I'm currently looking for a turbo and I didn't see an Fd with RX6 P27 setup running over than 16-17 psi. Is it because beyond that point it push to much hot air. We see 20-25psi on an MR2 with a RX6 P25.

Which turbo do u think is my best bet : BNR stage 3 or IHI RX6 P27?

Alex

 

Qustion is do you want to stay twin or reduce the complex vac line system and go single?

 

The rx6 is a small turbo. Anything over 17psi may be more heat than power. That being said it spools really really well. Id take a well done IHI setup over the stockers.

 

The BNR Stage 3s will spool faster (seq) and make at least as much power at the same boost levels. You also don't have to do all of the other work associated with installing a single turbo kit. All that said, if I lived in a state without emissions checking, my car (which is only a weekend/track car now) would have a single turbo.

 

You better go single if you want to chase Chris's monster...

 

Not sure why you are saying that, Jack. My car with BNR3s will eat your single turbo car for breakfast. That is leaving the driver variable out of the mix, because I know you are an amazing road racer.

I've driven three FDs with that apexi kit and in my opinion it is NOT worth the price they charge. The hotside it way too small. Sure it spools well, but it has no high rpm pull. That turbo is more comparable to the stock twins in terms of power output. The BNRs are more comparable to a T-78 in terms of power output, mods and boost being equal.

 

How come some people from the Mr2 board (mr2oc.com) make 630 whp on a 4 cylinder engine with a RX6 P25(A/R 0.98)...while you guys say you make only 400-440 whp max with a RX6 P27(A/R 1.06)

pleas explain why?????

here is the link to the Mr2 that did 630whp

http://www.mr2ownersclub.com/mr2records/dyno/vince.jpg

 

rascaca: Don't forget that our cars are only 1.3s. (Talent)Vince's car is stroked if I'm not mistaken. I'm pretty sure it is at least a 2.2. A lot more displacement there to play with. BTW, I miss my MR2.

Dee

 

A rotary will not make the same amount of power as a piston powered car with the same turbo.

 

That is where you are wrong. You have to compare WORKING DISPLACEMENT, not physical size displacement. Our engine is equal to a 2.6L 4 cycle piston engine.
This has been explained many times on the forums.

 

Oops. Sorry cew. I have heard that, but I thought that was not true. I've only been into RX7s for about a year now. I was into MR2s.

Dee

 

also how come we can run 25 psi with one turbo and you guys only run like 17???

 

Um, alot has to do with the compression ratio of the motor. Taking that into account there is a boost threshold that any given car can go up to on pump gas without preignition occurring. On an FD, most run 15-17 psi on pump gas to remain 'safe' and avoid engine damage. A lot is in the AFR and spark timing, as some run as much as 20 psi on pump gas with added safeguards such as water injection or methanol injection.

If you perform a simple search, you'll see that many rotary owners run 25-30 psi, but on high octane race gas.

 

The 13B flows like a 2.6L (it does; let's not debate this point), so the RX6 doesn't flow enough to efficiently feed a 13B at the same boost level that you might run with a smaller engine.

-Max

 

What max said , the air pressure is not allowed to build up in the intake manifold , since the motor uses it faster than the turbo can supply it.

 

like what most stated, the turbo isn't big enough to produce the flow at higher rpm to support higher than 17psi. You can set the boost to 25psi and it'll stay there from 4krpm-6.5krpm and then drops down to 17psi from 6.5krpm-8krpm. it has nothing to do with the wastegate or the engine. Rotary engines require higher CFM to flow the same amount of hp as the piston engines. That's why we need at least a T66 turbo to get 500rwhp while a honda can get the same with a GT28 turbo.

I have tuned enough RX6 turbo to know that they won't hold more than 17psi consistantly above 6.5krpm.......