3.9 g6 GXP flywheel

[Joseph Upson]

Pocket Rocket,
The dual mass is a key piece of hardware... just not the stock form of it. I agree why would I put a 290 Ftlb torque limited device in a modified vehicle. I wouldn't. In actuality thats why I started this thread (I think).

After now reading much about them I'm probably going to set about trying to figure out how to have my cake and eat it too....

I think my first step might be to modify the stock unit with a better friction ring. The second step will be to figure out what RPM the thing is tuned for and then figure out what my mods require and tune an aluminum one for that.

I'd be interested though to know what a solid flywheel sounds like.

The other concern I have is that the torque pulses of a modified or high output engine could play complete havoc on the drive train. I'd hate to put all the work into a 500-600 HP V6 and then blow a tranns up by putting it into a harmonic resonance.

I applaud your efforts but I honestly think you are taking this dualmass matter far more serious than GM did. Your concerns are just not supported by a serious enough problem with all of the previous excessively over torqued single mass GM transaxle combos behind existing swaps plarticularly stump pulling V8s.

lb/ft and its rate of onset is what kills these trannies not hp and a dualmass is not going to put you in the safe zone because you're still aiming far in excess of what the transmission is rated for, many of the OE dualmass units across nearly all manufacturers are being fixed with single mass units in performance builds save the few that are not designed to slip.

A lot of these HP builds are using solid clutch hubs (especially the Fiero crew) so there's no telling how much that would cut the failure rate if a sprung hub had been used instead.

I say focus on building your motor and if you have a problem that warrants it, then build a better flywheel.

Here is a brief mention addressing the Ford Diesel problem and a statement which I also made regarding the sprung clutch hub absorbing shock loads on single mass units.

http://www.clutchcityonline.com/dualMassFlywheel.htm

This is a good one suggesting they were adapted from diesel use for benefits other than torque taming in domestic vehicles including noise.

http://www.amsautomotive.com/flywheels_dualmass.php

[NateD4]

All that is true. However even at redline of 7K RPM to make 550 HP you need nearly 413 ftlbs of torque.

I agree on working on the engine build. It should be done in about 2 weeks if all goes well. In the mean time I've gotta get my clutch and flywheel picked out.

Which brings me back to my previous question. Has anyone ever used the 2.8 flywheel geometry with the F40? I'd imagine the recessed splines and different installed height of the pressure plate spring area requires a custom clutch and possibly pressure plate.

Might be easier to just build a replica of the stock dual mass....

[Joseph Upson]

Which brings me back to my previous question. Has anyone ever used the 2.8 flywheel geometry with the F40? I'd imagine the recessed splines and different installed height of the pressure plate spring area requires a custom clutch and possibly pressure plate.
.

Some Fiero 2.8-3.4L with an F40 install kit from V8 Archie. He uses a billet aluminum spacer that bolts to the stock flywheel and uses a Spec clutch assembly but could also use stock with the appropriate 23 splined disc shared by some Ford Ranger and Focus models. I believe it costs as much as a custom flywheel though.

All that is true. However even at redline of 7K RPM to make 550 HP you need nearly 413 ftlbs of torque.

...

Yes but there's a big difference between working your way to 400 lb/ft of torque over a span of rpm range with a turbo V6 than starting off the line with near that much torque on openning the throttle with a V8 and no forward motion at all. The Getrag and Muncie have taken this kind of beating for a while and even the Isuzu has taken its share of punishment in a few swaps. The F40 has a higher rating in a much heavier car so I think you'll be fine.

I used a modified F-body flywheel, tried to post pictures but the drag and drop feature with saved attacments would not work and uploading another pic was taking too long for some reason. There are two pics of it somewhere here on the forum.

[Kenova]

Does the 3.6 in the new Camaros use a Dual mass flywheel? Can it be used behind a 3900?

Ken

[NateD4]

Sorry Joseph you lost me....

There are really only two factors that play into torque the flywheel sees. 1) Available traction and 2) Inertia loading of the flywheel at RPM. No matter how you slice it though the available torque at any given time is the function of: HP = RPM * Torque/5252. Solve it however you want. The max engine out put is the max engine output. Regardless of whether the car is moving or not.

In any rate I prefer not having failures of the flywheel. Hopefully I'll have a few made in the next month or so.

[NateD4]

I suspect the 3.6L use a totally different flywheel and probably even bolt pattern on the crankshaft.

The harmonics of the 3.6 an the 3.9 could be totally different as well, which, is especially critical if they use a dual mass flywheel.

[Joseph Upson]

Sorry Joseph you lost me....

There are really only two factors that play into torque the flywheel sees. 1) Available traction and 2) Inertia loading of the flywheel at RPM. No matter how you slice it though the available torque at any given time is the function of: HP = RPM * Torque/5252. Solve it however you want. The max engine out put is the max engine output. Regardless of whether the car is moving or not.

In any rate I prefer not having failures of the flywheel. Hopefully I'll have a few made in the next month or so.

I agree, but my concern involves the transmission shock loads not flywheel failure, as it relates to instantaneous load. From a mechanical standpoint devices tend to endure exceeding load capacities better with a gradual onset better than instant, stacking 500 lbs on a 475 lb capacity board in four increments vs all at once. There's more science above my level of knowledge regarding the theory but I believe most tranny/drivetrain failures behind the same engine at the track usually occur at the starting line as opposed to mid track and I suppose the missing recipe would be the exposure time to the high load and at what point it's greatest. Clutch dumping with stock motors can break trannies for more relevance to the shock load subject.

I just don't see the need for such a scientific approach to a dualmass flywheel on motors that have performed dependably for decades with a solid unit except for the chatter that results in a 6 speed unit without it, including in the Corvettes.

[Joseph Upson]

Does the 3.6 in the new Camaros use a Dual mass flywheel? Can it be used behind a 3900?

Ken

The proper manual flywheel for the 3.6 can be found in the Cadillac CTS and the appropriate Saab cars with the same engine platform. The first itteration of this motor occured in the Caddi years ago when the CTS was first introduced if I recall correctly, however it was a different displacement.