Hi

One for the mappers...

Car: MY08 STI UK, decat 2.5" cat-back, intake, OE boost solenoid, ECUtek remap. Map has been set to give ~19psi max boost.

I notice in 1st, 2nd and 3rd that I only ever get 16.5psi boost, whereas the full boost is delivered in the other gears (aside from reverse ).

Is this down to the actual mapping, or the fact the turbo can't generate enough boost in the lower gears?

Thanks already.

Stu

 

Stu there is not enough load on the engine for you to get full boost in the lower gears, the way round this is to increase the start duty in each gear to hit target boost. This can be done through ecu (if the ecu supports this function) or an electronic boost controller such as an apexi avc-r.

Banny

 

Cheers, not too sure if the my08 OE ecu can do in-gear boost...

Stu

 

Does having higher boost in lower gears make that much difference?
Surely it would just redline faster?

 

AFAIK the MY08 does have in-gear boost control but as banny says the engine load isn't going to be there so may not be too much help apart from 3rd gear.

Shaun

 

if it redlines faster, then it means you are accelerating faster

 

, yeah I didn't want to say that!

I'm going to talk to the guy who mapped it and see what he reckons

 

If you want to boost in low gears or neutral for dragging then buy an AVCR and activate scramble boost

Otherwise the on road behaviour of low gear / low load with slightly less boost will not be noticable.

Shaun