Max psi on t25 on stock 420a

[Misterbeechy]

Im running stock motor and will be running MHI T25 with FMIC 2.5 piping all around.

Ok being that every type of turbo has different flow rates,

People tell me that "your motor is fine running 8lbs max on 420a"

but being that the MHI T25 flow rates arent that great compared to 14b and 16g how would i be able to tell what could be the max psi i could run?

for instance i was thinking maybe i can run a wideband and slooowly increase boost until i see it get it leaner around 13.0-14.9 AFR

and then mark that boost level as max..

what do you think? if im wrong please shed some light and a reason why..

 

[LiquidX]

15ish is about the max due to it's Efficiency range. After that it's just blowing hot air and slowly weakening it.

 

[jjrock5]

You're going to have a hell of a time making an o2 housing for that engine/turbo setup.

 

[gst96spyderman]

t25 maxed out around 14-16 psi

 

[knochgoon24]

Are you asking where the turbo runs out of breath, or how much boost your car will handle.

Your plan of just upping the boost until the car starts going lean isn't that great. Check the 420a forum to see the proper steps to turbo your car.

 

[Misterbeechy]

You're going to have a hell of a time making an o2 housing for that engine/turbo setup.

yea tell me about it.. i did tho.. on ebay they sell the o2 housing flange and welded a pipe.. bent it down to the 2-1 exhaust i had there..


i know the max on that turbo is 14-16 psi.. i dont know if you guys are understanding..

the question is.. would i be able to measure my max boost level by using a wideband and seeing where it starts getting lean around 13.0- 14.9 and just call that my max boost level.. i know the turbo wouldnt reach 15 psi by that time..

Are you asking where the turbo runs out of breath, or how much boost your car will handle.

Your plan of just upping the boost until the car starts going lean isn't that great. Check the 420a forum to see the proper steps to turbo your car.

yea i figuered it isnt that smart, but maybe a cost effective way to get close.. because i dont want to run a t25 at 8psi where in fact the motor could take more and the turbo can produce more, understand? i dont know im just getting ideas

 

[gst96spyderman]

yea tell me about it.. i did tho.. on ebay they sell the o2 housing flange and welded a pipe.. bent it down to the 2-1 exhaust i had there..


i know the max on that turbo is 14-16 psi.. i dont know if you guys are understanding..

the question is.. would i be able to measure my max boost level by using a wideband and seeing where it starts getting lean around 13.0- 14.9 and just call that my max boost level.. i know the turbo wouldnt reach 15 psi by that time..

yea i figuered it isnt that smart, but maybe a cost effective way to get close.. because i dont want to run a t25 at 8psi where in fact the motor could take more and the turbo can produce more, understand? i dont know im just getting ideas

You are making this complicated man. 15 psi on your boost gauge is max... That is the end of the story.

 

[oldman420]

Haha no he's asking how much boost can he run on his setup. Not how much boost does a t25 top out at.

Without fuel mods I would be shocked if you wouldn't run lean at 5 psi even with the low flow of the t25. Are you aware of just how small the stock injectors are on a 420a?

 

[RadDsm]

T-25s aren't MHI turbos, just sayin.

You definitely don't want to be at 13:1 AFR on pump gas in boost.

 

[97-gst]

You are making this complicated man. 15 psi on your boost gauge is max... That is the end of the story.

Yeah either way 15 psi is the most the turbo can effectivley boost, with a good tune it should be okay

 

[TurboAnything]

You can not run any turbo on a 420a without some sort of fuel management and a fuel pump upgrade. A rising rate fuel pressure regulator and a larger fuel pump will let you run the min boost that a t25 will put out on that motor about 12psi.

If you try to run 13.0-14.9 AFR you will melt a piston in no time flat. You would be aiming for a 10.5-11.0 AFR.

 

[96 420a-t]

With all supporting mods 8psi max. 10 on fresh motor. A/f has nothing to do with max boost. It is how much stress the internals can handle. Anything over10 you will soon scatter your ibternals on the asphalt.

 

[Misterbeechy]

You are making this complicated man. 15 psi on your boost gauge is max... That is the end of the story.

hahaha ok man.. i guess this is for turbo gurus theres more science behind slapping a turbo on a motor and putting 15lbs and call it a day..

say you have a t25 with external WG set to 15psi then you swap turbos to a 16g,
do you believe your getting the same 15lbs?

THE boost guage thinks so but the motor says wtf?!?!

this is where you can say would you rather get hit with a bag of 15lbs if feathers or bricks.. THEY both way 15lbs on the scale but your face can tell, which, is in what bag...

thx for the time guys,, i guess ill be the first to try

DSM <3

 

[oldman420]

You can not run any turbo on a 420a without some sort of fuel management and a fuel pump upgrade. A rising rate fuel pressure regulator and a larger fuel pump will let you run the min boost that a t25 will put out on that motor about 12psi.

Excellent advice, might I ad if you are going for 12psi you will have to create and intercooler setup for that air charge. Their are lots of ways of running that t25, none of which involve slapping a turbo on and driving it around.

http://www.dsmtuners.com/forums/art...uild-420a-stage-2-turbo-kit-under-1000-a.html

This will be a good read for you

 

[Misterbeechy]

With all supporting mods 8psi max. 10 on fresh motor. A/f has nothing to do with max boost. It is how much stress the internals can handle. Anything over10 you will soon scatter your ibternals on the asphalt.

ok so basically only 8lbs would fit safely in that compression..

i just figured that flow rate had some play i guess..

so i guess i wont try it o 8lbs it is

thx again guys ..

 

[96 420a-t]

Stock compression is too high to run more safely. You can run more. But that's on borrowed time.

 

[Misterbeechy]

Stock compression is too high to run more safely. You can run more. But that's on borrowed time.

haha "borrowed time"..

Turbo says: ill let you run more boost in exchange of 2yrs off your motor life.. ME: hmmmm ... DEAL!!! hahaha

 

[TurboAnything]

I have personally run 15psi on a Hann Kit in a GS with a pump upgrade and a Rising rate FPR. That kit comes with a 16g in a 8cm t3 housing. this was on a completely stock 420a. The motors are strong and can handle the extra power no problem if it is tuned correct.