This is topic I think i have belt slippage in forum Tech Talk at Northern California Ford Owners  .


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Posted by 306ci89Vert (Member # 1437) on :
 
Well i got my 42# injectors in yesterday and I went for a test drive....right at 5000RPMS and 10lbs of boost the boost will drop to 6 then flucuate.......that sounds like belt slippage right? The belt is fuckin tight and i dont know how to get it any tighter. What else could be the problem if its not the belt.

Mike
 

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Posted by Chosen1 (Member # 1906) on :
 
it sounds like belt slippage...

is there a chance, for whatever reason, there is detonation you cant hear, and the computer is pulling out timing, thus not allowing for full boost?i had those exact same symptoms on a grand national i was working on, and that doesnt use a belt (turbo). we adjusted the regulator a little bit and ran a little race gas and it made everything better.

just a few suggestions from left field.

[ February 20, 2004, 12:13 PM: Message edited by: Chosen1 ]
 

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Posted by Jeff S (Member # 371) on :
 
Sounds like belt slippage to me. How old is the belt? Are any ribs missing from it? Try tightening it again using a 1/2" breaker bar and little MUSCLE!

You insert the 1/2" square drive into one of the two square holes in the idler bracket:



[ February 20, 2004, 02:00 PM: Message edited by: Jeff S ]
 

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Posted by Jeff S (Member # 371) on :
 
The only thing besides the belt/blower that I can see causing boost drop is the bypass valve.
 

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Posted by 93PONY (Member # 60) on :
 
Turbo GN's have a knock sensor. The computers can pull timing based on these sensors.
Mustang computers don't know if the motor is detonating or not....& can't compensate for it.
 

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Posted by 1SLOWLX (Member # 558) on :
 
I wonder how this car is going to dyno
 

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Posted by Chosen1 (Member # 1906) on :
 

quote:

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Originally posted by 93PONY:
Turbo GN's have a knock sensor. The computers can pull timing based on these sensors.
Mustang computers don't know if the motor is detonating or not....& can't compensate for it.

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quote:

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I wonder how this car is going to dyno

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Gotta sort the gremlins out first :/

Mike
 

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Posted by DropTopFox (Member # 1689) on :
 
If it was belt slip wouldn't it be random when it occurrs not only once you get to 5000 rpms. I find it odd that it would occur at the same point all the time
 

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Posted by 306ci89Vert (Member # 1437) on :
 
Belt slippage only occurs usually at high rpms, where there is more tension on the belt as it has to spin the supercharger harder and harder.
 

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Posted by CobramanPhil (Member # 2170) on :
 
I'd say simply check the belt. Do you have a lot of belt dust? Try experimenting with different brands of belts and see what happens. Perhaps yours is just worn?

I never did it, but some people put that vht stuff on the blower belt just to see if the symptom goes away. If it does it is the belt. If not it is something else....good luck.
 

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Posted by 2stangs69-91 (Member # 1951) on :
 
If you look at the pic posted it had the answer there already. I purchased one of those belt tensioners and it works great.
 

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Posted by Bill/APEX Motorsports (Member # 636) on :
 
Are you using a Goodyear Gatorback belt with the perpendicular slits in the ribs, or are the ribs smooth all the way around? We've had the best luck with the smooth Gates/Napa/Dayco belts.
 

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Posted by 98slowhoe I don't have a fast car (Member # 895) on :
 

quote:

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Originally posted by 2stangs69-91:
If you look at the pic posted it had the answer there already. I purchased one of those belt tensioners and it works great.

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quote:

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Originally posted by 306ci89Vert:
How tight does the belt have to get for a 2.95" pulley (14-15 #'s with a power pipe?

MIke

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