Hello all,
Here's what I've got and I posted in Forced Induction since the belt arrangement is due to my front mounted T6 setup.
A little background, I picked up a project car from a friend of mine and I've been going through it finishing and fixing all the little things that come with a project car.
I've worked my way up to the point where I'm now doing WOT testing and tuning and have run into an issue with my belt drive.
The car is a 99 Camaro LS1, with a Craig Davies cooling system so no PS, no AC, no mechanical water pump, only the alternator which is a 175 amp unit mounted with a Goat Built bracket and a Fluidamper balancer.
Initially the alt had a stock size pulley on it, I made a few short hits (no top of second or third gear) keeping the rpm low in the 4-5K range since I just gotten the car and the belt stayed put.
I added a 3" Motion Race Works alt pulley recently to keep the alt charging until 7K where I'm shifting at where as the stock pulley was out at 5,200 rpm.
The car wants to toss the belt when I spin the engine higher, it tossed the belt the first time at a full hit at 5,600 but yesterday I ran it out to 6,800 rpm through all three gears (TH400) and it twisted it up and chewed it all to hell, lucky I didn't damage anything.
I found a new belt that is slightly shorter than the previous one which seemed at the end of the tensioners load, the new one loads the automatic tensioner a bit more but I also ran a string across the front of the alt pulley down to the crank to check alignment and the crank pulley appears to be behind the alt pulley at least 1/4 of an inch.
Is my string measurement accurate and can I pull the Fluidamper balance forward to true up the drive?
Do I need to disassemble the Goat Built bracket and shave down the mounts on a mill?
I wanna try again with the new belt but don't want to press my luck?
Anyone run into something similar?
Thanks in advance gents.

 

So the pulley setup is all f-body spacing?

 

What brand belt? My car would shred a Gates, put a Goodyear gatorback on & never had another problem.

 

That's the confusing part, it says truck spacing on the website but has directions for F-Body spacing too except the link to view the directions doesn't work.
The previous owner may have bought the kit used and it may be for a truck setup, its tough to know.
Is the truck setup shorter than F-Body?
I went out and measured again and was mistaken, the alternator appears to be 1/2' behind the pulley using the string measurement, if the string measurement is actually accurate....
I'm thinking I can stack 1/2" worth of washers behind the three main spacers and bring the alternator forward.
It didn't toss the belt before because the hits or dyno pulls were so quick, running through all three gears at 6,000+ rpm gives the belt more time to work its way off is my theory.

 

It's just a cheap autozone unit for now, it tossed the last one which I went back and found but this last time it twisted it up and wrapped it around the opposite side of the tensioner.
I think I have an alignment problem for sure, it's just driving an alternator so the stresses shouldn't be that bad?
Does my string measurement hold water you think?
Couldn't think of another way to check alignment without removing all the stuff from in front of the engine.

 

F-Body spacing is closer to the engine, truck/5th gen is farther.

 

straight edge to align, use idler with side wall on tensioner

 

^^^^ Straight edge on the balancer if you can get to it. ICT Billet has balancer measurements in their swap guide section. I picked up a Gates laser alignment tool only because
my alternater faces backwards.

 

Okay so string theory doesn't work for ****...
I got about 1/2" of difference with the string, stacked 1/2" of washers behind the mounts, belt immediately came up the wall of the alternator pulley which has a tall wall btw at idle.
Pulled half the washers, for a 1/4" total offset, same result.
Pulled all the washers and went back to the start, found a section of new 5/16" brake line I had laying around, laid it on a straight edge and its damn near perfect, lined it up on the face of the balancer and well wouldn't you know, alignment is damn near perfect.
Revved it up a bunch of times, the belt moves from side to side on the tensioner a little but always lands back in the middle.
Now I'm stumped, thinking I'll see if I can't source a pulley with a side wall for the tensioner maybe?
Only other thing I did was pull the pulley shim that came with the pulley thinking maybe it wasn't needed but I wouldn't think that little sliver of metal could throw it off that much.
I really don't want to buy $20 belts every time I make a hit.
Any thoughts gents?

 

You have talked about spacing in one dimension, particularly front to back from the engine. You have to measure all 3 dimensions, as an accessory could easily be at a slight angle in any direction, but still have the centerline spaced the same from one pulley to the other. I would also add that any individual pulley could be angled, but that would be visually obvious, so I am sure that is not your issue. Also, you have to watch for any play in your belt tensioner if using a spring loaded tensioner, as a worn bearing in one of those could allow your alignment to change with varying tension loads.

 

1. Check that it's all the same spacing, it's different for diffent platforms
2. Is it pitching the belt when you let off, or is it walking off while you are making power?
3. Long time ago we used to source high-flanged pulleys from ASP

I have an ICT manual tensioner on my setup, hopefully won't do this.

 

The alternator looks like its at a slightly steeper angle but it could just be optics, its tough to get any kind of measurement comparative to the crankshaft.
The tensioner assembly and pulley are sound, no play in them at all and the tension feels good too, the whole set up is fairly new.
Wondering if maybe an idler pulley is needed about where the water pump pulley would have been?

I'm gonna guess its correct after using the straight piece of brake tubing.
According to my logs it appears to pitch it on decel because as soon as it tosses it, my AFR gauge stops working which happens at the end of the hit.
I was looking at high flanged pulley's online but didn't see anything that might work but will keep looking.
Wondering if the distance between the crank and alternator is too great and some kind of idler is needed?
The previous belt seemed a bit too long as well, the tensioner was close to the end of its travel so I'm wondering if may be the new belt is better since its about as short as it can be and still get the belt on.
Really appreciate all the input gents.

 

My setup prob is too different from yours, I have the alt pass side top, and then a ICT tensioner where the power steering bracket would normally be.

 

Maybe an idler puller with side walls will bolt onto the tensioner? Kinda with you in thinking an ider on the topside of the belt may be needed.

 

Okay gents, I've got a plan.
Found an idler on Amazon with a built in stand off, there's a bolt hole not in use on the main bracket because I'm not running a water pump, the bolt in the 2 o'clock position next to the tensioner pulley.
Gonna install an idler pulley there and see if it helps.
If not I may fab up a bracket of that bolt and the one next to it to move the pulley a little closer to the crank.
Thinking that the existing hole is almost mid way between the two so hopefully it solves this.
Never had a turbo car run to 6,800 rpm so freely before so I'm excited to add some more power and really see what it'll do and this belt thing is killing me lol.

 

I had same problem as u. For about two yrs. I was too cheap to buy a lazer. All the belts that i went through i could have bought a new car. I tried everything. Took me less then one day to file my problem after i buy it. This is with f-1x snipping 7k over 1000hp and averaging 26ish of boost. I used it once. It has an 1in of dust on it, but i'll never leave home without it.

P.s. I can bounce of the limiter all day and no problems

 

Can you please provide a P/N or picture of the laser?

 

*Update*
Ordered the Dayco belt alignment tool from Amazon and an additional pulley, all should be here Monday so I will report back next week once I return from Indy.

 

Funny, I had the exact opposite experience. I chewed up two Gatorbacks and switched to Gates and never had another problem.

 

My truck would throw belts, as I remember it had the ICT Billet brackets, but a factory spring loaded idler. I noticed if I pulled on the idler, it wouldn't snap back like I thought it should. I used the shortest belt I could find to keep the idler in a more springy location. Kind of like a supercharger, the alt. is trying to fight the crank with a load, making the belt want to jump over the pulley, so the belt needs pressure to keep it in contact with the pulley. I have added a fixed idler an alt. to provide more wrap. Plus alignment needs to be pretty spot on.