froggy47

I am thinking an ATI replacement, which one do you guys recommend for street/track/autox?

2004 z06 50k miles.

A "Corvette Specialist" worked on this when he fixed front cover leaks about a year ago. Replaced with stock part as original was "gouged" a common issue.

I figure this bubba flubbed the install. It was safetywired & I don't know how a safetywired nut can back off unless he did that wrong too.

Going to do it myself, got a link to a good writeup, has to be a few on the forum as this is a common issue.

Thanks all.

davidfarmer

how do you safety-wire a spinning bolt???? Anyway, either was mis-torqued, didn't use a new bolt, or used a bad damper. No matter what you put back on, pin the crank and use the old bolt to seat, new bolt to final torque.

froggy47

Thanks for the post David, I have no idea what this old bubba thought he was doing, not much as it turns out.

Which aftermarket HB do you like, I trust your opinion a LOT.

davidfarmer

I've always used the aluminum underderive ATI, assuming no AC. If you run AC, I'm not sure. PRobably still go with ATI, as they actually worked with GM when they did the original LS racing damper. You have to be careful with the bolts hitting the rack etc, depending on which setup they send you.

geerookie

100% agree. Get the small (I think it's 5 1/4") aluminum one, especially if you are running a QM 7.25 clutch. It's basically a perfect match. Same combination used in the ASA cars.

Did the bolt come out or just the outer ring let go? On mine just the outer ring let go.

RX-Ben

I was told that by ATI that the 5.5" setup is not large enough to offer sufficient damping for anything other than a stock engine setup. They said they only made it to fill a market need and would not sell it to me for racing.

froggy47

I still have the a/c as this is street/track 50/50.

froggy47

I can see the bolt up against the rack. It shows in the video a little bit. It was a new stock one installed by bubba when he fixed leaky front cover about a year ago.

The older I get the more I find I need to do stuff myself to get it right.

These old local shops claim to be Vette specialists (this guy at least 25 years) and turn out crap like this, it's unbelievable.

Sheesh.

froggy47

I will call ati & see what they say.

geerookie

I hear that all the time but I have read articles with quotes from GM and Katech regarding harmonics on an LS1/6 with a lightweight clutch from ASA testing stating that the harmonics were within GM expectations without a harmonic balancer so the small one would be all that was needed.

froggy47

Talked to ati & they suggest #917278 which Summit has for about $420. Need a new arp bolt & 2 new shorter belts and new seal. Anything else? This is alum 10% UD.


Questions:

Do I need to drill and pin this? The arp instructions do NOT specify it.

I think Katek or Lingenfilter sells this drill/pin kit. Maybe for higher HP (#800 say) applications?

http://www.atiracing.com/instructions/Super-Damper.pdf

Is there an index mark on the crank?

The instructions also mention to hone the steel hub to a certain spec? Do you guys do this?

The 917278 is a steel hub with alum shell so two parts two metals. Just to be clear.

I have not done this b4 so if any of you guys have, I need the details help please.

Do you need to "PIN" the motor so it doesn't turn when you get the final torque spec (over 200 ft lb I think)?
Thanks.

Scooter70

You can get "blemished" units direct from ATI. I paid $250 shipped (each) for two of them last year. E-mail James Beattie at jcbuncc@gmail.com. He works on the damper development team.

No, you don't "need" to pin it. They say that it's necessary for supercharged cars where the additional torque of the blower on the pulley via the belt could cause it to slip or loosen.

I did not have to hone anything. When you do the install, heat the metal hub part in the oven (200*) for 20 minutes or so. It will slip right on the crank and you won't even need to use an install tool to pull it on.

froggy47

Thanks dude, I owe you big.