How long should T-25 boost hold?

[DSMAddict]

Well we installed my friends HKS SSQ.. simple install, and then we put his mbc on. We built the mbc followed outlined directions, and installed that as well(boost gauge as well, of course). Well we eventually got him to 15 psi, but it seems his boost isn't holding as long as id expect. He goes back to 10psi by 5k rpm, and we've tried fully tightning the screw in the back and totally loosening it. As far as we know the mbc/gauge/bov are working correctly? Is there something wrong or does the t-25 just suck that bad?

 

[candela]

T25 sucks that bad...

 

[DSMAddict]

anything we can do, to make it hold a bit longer?

 

[candela]

not really...My t25 falls off at aroun 5k also. No matter what I set it at, its at ~12psi by 6k and 10psi above that...

 

[umiami80]

Best you can do is port it or OPEN boost it, either way would kill the turbo fast as it is well beyond it's efficiency range.


Me thinks you have a Stock SMIC, so you wil be heating that thing up BAD and have intake temps of well past 200, so you will get pulled timing, and then Knock and then it will be really slow.


You could put in a fuel pump, and get a nice 18 PSI spike to lauch but will ALLWAYS fall to 10-12 PSI.


Get a Bigger turbo and a FMIC, you will fly.

 

[abrxy3]

so im gettin bad heat with only 15 pounds? i thought 15 lbs on a basically stock car is within the safe limits

 

[boostineklipz]

15 psi is safe on the t25

And yeah the t25 sucks that bad. It doesnt hold boost for sh-t. If you want to hold boost to redline, you are going to have to upgrade the turbo.

 

[98TsiAWD]

How come everyone talks about boost falling off with their T2small, mine doesnt?
I push 15-16psi all the way to redline.

 

[FourG63 97GST]

maybe your T25 is "special"

 

[umiami80]

im gettin bad heat with only 15 pounds? i thought 15 lbs on a basically stock car is within the safe limits

You would get Heat soak 100% stock, it just happens and then you get pulled timing and then the car makes less and less power. 15 PSI is safe as you won't kill your care, but your SMIC not only has a pressure drop of 2 PSI as it is extremely inefficient, it will also heat up but the top of 3rd gear from a stop, buy a Toyota Supra SMIC, and see you car WAKE UP, it won't heat soak on a T-25, and can handle 500CFM's, your T-25 has like 240-260.


Change the Turbo and IC and you will see a monster with proper furl mods.

How come everyone talks about boost falling off with their T2small, mine doesnt?

Hell I have seen 20 PSI on a T-25, just weld the wastegate shut and watch it get WHITE hot before it explodes, if you run race gas and can driver it will get you into the high 12's before it just dies.

 

[Enraged78]

Porting a T-25 will allow you to hold more boost until redline. One member on this board ported his to great effect, allowing him to get 15PSI at redline. Getting rid of intake and exhaust restrictions will also allow it to spool faster and hold boost longer. With an intake, BCS removal, BOV, and test pipe, I got my old T-25 to hold 12 PSI at 7500RPM. Woohoo! Then it died a horrible death after 163,000 miles.

Later,
Matt.

 

[larryd]

Mine held boost pretty good up to about 6500 and then died

 

[Ed98GST]

An additional idea, if you're in the same situation as me, is to fab a CO2 I/C sprayer for those times when you really need to squeeze the extra boost out of the T25 and stock sidemount. I don't want to upgrade to a larger sidemount b/c I'm going with a larger turbo at year-end and will upgrade to a front mount then. Also, a front mount's not warranted yet, and I just don't to fork out the money until later this year.
There's been lots of discussion surrounding effectiveness of CO2 spraying on a larger I/C, but I think everyone agrees that it's extremely effective on a sidemount that's too small -- like ours.