Turborex

It's true that it is hard to get a lot of boost out of an engine with a high CR because it will get really really hot and be very prone to detonation. But you can add boost to any engine. With the high compression ratio that means you wont loose as much of the quick response and bottom end. We will just have to see how strong the renisis really is once these kits start coming out.

Crashunit

If Mazda wanted to make another Turbocharged rotary, they would have just stuck to the last generation RX-7 twin turbo 13B or improved on it, instead of redesigning the whole motor to make the same amount of power naturally aspirated. Mazda didn’t want to go thru the same problems with the RX-8 that they had to with the FD. The rotary engine on its own already makes too much heat, and the overly complicated sequential twin turbo system wasn’t helping with that. FD's were notorious for overheating due to so much excess heat from the engine and turbos that it taxed out the inefficient cooling system that it had. Trust me, Mazda knew turbo charging the RX-8 would cause reliability issues, so they decided to keep it simple. Plus if the RX-8 was meant to be turbocharged it would have come with one, or at least have a lower compression and a different layout to play with the idea. Does this mean I won't or anybody else won't try to turbo charge it anyways? Or that Mazda won't ever make a Turbo RX-8? Course not, there’s always hope for Mazda to do something right . I had an FD and would love to see a turbo in this car, and I’m sure Mazda would want to do it as well, if they could do it right. But this motor wasn’t designed with forced induction in mind because of reliability issues.

Crashunit

II never said you can't supercharge or turbocharge a car, since that would just be plain ignorant . I just wanted him to know, that not all cars are built for it, and that without the proper knowledge it will probably hurt the car more then do good. Just like how everyone loves to thinks all you have to do to make a car go fast now, is to use NOS .

mikeb

chrashunit
your car is sick
I've seen it in cali car shows

rotarygod

I can't completely agree that if Mazda intended for the car to be turbocharged it would either have one or have a lower compression ratio. Lets go back to late 1985. The new RX-7 was coming out ('86 2nd gen). For '86 it was only naturally aspirated. It had a 6 port engine with a 9.4:1 compression ratio. In '87 the T-II became available. It had 8.5:1 compression and a 4 port engine. How can anyone say that the RX-8 would have lower compression in anticipation? It is far more logical that they would install a new engine with different compression. Back in '87 with way low horsepower and a much lower compression ratio they were worried about detonation on the turbo models. They won't just turbo the engine in it's current form. They would make changes. We have 2 different engine styles now and this was only around a power level. Many speculated that it would have just been detuned but it wasn't. My guess would be a lower compression 4 port Renesis if they do it. Maybe they will add forced induction and maybe they won't. It would be very logical to assume it will be a slightly different engine though.

wakeech

how come so many people aren't even listening when it's said "the 6 port motor isn't the one to turbo"??

if you're dying to turbo something, what you need is a Euro or Jap spec base model (the low power 4 port with the 5 speed tranny), take it apart for porting, rotor mass reduction, and grinding the recess (reducing the compression ratio). then my boost-hungry friends, you'd be set.

^^ the right way to get it done ^^

Goose

And i'll be right there with my cheque book when they do!

Hopefully someone over this side of the pond will take on board your comments Wakeech and unleash my 'low power'!!!!

Turborex

I think people just want a fairly reliable, and reasonably cheap way to make power with their 8. It would not be cheap by any means to import an entire drivetrain from japan, have motor work done and then have the whole thing installed. I agree with you though, that this may be the only way to successfully turbo the 8. It looks like 8 owners stateside are going to have to deal with 13's at best on the renisis. Unless of course these turbo kits that are being developed are as successful as the manufacturers hope, someone may see the 12's before the engine blows.

RXTACY

Read the ROAD & TRACK GUIDE TO THE MAZDA RX8. They asked Noboru Katabuchi, RX-8 program manager a series of questions.

Here is a quote from the interview:
Question:
"Because the RX-8's rotary engine is naturally aspirated, did you have concerns about the lack of low- and mid-range torque?"

Noboru Katabuchi's Answer:
"Not really. Of course, if you compare the RX-8's Renesis to the twin-turbo 13B power-plant of the RX-7, low- and mid-range torque is down. However, we didn't want to give the RX-8 a pure sports-car, head-snapping feel. We wanted to give it some smoothness and linearity. So when you step on the throttle, you're not violently jerked around in the cabin, but accelerate in a smooth, pleasant way. And as with the suspension, those who want more of that head-snapping power will be able to customize the car in their own way, weather that be in the form of a turbocharger or supercharger kit."

Looking back, it took 18 months after the new 86 body-style RX-7 change before mazda came out with its 87.5 model year turbo. Looking at the guage placement in the RX-8 makes me think a turbo 8 is in the works. But we probaly will not see it untill half-way thru the 05 model year, and only if the 8 does well this year.

compaddict

Someone on Miata power list just mentioned that the 2005 RX-8 will have a supercharger available that will retrofit on 2004 models with full factory warranty.
Any truth to this?

Vince

RXhusker

Vince -- you better ask him to post all of his raw data on this supposed supercharger

XeRo

I call BS...

i talked to the guys at the two local Mazda dealerships one being a Mazdaspeed dealer and the sad thing is I knew more about the car than they do...

They showed some brocures that were meant only for Mazda employees and they really didn't state that much about anything in particular...according to the sales and parts personel there are no plans of a SC or TC for the U.S. RX-8 in the next year. There is a bunch of talk but no immediate plans...

Plus going over the numbers...compression of 11:1 and any kind of forced induction just don't go together well without blowing something up...but i'll save my pessimism till after all the fellas in this forum who are in the middle of R&D on a aftermarket have some hard evidence...

I just don't think $:increase in performance are going to be worth it....JMTC..(chaching)

Red Devil

Rikki,

That's very disconcerting to know your transmission failed...how much extra power could you possibly have been running? I think I remember in another thread that you were at 173whp and then as in your sig, 186whp at the most...you think it's a fluke, or is it that weak?

compaddict

I'll ask for sources. I remember someone here said reliable sources said no.

Vince

Brian Goodwin

I suggest that was a defective transmission, because there are plenty of folks putting down 250+ at the wheels to this transmission in the Miata application. I am only running about 200 at the wheels in my supercharged Miata but the transmission has been bullet proof for years of hard track days. In another Miata with a big Aerodyne turbo we did 265 rear wheel hp and the trans held without complaint.....well, at least until my little brother put that car into the wall at 80mph.

I have been told that this motor was built for boost. I have a hard time imagining a bolt on supercharger kit from the factory but I certainly think it can be done. At SEMA last week I talked to one company not ready to go public on their own RX8 supercharger setup...but they are working on one. I also talked with the Mazda guy in charge of the MazdaSpeed projects (Weldon Munsey) and while I got the full tour of the newly boosted MazdaSpeed Miata (with help from the product guy on that, David Mathew), and I got to see all the cool MazdaSpeed Rx8 stuff that is coming to a dealer near you, there was no hint of factory boost for the RX8.

Interestingly enough, they did explain that there will be three levels of MazdaSpeed mods for the RX8. Blue performance accessories that are installed by the dealer and get FULL warranty support. Green performance accessories that get a 12 month or 12k miles warranty. Finally, Orange peformance accessories which are sold "as is." This last catagory will be the most interesting....and certainly this means they will have a structure in which they could sell such items as boost kits.

Brian Goodwin
Good-Win Racing

mikeb

LOL

compaddict

he sent me a link:
http://motoring.nzoom.com/motoring_d...88-390,00.html

Old info and no warranty information.

Sorry!

Vince

santino

I would listen to Brian Goodwin guys....he is a pretty reliable source of good tech info as well as for the rumor mill.

santino

Omicron

I agree, sounds like a defective tranny.

WTF no turbo

I posted that link a month ago.Ive done alot of research in this myself and sources ive talked to said yes,a very low parasitic sc is in develpment for an 05 jap late 05 06 release stateside.On the other hand the same resources say a 1.6 liter version is also in the works for the rx-7 making 260ish whp time will tell i guess.

Brian Goodwin

Sounds good to me....I really hope that source is right. I will see if I can find any confirming on this end. I would buy that SC today and if a bigger motor RX7 comes out I would drop that motor in my RX8.

Brian Goodwin
Good-Win Racing

Omicron

How about the bigger motor AND the SC? :D <== Evil Grin!

wakeech

how about forgetting the supercharger garbage and put a good turbo system on a turbo motor??

chinx

greddy has a turbo kit out in japan already? can you guys tell me more about it?

Turborex

can you post a link or something? How do you know this? I know they have a twin turbo for the 350z but i didnt hear anything about the 8