drbooba1

Man there is a tremendous amount of truth in your thread RK and I don't think anybody will try to cut you out of the Market so lets have a come to Jesus on this. I have an extensive dyno facility and I would be interested in more Facts, there are some dampers out on the market and Viscous are at the bottom of the list lets hear who Dynoed it and what test parameters and how about posting the torsional graph.
It is not my intent to provoke here but this is a serious matter and it could move the development of the longer stroke big bore engines into the realm of possibility.
Once again I apologize for the frankness of this post but these are not trivial matters to some of us.
regards

RKAutowerks

Let me discuss internally how much we can share and good catch on the typo in there. The damper is a custom ATI super damper, so no fluid in it. It's sized orings. I fixed it in the original post. Somethings were copied from previous work... Sorry about that!

CRex

Most interested, but like others have said, I need to be convinced with provable facts. It's an eloquent writeup but the proof is in the eating...

Ur20v

Hi James,

I use SKF vibration analysis equipment and accelerometers, you? I have been considering running some tests and some strain modelling for a while as I believe you are correct with the destructive forces and outcomes we see.

I think I might run the test at my local dyno and then do a back to back with your solution and see the benefits.

Have you got the data to show the the delta pre and post RKAutowerks harmonic damper you can share?

Were the tests done on your 3.6 or 4.2 and from both ends of the crank?

Cheers
Jay

TAI2

Love to learn more along with engine test data........

Mvez

Figured it was an ATI, great piece.

So basically, it's not the DE that is causing the real damage, it's driving to the DE that's causing it. Extended highway cruising at 3000 RPMs.....makes me glad I've always towed, and rarely drive it on the street.

Hopefully you can post some data or graphs, but it sounds like you did things the right way. As long as the same internal O-rings can be used for the 3.6, 3.8, and 4.0....then all should be good.

a_Y

Subscribed!

AudiOn19s

Subscribed.

Note to self...drive back and forth to the track this weekend as if at the track.

Mvez

LOL, I was just thinking the same thing, as I have to drive over to my shop for service. Excuse to be a hooligan on the street.

RKAutowerks

Working on it. Will have more by the end of the week

Will send you a PM Jay...

Yes it's the low rpm that is causing the issues. Hence you don't hear much about cup cars spitting out bolts, 4.0 cup cars, have, but not as prevalent as the street cars...

andrew2008

Is this an issue for stock engines? There must be some kind a resonance that causes
engines to break at low rpms. There have been a lot of street miles put on a lot of
GT3's and I haven't heard of this problem.

If I was doing a 4.2L build, I would definitely look at something like this. I'm just
wondering if there's any evidence that this would help either performance or engine
life in a stock engine.

m42racer

Alot of street engines have had Crank Pulley bolts come loose and the Cam Actuators bolts back out.

check some of the other posts. nd these are just ones that we read about here.

andrew2008

Yes, but the vibrations causing bolts to come loose may be different from those which
cause major engine damage. For major engine damage to occur at low rpm there's probably
some resonant buildup of energy, and this is what a harmonic damper would fix.

facelvega

Pulley replacement DIY here.... The most controversy seemed to be how you hold the crank in place while you tighten the bolt; might want to include a specialty tool in the kit (easy/cheap to make).

m42racer

This is the problem I understand from reading the post about these failures. There are different failures and the results show bolts coming loose and pump gears breaking.

I have not read of any engine failures in GT3 engine other than these. I had an engine fail at the track after only a few laps. The engine was removed at the dealer and a new one installed under warranty. The engine was shipped back to Germany and I never knew what went wrong. What I do know, the Oil Tank was "empty" and all the Oil was in the engine. This happens when the Oil Pump ceases to work correctly. I'm thinking the pump gears broke as explained in the long post. The 2nd engine had the actuators come loose twice. The same one. Passenger side Intake.

I'm not an expert but I have to think that they are all interconnected. The problem has to stemming from the same cause. Whatever the vibration is and at whatever RPM, it has to be the cause for all of these problems.

BTW, I have had my fair share of these sorts of problems. I had a 6 Cyl Panamera and it broke the LHS Intake camshaft in two. I was told by the dealer this had happened before. They had a campaign to remedy this along with different actuators. Seems the GT3 is not alone.