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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
On the bolt that holds the tensioner arm to the AC bracket check that for tightness. On mine the threads were stripped out of the bracket. Even though it seemed tight when the motor heated up the clearance (aluminum versus steel) would allow the bolt to wiggle and threads eventually gave out. I had to heli-coil the hole. When you tighten it and it feels like it could still tighten the threads are going and need to heli-coil. With it wiggling the tensioner it will cause the belt to move around and since the ATI balancer does not have the big shoulders like factory (which has .100 edge on it) to hold the belt in place (mine the belt would go in one notch toward the motor) if something is materially off.
Update: So far, so good. I changed the belt to a Dayco belt part #5040425 and a Dayco tensioner pulley.
Hey it's your old car😬
I recently threw a belt off, did a Google search and found this post, bought this belt, and 1 night of driving and 1 quick pull maybe 5500 rpm and belt slipped off again. Just seeing if you did anything different since this post to correct problem.
I recently threw a belt off, did a Google search and found this post, bought this belt, and 1 night of driving and 1 quick pull maybe 5500 rpm and belt slipped off again. Just seeing if you did anything different since this post to correct problem.
Loving the car still though
No. That one seemed to hold up just fine for me including a track day on the 1/4 mile strip in Baytown. I don't recall Jason ever having a problem either during the time he owned it. Welcome to the wonderful world of aftermarket mayhem.
Ran on dyno last week a few times for tuning.................out and about this past weekend driving................gave'er a few times......................belt still on.
Supposedly the newer ATI parts have a lip on them where this doesn't happen anymore. May want to look into it.
Yes..spoke with ATI yesterday and they confirmed the design change. You can convert an older design to the newer by replacing the existing "shell assembly" with a new replacement "shell assembly" that includes the new AC pulley with the shoulders you mention. You retain the existing damper hub. I was provided ATI # 917049 for the new design shell assembly which sells for $ 388 at Summit. I believe that is for no under drive.
Yes..spoke with ATI yesterday and they confirmed the design change. You can convert an older design to the newer by replacing the existing "shell assembly" with a new replacement "shell assembly" that includes the new AC pulley with the shoulders you mention. You retain the existing damper hub. I was provided ATI # 917049 for the new design shell assembly which sells for $ 388 at Summit. I believe that is for no under drive.
Yes I talked with doubleo6 a few weeks back and had gotten the information, I've been working a lot lately haven't had much play time with the car, but last weekend I bought a new factory ac belt and ran around Saturday without any issues. But when I get some time I'm going to retro-fit the new shell assembly.
Yes I talked with doubleo6 a few weeks back and had gotten the information, I've been working a lot lately haven't had much play time with the car, but last weekend I bought a new factory ac belt and ran around Saturday without any issues. But when I get some time I'm going to retro-fit the new shell assembly.
I see no one's posted here in a while, but I'm stumped with an ATI Super Damper problem.
I had Katech put a Street Attack LS7 in my '12. Katech's Jason Harding convinced me to upgrade to the ATI SuperDamper PN 917049U which has the main belt 10% underdriven and the HVAC belt running on a stock diameter pulley and is said by ATI to use a stock HVAC belt.
Anytime I run the RPM past about 6000, the hvac belt will "jump" a groove to the rear and start rubbing on the front cover. Eventually, if I don't get under the front end and re-position the belt, it frays then breaks.
I told Jason about it and he said to change the tensioner, so I did and that had no effect. I tried emailing ATI's tech address and got no response. A week later I tried calling them and got a customer service guy. I told him my problem and that I had communcated with Katech about it. All he said is that he'd have to find out who at ATI talked to Jason, then he'd get back to me. Other than that, the guy was not helpful. ATI has never called me back and it's been a week.
I read here that some others have had this problem.
Have anyone developed a solution other than changing the tensioner which I've already done?
Also, does anyone have a contact at ATI that's at a higher level than customer service?
Ok...we're dredging up two-year old thread. One reason is my problem with the HVAC grooves on the Superdamper throwing the HVAC belt has been long standing–going back to 2017. This three-year project happened because my car had to go back to its engine builder three times before they could the piston/ring package right such that the engine's oil consumption acceptable. For that reason over the last three years I've had minimal time to troubleshoot the belt tossing issue.
Living with this problem for three years, I've become of the opinion that, given proper alignment of the two sets of HVAC belt grooves, the problem is not just high-rpm but the dynamics of the HVAC accessory drive when you lift off the throttle abruptly when the engine as at 6500-rpm or higher.
Earlier in this thread it was suggested that ATI made a design change to the Superdamper outer ring such that the height of the rear edge of the HVAC belt groove was raised to make it closer to height of the edge on the OE balancer's backside.
In talking with ATI a month or so ago, when I gave them the part number of the outer ring used on the 10% underdriven Superdamper for LS7s, I was told there had been no design changes to that part. It is possible that ATI changed the design of the non-underdriven part but not change the 10% under unit. ATI also told me it was not possible to change just the outer shell from the 10% under shell to the standard shell because the two use different hubs. Because I'm frugal, I didn't want to buy a new damper and, since I lack the tools and the time to make the change, I looked for an alternative.
That alternative was a new HVAC belt tensioner and a shorter belt. Going to the next length shorter belt causes an increase in tensioner spring pressure. My belief was a little more tenisioner pressure would keep the belt in place. Finding just the right belt took some research. The OE HVAC belt for LS7 engine is four-rib belt that is 41.70-in in effective length. Typically I use Continental Poly-V belts and the Continental PN for that is 4040417 and the universal metric number is 4PK1060. First I tried a 41.2-in belt and I could not get it onto both pulleys even with the tensioner retracted all the way. There are a number of engines used by Asian manufacturers that use a four-rib, 41.5-in. belt to drive either the coolant pump and alternator or the power steering pump. The Continental PN for that is 4040415 and the metric number is 4PK1055. This belt is 0.2-in shorter than the stock LS7 HVAC belt and I ordered it from Rockauto.com
Wanting to start fresh, I replaced the stock HVAC belt tensioner with a Continental tensioner (PN 49403) and then installed the shorter, Continental HVAC belt (PN 4040415). Got the tensioner from Rockauto.com, too. Then I put the main accessory belt back on and started road testing this set-up. I've been running my ZO6 this way for about a month and have made a number of third gear runs to 7000 then lifted. I've also made seven chassis dyno passes in fourth gear lifting at 7000. So far the belt has stayed in place.
Update on 9/20/20
Well...that didn't work. See #43 below.
Last edited by Hib Halverson; 11-13-2020 at 01:55 PM.
Other than an initial failure of the entire ATI hub on my Superdampner back in 2016, I have had no problems with mine, however I run a standard drive pulley and the Katech Billet tensioner. With a good number of road course events and straight line events I have given it a good workout. ATI admitted back in 2016 that they had a batch that failed apparently due to improper heat treatment prior to assembly of the ATI Dampner. My standard drive ATI takes a one size larger belt than OEM.
Correction, I did throw a belt at a 1/2 mile event in 2017 or 2018, possibly doing a burnout, but didn't realize it until near the end of the run, no problems since.
Other than an initial failure of the entire ATI hub on my Superdampner back in 2016, I have had no problems with mine, however I run a standard drive pulley and the Katech Billet tensioner. With a good number of road course events and straight line events I have given it a good workout. ATI admitted back in 2016 that they had a batch that failed apparently due to improper heat treatment prior to assembly of the ATI Dampner. My standard drive ATI takes a one size larger belt than OEM.
Correction, I did throw a belt at a 1/2 mile event in 2017 or 2018, possibly doing a burnout, but didn't realize it until near the end of the run, no problems since.
Dave, we're talking about the A/C belt, which is not the main drive belt that is covered with the Katech tensioner. I thought mine was solved, but the new owner came back and said my car was still doing it on occasion.
Dave, we're talking about the A/C belt, which is not the main drive belt that is covered with the Katech tensioner. I thought mine was solved, but the new owner came back and said my car was still doing it on occasion.
Sorry I misunderstood. I have had no problem with that belt at all.
I am also having issues with my 10% underdrive. I am actually running a 41.0" belt with the stock tensioner. I am going to swap over to the dayco tensioner and a 42" belt this weekend and see what happens.I thought about machining my own idler pulley so that I could make one with guide edges to help keep the belt centered, but the idler pulley is on the exit side of the belt so I'm not sure that would help much as it would only center it before it enters the A/C compressor pulley. I bought this one from Texas Speed about 4 months ago. So I would assume if there was an updated shell I would have it. To me it doesn't look like there is anything on either side of the belt to help hold it on.
08-20-2014, 07:59 AM
One other thing to check
