FT86 @ Vorshlag.

Last up was the installation of the front camber adjustment bolts. Unlike the smaller diameter Subaru crash bolts we installed on Britney's FR-S, Mark went with the eccentric camber bolts from Whiteline. Again, these replaced the big 16mm shank upper strut mount bolts on the front struts and also allow the struts to be tweaked relative to the spindle, for some slight camber adjustment. Again, about a 1 degree change is normal. We sell this kit here at Vorshlag, as well as all of the Whiteline parts for the FT86. This is another cheap and easy way to get some camber adjustment in the fronts of these cars. But ... just like with slotted strut mounting holes, there are downsides.

First, given enough lateral force on the strut mount, the smaller diameter or eccentric bolts could slip, which would knock your camber out of alignment on one corner. This could happen from tapping a curb or heavy pothole, or even aggressive track driving with high enough grip tires. This didn't happen on Britney's FR-S on 215mm RS-3 tires, even with crazy KenO driving it, so that was a good test. Mark's car seems to be holding up with these eccentric bolts as well.

Next, any time you tweak the strut angle relative to the spindle you are removing wheel and tire room inboard at the strut. Now this doesn't pose a problem unless you are pushing the envelope on wheel/tire room inboard - on Matt's car with the 255mm tires, it was a big deal. Even without any strut mounting tweaks the 245's barely fit inboard, and the wider 255mm tires needed a 5mm spacer. If we had done crash bolts instead of camber plates, both situations would have needed to move the wheel outboard more, with more spacer thickness. There is no free lunch - every modification always has pros and cons. Just keep that in mind when using crash bolts or slotted strut mounting holes to gain negative camber. For street use on normal street tires of normal widths it isn't an issue. And keep an eye on your camber; if it slips, get the car re-aligned.


Left: Before with the OEM springs. Right: After the Swift spring and Whiteline bushing installation.

Mark's finished FR-S now sits 1" lower, rides better, and should handle better with a bit more spring rate. The camber is adjustable both front and rear and the rear UCA has Whiteline elastomer bushings. The added negative camber up front will help handling at the limit and save tire wear on the track. I'm still not a huge fan of camber bolts, but on certain set-ups and street tires, they can work. And honestly we sell camber plates, so crash bolts are never going to be high on my list of approved mods.


2013 Scion FR-S on Swift lowering springs + Sparco 18x8 ET48 wheels.

Mark also has our Subaru M12-1.25 long wheel studs installed on the rear hubs of his FR-S. He uses the longer studs to work with a 10mm hub-centric spacer he needed to make the +48 offset 18x8" Sparco wheels sit with a wider rear track out back. He said it fit without the spacer, it just didn't fill out the fender very well.

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