siggyfreud

Okay so the first time it happened I didn't pay a whole lot of mind to it, but yesterday it happened to me twice in a row. Under WOT, as I hit about 5000-5500 RPM, but boost suddenly disappears and I lose power (not electrical). As soon as I let off the gas or go less than WOT, it comes back.

My theory - I think my intake tube is sucking itself closed. The three times it has happened, it has been a pretty hot day, so I think the rush of air, combined with the loosened rubber is causing the issue. My only other though is that it could be belt slip, but the belt would have to be completely slipping to cause me to lose all boost, and I am not hearing any of the typical belt slip/screech noise.

There is no associated popping, or black smoke, but I am also letting up off the throttle pretty instantaneously. I know the stock Saleens that were at my power level generally used a solid intake tube, and maybe for good reason.

This didn't occur on the dyno and I think it was for two reasons. One, the intake tube had better cooling/was cooler, and two, the open hood may have caused less pressure within the tube, as there was more area for air to enter the air filter and thus, less suction on the other end.

Any thoughts?

VRFlip

Wouldn't the car die if the intake tube closed?

siggyfreud

I would think that if it did for any longer than 1 second it would. When I say close, I doubt it's creating a complete seal. But as soon as the boost is lost, the vacuum pressure in the intake tube should cease and it should reopen. Power creates the problem, the problem creates lack of power, that lack of power fixes the problem.

At least that is how I've rationalized it in my head.

hammeron

i'd say your intake tube theory is sound. the only other thing i can see happening is maybe something with the boost bypass valve. but like you said it didn't happen on the dyno, so that makes me lean more towards the intake.

marcuskeeler

belt slip ?

siggyfreud

Belt slip is my second theory. But it wasn't happening on the dyno runs so either I got lucky, or there was something different about those runs versus on the road that may be affecting things. But I have to think there is a reason why all the kits running my power use a solid intake tube.

Cal26Stang

check your vacuum lines, thats a common issue..might cause a loss

vasman

The warmer the weather gets the softer the plastics, the most likely your theory is right. (I had similar issues with my vacuum lines bending shut when hot). Is that the stock intake tube? If so, I think this is a known issue with Saleen superchargers. I believe there is a replacement hard tube for it (call brenspeed they have it).

vasman

Although indeed vacuum lines will collapse as well, the outcome is usually stack throttle (like 2500 rpm or so) and sluggish throttle response, not loss of power at wot. (please correct me if I am wrong, but thats my experience with vacuum lines so far).

siggyfreud

Brenspeed agrees that it's my inlet tube closing. I'm going to put my Steeda up for sale and once I have a buyer I'll be ordering the Extreme setup.

More money gone . . . lol.