What PSI is a stock CA18DET T25 good to?

[KaZ (VaBch)]

Now fuel isn't an issue... I'm running 450cc injectors on the car it would be going on... I'm just curious what the maximum PSI is for that turbo before throwing efficiency out the window. I've got a GTiR T28 on my '84 200sx at the moment but my brother wants it for his CA18DET so I'm going to put my stock T25 back in its place... anyone know what the maximum boost level you can run on it might be before you're just blowing more hot air? With the T28 and the 450cc Injectors I'm piss rich 24/7... so I figured dropping down to the T25 I'll be safe as far as fuel is concerned... I'm just curious what the threshold for the turbo might be...

Thanks,

[Notchbackca]

14lbs is pushing it for that turbo, and are you running 450s without retuning your ECU? if so you need to get that taken care of asap, downsizing the turbo won't help your A/f any

[pulsar gtr]

T25 max is 16 psi, but it won't last long before you blow it up, you can run safely around 12-14psi

PULSAR GTR

[KaZ (VaBch)]

I knew it wouldn't help... ^_^ I'm just saying I won't be running lean...

I've got an SAFCII installed in the car leaning it out with a Z32 MAF & Air Filter... I'm its tunable... I just wanted to know what I could push that turbo to! Thanks!

[paul_s13]

A T25 is at its limit @ 15psi, and you'll never max out the stock injectors with a T25!

[float_6969]

Mine was running out of breath at the stock setting in the upper limits. Hmmmmm

[GoofyATX240]

Same here mine just starts dying off lmao.

[paul_s13]

Well with the stage 1 chip I used to make you had no chance of doing that, it would fuel enough fo 270bhp and there is no way you will get near that power with a T25 or a hybrid T25, and even if you were to wind the boost up to a silly amount on a hybrid the turbo becomes so inefficient that you don't gain anymore bhp.

[boost_boy]

I wouldn't personally take the stock T25 past 12 psi. For those that want to just be plain and simply turbocharged, then this the way to go. But for you true boost heads that want more, ditch the T25 quickly or you'll be munching pistons and burning headgaskets as well as crapping turbo seals. I've taken out 4 T2smalls in a very short period of time, but the hybrid units do a little better up to 16psi.

Dee

[paul_s13]

I wouldn't personally take the stock T25 past 12 psi. For those that want to just be plain and simply turbocharged, then this the way to go. But for you true boost heads that want more, ditch the T25 quickly or you'll be munching pistons and burning headgaskets as well as crapping turbo seals. I've taken out 4 T2smalls in a very short period of time, but the hybrid units do a little better up to 16psi.

Dee

My first turbo upgrade was a Turbo Technics T25 hybrid, I ran it at 19psi for about a year and it never had any play when I sold it, but even a T25H will struggle to max out the standard injectors, from all the cars I've tuned it seems that a T28 at 15-16psi is the limit on 370cc's, and even then your fuel pump has to be good and raised fuel pressure might be needed.

[float_6969]

Hence my purchase of 550cc. I'll NEVER use all that injector! Bah, who needs idle anyway..

[boost_boy]

Quote »I'll NEVER use all that injector! Bah, who needs idle anyway..[/quote] As long as you use a T25, you're safe. I've maxed out 50lb/hr to the tune of 107% duty cycle on 18psi and my fuel pump was functioning just fine and this was with a T3/T04E stage III hair dryer. You have to do the math on these motors. A 1.8 litre can muster around 360hp with a set of 550cc injectors.

Dee

[biosehnsucht]

107 %? is that higher than normal fuel rail pressure to get that ?

[paul_s13]

I'm just wondering exactly what the uk-us bhp measurement difference is, because I have seen many many CA's t25's and T25 hybrids run out of puff WAY before the injectors, I was maxing out my 370's at 14psi with a T3 and I recorded 301bhp (with a rising rate FPR) and I have never seen a T25 put out more than 250bhp and thats not going to trouble the stock injectors.

[boost_boy]

Quote »107 %? is that higher than normal fuel rail pressure to get that ?[/quote] Fuel rail pressure was set at 37psi at idle and rises upon acceleration. Anything higher screwed with the idle of the motor and risk an injector locking-up at high boost which means disaster. For 3 years I ran that said with no engine damage in which the same engine is still alive to this day with better than 155psi per cylinder, so I definitely know that this is the limit on 550cc injectors on a 1.8 litre motor. But if you care to try it, be my guest.

Quote »I was maxing out my 370's at 14psi with a T3 and I recorded 301bhp (with a rising rate FPR)[/quote] Paul, this sounds mathematically correct, but I can't see say I know the differences either. The hybrid T25 with T3 wheels I used seemed to be pretty wicked up to 18psi, but in a CA18's T25 housing the flow will get choked off anything after that.

Dee

[paul_s13]

Paul, this sounds mathematically correct, but I can't see say I know the differences either. The hybrid T25 with T3 wheels I used seemed to be pretty wicked up to 18psi, but in a CA18's T25 housing the flow will get choked off anything after that.

Dee

A hybrid t25 may have larger compressor wheel but the T3 I had was a true T3 with a much larger exhaust housing than the puny T25 effort, the thing i don't agree with is some of the figures banded about for t25 power levels, as i have already said i have NEVER seen a CA18 with a standard or hybrid T25 get more than 240-50bhp@ the crank, and I have seen nearly a hundred s13 dyno runs (i have been to many sxoc dyno shootouts) 300bhp @ 14psi is possible with a true T3 and maybe 16-17 psi with a T28.

I'm just going on my experience of mapping them and watching many dyno runs, to me there seems a big discrepancy with the uk and us figures, some of the figures of 250rwp seem far to optimistic, if you have 250 @ the wheels that usually means about 280-ish @ the crank.

I have one prinout for my old car that stated 296@ the crank and 267 @ the wheels, for some reason i only lost 29bhp through the gearbox, and most of my friends cars were loosing 40bhp.

From varoius things i have heard i calculated what my power would be using info from an aussie site about DIN/SAE differences and my adjusted power came out at 343bhp @ the wheels !

[boost_boy]

I wish I would have dyno'd my T25 hybrid before I removed it. I figured I was up and around 260ish-270ish whp, but those are just guesstimates. We have a forum member here in which I've had a T25 prepped for him in hybrid fashion and am interested to see how it goes for him.

Dee