Single Turbo Question

[pwpanas]

Originally Posted by fastsupra

I have been looking at some turbos and I came across what looked like a good turbo but Id like to know what you think. I am looking for a good 650whp turbo that has the quickest spool time I will also be running methanol in the car.

Pure methanol in the gas tank, or methanol injection? Just curious...

Originally Posted by fastsupra

This first turbo is the turbo that was reccomended to me along with a kit that I would substitute the turbo out for this one. The second turbo kit is the one I found on my own and it seems pretty promising. Let me know what you guys think, I will be purchasing it at the beginning of the summer. The second turbo kit is the Powerhouse racing Stage 1 turbo kit with the dual ball bearing turbo

http://www.spracingonline.com/store/...urbo_6262/3663

http://www.mvpmotorsports.com/Templa...211&SearchYN=N

1) That SP turbo will not produce 650rwhp. Its spec is 670hp*.85=569.5rwhp (through a 6psd). ...and to get that 570rwhp, you'll need to run a LOT of boost ... possibly more than your meth injection kit alone could handle.
2) That PHR stage 1 kit is a 630rwhp kit (not 650rwhp), and same as my previous point, they likely ran a lot of boost with race fuel to get it. Probably about 30psi, I'd guess...which is significantly more boost than most meth injection kits can handle.

Are you willing to supplement the octane of your methanol injection with race fuel in your primary fuel tank?

Please remind me - are you going through a 6spd or an auto tranny?

My recommendations:
1) Get both the turbo and the kit from the same supplier (eg. Sound Performance).
2) Regardless of which supplier you choose, pick a slightly larger turbo, so you won't have to run as much boost to get 650rwhp. Sure, it'll lag a little bit more, but at least your engine will stay in one piece! I'd recommend something with approximately a 66mm or 67mm inducer.
3) The exact turbo honestly doesn't matter that much. Really! Anything with approximately the same inducer diameter and turbo design will spool roughly the same. You really won't notice a couple hundred rpm up or down while driving (a couple thousand, sure...but to get that big a difference, there's no way the turbo is the same size). After you square away your turbo upgrade, there are so many other things to worry about (eg driver training, tuning, traction, braking, driver training, precise boost control, etc., etc. (did I mention driver training? )). Please believe me that in the grand scheme of things, unless you're professionally racing for $ with rigid regulations, a hundred or two rpm one way or another will be the last of your concerns. Besides, all of these racing turbos last about two or three years at most - consider them to be a semi consumeable like your engine's timing belt. These turbos are designed for maximal performance, not maximum reliabilty like an oem-spec turbo. Why spend six months analyzing a turbo choice when two years later you'll be swapping out for something different anyway?

Lastly, please remind us of your application? (i.e. drifting, daily driving, top speed, autocross, drag, daily driver, roadracing, burnout contests, etc.) If you're going to be running your Mkiv Supra in a professional competition, then sure - perhaps 100rpm of spool time would be relevant...