Renesis 16x

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05-28-2008, 07:32 AM
MX-5EE

Renesis 16x

I mentioned this in Randy's Saab thread, but I decided I should stop hijacking his thread and post this here.

I found a few links to the new 1.6L rotary engine, the RENESIS 16X.

http://www.mazda.com/mazdaspirit/rotary/16x/

It looks like the rotary epitrochoid is bigger, but the width of the housings are narrower. Edit: The rotor housings, just to be clear.

I have always thought it would be neat to make an attempt at rebuilding a 13B and get an FC or FB to like-new condtion (not an FD, I am not made of money here!).
05-28-2008, 07:36 AM
tailchaser

Quote:

Originally Posted by MX-5EE

I mentioned this in Randy's Saab thread, but I decided I should stop hijacking his thread and post this here.

I found a few links to the new 1.6L rotary engine, the RENESIS 16X.

http://www.mazda.com/mazdaspirit/rotary/16x/

It looks like the rotary epitrochoid is bigger, but the width of the housings are narrower. Edit: The rotor housings, just to be clear.

I have always thought it would be neat to make an attempt at rebuilding a 13B and get an FC or FB to like-new condtion (not an FD, I am not made of money here!).

I recommend starting with this one...

http://dallas.craigslist.org/car/693154244.html

On the funny side of things, that car has fewer miles than the '83 Limited Edition I bought in '91 for $1300, drove for 124k miles and sold for $1700...
05-28-2008, 07:56 AM
altiain

I'd hate to disappoint Raymond, so here's my response. :wink:

Quote:

Originally Posted by MX-5EE

Like I said, keep an eye on the new 1.6L rotary engine Mazda is working on. I would google you up a link, but I don't feel like it right now. The 10 second cliff's notes version is that the new design has a better combustion chamber shape that has a lower surface area-to-volume ratio, giving better thermodynamic efficiency and hence much better fuel economy. The high area-to-volume ratio is the #1 reason for the poor fuel economy on rotaries, or such is my understanding.

I've read quite a bit on the 16X, and I agree that it does hold the promise of being the first real step forward on the rotary since the original 13B over twenty years ago. That said, but I'm not holding my breath. Go back and reread the pre-release press on the Renesis - Mazda has made these promises before. The Renesis was supposed to offer "substantially" better fuel economy than the 13B-REW out of the FD while making the same power. Not only was the power missing (down 23hp on paper, and closer to 35hp in reality), but my modified FD actually got better highway fuel mileage, because it was geared much taller than the '8.

I'm just not that impressed by the Renesis. Here you have an engine that barely makes 230 horsepower (and that's only when the tertiary ports haven't gunked up and the ignition system is working properly) in a 2800-lb car that gets worse fuel economy than a 6500-lb 4wd SUV. Is the car a blast to drive? Yes. It has a brilliant chassis, wonderfully communicative steering, and excellent brakes. Unfortunately the engine - which is supposed to be the showpiece of the RX-8 - is the biggest letdown.
05-28-2008, 07:57 AM
altiain

Quote:

Originally Posted by tailchaser

I recommend starting with this one...

http://dallas.craigslist.org/car/693154244.html

On the funny side of things, that car has fewer miles than the '83 Limited Edition I bought in '91 for $1300, drove for 124k miles and sold for $1700...

Heh... I remember my first roomate had an '83 GS. Last car I ever remember seeing with a choke knob on the left side of the dash. :mrgreen:
05-28-2008, 08:21 AM
CosmosMpower

Quote:

Originally Posted by altiain

I'd hate to disappoint Raymond, so here's my response. :wink:

I've read quite a bit on the 16X, and I agree that it does hold the promise of being the first real step forward on the rotary since the original 13B over twenty years ago. That said, but I'm not holding my breath. Go back and reread the pre-release press on the Renesis - Mazda has made these promises before. The Renesis was supposed to offer "substantially" better fuel economy than the 13B-REW out of the FD while making the same power. Not only was the power missing (down 23hp on paper, and closer to 35hp in reality), but my modified FD actually got better highway fuel mileage, because it was geared much taller than the '8.

I'm just not that impressed by the Renesis. Here you have an engine that barely makes 230 horsepower (and that's only when the tertiary ports haven't gunked up and the ignition system is working properly) in a 2800-lb car that gets worse fuel economy than a 6500-lb 4wd SUV. Is the car a blast to drive? Yes. It has a brilliant chassis, wonderfully communicative steering, and excellent brakes. Unfortunately the engine - which is supposed to be the showpiece of the RX-8 - is the biggest letdown.

I can't think of any 6500 lbs 4wd SUV's off hand that get 18 mpg city. Seems like most things in that category get 18 mpg highway. 18 is pretty unacceptable either way though, if the car got 23-25 mpg city that would be very acceptable (to me at least).
05-28-2008, 08:37 AM
Titus

Quote:

Originally Posted by CosmosMpower

I can't think of any 6500 lbs 4wd SUV's off hand that get 18 mpg city. Seems like most things in that category get 18 mpg highway. 18 is pretty unacceptable either way though, if the car got 23-25 mpg city that would be very acceptable (to me at least).

It isn't 6500 lbs, but the Tahoe hybrid 4wd is rated at 20/20.
05-28-2008, 08:42 AM
CosmosMpower

Quote:

Originally Posted by Titus

It isn't 6500 lbs, but the Tahoe hybrid 4wd is rated at 20/20.

Yeah but it's a hybrid, not apples to apples. We're not comparing the hydrogen Renesis to a hybrid SUV. I don't think a Range Rover Sport gets 18 mpg city.
05-28-2008, 08:45 AM
trickyrix

Quote:

Originally Posted by tailchaser

I recommend starting with this one...

http://dallas.craigslist.org/car/693154244.html

On the funny side of things, that car has fewer miles than the '83 Limited Edition I bought in '91 for $1300, drove for 124k miles and sold for $1700...

I don't need it, but it sure would be fun... I love those cars!

Rack and pinion steering kit?

I didn't know they made a conversion... neat.
05-28-2008, 09:02 AM
Titus

Quote:

Originally Posted by CosmosMpower

Yeah but it's a hybrid, not apples to apples. We're not comparing the hydrogen Renesis to a hybrid SUV. I don't think a Range Rover Sport gets 18 mpg city.

So a hydrogen Renesis is apples to apples to a gas engine SUV as long as it is non-hybrid. OK. At some point in the not so distant future, all cars will be "hybrid". Just like CAFE pushed all cars to Fuel Injection, CAFE II will do the same for Hybrid.
05-28-2008, 09:09 AM
altiain

Quote:

Originally Posted by CosmosMpower

Yeah but it's a hybrid, not apples to apples. We're not comparing the hydrogen Renesis to a hybrid SUV. I don't think a Range Rover Sport gets 18 mpg city.

Neither does the RX-8 (EPA 16/22 city/highway).
05-28-2008, 09:12 AM
altiain

Quote:

Originally Posted by Titus

It isn't 6500 lbs, but the Tahoe hybrid 4wd is rated at 20/20.

No, it's 7300 pounds. The 7100 pound 2wd Tahoe hybrid gets 21 city/22 highway.

By the way, the 7300 pound, non-hybrid, 4wd 5.3L V8 Tahoe gets 14/19, which is pretty damn close to the RX-8.
05-28-2008, 09:18 AM
Titus

Quote:

Originally Posted by altiain

No, it's 7300 pounds. The 7100 pound 2wd Tahoe hybrid gets 21 city/22 highway.

Ahh.. you were talking GVWR. I was looking at Curb weight, which is about 1800 lbs less.
05-28-2008, 09:37 AM
CosmosMpower

Quote:

Originally Posted by Titus

So a hydrogen Renesis is apples to apples to a gas engine SUV as long as it is non-hybrid. OK. At some point in the not so distant future, all cars will be "hybrid". Just like CAFE pushed all cars to Fuel Injection, CAFE II will do the same for Hybrid.

Maybe within the next 10-15 years but I doubt hybrid will be mandatory within the next 5. Fuel injection was just a different method of fuel delivery, hybrid is changing the type of "fuel" all together.

Besides what do I care, both my cars average 25 mpg together, I already rid myself of the gas guzzler curse :)
05-28-2008, 09:43 AM
Titus

Quote:

Originally Posted by CosmosMpower

Maybe within the next 10-15 years but I doubt hybrid will be mandatory within the next 5. Fuel injection was just a different method of fuel delivery, hybrid is changing the type of "fuel" all together.

I don't think hybrid will be mandatory, but I do think it will become standard. There will be a few holdouts, just like with fuel injection, but it doesn't make sense to waste energy if it can be easily used. As far as the type of fuel, last time I checked Hybrids still use gas as the only fuel you need to add. ;)
05-28-2008, 09:44 AM
tailchaser

Quote:

Originally Posted by altiain

No, it's 7300 pounds. The 7100 pound 2wd Tahoe hybrid gets 21 city/22 highway.

By the way, the 7300 pound, non-hybrid, 4wd 5.3L V8 Tahoe gets 14/19, which is pretty damn close to the RX-8.

Huh... I'm averaging 19.8 commuting, did 24.5 on two sub 14 hour 1,023 mile runs in March... Maybe yours doesn't like you! :-)
05-28-2008, 07:40 PM
MX-5EE

Quote:

Originally Posted by tailchaser

I recommend starting with this one...

http://dallas.craigslist.org/car/693154244.html

On the funny side of things, that car has fewer miles than the '83 Limited Edition I bought in '91 for $1300, drove for 124k miles and sold for $1700...

Thanks, but right now it's either buy and fix up an RX-7 or buy a bike. And since I don't have a house and garage an RX-7 would be a little hard. Further, since my wife and I are wanting to start a family I think this all may be just dreaming on my part for the time being.