What is the max boost i can put on my STI V5 safely...with a front mount/Water spray and 3" exhaust, no ECU mods yet.....i have various answers to this ....so what do u all think?

 

It's a tricky one 'cos it's kind of a "how long is a piece of string" type question.

Simple answer is probably about 1.2bar, but even then, you should have a boost gauge, Knock sensor and AFR.... (IMHO obviously )

What were you planning on using to control the boost?

Matt

 

Unless you actually have something (ilke ecu or boost controller) your not going to be able to actually increase the boost anyway - or should that read safely increase the boost....

Standard intercooler on my sti5 with possum link was running @ 1.4 bar, fitting the front mount didnt actually mean it was safe to run more boost and from memory it ran exactly the same boost level after it was mapped with the front mount on, as it was felt this was about max for the std turbo.

 

a lot of sti 5s have cast pistons, meaning they arent as resilient to higher boost pressures as some of the earlier stis.

1.2 is a nice guess, but I have never liked the idea of upping boost without sorting the fuelling properly.

You would be far better off modding the ecu then you can extract more efficient power from less boost, such as by altering the timing. This alone at standard boost can make a massive difference.

 

Have to agree with Adam, my car is running "only" 1.2 bar with a FMIC, but with a decent remap, it is giving 330 BHp/300 lb.ft (on a good day) (and it is running quite rich so there is definately more to come without upping the boost)

 

Buy a copy of DeltaDash - it'll let you see what's happening yourself as you raise the boost

Richard