I have a 1999 Audi A4 1.8t.
Right now the car is stock but i would like to get more boost out of the car.
Right now i am boosting 5-7 psi.
Is there a way to get about 5 psi more by just doing one thing to my car?

 

Welcome, read the FAQ sticky-d above.
Get a tune and an upgraded DV. This will allow you run an extra 10+psi while allowing proper fueling.

 

is there a way to get more boost by just changing something thats on the car now, without buying anything new

 

You could disconnect the N75 valve and get a manual boost controller, but that wouldn't allow smooth boost delivery like you have right now. Also keep in mind that a proper tune will yield more satisfactory results.

 

No.

I really wouldn't recommend this on a 99. If you turn the boost up using that method the ECU will only be able to compensate with more fuel using MAF readings and you're liable to run lean and cause detonation. That's bad.

 

Very true, but if the MAF is properly functioning I see no reason why it would be an issue to run a few more psi.

Heck I was running a blow-through MAF setup with a 3" MAF on a GIAC PC-16 tune... this tune is designed for a 2.75" MAF so I also compensated by increasing fuel delivery. When I unplugged the MAF my air-to-fuel ratio dropped to about 9.5:1 (stoichiometric is 14.7:1) so I actually had a bigger potential issue running that setup than the OP would have running a few extra psi.

However I knew what I was doing and I have a wideband gauge to tell me if anything is wrong. So I would say that as long as the OP has a decent idea of what he's doing, he should be okay.

 

Ahh but therein lies the key. Plus you're right about the MAF, but only up to a certain point. There will be a point where the MAF and likewise fuel delivery can't keep up, that's where you start running into issues.

 

Yep, it is nice to know how my engine's running at all times

The way I see it, adding 5 extra psi will only increase MAF values by maybe 20 g/s which I imagine the ECU should be able to handle.

In any case I'm definitely not a fan of removing the capability of the N75; if for some reason the car needed to go into limp mode (misfiring for example) the car would still be MBC-controlled and would essentially be fueling the fire (so-to-speak).