Drove a weak GSX

Today i drove a GSX with a full T4 setup, 1g head & BOV, intercooler, exaust manifold, and a full exaust. I thought this was gonna be pretty sweet but after driving it it felt as slow or slower than a NA. He said he was only running 6psi and there was a slight exaust leak between the manifold and the exaust housing. Even so, with a T4 should this be faster and, if not how could i safely make it faster if i bought it. He offered to throw in 720cc injectors and an Apexi AVC-R EBC. is this all i would need to make this thing at least as fast as stock?

How much does he want?

I think something else is wrong. Why only run 6 PSI when you have a t4??
Only reason would be because something was seriously wrong or about to blow.

6 psi is a joke. Stock these cars run about 12-14 psi. That t4 shoulda been set to at least 16 for the streets and pulling nice and hard. Did he not have any tuning devices on it yet?..

6psi is so far out of that turbo's compressor efficiency. I don't even have to know what turbo exactly, it's probably slower than stock.

I know, his problem was he had too many projects so he got this one set up to go fast but bailed on it cuz he has a 911 hes gonna twin turbo, and a chevlle that hes workin on. he actually has a bunch of extra parts for it. he had a AEM EMS he bought but hadnt installed i already said that he was gonna throw in the apexi. Im thinking if i get the EBC and injectors installed and crank up the boost i should be able to run like u said at least 12 psi safely. I think another reason to keep it slow is that hes trying to sell it and he doesnt want to try and sell a beast to some 16 yr old girl. I do trust this guy with a wrench, he worked in stock cars and raced his own car for a long time and defenitely knows what hes doing.

And if anytbodys interested in some of his spare parts i can give you his #, he live outside of denver CO. hes got a BOV, the Apexi is mine, an AEM EMS, another 1g head and a 7 bolt aluminium lightend flywheel, and some other parts off his race car. And if anybody wants a serious frankenstein he found a monstrous turbo off an rx-8 race car that somebody might be interested in.

Will i need a new fuel pump to cope with the T4?? and 720cc injectors

Yeah, you'll definetly need a new fuel pump and injectors if he hasn't already upgraded them.

6psi seems weird, I'm assuming its externally gated so he would have to have a weak spring in it

You assume correctly, i think theres a different problem, i think its leaking somewhere either between the turbine housing and manifold or somewhere along the intake tubing, it has to be even at 6psi ud feel it kick in somewhere and it didnt at all it was as slow as my v6 explorer(really slow). Could a serious intake/exaust leak be the culprit of the wekness?

could be a boost leak

thats what i thought it could be but i hear thats a difficult thing to fix?

only hard part is finding them and that isnt hard

yeah, sounds like a boost leak, the guy noticed it, turned the boost down because he was to busy to fix it with all the other projects he's got going on. Already has an exhaust leak, he probably figured, the hell with this, and now is selling it.

The reason it's so slow is because the turbo probably isn't even building pressure, so you're basically driving a turbo car, without the turbo. That's why it feels slower than stock. If he hasn't upgraded the fuel pump or injectors yet, you definitely need to do that, and also get a logging device set up ASAP before you boost at all. Depending on exactly what model of T4 it is, that could put down some pretty good numbers. Like crunchy said, 6 psi isn't even on the compressor map, it's too big of a turbo to be runnning a mere 6 psi and be anything efficient. You'll also want to upgrade that BOV too eventually.