Here's a question that I rarely see asked, if ever. Everyone is concerned about what the fastest turbo is to 350,400,450 rwhp. What about for smaller turbos? What's the quickest spooling turbo for 250 rwhp? At what rpm is full boost achieved, and what is full boost on the turbos mentioned? Does it hold its boost all the way until redline or does it taper off after a certain rpm?

 

for that?
stock??? t28???

 

how bout taking a stock turbo, porting the wastegate, full 3" exhaust, CAI and FMIC (maybe), slightly larger secondaries, and maybe some fuel management. That would get you to 250, maybe more, without having to buy a turbo, manifold to fit, external wastgate, downpipe to fit plus what I already stated

 

Yes stock with wastegate mod, fuel upgrades, exhaust upgrade, intake, and fuel cut defender.

 

Damn I hate when people slip in while I am typing!

 

sorry...

 

Stock will do, or a BNR will work.

I dyno'd 240 at the wheels with an intake, exhaust, Rtek ecu, and no Fuel mods, but i strongly advise doing some kind of fuel mods.

 

you could actaully get a more efficient turbo then stock for around 250 whp, with a better designed turbine wheel that would spool it up faster and be less restrictive. as well as a better then stock exhaust manifold with an external wasteagate. the quastions is why spend all the money and effort on a setup like that to make marginal diffrance in spool and efficiency for only 250 whp. that is very little to ask from a turbo rotary, maybe you need an NA?

 

I'm not interested in the power, but the spool rates and at what rpm they make full boost, and if the boost is held all the way to redline or if it starts tapering off. If I was interested in power, I'd shoot a lot higher, say, T78, T88, GT35, etc...

I felt that the stock S4 turbo spooled a bit too slowly for my tastes, the lag was noticeable under hard cornering.

EDIT: Wow....two instances of people sneaking in while typing in one thread.....what are the odds? Kahren, do you know of any aftermarket turbo's that do have such a turbine wheel that you mentioned? I was thinking maybe a Garrett GT25R but my friend suggested a Mitsubishi 16G small wheel. I figure for 250 whp, small turbo's boosting at 8-10 psi would make such power?

 

If I can ask, why do you want quick spool vs. higher power numbers?

 

Three words: Minimizing turbo lag

This won't be a quarter-mile car, I have other cars for that. I need something this specific for my project.

 

get a 13bre =P

 

T28bb

 

the 28 spools faster than the 25?

 

stock will be fine

 

I did that and blew my turbo in 6 months. Stock turbos cant keep up with the flow of a full flowing rotary engine. You need somthing with a good thrust bearing package or a all out ball bearing turbo that is made to handle crazy amounts of flow. Im upgrading to BNR turbos because in know that interanlly with the 360 thrust bearing package there bullet proof when it comes to flow from what ive been told and researched. Im talking at 12psi max too not crazy amounts of boost.

 

About the same give or take 200 rpms extra on the t28bb.

You can get a gt28r, or a gt28rs which has a higher hp rating.

 

two words...ball bearing

 

Only difference between a t28 and a gt28r is the inconel exhaust wheel; doesnt make much of a difference. The ball bearing t28 and the gt28r might share different wheels but both are capable of the same power/spool times. Just higher efficency in the gt28r. That is all speculation since I have yet to have either apart next to each other
A gt28rs is very efficent but produces significantly less torque then a gt28r is capable of but barely anymore peak power. Personal oppinon, gt28r or a gt2871R. The 2871r will have the ability to give more peak power but with the same torque curve of the 28rs

What do you mean by lag? It gets thrown around so much incorrectly, just want to see what you actually mean

 

i think he's talking more like "boost threshold"

 

That's cuz u is one crazy ****...I'd stick with a BNR.

 

In which case ballbearing doesnt matter since it mostly effects turbo lag and not boost threshold, the RPM range where you start making positive manifold pressure. Turbo lag is how long it takes you to start making boost after you step on the gas in the turbos functioning rpm range. Not a very good explination but some of you know and could elaborate if you felt like it.

How fast do you want the car to be?....

 

+1 for Kahren...why not stay N/A?

 

I'm pretty sure that almost a word for word definition from maximum boost

 

Oooo! Nice for me then! I havent read it yet but I ordered it about a week ago. Waiting for it to arrive =)