A quick thank you to Tom....

[HotsideHamid]

Hey all!
So I just wanted to post an FYI for everyone, as well as a thank you to Tom. I don't know if many of you remember, but ever since I bought my hotside BRP kit (2 years ago?) I have been having an issue with my six rib belt setup. It would never quite track right no matter what I tried. I had been using the auto tensioner setup that BRP had supplied, but after numerous days and weeks of meticulous adjusting, I would find belt dust everywhere. Not to mention, the belt would always seem to rub the PS pulley, and then eventually shred. I was unable to figure out the issue, until one day I noticed that the auto tensioner was actually pushing the belt toward the engine! I think some of you were able to remedy this problem with either flipping the pulley around or using spacers--- but none of that crap worked on my setup.
Anyways..... I bit the bullet and decided to buy Tom's auto tensioner setup. It works perfectly! My wife no longer has to hear me bitch about the belts getting chewed up. I might not seem like a big deal, but this was an ongoing problem for a long time.
That's all for now! Now I gotta finish my TDR intercooler install.:seeya:

-Hamid

[Tom @ Fast Forward]

All I can say is that you made my week. Once in awhile I have to have a thread like this just to keep my sanity. Bless you.

Whatever you do, DO NOT post that on mnet. That would negate the goodness you just provided.

[BlownMX5]

Hey Hamid, I have exactly the same problem on my '94. Unfortunately, I'm already running Tom's tensioner. I've tried everything I can think of with the last resort of going back to my BRP manual tensioner. Tom or anyone, can you think of something I can try? At the track this past weekend, I shredded a belt and it has been rubbing on the p/s pulley also. I tried realigning the blower to the crank pulley with a straightedge which meant moving it back about 1/8". Now, without shims, the tensioner pulley makes contact with the p/s pulley. I ended up cutting one rib off of my backup belt just so it wouldn't rub. I thought I might try a slightly shorter belt so that the tensioner pulley will ride above the p/s pulley. Then, I wouldn't need to shim it. My current belt is a #060420 (I'm 105/65). I'm pretty sure it's slipping a little now as I'm only making about 4 psi. I'm not sure if the lower boost is due to the belt or due to my new A/A IC, or a combination of both. Anyway, I need to solve this thing.

[HotsideHamid]

No problem Tom! I have been a member of Mnet since '95 (back when Estable was the only Troll). It seems like just within the last year or so, something has seriously gone wrong. It used to be a daily staple for me, and now I'm about done with it. I figure if I want advice on my SC setup, I'll come here- I feel much more welcome. I know I haven't bought a lot from you, but your advice and your products seem excellent! Keep it up.

-Hamid

[HotsideHamid]

Pat-
When you look down on your belt from above, does the lower portion of the belt rub, but the upper portion does not? This was what was happening on mine. So for me, it had to be the old tensioner pushing the belt back.
When you started using Tom's pulley, did you use his entire setup, bracket and all? I mounted mine on the BRP supplied plate- which is actually slightly different than Tom's design.
When your car is idling, does the auto tensioner have a slight bounce to it? Mine did, and for the longest time I thought my crank pulley was off center.
The four bolts that were holding my blower onto the sliding bracket did not have any washers either. This, at the time didn't seem like a big deal, however since the bolts did not have a good enough grip on the mount, it would VERY SLOWLY slide backward towards the engine until the belt was rubbing very badly, and then it would shred. It would literally take about a month for it to move back. I bought locking washers that create more surface area, and that did the trick.
I know how frustrating this is for you, so I'll help you out any way I can.

-Hamid

[V8KILR]

THATS EXACTLY HOW I FEEL. I would not only tell someone that needed advise on an SC to go to FFS, but I would say, DON'T YOU DARE GO TO MNET. And thats terrible for it to have to be that way, because a lot of guys on there are really smart.

[HotsideHamid]

Actually, I should rephrase one of my questions Pat. Does the portion of the belt directly under the auto tensioner pulley rub the PS pulley, but the lower portion of the belt is further out toward the radiator?

-Hamid

[Tom @ Fast Forward]

Pat,

I would love to get my hands on it. I still kind of think your supercharger is not far enough forward. Or, at least, the supercharger pulley is not far enough forward.

Of course you do have 2 PC-Pros and a Timing Card. That could be the problem. ;)

Hey Hamid, I have exactly the same problem on my '94. Unfortunately, I'm already running Tom's tensioner. I've tried everything I can think of with the last resort of going back to my BRP manual tensioner. Tom or anyone, can you think of something I can try? At the track this past weekend, I shredded a belt and it has been rubbing on the p/s pulley also. I tried realigning the blower to the crank pulley with a straightedge which meant moving it back about 1/8". Now, without shims, the tensioner pulley makes contact with the p/s pulley. I ended up cutting one rib off of my backup belt just so it wouldn't rub. I thought I might try a slightly shorter belt so that the tensioner pulley will ride above the p/s pulley. Then, I wouldn't need to shim it. My current belt is a #060420 (I'm 105/65). I'm pretty sure it's slipping a little now as I'm only making about 4 psi. I'm not sure if the lower boost is due to the belt or due to my new A/A IC, or a combination of both. Anyway, I need to solve this thing.

[BlownMX5]

Hamid - yes, that is it exactly. Where the tensioner pushes down on the belt, it forces it to the rear and rubs on the p/s pulley. The lower portion has plenty of clearance from the p/s pulley. If you look straight down from above, the upper ("loose") and lower ("tight") portions of belt are not parallel. Also, thank you very much for your kind offer of help!

Tom - it did this even when the blower was all the way forward. The strange thing is though, before I recently removed the blower to install my header wrap, even though it was also all the way forward then, it didn't rub as badly then. It did rub slightly; there was fuzz all over the p/s adjustment linkage. But now that I've R&R'd the blower, it is somehow worse. When I removed the blower, all I did was remove the four bolts. The mounting bracket that is attached to the header studs was not disturbed.

I'm afraid I don't know enough about the belt alignment dynamics and what can cause the belt to deflect like that. It obviously isn't as simple as the blower being too far back since it did it with it all the way forward as well. It almost looks like the tensioner is somehow not square to everything else, but how can that be, when it is mounted simply on the three standoffs which all are the same length? Yes, I do have it shimmed, but the washers are all identical.

I'd like to try a shorter belt so that the tensioner "arm" isn't swung so far downward. I could then remove the shims because the tensioner pulley wouldn't be near the p/s pulley. What would be the next shorter belt from an 060420?

[HotsideHamid]

Pat-
How about your crank pulley. Do you have it setup using the spacer or not? I originally had my pulley on without the spacer, but I really shouldn't have. It only made the problem worse. I did drive the car around like that for a good 6 months that way though, until the problem just started to piss me off too much. I then put the spacer on, but it only helped slightly.
I would be tempted to try another tensioner for the hell of it. I don't know if Tom ever changed brands for the tensioners, but I know that the one I bought from him about two months ago is made in Canada and is much more stout than the one that came with my BRP kit.
You're not having the sliding blower problem are you?

-Hamid

PS- On a side note, I'm thinking of possibly getting a PWR radiator with my IC'd setup, so I'm following your progress closely. I hope the low profile fans do the trick!

[BlownMX5]

Pat-
How about your crank pulley. Do you have it setup using the spacer or not?

I don't recall, but based on the descriptions Tom has made regarding the spacing of the blower crank pulley relative to the p/s crank pulley, it looks right to me. It has that little gap of about 1/8".

I would be tempted to try another tensioner for the hell of it. I don't know if Tom ever changed brands for the tensioners, but I know that the one I bought from him about two months ago is made in Canada and is much more stout than the one that came with my BRP kit.
You're not having the sliding blower problem are you?
No, it's not sliding to my knowledge, but I don't have washers on them. Tom, has there been any change in the auto tensioner design or equipment since I bought mine? That would have been maybe a year ago I think?

PS- On a side note, I'm thinking of possibly getting a PWR radiator with my IC'd setup, so I'm following your progress closely. I hope the low profile fans do the trick!
Man, so do I. I should have them in about two weeks, I think it takes them about three weeks to put them together and ship.

[Tom @ Fast Forward]

We have used the same tensioner from day one. No changes. We use the same one for both hotside and coldside.

[BlownMX5]

Is aligning the pulleys as simple as laying a straightedge across both pulleys and having it make contact with the four surfaces (crank: far/near, blower: far/near)? This should be correct if both pulleys have the same "margin" - the distance between the outer flat surface and the first rib. Do I have this right?

Also, how much can they be out of alignment and still have the belt track correctly?

Finally, I notice *some* wobbling of my crank pulley, although I don't know how much is "too" much. Since I didn't do my own engine rebuild, I don't know for a fact that the pulley was put together correctly. I am a bit worried about this and I'll check the bolt when I go to put my new fans in. Hopefully, it isn't too late... :no:

[Tom @ Fast Forward]

Well, I think there are two things that have to be looked at. One is the in and out. It can be tested by laying a straight edge across the two pulleys as you described. The second might actually be more criticaal in your case. Hard to describe but I'll try. It is tilt of the supercharger up and down. The tensioner is bolted to the supercharger and is at it's mercy as to the tilt. If the SC is tilted down, for example, the belt will tend to ride on the back of the tensioner pulley as it is long and will exagerrate the tilt. Conversly, if it is tilted up, the belt will tend to ride towards the back of the tensioner and push the belt even further that direction. Not sure of a good way to test but one thought came to mind. If you had a 2x4 that was flat (if there is such a thing?) a little longer than the distance from the outside of SC pulley to the opposite outside of the crank pulley, you could drill a clearance hole for the SC shaft to stick into so that the board could lay flat against the SC pulley. Then see if it lays flat across the crank pulley as well. If the board rocks, the pulleys are not FLAT to each other. IOW, the faces are not in the same plane.

A second idea might be to put a level vertical across the crank pulley, jack up the front or rear of the car to make it vertically level. Then check the SC pulley the same way and see if it is off?

Just a thought. We've shipped about a dozen or so of those tensioner assemblies and they all (but one) appear to work fine.

[BlownMX5]

But if somehow the s/c was tilted, that would show up when laying a straightedge across the pulleys (pullies?) also. I definitely have it square with a straightedge touching all four places on both pulleys. If the s/c was tilted, it couldn't do that, could it? Besides, there is no adjustment for that; the bracket only has the four elongated holes that allow fore/aft movement, it can't tilt (maybe fractions of seconds of a degree, perhaps).

Because of the length of the belt I have, the tensioner "arm" has to swing so far down to apply the correct tension that the tensioner pulley actually overlaps the p/s pulley. It could be that the farther it has to swing down, the farther out of alignment it gets. Hamid or anyone else with a hotside/auto tensioner, how far down does your tensioner sit when fully engaged to the belt? My belt is a 060420, Tom I remember you describing to me how they name those belts - the name refers to the length somehow, right? If I got the next shorter belt, maybe the tensioner, now not having to move so far down, might align better?

[HotsideHamid]

Pat,
The belt that I currently have on mine is actually too long. I want to say that the last two digits are 15, and I'm on the stock pulley with 6psi of boost. The belt is so long in fact, that if I squeeze the belt together with my two index fingers, the belt can actually touch itself. I have a feeling your belt is too long. My tensioner pulley is nearly in the middle of my PS pulley. I should swap it out, but I'm going to a 125mm pulley within the next few weeks so I'll have to swap to a completely different size anyhow.
As far as the tilt goes, I've never tried that, and I don't know how much slop I have on the mounting holes. The only way I can think of to tilt the blower is if the belt is off so it doesn't create tension. I suppose that tension can create a downward angle to the tensioner.
The only way I could get my setup to work right is if the belt was hanging off of the tensioner pulley by about 1/8th of an inch toward the PS pulley, and it rubbed ever so slightly.
Now, when you say you think your crank pulley has a slight wobble, what are the signs? The reason I ask is because for a good year I though I had a eccentric wobble with my pulley because the tensioner would kind of "hop." I remounted that pulley about three to four times, and nothing worked. I could have sworn that I could see the pulley wobbling too! It turned out that with the bad tensioner pushing the belt inward, it literally caused a few of the ribs of the belt to try to jump onto another groove. Since that was the case, it made the tensioner pulley have a slight jump on every rotation. This was the cause of the apparent wobble!
I know you'll get this fixed-- there are just so many symptoms to this "little" problem.

-Hamid

[Tom @ Fast Forward]

Pat, Looking down from the top you will see a single mark, space and then a double mark. On the other part there is a single mark.

http://www.FastForwardSuperchargers.com/Hotside/Tension-limits.jpg

The closer the indicator gets to the double mark the better. If it is down near the single mark, your belt is probably too long. If it is past the single mark, it will probably not work and the belt may jump a notch or more.

I have seen the crank pulley wobble if not properly installed. There is a locating pin on the main crank pulley. If you use the spacer, that locating pin is supposed to be in the fifth hole in the spacer. It has four evenly spaced holes for the four bolts and a small fifth hole for the locating pin. If you do not use the spacer, the pulley also has five holes. Four for the bolts and one small hole for the locating pin. In either case, if the locating pin is not in the small hole, it will tilt the six rib crank pulley ever so little. I think the pin sticks up less than 1/8". When it comes to wobble on the crank pulley, a 'little' wobble is like a 'little' pregnant.

[BlownMX5]

Yeah, mine is much closer to the single mark.

Since I now have an intercooler, I am going to get a larger crank pulley provided my new fans let me. At that time, since I'll be removing the pulley anyway, I'll check everything out. So, the question is: with stock injectors, E-Cool and PC-Pro TC, JE (9:1)/Carrillo/ARP, how big should I go? 120? If so, what size belt?

Congratulate me, I have now completely hijacked Hamid's thread :2guns:

[HotsideHamid]

No worries Pat! I want you to fix that issue, because I really hated it. Besides, what I wanted to tell Tom and everyone else was in my original post!

-H

[Tom @ Fast Forward]

A shorter belt might help cure the problem. If you do not have sufficient tension, it could vibrate. Remember, when you get on the pedal that belt really stretches. That is why the manual tensioners have a problem. I had video around here someplace of the tensioner moving just in the driveway and it is amazing. Under load, the supercharger is around 25 HP load on the belt. It stretches even further.

Does your bracket that you got from me have one set of holes for the tensioner to mount or two sets of holes? I'm not talking about the three holes down the edge that mount the plate to the supercharger but the holes that mount the tensioner to the plate.


Yeah, mine is much closer to the single mark.

Since I now have an intercooler, I am going to get a larger crank pulley provided my new fans let me. At that time, since I'll be removing the pulley anyway, I'll check everything out. So, the question is: with stock injectors, E-Cool and PC-Pro TC, JE (9:1)/Carrillo/ARP, how big should I go? 120? If so, what size belt?

Congratulate me, I have now completely hijacked Hamid's thread :2guns: