7 months ago when I first had my blower put in, I was hitting about 8.5psi @6600 rpm. These last 2-3 months I've been noticing boost loss so I went to dyno my car yesterday.
I tuned my car myself on the dyno and got 350rwhp. 350 aint bad considering I'm only hitting 6.9 psi at 6700. I've been trying to figure out why I'm losing so much boost, I USED to be getting 8.5 and now I only get 7psi if i'm lucky. I tried a tighter Gates belt, tightened it up quite a bit and no luck.
Some people tell me its the drop in barometric pressure and extreme humidity in my area but several other supercharged vehicles in my area is NOT experiencing this problem.
Any OTHER ideas on why I am not getting as much boost as I was before?

 

You sure you don't have a boost leak?

 

perhaps the piston rings are wearing from the boost, and allowing blow-by?

 

So the R4 software itself is saying only 7psi with you record the dyno run? If you record a street run, what are you seeing as the psi versus rpm numbers? i.e. is it falling off only at the top or is the boost lessened across the entire band.

A compression test might be in order, but that's not the first thing I would suspect.

--Steve

 

Guys, I think starting with the easiest possibilities like a boost leak on one of the pipes should be done way before what's being suggested. You guys are suggesting that he has a damaged motor?? Come on now.

 

The first thing that I would suspect would be that you have a leak somewhere. I tend to think that it is not at a coupling or I would have thought it would have popped apart. I would suspect that the BOV is leaking.

 

bov is quite possible, IMO.....

try an adjustment on the bolt..... i found anywhere from 4-6 threads showing allows closure to happen at about 2-4 in HG....

next up, pinch the vac. line and listen to hear if the valve is actuating... if the car is up (and you can see the valve inside) just pinch it and have a look......

adjust till you are just free from flutter...

also, try another boost gauge, if possible...


could be a leaky line, or, (longshot, i know) the gauge could be faulty...

i will ask to find more possibilities, but also think that "forced" from vortech should get in here and help out...

es


ps- i REALLY doubt the motor is getting blow-by at this point inthe game..... these kits are so de-tuned out of the box that it should be VERY safe at 350 rwhp....

 

both my greddy boost gauge and split second box is reading about 7 psi. Boost is lost throughout the whole rev band.
I'm going to check all the plumbing sometime next week. I have already tried tightening the BOV and loosening it, no luck.

 

I think I know the solution to your problem... (but it's gonna cost you). When you coming down?

--Steve

 

Check PM!!!