Why is this happening? Re: Boost Falling Off
If your belt is slipping that much, you are going to be seeing black powder all around the supercharger head unit. Since you are hearing a whooshing sound at the time that the boost build up diminishes, I would tend to agree with previous post that you have boost leaking somewhere, most likely at the BOV. You could also have a crack in the intercoolers, or in the plumbing somewhere, that only opens up under boost. I have seen it happen. The easiest way top find this out is on a chassis dyno that loads the chassis, as my Mustang Chassis Dyno does. We can stand right there, and watch what is going on as we simulate the car driving up a 20% grade, or running the 1/4 mile, etc. Bob
Originally Posted by Exotic Performance Plus
If your belt is slipping that much, you are going to be seeing black powder all around the supercharger head unit. Since you are hearing a whooshing sound at the time that the boost build up diminishes, I would tend to agree with previous post that you have boost leaking somewhere, most likely at the BOV. You could also have a crack in the intercoolers, or in the plumbing somewhere, that only opens up under boost. I have seen it happen. The easiest way top find this out is on a chassis dyno that loads the chassis, as my Mustang Chassis Dyno does. We can stand right there, and watch what is going on as we simulate the car driving up a 20% grade, or running the 1/4 mile, etc. Bob
Might try to isolate the system from the head unit and the TB with some inflateable plumbers plugs and pump up-pressurize the system and do a real good leak check with soap and water. And see what happens, would save on the dyno time and $$$............Just a thought.
TECH Addict
Joined: Nov 2001
Posts: 2,659
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From: Bellevue, Wa
key or pin that crank too or your gonna be sorry later.
for now definetly look for leaks, you can run without the bypass for testing purposes coming out of boost once without it will be fine. just help it out a bit by not slamming the throttle shut.
for now definetly look for leaks, you can run without the bypass for testing purposes coming out of boost once without it will be fine. just help it out a bit by not slamming the throttle shut.
Ok... 
I pressure tested the system today from the plenum to the elbow before the blower. I got it up to about 10psi and found a hole in my passenger side intercooler. Its not big but you can definity feel it and hear it. The bypass is leaking also, but barely at all, and when I blow on the vaccum line it closes almost air tight. I didnt find any other leaks. I am wondering if the intercooler opens up under more pressure. I am going to try to seal the intercooler but it doesnt look good. I dont really feel like paying $400 for a new one. Looks like im going FMIC. Which I can't afford. Also there is a thin film of oil in the intercoolers and the tubing. So it looks like my head unit is leaking oil...
This **** just never ends
I pressure tested the system today from the plenum to the elbow before the blower. I got it up to about 10psi and found a hole in my passenger side intercooler. Its not big but you can definity feel it and hear it. The bypass is leaking also, but barely at all, and when I blow on the vaccum line it closes almost air tight. I didnt find any other leaks. I am wondering if the intercooler opens up under more pressure. I am going to try to seal the intercooler but it doesnt look good. I dont really feel like paying $400 for a new one. Looks like im going FMIC. Which I can't afford. Also there is a thin film of oil in the intercoolers and the tubing. So it looks like my head unit is leaking oil...
This **** just never ends
Well I am glad you found it. Like you say with more heat and vibration it must be opening up more under boost. If I were you, instead going with the FMIC I would look at the new BIGGER ones ATI just came out with and do a upgrade. Would save you a lot of time and you would be back onthe road a lot sooner. Depending on how old these are, whos knows maybe they will do some type of credit for you with these.
I to am checking into the larger ones.
"HEY BOB@EPP any info on the new intercoolers?"
I to am checking into the larger ones.
"HEY BOB@EPP any info on the new intercoolers?"
