Missing Boost

pokeyl

New valve is on, BUT, still missing boost. As soon as the traction fluid is warm the boost goes away.

If I WOT as soon as the oil temp is 160 I get 3 PSI at 3K

15 minutes later I get ZERO boost at 3K

outside temp is 75F

I looks like I may need a new supercharger. I have found other rotrex failures over at the BMW sight.

A lot of talk about overspeeding the SC causing the problem, and the user I bought mine from had the smallest pulley GMT makes on it with the stage 1 intake. He may have fried the unit and then sold it to me. As I did my install in the winter, the fluid was cool enough to keep the boost up.

I am working with Sam and Mike to come up with a solution.

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It's not my fault I'm old, I was born a very long time ago!

Baer383

Check to make sure you did'nt kink the SC hose coming out of the unit going to the SC filter.

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2013 ZL1

754 rwhp 747 rwtq

pokeyl

I will look, I would think that a low oil flow would have destroy the SC.

Rotrex wants the belt changed and a smoke test for leaks after that.

The belt is old, my SC makes a high pitch whistle, I always though it was intake noise, I hope it is just a belt. Autozone will have one here tomorrow.

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It's not my fault I'm old, I was born a very long time ago!

pokeyl

Inspected the belt, cracked, dusty and looks like it may be at the limit of the tensioner. So I stoppeed at Autozone and sprayed the belt with dressing. Boost now seems constant 3 lbs at 3K. It was raining and the racelogic had its hand full. Will test more this weekend with the new belt. If I hit over 10PSI I'll call it good.

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It's not my fault I'm old, I was born a very long time ago!

pokeyl

Installed new belt, it is a 1045K7, GTM spec.

It looks longer than the one I pulled off. Belt wear indicator is not in range.

I had no squeal fro the first 20 seconds and then it came back. I think my belt is too long.

What a pain to change...

Now looking for a 1040 or 1035.

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It's not my fault I'm old, I was born a very long time ago!

Sh0velMan

In my experience, it's really hard to find a 7PKXXXX belt if you need a non-standard length.

I ended up going with a 6PK (6 rib rather than 7) and it works fine.

Here's a 6PK1035 Amazon.com: Bando 6PK1035 OEM Quality Serpentine Belt: Automotive

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pokeyl

What pulley are you running?

Underdrive crank pulley?

I can find 1040K7 and 1030K7, but no 1035K7 is this the one I need with a standard crank and the small GTM pulley or will the 1040K7 be short enough? 1045K7 looks long.

What is the difference from the 7PKXXXX and the XXXXK7 belts?

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It's not my fault I'm old, I was born a very long time ago!