Sway bar benefits.....?

[joe.MIATA]

I have finally ordered a front sway bar for my car. It was feeling bad after xmas because all the other miatas rec'd gifts.

In speaking with the tech guy at Flyin' Miata, he did not recommend installing only a front bar. Does he have something there, or was he just trying to sell me a 2nd bar for the rear?

I know that the car is going to want to push more, but will that negative aspect be outweighed by the benefits. I'm sure that it will, just looking for more info. on what to expect.

TIA.

[tailchaser]

Racing Beat, OTOH, recommends against changing the rear bar...

If you want to play (legally) in stock classes, then changing the rear bar is a no-no... The key comes down to whether the car handles more like you want it with the bigger bar.

I know that I could have made great use of a big honking front bar in Oklahoma last Sunday, but I'm happy with the car (apart from body roll) on the surfaces here...

I guess all you can do is try it. Bring jack stands and tools to the next available test & tune you can find, and you can do a before & after comparison in track conditions.

[altiain]

I know that the car is going to want to push more, but will that negative aspect be outweighed by the benefits. I'm sure that it will, just looking for more info. on what to expect.

TIA.

FM has always been of the opinion that the sway bars should be "upgraded" together. They sell more bars that way. :P

Seriously though, nothing against FM (I buy stuff from them too), but they aren't a race shop. They sell some aftermarket parts, and they make great forced induction kits. But when it comes to car prep and suspension setup, you'll notice that they don't offer much in the way of sophisticated choices. FM is geared more towards the enthusiastic street car than the competitive racer.

I will say this - my car was much more tail happy with both the front and rear FM bars. Both on the stock suspension and with the Teins. I find the car much less prone to oversteer with the FM bar on its softest setting up front and the OEM Sport bar on the back. Heck, most of the competitive CSP guys run a big front bar, spring rates with a much higher front bias, and no rear bar at all.

As for a front bar making the car push, that's not necessarily true. Making adjustments to your alignment can counteract some of this tendency. For example, you know how the common alignment wisdom is half a degree more negative camber if the rear? I know that more than one Nationally competitive C Stock car is actually running equal or less camber in the rear. I plan to play around with my alignment settings early this season and try something similar.

Lastly, most of us will probably have to alter our technique a little bit to get the most out of the car with a bigger front bar. You can't go into a corner too hot or too deep, or the front end will just wash out. Jon and I especially are going to have to be careful of this, as we both tend to overdrive the corner entry. On the flip side, however, a bigger bar will enable you to get back on the power sooner coming off of a corner, and it will also improve your car's transitional (slalom, offset) respsonses.

[joe.MIATA]

As for a front bar making the car push, that's not necessarily true. Making adjustments to your alignment can counteract some of this tendency. For example, you know how the common alignment wisdom is half a degree more negative camber if the rear? I know that more than one Nationally competitive C Stock car is actually running equal or less camber in the rear. I plan to play around with my alignment settings early this season and try something similar.

It's a trick! Might as well tell me to put different tire pressures all around for better handling.

Actually, I am in need of an alignment before this season. I will keep an eye on this.

Thanks.

[altiain]

A little more feedback on this subject. I had the opportunity to do some thorough testing of the car today, and even with the bigger front bar (on its softest setting), the car was still slightly prone to oversteer on corner exit and in transitions. Unfortunately, I didn't have the tools (or the desire, since I was feeling a little under the weather) to change the bar settings, so I didn't have the opportunity to experiment with the bar on the stiffer setting. I was also on street tires, so it's hard to say for certain how accurately this data can be extrapolated to race rubber.

I plan on moving the front bar to the stiffest setting for the first S2000 event of the season to try and combat the looseness a bit, since I'm already running a full half degree camber split and an 1/8" of rear toe-in to combat oversteer. Maybe my car would rather be a drifting car? Or maybe it's operator error? I guess we'll find out.

[Kestrel]

Well, I put a bigger bar up front (Racing Beat Tubular), and have made no other adjustments... yet. I haven't been able to test this set up, and I'm guessing my first couple of events are going to be pretty frustrating as I try to:

• (1) get good times,
  (2) figure out how to drive this "new" car (I'm guessing I'll suffer the same stuff that alitian mentioned, as I tend to enter a corrner hot, brake hard, yank the wheel, and get back on the gas), and
  (3) make adjustments both to the car and to my driving style all at the same time.

I really hate push, and I know that putting a bigger bar is going to cause more push. But I'm hoping that with adjustments to my other suspension components (mainly alignment and shock settings), things will improve. I can tell you this -- the car feels better on the street, and there is less cowl shake. I can't put a STB on (which would really help with cowl shake) and stay in Stock class, but I'm happy with the improvements on the street. I hope it translates into improvements on course...

[POS Racing]

Well, I put a bigger bar up front (Racing Beat Tubular), and have made no other adjustments... yet. I haven't been able to test this set up, and I'm guessing my first couple of events are going to be pretty frustrating as I try to:

Hey Kestrel what are your thoughts about your front sway bar now that you have run an event with it?

I'm thinking the POS Racer may benefit from a larger front bar, guess I need to figure out what size for the courses we tend to run!

[altiain]

Here's some additional feedback from my car:

I ran the 1" FM bar on the stiffer setting this weekend during timed funruns at the PCA autox school. Instead of a slight tendency towards oversteer like it had on the softer setting, the steady-state tendency is now slightly towards understeer.

The downside: the car can be a little frustrating in steady-state manuvers. We had a 100' diameter skidpad, and getting the car quickly around that was tricky, as too much throttle would cause the front end to push wide and lose traction. On a similar skidpad last year with the Tein HA coilovers, I would throw the car in, give it some gas and a little bit of countersteer, and drive around the skidpad with wheel steady and balancing the tail out 5-10 degrees with the throttle, which was much faster.

The upside: The car is now rock solid in transitions. Slaloms used to be a real pucker factor for my car (especially at high speed) which would go something like this: turn-slide-catch-turn-slide-catch-turn-slide-catch, etc. It was always hard to balance the desire to go faster with the car's desire to hang the tail out and pendulum. Now it goes like this: plant your foot on the floor and turn-turn-turn. The back end is completely stable, and as a consequence not only is my speed through the slaloms higher, but my confidence level in the car through these exercises is higher as well.

Second upside: I can now get back on the throttle a lot sooner coming off the corner. There was a particular tight pivot cone that was giving everyone trouble yesterday - cars were either going around it in 2nd gear and lugging off the corner to the next element hitting ~20mph on the way (this is what I tried in one student's S2000), or going back to first and hanging the ass out wiiiiide coming off the pivot, then trying to gather it up before the next element. I was able to go back down to first, mash the throttle as I turned into the pivot, and came out pointing directly at the next element every time, with no unwanted oversteer. As a result, I was just brushing the rev limiter in 1st before braking for the next course element - a good 7-10mph faster than I guesstimate I saw anyone else take it yesterday.

Overall I think the car is much faster with the stiffer front bar setting. The almost complete lack of oversteer is a little hard ot get used to at first, as my car has always been "loose" to one degree or another. You can hang the end out if you really want to, but you have to work very hard to do it. Conversely, you can push the car a lot harder without having to worry about it coming around or getting away from you, and I think that not only physically helps the car go faster, but it also improves the driver's confidence and allows you the comfort zone to push the car a little harder. It does for me, at least.

Iain

[tailchaser]

Which bar are you using, Iain? I notice that FM now sells the "front bar only - for you SCCA types"... And $99, even...

[POS Racing]

Which bar are you using, Iain? I notice that FM now sells the "front bar only - for you SCCA types"... And $99, even...

You talkin' about this deal?

[tailchaser]

Hey... you ARE the of cheap!

[altiain]

Yep, I'm using the FM 1", two-hole, adjustable front sway bar. I actually bought mine as part of the front & rear swaybar set when I was playing in CSP, but decided to use just this front bar in CS instead of paying another $200 for the lighter RB hollow front bar. Does that qualify me to be a member of Team Cheap Bastard? :P

Iain

[POS Racing]

So a stock '92 has a 19mm front bar (I'm 99% sure) and the one FM offers for my car is 7/8" (.875") or 22.225mm, that's not much bigger than what I have on the car. It's just 3.225mm or .1279" larger.

How would you guestimate how much of an improvement that would offer??

I found this Cool Chart!

[POS Racing]

So a stock '92 has a 19mm front bar (I'm 99% sure) and the one FM offers for my car is 7/8" (.875") or 22.225mm, that's not much bigger than what I have on the car. It's just 3.225mm or .1279" larger.

How would you guestimate how much of an improvement that would offer??

I found this Cool Chart!

That is a cool chart! So what's the answer?

42!

Looks like an approx 85% increase in rate.

[tailchaser]

42!

Looks like an approx 85% increase in rate.

More if you use the inner mounting hole...

[altiain]

Does that qualify me to be a member of Team Cheap Bastard? :P

Iain

Absolutely! I'll give you one of 'our' magnetic stickers next time I see ya'!

"Not only am I a member of Team CB, I'm the president!"

It won't cost me anything, will it? :P

Iain

[POS Racing]

What size sway bars do the NB's have on them???

Are the interchangeable with the NA's?

Miata.net shows they are interchangeable but can anyone here confirm??

[tailchaser]

What size sway bars do the NB's have on them???

Are the interchangeable with the NA's?

Miata.net shows they are interchangeable but can anyone here confirm??

You do realize she reads these forums, too, don't you? Hmmm... I think you're actually the of cheap if you're gonna steal the front sway off of Vivid's car...

[POS Racing]

You do realize she reads these forums, too, don't you? Hmmm... I think you're actually the of cheap if you're gonna steal the front sway off of Vivid's car...

I would never dream of doing that! How dare you even think I would pull the sway bar off of Vivid's car and put on the POS Racer! That would just be wrong!

BTW, I found more good bar stuff at http://www.addco.net
Some Important Notes of Bar Diameters

Torque resistance of an anti-sway bar changes with the square of the cross sectional area. Therefore, even a small increase in diameter provides a major increase in anti-sway bar effectiveness. The chart below shows the effectiveness of ADDCO replacement bars as a percentage of resistance of a stock bar of a given diameter, keeping in mind that the relationship applies only to two bars of identical shape.

Remember, Bigger is not always better. Play it safe and stick with DDCO's recommendations for your particular application

[Kestrel]

Hey Kestrel what are your thoughts about your front sway bar now that you have run an event with it?

I really like it!

I had feared an obnoxious amount of understeer... and I hate understeer. But I didn't experience any additional understeer, and probably a little less than usual. Body roll was noticeably reduced and slalom transitions were noticeably better. But I'm the of "I have no idea what settings work well". Heck, I can't even get tire pressures right. I may have just lucked into good settings and good conditions this weekend. Remember, I'm the guy who came in 4th place.

On the other hand, I decided to write down my settings this time (tire pressure both front and back, shock settings both front and back) in an effort to (1) better understand my suspension, and (2) try to duplicate the "good things" and avoid the "bad things". This will be particularly important for me as we get back to Pennington Field. The "broken" surface of Mineral Wells doesn't communicate understeer problems to me the same way the concrete surface at Pennington Field does. At Pennington, understeer feels like I'm going to rip the car off the suspension linkage.

Bottom line? Get the Racing Beat 1.125 Tubular front bar, and install it on the softest setting. I don't think you'll be disappointed.