Hey all, I've been having belt slip problems around 6000 RPM's with my Procharger P-1SC. I put an 8 rib conversion on it, and while the problem has gotten better, it still slips a little. As a result, I have to shift around 6000 RPM's, which is a bit before I'm making peak power. I've been considering doing the upgrade to the D-1SC but the internal gear ratio is the same as the P-1SC, so I'm not sure if that would fix the problem. The F1 series has a different internal gear ratio, but that would require an entire new head unit. Anyone have suggestions or proof that a D-1SC would help fix the belt slip issue?
D1SC flows more air at all RPM levels than the P1SC, does it not? In which case you should be able to go with a slightly larger pulley, while still making the same amount of airflow and therfore power levels while reduce the chances of belt slip. ...or you could always opt for a non-slip pulley. A few companies make them. They'll shorten your belt life a little....but then again, so will a slipping pulley.
Thanks for the reply Brian. I have a Reichard Racing pulley on there now, and it isn't doing a whole lot to help. I called ProCharger a few days ago and they said anything less than a 3.2" pulley would slip. I'm thinking I would have to modify the crank pulley size to help get more belt wrap, but I don't want to spend more money on something that might not help. As it sits right now, it has a larger crank pulley and it still isn't solving the problem. I think I might do what you suggested, and go with a D-1SC at the end of the season and put a 3.2" pulley on it. The upgrade from a shop is gonna be about $1200, I'm wondering if putting an F1 on there for a few hundred (possibly) more would be more beneficial. Any idea how much an F1 head unit costs?
How much larger is your current crank pulley? The factory unit is 6.78" if I recall. Both Innovators West and ATI make a 7.25"-7.50" one piece 8-rib crank pulley that will certainly overdrive your blower (if the one you currently have isn't that size already) which will allow you to step back on the blower pulley size a little. It may require a little clearancing with a die grinder on the stock front timing cover, but it still should work with little fuss. I have heard that the ATI brackets aren't famous for their "beefy or rigid" construction. It’s possible you're getting some flex out of them, which might also be what's causing the pulley slip? Has it ever thrown a belt under hard acceleration? When I run mine at the track on Drag Radials, I tend to get some slip with my 2.35" blower pulley and to cure this I usually spray a little "Sticky Stuff" spray adhesive onto the belt surface every couple of runs to improve the traction. It does work, but over time, the glue will eat up your belt, so I wouldn’t use it for normal street duty.
I don't recall how much larger the current crank pulley is; the car is being re-tuned at this time. I was half thinking about going twin turbo, but I really can't justify spending another 6K at this time w/ the economy and such. A D-1SC might do the trick; I was hoping that someone would have some experience in doing the upgrade and if it fixed their problems - or just made more power. The ATI bracket is pretty solid on mine, I couldn't find any indication of it flexing under load. It has thrown a few belts under hard acceleration, but that was due to the belt jumping (saw belt dust on the alternator). I don't think it's feasible to run that sticky spray when i wanna take it out on a Friday night though; track use wouldn't be too bad though. I think at this point, my options are to do the D-1SC upgrade and pulley swap ($1300 roughly) then have to get it retuned (coule hundred) OR just deal with shifting at 6K for right now.
I would love to, however I don't have $6000 to drop on another power adder at the moment - unless you know some place to get a deal on a Hellion setup.
yes it does cost some money......for me I ordered my kit from a friends shop and they took money off maybe you can try that.
I am making 18psi thru my novi 2000 with no belt slip. I am running an IW 10% OD crank pulley and 3in S/C pulley. I am still 6 rib.
That's impressive....maybe something is different with the Paxton blowers? I've only heard of this problem w/ the Procharger units...wonder if I could find a Novi head unit to put on the Procharger piping? That would probably be cheaper than the turbo route. And unfortunately, I don't have the hook-up at any shops around here who could get a HP or Hellion kit for me.
The cause of the slip in most cases is the Prochargers 4.10:1 internal step up ratio (vs the Novi 2000's 3.50:1 ratio). The higher (numerically) internal gearing allows the P1SC to more effectivley move more air, earlier in the engine RPM range which is why most P1SC's have such high and early torque figures compared to most other similarly sized centrifugals. The drawback to this of course, is that you've really gotta spin them at the high end to move a comparable volume of air flow to a Novi 2000 when you hit the upper ranges of the tach. The drag on the head created when spinning it that fast in order meet the top end airflow requirements is probably what causes the belt slip....even with the larger pulley. And to be fair, the D1SC is a closer match to the Novi 2000 than the P1SC is.
Right on, I figured the air flow of a D1SC would be similar to the Novi 2000. I guess the P-1SC has its pros/cons. I just find it hard that Procharger hasn't offered an additional bracket or anything to get more belt wrap to aid with belt slip, I'm sure there are a number of Procharger guys running pulleys smaller than 3.2".
