uping the boost

is it better to up the boost via the actuator rather than a bleed valve???running 11 psi(standard)want to up to 14 psi,but have read that bleed valve is the crude way,lenghten the actuator arm slightly does the same job??

Shortning the actuator rod will increase boost, but the boost response will be the same as it was, so if you have a weak actuator is will still boost slowly for instance.

Theres nothing wrong with a bleed valve, they can only cause spiking problems on cars that are really hiking up the boost, say from 10 to 20psi...Fitting a gated bleed valve, which does not bleed air to atmosphere, but actually restricts the feed to the actuator until the required boost is set is the best way....

Don't forget you need to remove the boost limit in the ecu. I think they are set at 1 bar but boost always peaks a few psi above what it holds so you won't be able to run virtually anymore boost than standard without hitting the limiter

thanks for the advise,thought you lenghtened arm so when it moves the wastegate opens slightly more to increase boost??do have a fcd aswell,so do i need to fit this first then the bleed valve,but a little unsure whats next,i know that both have adjustments so i want both set for 14/15 psi,but if i go for a run and hit the limit early is it going to be the bleed valve or the fcd set a little low??

What FCD is it? If its an ART, ARR or superchips one it should allow you seriously increase the boost with out tripping the limiter, I believe all 3 of these remove the limit altogether. You'll need to fit the ecu mod first its a very unpleasant experience tripping the boost limiter in a GTA (it nearly puts you through the windscreen!) so best avoided. Once thats done use a bleed valve, dawes device or an electronic boost controller to adjust the boost pressure. The car won't fuel for much above a bar anyway so next stop will be to increase your fueling capacity - cheapest way is an adjustable fuel pressure regulator about £100.

You shorten the arm, so there it holds the wastegate shut to run more boost. If you set the boost the say 14,15psi and it hits cutout, adjust the fcd.

Be wary of running any extra fuel on the standard management. Even the slightest increase saps power and torque. Programmable EFi is required for further gains..

yeah it was the bleed valve/turbosmart fcd,to be honest i,am pooping it about messing with it!!!maybe i should get someone else to fit it!!i,ve ordered a front exhaust section which doesn,t include the front box(b290/b29w)so that should breath better,already got a j&r filter insert,doing the bleed valve/fcd mods should help,but if i need a better fuel pressure reg then i will buy one(whats suitable)and i do have a brandnew boxed ecu spare,should i chip it,again i think it might be a bit of a waste as i,ve read in other posts,just want to get the 0-60 time down a bit,the route of changing turbos etc is really a little drastic in some ways as if i go larger turbo,more lag etc,not much room for intercooler mods on a 25,i,ve removed the restrictive plastic in front of the intercooler,and replaced it with a new old stock unit,poxy dump valve annoys me!!always wooooooshing,get silly,even under light throttle,going to change the spring,got a spot on psi gauge in the glovebox,reads 11psi spot on,running optimax with redex octane booster(can get avgas?)i don,t want to turn it into any type of racing car(its a 25!!!)but just want to suprise a few boy racer idiots,very really use it,always polishing it etc,looks totally standard,maybe i should leave well alone!

Don't worry about the book 0-60 times on the 25T. My old one running a bar of boost, used to go like absolute stink. The gearbox is shorter ratio than the GTA, and thus faster through the gears, but affects the 0-60 run, as it needs three gear changes.

Check that your car is running at least as it should from the factory, before you start modifying.

To set up the manual FCD, (make sure you have a boost gauge first), increase the boost just until you hit boost cut, then open up the FCD a little untill it is removed. Do this, up until the boost holds at 15psi.

I never had a problem with the original intercooler saturating until after about 2 minutes of continuous full boost abuse. Its a better setup than on the GTA. Front mount would be nice though....

just went out to have another look!!don,t know about the gta,s but i have an overboost cutout switch(same as 21 turbo)i know if this is adjusted(involved pressure tester/volt meter)then the overboost is upped to what ever you want(in my case i would set to 15 psi)my question is does the fcd do the same thing,and the reason gta,s use one is because you don,t have an over boost switch to adjust??if i,am talking rubbish(yet again)what are the switches set to,i would guess around 13 psi??

Ah yes, the 25 does have an overboost switch. Bin it, because the ecu still has a cutout at 14.7psi too, through the map sensor. The fcd needs fitting to the map sensor feed, not the overboost sensor feed.

so if i leave it alone surely it will cut in below 15 psi???its either got to be adjusted higher or as you say disconnected,but then i don,t have much to save my engine from going bang?i think maybe adjusting to 15psi,fcd,bleed valve will all add up to some sought of improvement

now adjusted the overboost switch to 15 psi,was set at 12 so would of gone through the screen then!also my custom exhaust has arived so thats going on tonight,then it will be the fcd/bleed valve,should sound nice with just the back box?

fitted exhaust,has a slightly deeper growl,nothing silly,upped the boost to 14psi spot on,goes well,do notice it peaks at 14 for a short while then dies back down,i think this is the turbo saying THATS ALL I HAVE!!think this is called compressor stallit goes down to factory 11 psi

check for boost leaks, my old 25 would hold solid at a bar..

will do tommorrow,have had intercooler out,but will change all the clips etc,i have checked all boost hoses of car,all fine