[SammYyYyY]

Apologies for the slightly-duplicate post; I posed a similar question on a prior thread but it ended up evolving into discussion of another point.

My car is getting a BTR Stage 2 cam soon. I have all supporting mods figured out at this point other than a lower harmonic dampener/pulley.

Is the stock dampener a reliability hazard at 7k-7.2k RPM? If not, and I do a lower harmonic balancer, is there a mild lower pulley I should do? The car has a stock, unported blower, so I assume the stock pulley size is likely best but I thought I should check.

Thanks all!

[SOCAL.M6.ZLE]

Hey Sammy... lots of benefits to the ATI damper... I would consider it a no brainer when doing a cam. I suggest starting with an 8.8" lower pulley which is only 10% OD, and will help offset the loss in boost from your head and cam package. Once you are ready for more power... you can easily change lower pulley for more boost.

The ATI damper eliminates dangerous torsional crankshaft vibrations... and does so with 40% less weight then the OEM.

https://www.griffin-motorsports.com/...4-lower-pulley

[Joshinator99]

Originally Posted by SOCAL.M6.ZLE

Hey Sammy... lots of benefits to the ATI damper... I would consider it a no brainer when doing a cam. I suggest starting with an 8.8" lower pulley which is only 10% OD, and will help offset the loss in boost from your head and cam package. Once you are ready for more power... you can easily change lower pulley for more boost.

The ATI damper eliminates dangerous torsional crankshaft vibrations... and does so with 40% less weight then the OEM.

https://www.griffin-motorsports.com/...4-lower-pulley

Agree 100% on the ATI. Been using one on my stock LT1 crank with well over 1000 HP for going on 6 years…

[SammYyYyY]

Originally Posted by SOCAL.M6.ZLE

Hey Sammy... lots of benefits to the ATI damper... I would consider it a no brainer when doing a cam. I suggest starting with an 8.8" lower pulley which is only 10% OD, and will help offset the loss in boost from your head and cam package. Once you are ready for more power... you can easily change lower pulley for more boost.

The ATI damper eliminates dangerous torsional crankshaft vibrations... and does so with 40% less weight then the OEM.

https://www.griffin-motorsports.com/...4-lower-pulley

Gotcha! Consider it done then.

For a road course car with stock heat exchangers, do you think the 10% OD pulley is going to create heat-soak issues? Or do you think it should be alright. I'm open to either option.

[PowerDemon]

If you wanted to keep the stock boost level, does anyone offer a stock sized dampener?

[SOCAL.M6.ZLE]

Originally Posted by PowerDemon

If you wanted to keep the stock boost level, does anyone offer a stock sized dampener?

Not that I am aware. 8.6" to 8.8" is the smallest I have seen. Keep in mind, thats only a 10%, so a stock car will gain less that 1 pound of boost. A cammed car would likely gain zero, as it will loose boost due to added efficiency.

[SOCAL.M6.ZLE]

Originally Posted by SammYyYyY

Gotcha! Consider it done then.

For a road course car with stock heat exchangers, do you think the 10% OD pulley is going to create heat-soak issues? Or do you think it should be alright. I'm open to either option.

Yikes, I think the OEM HX sucks... and even a stock car would benefit from an upgrade if racing... but depending on your fuel, and climate, you'd want to data log to see if IAT's are an issue.

If you were not already planning to upgrade your HX during your cam swap... I suggest you highly consider.

https://www.griffin-motorsports.com/...heat-exchanger

[christianchevell]

DSX makes a custom turned stock diameter pulley at a reasonable price, I am running a 8% overdrive on my ATI its what they Chose of my pulley choices at Rater R tuning in San Antonio. I also prior had installed all kinds of stuff like Speed engineering set of intercoolers and a nice screen to protect them..LOL I am running the stage two BTR cam, its got good lope when they tuned it for cold idle, as with any larger cam its harder for the brake vacuum down low so its just a little harder to stop at idle. They recommended a Converter with it but with none out there its still fine, feels like it is a Panther ready to pounce at a stop light. I did go with a 2650 though, and it sounds like the mild whistle of Blowing over a glass bottle when it does whine compared to the 1740, I do have the 1k DSX lid though.... with what I gave them I got 770 HP and 769 TQ on 92 octane form Oregon...Very happy with it.

[Megahurtz]

If you're tracking the car, don't overspin the blower more than about 5% or you're just going to have problems. Regardless of upgrading the heat exchanger, you are still limited to the bricks in the blower itself to transfer heat during track duty. You would really be better off getting the blower ported and doing a very mild 2.45 upper for a 2% over drive. If you can run flex fuel and get to E30, then going to a 2.38 (5%) upper would be perfect.

You would gain a lot of power up top simply by having the blower opened up and a 103mm TB and big intake so that the Cam can breath. The pulley change is to bring the torque in a bit sooner as porting the blower shifts the power to the right.

[JSH]

I destroyed the alum ATI Super Damper on my previous motor and am using a steel shell damper now.

[SammYyYyY]

Originally Posted by SOCAL.M6.ZLE

Yikes, I think the OEM HX sucks... and even a stock car would benefit from an upgrade if racing... but depending on your fuel, and climate, you'd want to data log to see if IAT's are an issue.

If you were not already planning to upgrade your HX during your cam swap... I suggest you highly consider.

https://www.griffin-motorsports.com/...heat-exchanger

Fair enough! Yeah, I'm kinda at the limit of my budget unfortunately, so I don't think I'll be able to do the HX right now.

I should clarify that when I say I road course my car, it's nothing competitive. Just 1-2 amateur track days per year, weekend warrior car that I rip in the mountains otherwise.

So to clarify, would you expect a 10% lower with a cam to heat soak any WORSE than a stock cam on a stock pulley? I want to do the harmonic balancer for the reasons you cited, but am not looking to make the car unusable with the stock HX if that makes sense.

[SammYyYyY]

Originally Posted by JSH

I destroyed the alum ATI Super Damper on my previous motor and am using a steel shell damper now.

Could you provide some details on what kind of dampener that is and where I could pick it up if I went that route?

[JSH]

Originally Posted by SammYyYyY

Could you provide some details on what kind of dampener that is and where I could pick it up if I went that route?

ATI, see their site