I finally got tto the track tonight. The car went 11.60 at 123 mph. Had about 6 passes. On the last one, I found my supercharger 12 rib belt frayed in 1/2. I cant figure it out. It looks like the pulleys are straight. Any ideas???
I was pretty happy for the numbers considering the car hasnt been tuned yet. As far as the cam goes, I agree that I should've put a custom grinder in there. I'm losing there a bit. I wanted a car that was very streetable. But I lost out on the top end a bit.
Timing was at 30 degrees with the chip out. No idea what the a/f is. It's going on the dyno on July 30th. Also, even with the 9" slicks, it's spinning out of the hole and in 2nd gear. So I'm losing there too.
I had a similar problem on my combination. I have the D1B with the same tensioner. After several thrown belts, I read an article that said to put a straight edge (prefferably metal) on the crank pulley and slide it up to the blower pulley. I dicovered my blower pulley was back to far. I had a friend make some replacement spacers for me (to move the blower forward) and have had no problems since. I hope this helps.
1991 Mustang LX 306 - D1B Edelbrock 5.0 heads Performer RPM intake DSS Super Pro Bullet short block 10.66 @ 127
It's either pulley alignment or the plate flexing under heavy loads..Vortech makes a 1/2" plate which seems to work well, or u could use a turnbuckle between the throttle body & SC to prevent plate flex..
I am not exactly sure what your brackets look like, but you might want to perform a quick check. First remove the belt, then grab the blower head unit and try to move it. If you can see it flex considerably then you might be missing a brace. When the brace is removed from my blower brackets, the head unit flex's up to 1/4 inch or more. When the brace in on it doesn't budge. I would certainly recommend calling Pro-Charger if you continue to have problems.
There are three different styles of 'street' brackets for fox bodies and p 600's.
the latest version is a variation on the P1/D1sc/D1 two piece 3/4 billet bracket, with a steel brace tube to the right rear AC compressor bolt. The steel brace tube can crack. often the spacers between the two brackets are a little short, and require washers to bring the head unit forward.
The 1 piece cast bracket had horible alignment on my car. there is also an older two piece bracket from around 95-96.
I have found a lage variation in thickness between the three blower pullies i have, enough difference in thickness that they require re shimming the bracket or head unit to swap them.
I have found squeezing the belt together is the easiest way to see what kind of flex you're having. even the billet 3/4 bracket will flex with this method. the automatic tensioner is supposed to limmit the amount of flexing by releaving some of the centrifigal force acting on the bracket through the belt.
The problem is, that as the tensioner releaves the force, it allows the belt to start flapping and slipping, and jumping ribs.
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