So I have the 3" Rotary Performance catless midpipe

On the car, the only performance mod I have that matters is the GReddy turbo (not even an exhaust - very very stealthy with the intercooler hidden behind my black grill and the engine noise muffled by the turbo)

If I install this midpipe, will I be running lean enough that I'll need to retune my e-manage, or can I just bolt it on?

 

Last time I read a turbo RX-8 thread, putting on a midpipe in addition to the turbo kit was supposed to add like 10 - 20 more hp to your total gains...or some **** like that. Dunno if maybe Boosted had a fluke or something though.

 

I hope you bolt this on cretnix, cause I want to go cat-less also with my Turbo. Like to know what your impressions are!

 

The RP shop in Garland was ready to install the Greddy turbo on a high flow SuperCat 8, so you might just call them and see how it worked out.

 

But nobody knows if it will create a dangerously lean fuel mixture?

 

bump

 

Uh, well, I don't have the Greddy, but I am catless. It will certainly reduce your spool time.
Whether it will run lean or not depends on if you have enough fuel available. There is a lot of variance from one RX-8 to another and the shop manual allows for something like 10% or so in high to low numbers on the actual fuel injection volume.
My E-Manage MAP allows for up to 10 PSI, if you are able to provide enough fuel.
I am running about 9 PSI, which is about 2 PSI above what the Greddy kit provides.

 

I had The Rp Bonez midpipe on, boost was peaking at 8psi but the car was running a bit choppy and Way to Lean in 4th a 5th gear around 7200 rpms we experienced some detonation, if your gonna run a midpipe you need to re-Tune your emanage, and i would add a fuel pump w/ a pressure regulator, make sure your gettin the right amount of fuel, Just a suggestion.

 

Ok so where can I get a fuel pump and a pressure regulator for the RX-8?

Also, I think I heard our system was returnless? Is that a problem?

Should this be enough fuel initially or will I need injectors as well, and if so, which sets and what sizes would you recommend? (Primary/Secondary/Tertiary confuses the crap out of me).

 

I don't know why people keep throwing this garbage around about a new pump and regulator.
The factory pump is good out to way past 400 HP. It is a 255 LPH, two-level pump!

Yes, the factory system is returnless and would require complete fabrication of a return system to use a conventional regulation system.

 

Alright so **** that then

I may just want to bump the 380cc secondary and tertiary injectors up to 440cc if I go for big boost.

I'm wondering if I use my MBC to set boost at a solid 4 or 5 or 6 psi throughout the rev range if it'll be safe for me to install this midpipe and drive around until I'm tuned, or should I just be safe and get it all tuned at once?

 

You can't set a MBC to a point below the mechanical limit of the wastegate. It doesn't work like that.
You are limited on the low boost side by whatever the Greddy wastegate is calibrated for.

 

Many people think they need a new pump and regulator because Manuel did it and talked about it, so they think they need it too. Let me point out again that if 255 lph sounds familiar that's because the Supra uses the same volume pump. There are many things on the RX-8 that are well over-engineered.

CRH

 

I had the greddy kit and when i ahd no cat it back fired alot and smoked alot .... kinda ran liek **** .... I like it much better with the cat back on ... I currently have a high flow catco .... But when it was catless ... just WAY to much back fire thats all ... But other then that i did not run more boost or wanything like that ...

Shane

 

When we experimented detonations we decide to change the fuel pump. Probably we can resolved the problem only tuning the emanage, but we decided to change it.

first we do it thinking on the future, on that time we was thinking on install
850 cc injectors, a fuel rail, new ECU, etc. And that is what we're doin right now.


Manuel

 

That's the thing, Manuel. Many people haven't fully realized what your end goal is and they may think they have a lot in common with what you are doing. Much like Jeff's turbo and my nitrous projects, you are out on a similar limb and trying things on your own. Because Jeff custom-built his turbo application, he is able to readily adjust his boost levels and re-map at will. Those who try to follow and mimic his progress by using the GReddy kit are going to have different outcomes. I have a bit of a different(and simpler) situation with the nitrous but I am finding out the barriers imposed by the factory PCM. Right now, I am experiencing MOP problems that are mentioned in the Mazda MSP04 campaign and they shall be addressed on Monday by the dealer. Once I get that problem resolved I can get back on-track with the goal of high 12's on the bottle.

CRH

 

Just make sure it's the Jack Daniels bottle!

 

I tried that. It doesn't work so well.

CRH

 

I Don't recommend to change the factory fuel pump if the factory ECU is goin to control
it. The pump from factory receives high and low voltage and pump different amounts of fuels.

In my setting my pump is conected to a relay and always has 12v. Remember we installed a return fuel line.

Tuning is the key in all the proyects nothin is plug and play!

Manuel

 

bump

I don't have a greddy kit but I'm curious to know how it runs with the midpipe and if the management system can be tuned for it.

 

So far, not too well. If you are looking into the Greddy kit I would recommend you keep the stock cat on. Most of us with hi-glow cats are getting noticeable backfires. I have loaded the 2nd, updated Greddy map, but it still pops quite a bit. I will be tuning it in the coming weeks to see if that will help.

 

If there is already a thread about this let me know but I didn't see it.

What about porting the engine header and midpipe and tunning the system for it all with the turbo kit of course, has anyone tried or is anyone doing the R&D on this, I mean it can be done right?

 

Hey Fanman speak for yourself, just kidding. But I have installed the Rotary Performance high flow cat and love it , no problems with it... Also without me tweaking the turbo, the high flow cat made my boost go from 7.1psi to 8.1psi with no ill effects.. My AFR are good.

 

Greddyturbo1, which map are you using?

 

I am pretty much speaking for myself, & a few others. Some may have success, some don't. I have the Greddy updated map, but have not tuned it for my car yet. Just out of the box, you may have some issues. Just like our cars, even stock, some have issues, some don't. Unless you are willing to tune it, there is a large chance you may get backfires. Just be aware of that. That is all.