Turbo on RX-8

[Herblenny]

mazdamaniac, I'm glad you got on this forum... I'm learning something new and its firing my interest and thinking how this could apply on other levels.. I never thought about MAF nor 8 EMS and that kind of capabilities..

Question..

What's your take on this system in Low compression motor vs. high?? Maybe this is myth, but I've always heard problems with high is detonation is likely and needs to run richer to save engine..

[mazdamaniac]

Originally Posted by Herblenny

Hmm.. I tought about MAF based few years back and never thought about doing it as I didn't see any aftermarket computer I saw.

So, what you are saying is its possible to run REW with RX8 harness and EMS, with larger MAF to run higher boost (or push more air)?? I'm already thinking about getting 4 secondary LIM and using this system.. What do you think?? How about 3 rotor?? Any MAF EMS that might be able to run that??

Sorry about all these questions.. Obviously I know too little to get myself in trouble... And far as tuning, Is it that easy, just putting in n value?

You could do that.
The tuning is ALWAYS as simple as putting in a value.
The trick is knowing that value.
You do have to get the calibration for the MAF and other sensors right, also.

[Whizbang]

your site has more flash per square than another other mazda website in history.

that and i dig the Mx-3. I have been eyeing buying one from a local with 2.5

[mazdamaniac]

Originally Posted by Low Impedance

your site has more flash per square than another other mazda website in history.

Yeah. Sorry. A bit of Macromedia vanity, that. I wish I had more time to play with it.

Originally Posted by Low Impedance

that and i dig the Mx-3. I have been eyeing buying one from a local with 2.5

Mine was stupid. On a good launch, I'd practically torque-steer off of the track.
Then again, I am the suckiest drag racer on the planet.

Originally Posted by Low Impedance

You might be able to mimic the signals that the anti theft produces to fool the computer.

Well, its CAN bus, so its not "signals", per se.
The two systems talk to each other like PCs on a network.
If they don't give the secret handshake, you don't go anywhere.

[mazdamaniac]

Originally Posted by Herblenny

What's your take on this system in Low compression motor vs. high?? Maybe this is myth, but I've always heard problems with high is detonation is likely and needs to run richer to save engine..

Compression is compression.

If you don't have it static, you create it dynamically with the turbo.

a 10:1 motor on 9 PSI is the same thing as an 8.5:1 motor on 12 PSI.*

If you manage charge temps and fueling/ignition correctly, a high-compression motor with less boost will run circles around a low-compression motor with more boost at the same power levels because the off boost and throttle transition areas with be faster.

*(very, very, very rough and inaccurate exaggerated example, of course)

[Whizbang]

hmm...maybe you can bring the anti theft system onboard and then fool THAT into thinking everything is peachy keen

[mazdamaniac]

Originally Posted by Low Impedance

hmm...maybe you can bring the anti theft system onboard and then fool THAT into thinking everything is peachy keen

That is exactly what I do with the Grand Am cars.
Just wire-tie it up under the dash board and tape an ignition key fob to it.

[Phoenix7]

Originally Posted by mazdamaniac

What do you mean? My "public" dyno at 9 PSI on my nice, extremely streetable turbo is over 315 RWHP.
With meth and a bit more boost, I made 20% more over that.
If someone wanted a 400 HP RX-8 and wanted to deal with the street performance liabilites of that (just like the 400+ HP club of RX- owners do), they could go to a GT3571 or similar and be there all day.

The problem is, most people don't want a high-HP car - they just want to brag about owning one.
A 400+ HP turbo rotary is annoying at best in stop and go traffic. Add summer to the mix and the sacrifices you make in vehicle comfort to make use of that power and you have a car that no one wants to drive anywhere but straight down the 1/4 mile.
RX-8 owners like their DSC/TCS, A/C and power seats. Did I mention the cup holders and the Bose 9-speaker stereo?

On a road course, I destroy cars that are supposed to outclass me by a considerable margin.
Watch as this "500 HP", single-turbo 300 ZX desparately tries to catch me on the 1/2 mile straight at Firebird Raceway as I hit nearly 150 MPH.
Then watch as I out-brake him!
VIDEO
The Cobra and the Saleen did the same thing, only I watched them spin behind me in the second corner after that straight.
Very sad. I almost spilled my latte.

good post. Looks like I'm not giving the Renesis the credit is deserves. Thanks for patiently clearing things up.

Now regarding hi/lo comp:
I can understand how a high compression motor can match/outperform a low comp one at lower or the same boost levels. HP-wise the high comp motor wins but isn't the lower compression motor safer for boost application, like Herb said, for the safety of the motor? Or is this another misconception? I know that tuning plays a huge role in the safety and longevity of the motor but doesn't the high comp motor wear and tear at a higher rate?

Also, thanks for joining and taking the time to bear with some of us.

Also, What I meant by "yielding little power" was : yielding little HP per dollar spent (compared to the older rotaries).

[Herblenny]

Originally Posted by mazdamaniac

You could do that.
The tuning is ALWAYS as simple as putting in a value.
The trick is knowing that value.
You do have to get the calibration for the MAF and other sensors right, also.

how about sequential system?? Do you see any problem running it?? or solution to it??

I feel like now I'm just picking your brain... SO, I apologize if its wasting your time..

[mazdamaniac]

Originally Posted by phoenix7

HP-wise the high comp motor wins but isn't the lower compression motor safer for boost application, like Herb said, for the safety of the motor? Or is this another misconception? I know that tuning plays a huge role in the safety and longevity of the motor but doesn't the high comp motor wear and tear at a higher rate?

Every motor has a finite number of puffs in it. The more powerful those puffs, the fewer it will make over its lifetime.

Tuning is everything. Period.
If a motor is properly built, tuning can extract power out of it right up to the point it breaks from load.
Almost no one ever gets that far before they make a mistake or get it too close to the edge of what available fuels and prevailing conditions allow.

Originally Posted by phoenix7

Also, What I meant by "yielding little power" was : yielding little HP per dollar spent (compared to the older rotaries).

Now, that is a different question completely.
The people that have figured out how to make power with this motor are charging what the market will bear. Wouldn't you?
Do it yourself and the material investment is no different than any other motor.

As the charts I posted indicate, +300 HP is reachable for about the same cost as it would be on any motor that only made 190 or so to begin with.

[mazdamaniac]

Originally Posted by Herblenny

how about sequential system?? Do you see any problem running it?? or solution to it?

You mean sequential turbo?
First, why?
Second, air is air. The motor doesn't care how it got there.

These days, the water-cooled, ball-bearing turbos are so fast and so powerful, there is no good reason for multiple turbos on a tiny motor like the rotary.
Now, a 7 liter V8 is a different story, but they do fine with a big BB turbo as well.

[Herblenny]

Why?

I'm kind of thinking in terms of the market.. maybe for you..

If you could get this system to work for stock turbos and extract as much power potential as you claim (close to 400WRHP), just by the swap, stock FD set up without changing the turbo, you'll hit the market! Especially, you work out the maps and sending it to people... people no longer need so called tuners tuning cars. Like how you are doing with the 8 owners. It would be simple solution to quite a lot older turbo car users..

[Phoenix7]

well, I don't know if I'd agree with the last line about costing the same as a 190hp car. The TII is 160-170whp and with ~1200 bux you can make 300HP (BNR turbo, accompanying fuel and electronics). You can add another 1200 if you want to use a standalone. LIke you said, we're talking older technology, maybe that's what makes the differences in prices.

As far as sequentials:
I thought it might help with the top end. I see that the Greddy upgrade in your charts has great low end that tapers off after 6K RPMs in one graph and 7.5K RPMs in the other. Wouldn't a second turbo maintain linear power all the way through the powerband? Similar to the FD setup?

[Whizbang]

I see VNT technology being good for this application

[Herblenny]

yeah, I think its the difference in time.. I mean, I remember when PFCs were 1500+.. Now its only 700.

I'm beginning to like the idea of this and makes more sense. I guess i totally forgot about the whole maf system and been involved too much in tuning map based system.

I'm very intrigued to learn more about this as this could work for older generation turbo systems.. I think its bit more complex compare to map, but I do see the advantage over it.