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Triumph TR6 - Lightening Flywheel

Hi Folks,

I'm going to lighten my Tr6 flywheel that currently weighs
in at a hefty 30lbs down to about 20lbs.

Does anyone have a Tr6 Competition manual that tells you where to remove the material from the flywheel?

Any thoughts or ideas would be appreciated!


A. Berzins

Here it is word for word .
"The flywheel can be lightened by approximately
four pounds by cutting away the material on the
engine side." He goes on to recomend an aluminum
type flywheel.That is available from Moss
or VB.
Christopher Trace

Thanks, Chris! I was hoping for a bit more insight from the Comp. Manual - but oh well....


You might take a look at this. It's cheaper than aluminum.
L Anderson

Thanks Curt!

I will follow up on this. An interesting design to reduce weight - the oblong holes.

Aivars Berzins

I recently purchased an aluminum flywheel mfg'd by Fidanza from a guy on eBay that has a really good track record selling these items. I guess he bought a gross of them from Fidanza and sells them much cheaper than the catelogs. I got mine for $325 US and it arrived on time and well packaged etc. On eBay just search for "TR6 Aluminum Flywheel" and you should see the auction history. The Fidanza wheel looks like a piece of jewelry - just a beautiful part - light as a feather. Can't wait to install.

John Parfitt

What's the word on the street about the longevity of these Fidenza's over stock?
Rick Orthen

I'm planning to lighten mine this winter but I like the look of the one on the web site I listed earlier in the string. Lightened steel instead of aluminum and cheaper.
Curt Anderson

Talk around to mechanics who know alittle about road racing and the aluminum one they say is to light for the street.

Don--What are the concerns with it being "too light?" Greater mechanical stresses due to undampened rotational vibrations and quicker engine spool-up? I'm a bit skeptical about it since if it is so great, why not a lighter stock flywheel to begin with?
Rick Orthen

The lighter the flywheel, the trickier the launch from a stop. There are two reasons for the TR6 being such a brain dead launch, lots of low end torque and that heavy flywheel providing lots of inertia in the form of rotating mass. The marblepea take on all of this for a car that is an occasional driver/toy without alot of heavy stop and go usage, you can get away with an aluminum flywheel. If on the other hand it is a daily driver/commuter or if even that occasional usage is in heavy stop and go stuff, aluminum might not be such a good idea. Lightened steel or left stock would probably be a better option in those situations.

I too have purchased a fidenza aluminum flywheel - havent yet installed it but cant wait! From a driveability standpoint it doesnt matter whether your flywheel is aluminum or steel it is the weight of the unit that makes the difference. A lighter flywheel may or may not make launching more difficult depending on the weight - I have read many accounts on the web of people swapping to lighter flywheels (honda, BMW etc) who are very happy with the results and do not report negatively. Another source for flywheels is Ted Schumacher I think at TSI on the web $310 USD. - I think if it costs 275 to lighten a stock steel one you are better off to buy an aluminum one which will be stronger and will have some resale value.
Ready gents - start your engines...!

Aluminum Flywheel Driving Experience - In my younger, less sensible days I did a stupid thing; I purchased a used 1987 RX7 Turbo II with the Stage III HKS fuel and boost controller computers, big intercooler and an aluminum flywheel. At 300 hp it ate Porsche 944 Turbo's (and of course mid 80's corvettes) for lunch. Anyhow, the aluminum flywheel caused the engine RPM to drop quickly and sharply after backing off the throttle. A heavy, factory flywheel has more mass and inertia to keep the engine rotations from dropping that quickly. The sensation was one of "sharper throttle response" in both directions and most importantly, with the revs dropping quick it made high speed gear changes easier. Driving in traffic was no problem because the engine was so powerfull. I think if your running a TR6 with 100 ft/lbs it might be a problem in stop/go. But if you'v got 150 ft/lbs it won't be a problem.
(For the eplogue to the RX7 saga see tomorow's post...)

John Parfitt

When you let off the throttle with a very light flywheel you bettet have you seat belt tightened. The rotating of that tractor flywheel helps slow the car down with less stress on the driver. I had my stock one lightened by about 7 pounds. And I didn't spend no 275.00. I think it was around $100.00.
Don K.

I'm running a stock flywheel that I had lightened by about 7 - 10 lbs as per the comp. prep manual. I ran it for two summers and I find the "light flywheel effect" not very pronounced compared with an aluminum wheel. Based on some of the history books I'v read, the origins of the TR6 engine are based on Massey Ferguson tractor designs with very heavy flywheels designed to aid low rpm operations.


John Parfitt

Not a good idea to experiment here- if that lightweight flywheel bursts at high rpm look out for your feet ( or your passengers).
Peter Cobbold

Peter- Ted from TSI had that same advice for me. I guess I like to gamble.
Don K.

I talked with Fidanza and they say RPM's at about 8,000 and up warrant a scatter shield. Product liability wise thier not worried about flywheels breaking up at 6,500 rpm. (I ordered my steel toed work boots anywhay - and a set for my passenger. Just kidding - it is a point well made.

John Parfitt

This thread was discussed between 26/07/2002 and 30/08/2002

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