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Thread Starter
TECH Senior Member
Joined: Nov 2001
Posts: 11,603
Likes: 0
From: Chi-Town, IL
One of the techs thinks the head unit is ok........but about the vibration, where is it coming from?
The only vibration I ever felt was from the belt skipping on the teeth of the cog pulley, and you FEEL that......
The only vibration I ever felt was from the belt skipping on the teeth of the cog pulley, and you FEEL that......
If it wasnt there the last time you drove it then whatever you changed last screwed something up maybe. Is the pulley 100% flush with the damper, maybe its running out or the balancer is damaged. You 100% sure it goes away with the belt off? Is it possible its a real bad misfire and you think its a vibration - make sure all your header tubes are hot after running it for a few minutes..
The vibration in mine is due to the blower/cog set up. As Mark said you can feel the vibration all the way through the car even up through the shifter handle. I removed my belt and no more vibration. You can look at the clearance between the supercharger housing and the supercharger pulley and on mine the pulley/shaft moves outward and that's when the vibration starts. I have no codes even with the vibration. The belt isn't slipping and still looks new. This is the reason mine didn't make it to the dyno a couple weeks ago. All motor combo is looking better all the time. 
Tom
Tom
I have worked on a couple cog belt cars (mustangs) and never really noticed much vibration. Main problem with them was taking the teeth off the belts. Only cars I ever owned with cog type belts were dry sumps, 6-71 roots blowers and jesel belt drives and I never had one problem.
Maybe it has something to so with the pitch/tooth design of the belt and pulley and the HP rating of the belt, I was fooling with a carrol (non intercooled vortech) setup for a C5 last year and it used a short cog belt. Worked fine on the street/dyno but that thing would take all the teeth off on the 1-2 shift (m6) every pass. After trying every possible tension, messing with bypasses and going through a dozen 35.00 belts we just gave up and switched to a ATI/A&A setup..
Hopefully the SD setup works for you high-boost guys..
Maybe it has something to so with the pitch/tooth design of the belt and pulley and the HP rating of the belt, I was fooling with a carrol (non intercooled vortech) setup for a C5 last year and it used a short cog belt. Worked fine on the street/dyno but that thing would take all the teeth off on the 1-2 shift (m6) every pass. After trying every possible tension, messing with bypasses and going through a dozen 35.00 belts we just gave up and switched to a ATI/A&A setup..
Hopefully the SD setup works for you high-boost guys..
On The Tree
Joined: Apr 2004
Posts: 196
Likes: 0
From: northeast
Originally Posted by BIGBOS
60's are in.......idling fine......not completely tuned yet.....
Here is the problem......
They got the pin kit on the crank pulleys, so my worries from that are now over......
But at 4000rpms there is a really bad vibration coming from the blower, its causing the motor to actually slow down, like something is dragging it, its causing the COG belt to ride awkard on the pulley.......so the blower is getting pulled off, they found a chipped impeller tooth, this blower is basically brand new, hasn't been run that hard yet, haven't had a chance to.......
This is probably what caused the car to throw the P1336 code with the crank relearn deal.......
So its going to get sent into ATI and hopefully they will cover it under warranty.........
Here is the problem......
They got the pin kit on the crank pulleys, so my worries from that are now over......
But at 4000rpms there is a really bad vibration coming from the blower, its causing the motor to actually slow down, like something is dragging it, its causing the COG belt to ride awkard on the pulley.......so the blower is getting pulled off, they found a chipped impeller tooth, this blower is basically brand new, hasn't been run that hard yet, haven't had a chance to.......
This is probably what caused the car to throw the P1336 code with the crank relearn deal.......
So its going to get sent into ATI and hopefully they will cover it under warranty.........
Couple questions - what do you have for an air filter? Sounds like the chipped impeller blade is from dirt or contaminants. How big is the chip in the inpeller? Scott says that if the impeller is indeed vibrating because of the damage, the frequency at 50,000rpm's is too high to be felt. Unless half the impeller blade is missing! He feels the cog belts are hard on blowers and on cranks. He thinks that's where your vibration is coming from. I have your number and if Scott has a minute, we'll give you a ring!
does the cog set up have some sort of idler pully on it. if not you could always do that to have less tension on the belt but cover more surface area.
you think your cog's are deep enough? if there not the belt could possibly slip over the pully because of not enough holding force and the slipping could cause the vibration. you can always mark the belt and pully with white chaulk to see if it's slipping and how bad.
you think your cog's are deep enough? if there not the belt could possibly slip over the pully because of not enough holding force and the slipping could cause the vibration. you can always mark the belt and pully with white chaulk to see if it's slipping and how bad.
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TECH Senior Member
Joined: Nov 2001
Posts: 11,603
Likes: 0
From: Chi-Town, IL
Well...
I'm still waiting to hear back from the shop that does the work on my car, probably hear something new monday hopefully.......
I would like to get some high boost out of my setup, but I'm weary of 8 ribs, and I've spent $600 in the past on 8 rib, $600 on COGS, and now if I did the SD stuff it would be another $650.....its just more money.........
I'm still waiting to hear back from the shop that does the work on my car, probably hear something new monday hopefully.......
I would like to get some high boost out of my setup, but I'm weary of 8 ribs, and I've spent $600 in the past on 8 rib, $600 on COGS, and now if I did the SD stuff it would be another $650.....its just more money.........
Originally Posted by BIGBOS
Also......now that I think of it......that bad vibration you are describing could be the belt skipping teeth, I felt that all the way into the cabin when that happened, it felt like the blower pulley hitting the alternator pulley like it would back w/my 8 rib setup originally w/no bracket support....
It's the belt skipping Bos, Tightened mine a little bit today and I ran up the rpm's a little more before it started happening again, I'm not giving up on this thing for a while, I like a challenge! I have a few ideas to try, just going to take some time. I'll take your bracket support if you sell your stuff. I need it for a start to several other things I'm going to do.
Mark
Last edited by BlwnTA; May 15, 2004 at 07:26 AM.
