dbs1vette

I picked one up last year for my ls3 based 416 (ATI#917278) and have just never put it on. Car is currently in the shop and with an install cost of $500 just wondering what the pros and cons of this are over the stock ls3 dampner before I decide to install or not. Thx.

Road race and 1/2 mile roll race with shifts around 7000. Thx.

0Anthony @ LGMotorsports

We have always used ATI balancers on the race cars and have not had any issues with them. I will say they do need to be serviced about every 5 years, which you can send into them to have them do that.

dbs1vette

Thx for the reply Anthony. If I was a little more flush it would probably not even be a question. Seems about an $800 savings selling the part and not installing it along with the new belts needed. At the same time, I'm guessing if things improve with the biz next year I may kick myself for not going ahead and doing it now while it's getting some other work done.

Any gains to be seen on this in the way of hp, or just mostly added longevity to the crank and bearings?

brkntrxn

I have been racing my C5Z for five years now with over 10,000 race miles on it. All with stock balancer.

My power steering rack started leaking during the East Coast Champs and my plan is to change to an ATI damper and Hinson motor and trans mounts while the power steering rack is coming down. To me, it is a "might as well" when the rack has to come out. Otherwise, I personally wouldn't mess with it until you can see a definitive issue with your OEM damper.

dbs1vette

And at what will probably be a $600 add time after all is said and done (actually add in another $250 for what I paid for it), the "if it ain't broke don't fix it sure comes to mind. Add to that I'm laid up from neck surgery for another 2 months and then rotator cuff for 6 more, next Oct might be my first venture back on the track....decisions, decisions.

ZedO6

Is the typical OE balancer failure the dreaded inertia ring wobble?

brkntrxn

Yes and mine has had a slight wobble for five years. I have been living on borrowed time I guess.

ZedO6

Kevin, I wouldn't worry, you are pretty easy on that car!

VGLNTE1

Watching the balance of a stocker compared to an ati tells the tale.

johnny c

i've had brand new stock pulley wobble. i bought two, both wobbled and thought my crank was bent. i ended up buying a aftermarket one from texas speed. 25% under drive, now my idle needs to be above 900rpm or the battery won't charge :P


I'm planing on running a dry sump and ARE said i need a ATI pulley.

Anthony,
what one would you recommend? i have space limitations so i cant extend anything. i want the dry sump pump to be ran off the same location as the oem ac compressor. i would also like a 10% under drive or no under dive. 25% is just too much. I tried looking at summit but that search is impossible.

VGLNTE1

call Katech. Jason is always more than helpful

johnny c

i always feel like i'm bothering k tech.

froggy47

That is nothing short of a miracle to put that many race miles on a stock balancer, and not saying you didn't but wow, there are so so many threads about problems with them it's hard to fathom.

froggy47

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rfn026

I just finished an article on harmonic balancers. They're actually harmonic dampers and they have nothing to do with the balance of your engine.

"Every time the cylinders in your engine fire torque is imparted to the crankshaft. The energy that is transferred from the piston to the crankshaft can induce as much as 2 degrees of twist in the crankshaft. A harmonic balancer is mounted on the end of the crankshaft to help dampen this twisting.
Harmonic balancers are typically constructed in three pieces. The first piece is often called a hub. It bolts to directly to the crankshaft. This hub is then wrapped in rubber. The outside, or third layer is a heavy metal. This outer layer generally has grooves on it for the drive belts.
The pliable rubber middle ring is what dampens the crankshaft vibrations. As the crankshaft accelerates this rubber will twist and allow the mass of the outer ring to lag slightly behind center of the damper. When the crankshaft snaps back to it’s original configuration the mass of the harmonic balancer cancels the harmonic. By calculating the precise characteristics of the engine and sizing the harmonic balancer accordingly engineers can control torsional distortion. This helps to prevent critical harmonics that might break the crankshaft."

I probably need to post this on the Car Tech Stuff blog.

Richard Newton
Historic Racing Images

VGLNTE1

Not the first time I've heard that, but it's just how he is. Don't take it the wrong way. He's always there to help

johnny c

nah PS is fine. the car idles at 1100-1200rpm so the battery charges too. If i'm sitting in traffic or the pits it will like to creep up in temperature. ironically i give it a little gas up to 2000rpm and it will cool back down. :P but my radiator is 2/3's the size of a c5's rad.

i feel like a jerk calling the guys that make the c7r engine about my little club racing car hahah. " do you remember the ls1, i have one of those"

i'm surprised you don't throw belts. Stukas would throw a belt on his AI car (ls1) if the wind blew from the east.

Scooter70

ATI only started making an underdrive pulley for the LS1 a few years ago, and then it's only 10%. They had stock diameter for years though. As you've learned, they don't really like the 25% UD too much. I have the 10%UD ATI on my car and haven't had any issues with charging.

Katech hasn't made the engines for Corvette Racing since 2010.

You could send Jason a PM if you wanted to ask him a question. He's answered a few for me over the years.

Katech_Zach

917289

Corvette (excl LS7/LS9), 10%UD, with HTD pulley on the rear for the dry sump. Make sure the 28T pulley is the right combination for your oil pump.

http://www.atiracing.com/products/da...ts/damserp.htm

johnny c

jason,
You are a gentleman and a scholar thank you.
I'm looking at this pump.
http://www.drysump.com/3020pump.htm
can you verify the ATI dampener part number?
when i'm ready to buy i will call you to order.