T-25 Efficiency

[Chicken Patty]

I was just wondering, I know the stock T-25 unit is not very efficient, if any at all. I will be upgrading soon, but either way I just want the car to run right for now.

Right now my mods are Dave Brode upper pipe, HKS SSQV, 3 inch turbo back, injen intake, ACT flywheel and clutch, and FMIC. I have not done any fuel mods to the car myselft, although I don't know if the previous owner did or not.

Right now with the MBC i run about 19psi spike and for some reason it drops down to about 11psi by redline. Even with the intercooler to cool down the intake charge, is the efficiency of the t-25 still at no more than 15 lbs. What boost you guys think I should run?


my a/f ratio right now is under 11.0 the whole way from 4k to redline. the car has to have at least a fuel pump im guessing.

 

[98eclipsekidd08]

My t25 would only boost 14psi after that it was usless.

 

[eclipse_turbo97]

Probably the shitty stock wastegate would be my guess. Hopefully someone with more knowledge than me will chime in and help you out.

If ya wanted to upgrade I believe that FP has a wastegate upgrade for 99 dollars. I wouldn't recommend it with a stock fuel system though.

 

[98eclipsekidd08]

or without loggers/tuners/guages and so on

 

[Chicken Patty]

My t25 would only boost 14psi after that it was usless.

is the car actually quicker like that, than higher boost levels?

 

[dsmzoom]

Your t25 will not last very long boosting at 19psi, are you hitting fuel cut? I know running my t25 at 15psi with a logger I would hit fuel cut at WOT. At 19psi you should be over running your stock fuel system and knocking like a maniac. The t25 is not able to boost at such high levels, also the reason why your boost falls off at higher rpms. Your profile reads you have a FMIC, I would suggest taking it off as well your probably lagging like crazy on such a small turbo and losing performance.

 

[PieEyedPiper]

uhm.. don't take off your FMIC. Thats silly. While there might be some minuscule amount of lag, the T-25 spools so damned fast I'd bet you'd never notice.

But I agree with the other comments. Limit your boost to 15psi for maximum efficiency (not compressor efficiency, thats at a way lower boost pressure, I'm sure). 19psi is certainly beyond any efficiency and beyond a stock fuel system.

The reason your boost falls off in the upper rpm range though is because the engine wants to consume more air than the turbo can provide, thus boost drops to 11-12psi for most people. Thats just all the breath the T2Small has.
A larger unit will allow you to maintain much higher boost levels not to mention make great use of the FMIC you purchased and installed to take advantage of the potential that accompanies a larger turbocharger.

 

[kmoore]

Your t25 will not last very long boosting at 19psi

That's really all it comes down to.

 

[Chicken Patty]

Your t25 will not last very long boosting at 19psi, are you hitting fuel cut? I know running my t25 at 15psi with a logger I would hit fuel cut at WOT. At 19psi you should be over running your stock fuel system and knocking like a maniac. The t25 is not able to boost at such high levels, also the reason why your boost falls off at higher rpms. Your profile reads you have a FMIC, I would suggest taking it off as well your probably lagging like crazy on such a small turbo and losing performance.

I know it won't last long, i'm going to go big turbo within the next month. I just wanted the car to run at its best meanwhile. So if it goes, no big deal.

2nd I dont hit fuel cut, I think the boost drops so damn quick that it don't give it time to fuel cut.

3rd im running really rich, under 11.0's the whole time probably somewhere in the 10's. The car can have a fuel pump or something I dont know what the previous owner did. So i think if any knock it'll be minimal.

Also the intercooler did a huge difference to be honest. So i dont think i'm going to be taking that off. Anyways like I said im going big turbo really soon, so I'll need it.

 

[Chicken Patty]

Well, tomorrow i'll be doing a piece of intercooler piping that keeps popping off. Once I redo it then i'll turn the boost down accordingly and let you guys know how it goes.

 

[kenamond]

If the turbo is just spiking to 19psi and then dropping immediately back down to 14-15, you probably wouldn't see fuel cut. At high RPM, the turbine can't flow enough exhaust to keep the compressor at 14-15psi, so boost drops off. If you're holding 19psi at lower rpm (not a spike), turn down the boost. If the T25 grenades, you can filth up the entire intake including the nice FMIC, and your thrust bearing pieces will end up in your oil pan (and removing the pan on a 2g AWD isn't a barrel of laughs if you've never done it).

Get a logger sooner than later. If you're going big turbo, you'll probably be limited in fuel, and when you upgrade that, you'll need a fuel controller, and if you go with DSMlink, it'll also be your logger. 2g loggers aren't free like 1gs, so if you plan ahead, you can save yourself some cash by not buying stuff twice.

There are some folks around here who pushed the T25 pretty far. Sure, it's tiny, but you can get a lot more out of it than folks with stock setups. Just don't blow it up. And when you decide to swap it out, PM me about the T25. I'm on a "rebuild a T25" kick at the moment and want to do a couple (one is in the works already). But if you destroy it, it's only a paperweight.

 

[turboglenn]

I ran mine just like that , spiing 19-21psi then settling to 12 or so by redline, but i short shifted it so i didn't fall off that much when normally running the car. (no point in running it past the power band just to hear the motor scream in pain because it can't breathe )

Mine was fine, but it was only that way for a few months before i had a B16g to go on it, so if you upgrade soon it's fine. If not you bettter run it at 13-14 psi or whatever it holds decently and not wind the guts out of it at 7500RPM or you'll be driving and NA eclipse before long kenamond is pretty much dead on, so unless you wnt to fget real dirty don't push it.. i did because i'm a mechanic anyway and knew the turbo wouldn't be on for no longer than it took to order a new one and get it shipped

YOu shoudl be fine, jsut run lower boost and get somethign bigger if you're seriously going to try and make some power

 

[Chicken Patty]

If the turbo is just spiking to 19psi and then dropping immediately back down to 14-15, you probably wouldn't see fuel cut. At high RPM, the turbine can't flow enough exhaust to keep the compressor at 14-15psi, so boost drops off. If you're holding 19psi at lower rpm (not a spike), turn down the boost. If the T25 grenades, you can filth up the entire intake including the nice FMIC, and your thrust bearing pieces will end up in your oil pan (and removing the pan on a 2g AWD isn't a barrel of laughs if you've never done it).

Get a logger sooner than later. If you're going big turbo, you'll probably be limited in fuel, and when you upgrade that, you'll need a fuel controller, and if you go with DSMlink, it'll also be your logger. 2g loggers aren't free like 1gs, so if you plan ahead, you can save yourself some cash by not buying stuff twice.

There are some folks around here who pushed the T25 pretty far. Sure, it's tiny, but you can get a lot more out of it than folks with stock setups. Just don't blow it up. And when you decide to swap it out, PM me about the T25. I'm on a "rebuild a T25" kick at the moment and want to do a couple (one is in the works already). But if you destroy it, it's only a paperweight.

once I put the turbo i will get the fuel system right after so I should get away with like 10 psi or something. I will be going AEM so that is my logger as well. I'll let you know when the take the t-25 off.

 

[Chicken Patty]

I ran mine just like that , spiing 19-21psi then settling to 12 or so by redline, but i short shifted it so i didn't fall off that much when normally running the car. (no point in running it past the power band just to hear the motor scream in pain because it can't breathe )

Mine was fine, but it was only that way for a few months before i had a B16g to go on it, so if you upgrade soon it's fine. If not you bettter run it at 13-14 psi or whatever it holds decently and not wind the guts out of it at 7500RPM or you'll be driving and NA eclipse before long kenamond is pretty much dead on, so unless you wnt to fget real dirty don't push it.. i did because i'm a mechanic anyway and knew the turbo wouldn't be on for no longer than it took to order a new one and get it shipped

YOu shoudl be fine, jsut run lower boost and get somethign bigger if you're seriously going to try and make some power

yeah I tend to shift like around 6500rpm, before the 7k redline. the car just doesnt pull after that. the small turbos haunt me eveyrwhere I go. I had a SRT-4 before and it was the same thing, at redline the car falls on its face and doesnt go nowhere, except the srt-4 turbo is a lot better than our t-25 unit hehe.

 

[Dsm2nr89]

Chicken you crazy spiking 19. Like your headline on myspace says : " Turn the boost down you damn fool!" Turn it down to 14 psi, should be nice and set there. Pos t2smalls

 

[Project2G]

That's really all it comes down to.

I agree. You should not have your mbc turned up that high (19psi). I would keep it around 15-16psi since you don't have any fuel mods and if you want that little guy to last (t25). I'm surprised your not hitting fuel cut, I did when I had my t25 and turned it up to 17-18psi range.