Calling Heartbeat owners
05-06-2018, 01:17 AM
#221
Hey Brian. I didn’t get much of a chance to work on the Vette until very recently, to prepare for a race event that we had over the weekend. I did try the 98” Continental (Gatorback) on it again, and it’s slipping, possibly worse than the old Green Stripe, with the boost wavering by about 1 - 1.5 psi up top. This is with the stock tensioner. I’m going to try a new Dayco tensioner with with the heavier spring that I recently ordered on it again, most likely with the Gates belt, and see what that does.
As it is, the damn car makes way too much power to hook with the 325/45/17 M&Hs at 17psi on a prepped (albeit rough) surface. Managed to make a couple of test hits on Sunday, just to get some data, and it got crossways both times. Second time I pedaled it down the track and it was spinning in third. Everyone else seemed to be able to hook, but not me. I had fun though, but I still have some work to do. I’m actually contemplating pulling those stupid Viking coilovers off the front, because the springs are binding on the upper control arm and also because based on a couple of videos I saw, it doesn’t transfer for ****, even with their drag race “weight transfer” settings. Ah well, first world problems, as they say.
I’ll let you know how the new tensioner works out. It hard to say whether the GripTech pulleys are worth it, being that they are like almost double the price of the Magnuson pulleys, IIRC. But they are quality pieces and I can’t see how it hurts. I’m still not certain whether my belt is slipping on the blower pulley or slipping on that nice, shiny surface on the IW balancer.
As it is, the damn car makes way too much power to hook with the 325/45/17 M&Hs at 17psi on a prepped (albeit rough) surface. Managed to make a couple of test hits on Sunday, just to get some data, and it got crossways both times. Second time I pedaled it down the track and it was spinning in third. Everyone else seemed to be able to hook, but not me. I had fun though, but I still have some work to do. I’m actually contemplating pulling those stupid Viking coilovers off the front, because the springs are binding on the upper control arm and also because based on a couple of videos I saw, it doesn’t transfer for ****, even with their drag race “weight transfer” settings. Ah well, first world problems, as they say.
I’ll let you know how the new tensioner works out. It hard to say whether the GripTech pulleys are worth it, being that they are like almost double the price of the Magnuson pulleys, IIRC. But they are quality pieces and I can’t see how it hurts. I’m still not certain whether my belt is slipping on the blower pulley or slipping on that nice, shiny surface on the IW balancer.
Long time no see. How is the GS going? I have decided to pulley down to the 81mm, add 50/50 meth and retune. Been umming and aahing but just thought I would go for broke. Just a question for you and Rodney? I want to put a gates rpm belt on, and the size belt both Andy and Rodney had for the same set up in a Continental Elite, ie 96.7 inch belt, the Rpm belt comes in either 96.29 inch or 97.02 inches. Which belt would fit better do you think? By the way, my balancer is stock size. Thanks.
05-06-2018, 11:29 AM
#222
Le Mans Master
Put the smallest belt on that will fit. They all stretch as the load on them increases. The trick is to have some tensioner travel left at max boost and max RPM. No tensioner travel left = belt slip. I posted a vid here somewhere that shows how much slack the tensioner has to take up under full boost and rpm. It's eye opening.
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rajahhindi (05-07-2018)
05-06-2018, 02:22 PM
#223
Hey Sammy,
Long time no see. How is the GS going? I have decided to pulley down to the 81mm, add 50/50 meth and retune. Been umming and aahing but just thought I would go for broke. Just a question for you and Rodney? I want to put a gates rpm belt on, and the size belt both Andy and Rodney had for the same set up in a Continental Elite, ie 96.7 inch belt, the Rpm belt comes in either 96.29 inch or 97.02 inches. Which belt would fit better do you think? By the way, my balancer is stock size. Thanks.
Long time no see. How is the GS going? I have decided to pulley down to the 81mm, add 50/50 meth and retune. Been umming and aahing but just thought I would go for broke. Just a question for you and Rodney? I want to put a gates rpm belt on, and the size belt both Andy and Rodney had for the same set up in a Continental Elite, ie 96.7 inch belt, the Rpm belt comes in either 96.29 inch or 97.02 inches. Which belt would fit better do you think? By the way, my balancer is stock size. Thanks.
I've been traveling (in California) since late April, so I've not been working on the car lately and I've not been in this forum since I left, until now.
I've never used the 81mm with the stock damper, but I do recall that both Andy and Rodney used the 967 belt with that pulley combo. As Rodney says, use the smallest belt that it can take, subject to one caveat, based on my experience: if the belt is so short that the tensioner is parked in the fully closed position (right up against the stop), then during a WOT run, if you ease off the throttle quickly, the belt will contract and the tensioner will slam against the stop and bounce the belt, which can then cause the belt to jump off the tensioner pulley. Ask me how I know: It happened twice with me, with two different belts and two different tensioners. In fact, that's how I ruined the first Dayco tensioner, to the point where it jammed the tensioner in the fully closed position.
So, IF you are using the stock damper, the 967 belt seems to be the ticket. However, be careful if you have a stock sized aftermarket damper (which I think you do?) oull have to try it out for yourself, because although they label them "stock diameter" the actual measured diameter could be slightly off. In the end, you'll just have to try it and see. If the tensioner is in the almost closed position, then it should work fine. Good luck and let us know how it works.
I'm looking forward to getting back at my old car next weekend when I'm back home. Suffering from wrench withdrawal syndrome right about now.
05-06-2018, 02:32 PM
#224
Put the smallest belt on that will fit. They all stretch as the load on them increases. The trick is to have some tensioner travel left at max boost and max RPM. No tensioner travel left = belt slip. I posted a vid here somewhere that shows how much slack the tensioner has to take up under full boost and rpm. It's eye opening.
I agree with you on the amount that a regular belt stretches. The problem on the Hbeat setup is that the belt is so long (96"+) and the same belt drives everything, including the blower.
I have some crude videos that I made myself. The regular Gates belt stretches until the tensioner is fully open on these cars. The Gates RPM belt, on the other hand, barely stretches at all. But those suckers are so stiff that if you don't have the pulleys perfectly aligned and/or a tensioner stiff enough to keep them taut enough, they'll jump right off. That's what I believe was happening with me. I ruined two RPM belts before I figured that out. One of them only jumped one rib and the pulley lip cut that rib off, so I now have a 5 rib RPM in my collection.
But I'm going to do a bit more "research" soon though, and post up the results.
05-06-2018, 03:09 PM
#225
Le Mans Master
Even a blind squirrel.....I must have gotten lucky not to have had any of the issues you've experienced. I changed to the correct sized Gatorback belt, and, boom, done, no more issues. I'm even really close to sea level so I'm probably at max load on that serp belt for the drive ratio employed. My blower cam wasn't even nearly as big as a lot of folks use. No serious reduction in boost/load on the belt because of the cam.
I'm at a loss why I got by and you're having troubles. Maybe you pi$$ed off some voodoo witch doctor's princess....or some kind of other tropical jungle foot rot/fungus/gynecological curse.
Could be what got your coil overs too. Just sayin'
I'm at a loss why I got by and you're having troubles. Maybe you pi$$ed off some voodoo witch doctor's princess....or some kind of other tropical jungle foot rot/fungus/gynecological curse.
Could be what got your coil overs too. Just sayin'
05-06-2018, 11:51 PM
#226
Even a blind squirrel.....I must have gotten lucky not to have had any of the issues you've experienced. I changed to the correct sized Gatorback belt, and, boom, done, no more issues. I'm even really close to sea level so I'm probably at max load on that serp belt for the drive ratio employed. My blower cam wasn't even nearly as big as a lot of folks use. No serious reduction in boost/load on the belt because of the cam.
I'm at a loss why I got by and you're having troubles. Maybe you pi$$ed off some voodoo witch doctor's princess....or some kind of other tropical jungle foot rot/fungus/gynecological curse.
Could be what got your coil overs too. Just sayin'
I'm at a loss why I got by and you're having troubles. Maybe you pi$$ed off some voodoo witch doctor's princess....or some kind of other tropical jungle foot rot/fungus/gynecological curse.
Could be what got your coil overs too. Just sayin'
Anyways, it may actually be that I have belt slip issues because my damper is bigger than yours! How about that?!
Seriously though, I don't know anyone other than Joe White that ran the pulley combo I'm running on a C6 Heartbeat, and as I recall, he ran a 9.9 once and couldn't get it to run that number again, so who knows whether he may have had belt slip issues or not?
And for all I know, as I've said before, maybe the belt is slipping on the nice shiny, bright coat anodized surface on the balancer pulley. I will figure it out soon though.
The problem with my Viking coilovers is that the damn upper control arm is binding on the springs. I can't imagine that they screwed up on on their design like that, but then I noticed the other day when I put the front skinnies on that the front wheels have a lot of negative camber. So, it occurred to me that there's a simple solution to both problems. I'm going to get a set of the Van Steel or AMT upper control arm studs and shims and use those to adjust the camber with shims/washers at the upper control arms, to place the control arm more outboard and further away from the springs, which will hopeful relieve the spring bind. BTW: I have never touched the front camber bolts on my car, and when I pulled the upper control arms to instal the coilovers, I made sure to replace the washers exactly where they came from. But the car sits much lower in the front now, and that must've resulted in the camber angle I'm seeing now. IDK...
But, don't worry, regardless of blind squirrels and black cats, I'll soon get her sorted. I've got me a date with a whole herd of mustangs and a pile of local "sushi" too (*** cars are a big thing where I come from), so I have to get it hooking and going straight, pronto.
Last edited by CI GS; 05-06-2018 at 11:53 PM.