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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
Thanks for the update, and good to hear there may not be much in the way of collateral damage. A lot of us have the ATI damper and will be interested in learning the cause of any failure...material defects, manufacturing, installation issue, etc.
Sounds like this was your first track outing following the dampers removal and replacement for the cam install.
It was first track outing for the HCIE build; before was all stock parts including OEM damper.
Update on the ATI super Damper failure from Joe at CPR:
Similar ATI super Damper problem earlier this year on a rebuilt LS7 after less than 600 miles.
4 of the nine retaining bolts had backed out and sheared off. 3 had backed out but not sheared off. 2 were still tight. Loctite on all the bolts. Only noticed it while on the lift checking for oil leaks. Got lucky. Sent the unit back to ATI. They could not explain the failure but replaced the unit at no charge. ATI mentioned a few similar damper failures in engines with extreme detonation but did not specify type of engine.
New unit they sent had a different shell design with a fence for the serpentine belt. Installed the new unit with red Loctite on the shell bolts and now check the bolts on a regular basis. So far so good.
Original installation
Unlikely I had detonation as the engine was tuned for 91 and I mixed 6.5 gallons of 100 with the 91 which should have had 94+ tank octane. I was at 3/8 tank when I put in the 100 then topped up with 91 to make sure I got a full load mix in both tanks. In addition it was about 98* at 6AM 1st session and 104* at the 9AM session at 1200' elevation so the DA was probably very high, which would also eliminate detonation. Looking at the tail pipes (valves open on the B&B Fusion) indicated the engine was running more on the rich side than lean. That is the way the tuner set up the tune as I described the type of uses and elevations where I do my performance events. I had 700-800 miles on the ATI damper including the last miles at the track.
I guess it is good to know of another ATI SD failure first hand. ATI had indicated to Joe @CPR that they had a few fail.
Detonation was not my issue. I run Sunoco 260 GT (100 octane) fuel.
Dedicated track car. This engine had 20,000 miles use with an ATI balancer with no problems. For the rebuild I decided to buy a new balancer and have the used one rebuilt by ATI. It was the new one that failed in less than 600 miles.There have been some issues with the balancer slipping on LS7 cranks because their is no key way from the factory to secure the balancer. I don't now if this can effect an aftermarket balancer. When I balanced my LS7 crank for new pistons I had a full key way machined in the snout to secure the balancer. If their was enough detonation to loosen the balancer shell bolts I think there would be some internal damage to the pistons!
Joe updated in another thread, but the car is ready to be picked up. There was no collateral damage. Joe replaced the serpentine belt and radiator cap as a precaution since it spewed out fluid when I got back to the pits. I'll pick it up next week.
The ATI damper has been sent back to ATI to evaluate the failure, hopefully Joe or I can report back their findings.
There is so much good information in here. I am looking forward to your October results especially since our engine builds are similar. Good luck! I hope do better than you are hoping for!
For what it's worth guys our build was Katech's most resent build with the 501(SN#90), and we had Pfadt 1 3/4 tri y headers. And made 576 on their dyno, but had a slipping clutch so couldn't get a tq number, and might have been missing a few hp (less than 5) up top.
Full parts list as follows
Halltech 103
Stock 90 tb
Tony Mamo 102
WCCH stage 2 heads with .030 mill
Pfadt 1.75 with catless x
Monster lt1-s clutch (less than year old, no clue why it was slipping)
Built rpm trans and built 3.90 rpm diff, both of which are new and very few miles on them.
Our dyno could have been higher if we had the broken in stock tranny and diff with 3.42 instead of 3.90 (dyno less) and maybe a healthy clutch. Also stock tb hurt us some.
What helped us was the ported 102......
Had more things working against us then helping us......
Like I said earlier, take it for what it's worth.....The Pfadt headers can't be hurting to much compared to the standard.......
THis is your car, that just went 10.26@134, correct ?
Impressive run
I know this is an old thread but if you look at the picture and compare the primary pipe length to the secondary pipe the lengths are WRONG the secondary length is a 3/4 wave length of the primary pipe which will kill the torque if it was 1/2 wave length it would sum and add torque. My JBA tri Y's have totally different length pipes which is why they work just fine the PFADT are not a good design.
07-30-2016, 09:22 AM
