Hello all, Recently installed a boost controller and upped the boost on my factory vl turbo. Was running 5 pound at the most when we first checked boost levels. When we increased the boost anything over approx 8 pound upon strong acceleration there was a hissing noise coming from behind the dash area. I have recently replaced both fuel pumps. Any ideas what is going on? Thanks

if its inside the car could possibly be split or not properly connected vacuum lines running to your fan/heater controls.

Would this impact the cars driveabilty? Because the noise also impacted the cars ability to maintain and increase boost. Cheers Duff-Duff

yeah well if you've got any leaks it will definetly affect the way th car drives - your losing boost and metered air so the ecu is acccomodating for air that isnt their so it will be over fueling. try taking the boost controller off and seeing if the problem is their. also is it an in cabin boost controller or in the bay?

Manual boost controller is in the bay. My mate gave me his boost controller but said it used to spike heaps on his rb20. Perhaps if I try another boost controller? Cheers again

could be an idea. put the stock wastegate line on see if u still got the problems n the hissing sound

do you have a boost guage?? is the noise comming from around that area? if it is i would check the line that goes into the rear of the boost guage and make sure it is sealing proporly

it could be that u have the overboost valve still working on the manifold? apparently they dont let u boost over 8-9psi. thats what ppl have told me, duno if its true tho. mine boosts past it fine

^^ I think CLXGTS is spot on, Have u modifide the pop off safty valve or replaced it with a bung? It stops over boost, do a search.

Cheers for the help guys. The noise is coming from near the guage. I have not replaced valve with a bung.

if its near the gauge check the vac line for splits and double check if you have teflon tape on the thread of the brass fitting on the gauge. And piss off that valve and get a bung

if its near the guage it will be leaking air, just make sure its sealed correctly and has no splits n shyt in the line mine was doing the same when i bought the car, just pulled out the boost guage and tightened it up, fixed. Some original photos have not been recovered yet.

Thanks again guys. Car is getting some work done at the moment and will apply your advice when I get her back.