MelloYellow

Anyone ever replace their stock damper for an aftermarket 'improved' damper with better balance? They claim the stock damper isn't very effective above 3.5k rpm and results in more bottom end stress/wear?

They seem pretty damn expensive..
True? BS? Important for superchargers?

TIA

<small>[ March 22, 2002, 09:39 AM: Message edited by: MelloYellow ]</small>

Colonel

Stock dampners are fine below about 6800, IMO. Aftermarket dampners only start to shine above stock ones over 7000.

MelloYellow

Thx.. I figured they were blowing smoke. $400-500 for a damper. Ouch!

The company does sell a nice LS1 on the car Crank Key Kit tho for $120. I'll just key the stock damper.

SJH

well I don't know where you came up with that one Colonel, but I have to respectfully disagree with you bud.
Course that's Just Me <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
Comparing one of these things to a stock damper or ASP damper is like comparing whipped cream to shiznit.
You have got to realize the hp these things make over stock is from smoothing out the engine operation of the incredibly harmful torsional forces at work.
The mere fact they can usually make 30hp or so over an OEM damper at 7000rpm+ all from a smoother operating engine is quite a feat.
Putting a better damper on your motor may not give you a lot more HP but your motor will surely appreciate it in the long run!
Heck the money you guys blow on your motors, I am baffled why you would not use one <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
I understand for dragracing it's not a big deal. Not everybody only drives their cars 10 or 9 secs at a time though <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> .

They are used on nearly every professional Winston cup race car etc etc.
more info-
http://www.atiperformanceproducts.co...rs/dampers.htm
Steve

LS1derfull

SJH, all dampeners have a range of key operation, stock works at low speed, where detonation usually occurs and where most of engines time is spent. This makes it effective for most Ls1's, if you are trying to say there is "miracle works better every where" dampener than it would be Fluiddamper, not ATI style.

SJH

exactly, at high rpm's fluid dampers are not even in the same league.
Fluid dampers are nice street dampers.
I am not sure if there is such a thing as a ls1 fluid damper though.
ATI uses a dual damper design. One for low and one for high rpm harmonic reduction.
Still much better than the single ring OEM cast iron unit IMO.
But with a lot of guys turning 7000rpm now with ls1's , this is a viable option for their motors.
The more power you make the more the harmonic damper becomes an issue as the torisonal forces imparted to the crank are increased as well.

MelloYellow

Interesting..

So the gains would be at 6500+ mostly?

Colonel

So Steve, you don't think that the stock damper is ok below 6800? And you don't think that the aftermarket dampers really start to show benefits over the stock dampner only at high RPMS? So, one would GREATLY benefit both in HP and longevity from using an aftermarket damper even if they were only turning say, 6200, correct?

I'll have to find it but I've read some testing and the stock damper was actually BETTER at supressing vibration over the ATI below 6800.

"The mere fact they can usually make 30hp or so over an OEM damper at 7000rpm+"

I have an ASP pulley which I'm quite sure isn't as good as the factory damper for cancelling vibration since really it is mearly a pulley. So if it's a FACT that I should pick up 30 HP at 7000 RPM just by changing from a stock damper to an aftermarket one, then might I pick up even more since now I only run a simple underdrive pulley? Greater than a 30 HP increase at 7000 on my engine from a damper change...I'd have to see that. If that indeed is a fact then I'm REALLY missing out!

"I understand for dragracing it's not a big deal."

If it'll get me 30 HP or even 15 HP then it's a big deal to me. Unfortunately, the guy I spoke with at ATI couldn't guarantee me that I would pick up even 1 HP (he said they've never done any dyno testing on LS1.) Longevity was his selling point.

<small>[ March 25, 2002, 10:42 AM: Message edited by: Colonel ]</small>

Colonel

Here is a little more info to fuel the discussion. From ATI's website...

"Your car will run as fast or faster than with your present damper or your money back. Dyno tests have proven the Super Damper will allow the engine to produce as much as 45 HP over a Fluidampr at 7500 RPMs and commonly 12 to 30 horsepower over OEM and other aftermarket brands."

<img src="http://www.atiperformanceproducts.com/images/dampercharts/dchart.gif" alt="" />

Colonel

And this from Fluidampr...

"Over the last year or so, we have been asked by many users and dealers to explain the ATI advertising, which says Fluidampr® is inferior. We thought it might be useful to provide you with ALL the facts and let you decide.

In the ATI ad, the "y" axis (vertical or amplitude) side of the chart is labeled as "Crankshaft Displacement Deg/Sec, RM2". This is a measurement of torsional velocity, not the actual torsional twist.

The ATI chart also leads the reader to believe that bad vibrations occur on the small block Chevy engine at over 7000 rpm. This is not always accurate. Depending on the mass elastics of a small block Chevy engine, generally the worst orders of vibration occur in the 4000 to 7000 rpm range with or without any damper installed.

We thought we would go back to the field and reapply our expertise and do more testing. After all, we developed the Fluidampr by actual torsional tests at 42 locations around the country with different engine combinations from June 1985 to January 1990. Some of these tests were conducted at the request of the engine factories at their designated facilities.

The actual torsional test results are from a slightly detuned 600 hp Winston Cup Chevy 350 engine which had many parts supplied by Hendrick Motorsport. We wanted to compare torsional vibrations using similar size dampers. For example, compare the 6 1/4" Fluidampr with the 6 3/8" ATI damper. The Fluidampr outperformed the ATI damper on all orders of vibration."

Seems these two disagree. <img border="0" alt="[fight]" title="" src="graemlins/gr_punch.gif" />

SJH

don't know Colonel how it all translates to real life Hp increases.Your guess is as good as mine.
It's a superior damper to oem or an ASP that is for sure though.
Not to mention it is SFI certified also.
The asp damper has a much smaller than stock inertia weight and is much smaller in diameter.
They have to do this to run the large underdrive % because ls1's run off the outer circumferance of the damper unlike most motors which the drive pulleys bolt to the damper.
This alone will change the rpm range at which it is effective.
The asp is still also a damper though. It has a rubber ring separating the hub and pulley.
The ATI dampers are basically 2 dampers in 1.
They use a 4" and a 7" damper in 1 unit.
This gives it a wider operating range than a single ring damper.
<img src="http://www.atiperformanceproducts.com/images/dampercharts/figsd.jpg" alt="" />
I won't get into a fluid damper vs ati Damper debate.Every manufacturer claims to have the best products.
But look at what the Pro's use for a clue <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
A stock cast iron damper revving beyond 7000rpm is also taking a chance IMO. I have no idea how high they are rated to spin but that's well above what the factory intended limit is I am sure.
Especially on a nonkeyed crankshaft.

Steve

SJH

You would not be able to direct compare an asp pulley to ati.
The asp undedrives the accy's much more than an ATI.
The proper way to do this test would be with no drive belt and use an electric water pump to show gains made by harmonic dampening only and not gains from underdriving accys.