ATI Crank Damper

N

NaughtyNori

Member
Location
Jersey
Does anybody know the correct belts needed for this Damper? Been searching all over and can't come up with anything. Even called ATI and they didn't even know (But I think they were just blowing me off...).

What I have confirmed is that the ATI is both and Underdrive and Overdrive Pulley. The AC side of the crank pulley is 32% Underdrive from stock. And the Alt & P/S side of crank pulley is 15% Overdrive.

Stock length for our belts are as follows:
37.2047 inches for AC
45.1969 inches for Alt & P/S

If my math is correct, I am going to need a belt that's approx:
25.2991 inches for AC = (37.2047 - 32%)
and
51.9764 inches for Alt & P/S = (45.1969 + 15%)

Any help would greatly be appreaciated... Thanks guys...
 
Don't mean to de-rail the thread, but do you already have the ATI crank damper pulley?
Not sure why the ATI would be both under and over for the two belts - was this part number meant for the VQ engine or does it just happen to fit the crank?

Fluidampr makes a crank damper pulley also - overdrive or stock size for use with stock size belts.
 
Yes. Already recieved the part. It's part number #918588 forthe VQ35DE and came installed on my built motor from Kyle at IPP in Texas.

The engine is being installed but when they went to place the belts on, it was obvious that it wouldn't fit. Visually it appears as if the crank pulley which supplies the power to the AC is half the size of the stock while the pulley for p/s and alt is slightly bigger.

When I spoke with a tech at ATI, he stated that the pulley is 32% underdrive for AC and 15% over for p/s and alt side. Although when I asked what belt compliments it, he didn't know... WTF!?!

I would have gone with fluidampr but IPP didn't stock them and would have held up my order if I went that route.

I'm just getting super frustrated now and about to just slap on the stock pulley on the built motor... So I need I.S.'s help again!

---------- Post added at 09:27 PM ---------- Previous post was at 09:13 PM ----------

But if my AC is going to blow hot air when I am at idle, I am just going to stick with stock pulley for now. What do you think? Will it blow hot air? Cuz that would really BLOW!
 
I know you can buy whatever you need from here - get on the phone with them to figure out what it is you need, then ask them to quote a set. Shouldn't be much more than an OEM set of belts and it shouldn't be hard for them to figure out what you need.

http://www.gates.com/brochure.cfm?brochure=2911&location_id=3107

Once they have nailed down the sizing for you, you can search other brands by size. Using the tensioning bolt, you can adjust +/- a full "size" or more once the belts are on.

Always snags and speedbumps when doing great things, my friend. If it were easy, everybody would do it. You should be totally psyched for a built engine! Take the time to get everything right and it will treat you right.

Nothing wrong with using the stock pulley, but if you do plan to go high HP, then a damper on the crank is a good idea. Insurance on the crank seals of a built motor is a good thing. If you are not making big power now, the OEM pulley will be fine. It would be hard to judge if you would be blowing hot air but I really don't think so. The highest risk places are in the low RPM ranges - like idle - since that's the lowest the AC compressor will be driven. If you spend a lot of time in traffic, the risk is higher but you are not gauranteed to blow hot air even then. It's something you will just have to try unless you find somebody else running the same part.
 
tchuck said:
Whats the point of the over/under drive combo?
Click to expand...

Honestly only ATI knows for sure and if they didn't know what belt compliment needs to be purchased... what good are they?

That being the case, it would only make sense to me if they approached it from a crank balance standpoint. That is, they sized each side of the pulley to get closer to "equal" forces from each belt so there was no load bias to one belt/side. Wild guess and I could be totally wrong about that.

The rest of their damping technology is in the design of the damper itself. ATI uses a mechanical damper, which is said to be more effective at high RMP and less effective at low RPM because it relies on rotational speed to "actuate" the damping mechanism.

http://www.atiracing.com/products/dampers/charts/damserp.htm

Personally I don't have a problem with that because I think it's more important to protect your crank seals from crank vibration at high RPM and the short term wear on them at low RPM is probably fine - I would think not much more than OEM. ATI runs their dampers on many makes and models, but the company's biggest following is in American muscle.
 
jumbosrule said:
...
... it would only make sense to me if they approached it from a crank balance standpoint. That is, they sized each side of the pulley to get closer to "equal" forces from each belt so there was no load bias to one belt/side. Wild guess and I could be totally wrong about that.
...
Click to expand...

That makes sense. Interesting approach, though I would still ask what good it is to have a side to side balance when there is still such a top to bottom imbalance. I need to research this subject more...
 
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