I am getting a pretty much brand new engine for my 93 R1 (new parts from MazdaComp, housing, rotor, eshaft etc), with a big streetport.
I have:
Pettit Intake
HKS Downpipe
Random Cat
GReedy cat back
Apex PowerFC
Walbro 255 high pressure pump
850(4) injectors (switch to 850/1300?)
PFS IC
I am trying to pick out a turbo, a T04S from XS seems like a good choice, or a T78 or? I want pretty quick spool up as I will be doing Road Racing, AutoX and just driving around as well as the occasional drag race. Oh and I have GAB shocks, RacingBeat springs, Fikse FM5's and Yoko A032R's as well as cross drilled rotors so the suspension is doing ok. I also have a Autopower race roll bar, Corbeau seat and Sabelt harness for safety. Thanx!

 

first thing get a midpipe need more FLOW

 

Well I could run a midpipe but I think that would violate the 93db sound level at the local AutoX, I already got flagged for noise at Laguna Seca hehe. I've read that the difference between a midpipe and a high flow cat can be small and the hf cat even provides more mid-range torque. I suppose if I dyno at 400rwhp with the hf cat then I would try a midpipe

 

you are going to need a single turbo kit. if you are autoxing might want to get the apexi rx6 bb turbo kit. that should put you where you want to be and have minimal lag.

 

The Apex kit is nice but from what I have read it is more like a ~400rwhp turbo and not a ~450rwhp unless you can get a different turbo with the kit like you can in Japan. I liked the XS T04S kit because XS is only a couple hours from me, has a cast divided manifold and dyno slips showing 478rwhp with that kit (although there has been some speculation as to it's validity and the porting was very aggresive for the street...)
But yes, I would need a kit since I don't have the equipment to weld up a manifold etc.

 

Oh I also have a C's short shifter, ACT street/strip 30% over spring with HD plate and a M2 9.5# flywheel

 

I right now will be trying to hit 450+rwhp with the RX6, as soon I get my motor back we will see.

 

What about just a classic Garret TO4 turbo with a custom manifold and downpipe? Ask someone like crisspeed about this stuff.

Personally i wouldnt trust XS as far as i could throw them.

 

Regarding XS, I infer you are refering to the 476rwhp dyno that was not backed up by the subsequent drag runs? Or some other incedent?
I'd love to go with a ball bearing T04 or GT30 but I can't find much information.
I've heard that cast manifolds are better than custom ones in general, anyone have any data or experience?
Crispeed needs a webpage :-)