What do guys think about the ultra grip pulley? Is this really can help on the belt slip issue and will not damage the belt?

 

they def eat belts faster. although, you really shouldnt have belt slip with a properly sized and tensioned belt. i run up to 16 psi with no slip.

 

How do you know if a belt is slipping? Residue from the belts?

 

You can hear it, you will see some residue, non linear boost is also a dead ringer.

 

ya this is belt slip due to not tight enough idler pulley. couple turns of the 12mm and all linear.

 

hmm. Does "linear" in this instance mean "smooth", or maintaining boost up to redline (i.e., in the posted graph, is the noticeable belt slip throughout the rpm range, or only on top)?

I found some residue on my bracket and around the SC pulley, but this may be due to running an alternator belt that was too big and was squeeling. Now I have the proper size belt and everything is nice and tight. I don't hear any squeeling or abnormal noises and everything sounds nice up to redline.

My boost looks linear and peaks at 12 psi at ~5500 rpms. After that, boost begins to drop to ~9 psi by redline. But this decrease seems "linear" as well, there aren't any spikes in the psi reading. So I don't think any of my belts are slipping, but is just the nature of the SC I am running?

 

there shouldnt be any excuses for belt slip but the boost gauge can help you best.

 

belt slippage, clogged ic, or crapped out sc. one of those three

 

On a centrifugal blower, it should rise all the way to redline. Attached is the graph of the same setup as the log above, but with a tight belt.

You car makes 'turbo' torque #'s so maybe its supposed to have a turbo boost curve. Dont know enough about rotrex blowers.

 

Thx for your input bro.

When I brought my car in, it was retuned before the smaller belt was put on. I gained ~20 whp from the first tune and was sustaining power a bit longer:



Then, the smaller belt was delivered and put on and everything tightened up. Maybe I should have it put on the dyno again for numbers now that all the belts are tight and the car pulls nice now.

The HKS GT SC is a really compact blower, but employs "torque traction drive" or something like that and with the planetary gears, the blower can be driven more efficiently and spun up quick, but maybe there is a trade-off when compared to traditional gear-driven driven SC's?

Could the bypass valve be starting to crack a tad bit open at high boost, causing the boost to drop towads redline? The out of the box boost is ~6 psi.