dsc

I know Finny worked on this but I haven’t seen any permanent solutions. I check my belt with the Vrus chalk test and sure enough my belt is slipping. The belt was replaced about 6000 miles ago and is in good shape, just slipping. The car has about 29,000 miles on it so I don't think the tensioner should be bad. Ideas?

jangy

I've wondered about this slippage for sometime now as well. I always thought it was a sign of stretch by the belt or the tensioner. In your case, it sounds like the belt is "new". The tensioner is just that, so I can't see it being the issue, but who knows? I wonder if there is a specific TQ setting it is to move at?

chiromikey

i'm not so sure about that method to measure slippage unless the belt length/pulley circumference has a perfect whole number ratio (ie; 1:1, 2:1, 3:1). if not your chalk marks are rarely going to line up.

even if the ratio is perfect there's obviously going to be slippage since we can hear it every time the s/c clutch engages. i wouldn't be looking for a solution to a problem that you haven't proven...yet.

Finny

The dyno report will disclose any potential slipping issues.

Generally, the bigger the pulley the more potential to slip.

The truth will set you free...


A little bird told me that VRP will have a solution very soon for those with big ones...

E55 RUSS

We are looking forward to it

chiromikey

agreed!

dsc

Good points everyone, then for now I will not worry about it.
Thanks.

Jakpro1

VRP will deliver us from belt slipping bondage!! I have faith.

jangy

Any chance it is a lighter version as well? I'd love to get a lighter AND slightly larger one.

chiromikey

i don't know the specs on vrus' but i do know there is another lighter billet pulley in the works...probably in several flavors like 170 and 175mm.

jangy

Very nice. That would be right up my alley. I've been searching for a 170mm that is also lighter.

Finny

I'm lost.... Why Lighter?

Bigger counter weight = better torsional protection...

Better off removing weight from the fixed pulley area and add it to the counter weight.

Victor may have one of these as well.

jangy

Actually, I think I'm lost. I'm talking about the big cranshaft pulley. When I had all my fun with mine a while back, I just remembered it being HEAVY. I wondered if a weight reduction PLUS making it bigger wouldn't add. Let me know where I am off.

Jrocket

So does this chalk marking work out? Will they ever line back up in the same spot,if so how many revolutions does the belt have to make to get back to line up on the SC marks?

Anybody ever figure out the ratio here?

ROCKETW19

bump good question!

rflow306

I'm just speculating but if we make a mark at the belt and crank pulley let say a blue line for example and the top part of the belt at the supercharger pulley white we should be able to get to that point in rotation again with out a problem and should be a good estimate for slip. If we had a sprocket on the lower and sprocket on the top pulley they would always line up with the method above because it can't slip.(Very similar to marks on a timing sprocket)
So being that the ratio from bottom to top is constant I think this method is correct.

I guess we check by marking the belt like described and just let the car idle for a few minutes, shutting down and spinning or turning the engine until we see both lines line up, which I believe it will- perfect. Then going out and make a wide-open pass and see how far off the marks are now.

Or maybe I'm just.

Jrocket

Well...Rocket and I have been trying this very method.Only thing is,its very hard to actuallu get the timg to line back up due to the motor not being that easy to turn over with a breaker bar,or bumping it with the key.

What if I put the motor to TDC and marked the SC/belt with a bright white mark.Then put a timing light on #1 plug wire and tried to strobe the marks?

So far ive marked the SC pulley and belt,then warapped the throttle afew good times but didnt drive it.After repeated times trying to check it,the closest it got was a 1/2in off on the marks?

ROCKETW19

im with jrocket the belt isnt gonna line up again.

Vadim @ FD

Since the pulleys are not lined up along a common centerline, the belt will never return to the to the same spot.

The belt slips on all 55s. It is part of the design.

jcjmw

What is the vrus chalk test?

Jrocket

Wise guy! Where were you 2 hours ago? lol

Not my fault Rocket...I swear!

ROCKETW19

why would they do that?

side note where is your shop located at im gonna be down that way in 2 or so weeks is the murrieta area id like to stop by and check out your shop and all thoes p-cars

ROCKETW19

no biggie bro you were just tryin to help! beside you went throught it with me anyways....lol....

Jrocket

His place will be on the direct path to Murrieta for you.Santa Ana I believe.

bleek

JRocket, you can pull the pulgs out of the car and spin the motor over easily. But the problem is the belt still ain't gonna line up, you have to remember something when you have big pullies small pullies and such when you spin the motor over the belt will slip, maybe when all you put a belt on two pullies the same size it might not slip.

The belt slips on SLR's and it's not a big deal, Kleemann has a few cars that make over 700+hp and they don't have a problem, but when people don't actually understand what is going on and start talking alot of non-sense it causes much confusion over nothing, and these same people have nothing to show for with there own cars. There's only a few like Vadim that understand, make sure all pullies are clean use a new belt and if your really **** i learned this one from Stuggart Tech (too bad he ain't around no more) use some damn belt dressing done deal!

Anyways my car comes back next week and i got a video of my car with the new race exhaust. You all seen the pics of the headers right?