99WhiteSS

I heard these are really good for the rotating assembly, especially those of us with stroker or super-stroker engines. Does anybody run one of these? Looking for some basic info...

Is it a good mod (can you tell a difference is the supression of crank vibrations)?

Approximate price?

Best dealer for purchase?

Any other details?: Can you retain stock A/C? Etc..

I have a 383 and am looking to make the engine as smooth as possible. These bigger cams with the high flowing intakes tend to be less than "smooth" when flying through some of the RPM ranges...at least in my experience.

So, anyone have ANY information? I would really appreciate it. Thanks. <img src="images/icons/grin.gif" border="0">

Bob2of3

iTrader: (11)

Here's their Website

http://www.atiperformanceproducts.com/

<img src="graemlins/burnout.gif" border="0" alt="[Burnout]" />

Colonel

I know of only one person here that has one and it's on an internally stock engine (RUQWIKR.)

Is it a good mod? Depends on how well balanced your engine is. It may prevent a little power lost to vibration over a standard underdrive pulley or it may do little or nothing if there is little vibration present to begin with. I was told this by ATI. They said they have ZERO dyno test results on an LS1 engine. Basically it can't hurt but it may not improve track times is what they said.

Price? About $340 I think.

Best dealer? I don't know but you could call ATI directly.

Yes you can retain the stock A/C, etc...

I don't think the cam would have anything to do with the dampener. It controls vibrations from the rotating assembly (crank, rods, pistons.)

[ November 23, 2001: Message edited by: Colonel ]

[ November 23, 2001: Message edited by: Colonel ]</p>

just me

Colonel,
how well your engine is balanced(rotating assembly) makes no difference in how a Harmonic balancer works.
The Harmonic damper works on torsional vibrations that would destroy a crankshaft and bearings no matter how well it is balanced if it did not use one in very short time.
It is designed to cancel out the torsional or twisting vibrations created in the crank by the engines power pulses.

FYI, every ls1 Vortech kit comes with an ATI superdamper and I have one on my motor.They are are very nice pieces.
Nearly every Winston cup car uses an ATI super damper.

Steve
www.tech-ls1.com

Colonel

Hmmm...I must have misunderstood what ATI was telling me. I took what they told me to mean that some engines (ones plagued with ALOT of vibration) stand to gain "as much as 34 hp according to some of our tests" and that others that don't suffer from excessive vibration might see no gain. They also made it quite clear that a balancer like their's is much more important at high rpms (above 7500 or so.) I thought by vibration they meant as in having more of it if it weren't properly balanced. Thanks for the correction. <img src="images/icons/smile.gif" border="0">

Yes, Winston Cup uses them and they are FINE balancers, but that isn't to suggest that an LS1 will for sure pick up even 1 RWHP on the dyno with one nor fail to last 150,000 miles without one. That's the main point I was trying to get across of what ATI was telling me.

Again, I'm certainly not putting the ATI down...just passing along what they told me (more importantly, what they couldn't tell me.) I almost talked myself into buying one.

I'm just saying that I think my engine will last plenty long enough with my ASP pulley and that it'll make pretty much the same power. For those two reasons I'm not buying one until I can see some concrete evidence that my car would be faster with one.

So, IYO, would a perfectly balanced engine stand to gain just as much from an ATI balancer than a not-so perfectly balanced engine? Or might the imperfectly balanced engine stand to gain a little more?

[ November 23, 2001: Message edited by: Colonel ]</p>

RyanJ

Question: my stock pulley/balancer assembly wobbles. I was thinking of adding an ATI 10% underdrive pulley/balancer in the near future. will this work on my LS1? Kinda figure it will kill two birds with one stone.


Ryan

just me

I think for a strip car it's not quite the same issue Colonel.
Again, it's not rotational balance but the odd firings of the cylinders.
When each cylinder fires the crank twists. A harmonic balancers job is to cancel out these twisting forces.
In severe cases a crank can actually break from these forces.
Yep high rpm and endurance motors need a better harmonic damper than say a strip motor that operates for a few seconds at a time.

Just think of it like anything else for your car.
You have good, better and best.

They are one of the best.
It came with my blower kit. Would I had shelled out the money for one if it had not come with the kit? probably not.

Steve

LS194z

There are 2 different ones, One is steel the other aluminum. This replaces the stock balancer pulley. I would think going from the steel stocker to the aluminum ATI would be worth something. Ill let you know soon. <img src="images/icons/rolleyes.gif" border="0">

GeorgeC

Also, I believe the ATI dampers are the only SFI approved units out there... Important if you run faster than 11.00 and have a picky track...

Jason99T/A

iTrader: (21)

Joe Kizzire and GTS SS are running ATI Dampers and are really happy with them.

Give Thunder Racing a call. They are a dealer for ATI and have some in stock. They are not on the website yet, so call for pricing.

www.thunderracing.com

Jason

[ November 25, 2001: Message edited by: Jason99T/A ]</p>

Dave F

I run the ATI Aluminum 10% underdrive with no AC pulley, and I love it. Although the extra 3 star bolts must be left out on the corvette (they hit the steering rack), the unit is about 9 lbs lighter than the stocker (10lb vs 19lb) and fits and runs great. However, according to GM Racing, make sure you get the #14 rubbers. Appearantly ATI is still shipping some dampers with the original hard rubbers which causes bad harmonics. My first one came in with the wrong rubbers, and I had to send it back for new ones.

btw, this is on my 475hp Speedvision GT Road-Race Corvette.

Dave



[ November 25, 2001: Message edited by: Dave F ]</p>

99WhiteSS

Just got off the phone with someone at Thunder Racing. The ATI Super Damper is almost $500! Seems a little high if you ask me. Doesn't even come with a belt. Not sure when I'll be shelling out for this mod. Sure would like to pick one up but that is a lot of money to spend just before X-Mas. <img src="images/icons/frown.gif" border="0">

Dave F

Call Summit. I think you want #917276, which is the aluminum model with 10% underdrive and A/C, for an F-body. You can get a belt anywhere for a few bucks.

Dave

Dave F

$467 at summit, but it is special order.

Dave

just me

It is also machined for a keyway.
I just cut my own keyslot in the crank to accept a 3/16" wide 1" long Woodruff Key to lock the ATI superdamper to the crank as it was slipping with 10psi boost at 6500rpm.
They also now have some sort of drill fixture you can buy to fit dowel pins to pin it to the crank, which they recomend for circle track and supercharged use.
Gm goofed when they made a non keyed crank snout.
Steve

Geoff

iTrader: (3)

We have them in stock, ready to ship for $479, but I will be happy to match Summit's price of $467 if anyone is interested.

Angie
(Damn, I gotta watch what name I'm logged on under!)

[ November 26, 2001: Message edited by: Geoff ]</p>