Single Mass Flywheels

[Karl]

Originally Posted by A26B

I had new, aluminum billet flywheels made to the same dimensional specification as the stock, iron dual mass flywheel. They are available in 18# & 22#, the idea being to fill in the gap between the ultra light 13# flywheels (Fidanza, McCloud) and the stock dual mass weighing in at 35#+.
NOTE: The 18# & 22#, will readily use the stock clutch system disc, pressure plate & release bearing and retain the exact same fork geometry as the stock flywheel.

If you are looking for a lighter flywheel and keeping your stock clutch then either of these will work for you, especially if you are looking for a little more mass than the 13# units.

That is what I thought.

Thank you!

[Karl]

Originally Posted by efnfast

Karl, read my thread. I have a black tag 90.

I read it a long time ago.

Just double checking.

Going with one of Jerry's units.

Thanks.

[-=Jeff=-]

Jerry do you suggest a sprung hub disc with your 22# flywheel?

[A26B]

Originally Posted by -=Jeff=-

Jerry do you suggest a sprung hub disc with your 22# flywheel?

It depends on the power level and what type of use the car will see, rather than the flywheel. A sprung hub will absorb engagement shock better than a solid hub thus provide more drivetrain protection than a solid hub WHERE HIGH LOADS OCCUR, i.e. with significantly higher power output than stock. If the car will see frequent strip use with drag radials or slicks, I would recommend the 900/300 series disc with sprung hub. We do not stock this disc, but it is readily available from RAM.

For street/strip use (street tires), I would recommend the 300 series disc, sprung hub or solid hub, with Marcel carrier. We stock the RAM 11" 300 series solid hub disc, with a Marcel carrier for use with the stock pressure plate. The 300 series disc uses organic facing for a smoother engagement.

Intended use and driving styles make clutch choice subjective. With so many combinations available, disc types, facing material, sprung or solid hub, flat vs Marcel carrier, it can be difficult to decide. What one driver thinks of as spirited can be seen as hard driving by another.

So, there is no pat answer for all drivers and applications. It may be worthwhile to choose a higher load capacity clutch than actually needed to better insure the outcome. Just remember that the closer you get to building a race car, the less comfortable driving on the street becomes. (Ask me how I know that. )

A good read, scroll down to the clutch discs.
https://www.ramclutches.com/images/catalogs/cb2010.pdf

[HAWAIIZR-1]

Originally Posted by A26B

Karl,
The RAM 13# Flywheel requires RAM Pressure Plate, Disc & Hydraulic Release bearing, i.e. the entire RAM conversion from "pull-release" to "push-release."

I had new, aluminum billet flywheels made to the same dimensional specification as the stock, iron dual mass flywheel. They are available in 18# & 22#, the idea being to fill in the gap between the ultra light 13# flywheels (Fidanza, McCloud) and the stock dual mass weighing in at 35#+.
NOTE: The 18# & 22#, will readily use the stock clutch system disc, pressure plate & release bearing and retain the exact same fork geometry as the stock flywheel.

If you are looking for a lighter flywheel and keeping your stock clutch then either of these will work for you, especially if you are looking for a little more mass than the 13# units. They are good alternatives for replacement of the stock dual mass units, which are expensive and becoming more scarce. Being heavier than the really lightweight units should dampen the engine impulse a little more and result in corresponding difference in transmission rattle.

Hey Jerry,

I'm glad you posted about these flywheel options. What are the differences between the 18# and 22# other than 4# difference? I was about to send in a stock dual mass to Jim J for resurfacing, but really hate how heavy stock is. I definitely never want to consider a Fidanza again as I don't like the sound of all that rattling. Do you have any customers with the 18# or 22# that we can consult with about rattle?

Thanks,
Craig

[Paul Workman]

To help mitigate the rattle when using a 13# (Fidanza), the following steps together resulted in almost completely eliminating (you be the judge) while retaining the stock PP:

Camaro, sprung hub disc (Summit) part #381039
Increasing the idle speed to 850-900 rpm
Accel injectors #150821

Also, unrelated to the noise issue, an ARP bolt kit and tap was purchased. The purpose was to facilitated drilling and tapping the holes in the FW to approx 1+" to give the bolts a little more purchase due the aluminum vs. cast iron to secure the PP to the FW. I also used new Grade 8 bolts and red Lock-Tite to secure the FW to the crank. All GOOD for 6 seasons now w/o issues.

See what you think:

https://www.youtube.com/watch?v=y1YFa8ruh8A

Note: At the time this video was shot, it was 21ºF and the transmission was cold, and filled with synthetic Castrol TWS which is no longer available. It now has Redline Shock=Proof (HD) synthetic, which seems to work about the same as the TWS, far as I can tell.

[A26B]

Originally Posted by HAWAIIZR-1

Hey Jerry,

I'm glad you posted about these flywheel options. What are the differences between the 18# and 22# other than 4# difference? I was about to send in a stock dual mass to Jim J for resurfacing, but really hate how heavy stock is. I definitely never want to consider a Fidanza again as I don't like the sound of all that rattling. Do you have any customers with the 18# or 22# that we can consult with about rattle?

Thanks,
Craig

Hi Craig,

Re: Motive behind the 18# & 22# weights;

18#: (1) Same physical dimensions as dual mass unit & (2) as light as practical, given the dimensional requirement.

22#: (1) Weight inspired by the single-mass, iron flywheels produced by Doug Rippie many moons ago. Many years ago, Doug acquired Camaro single mass flywheel castings & machined the mounting flange for the 8 bolt LT5 pattern. They were very popular, but now very unusual to find one. (2) Having another choice to help bridge the gap between 13# & 37.5# to allow better flywheel mass tuning for driver preference.

Other than 4 lbs, there is no difference.

Re: Customer reference for noise mitigation with 18 & 22# flywheels.
We only have one 18# flywheel sold to date. That sale was to a European customer. Unfortunately, I can no longer access the sales record details to try & contact him to ask about transmission noise. I do remember that he wrote back to say the install went perfectly and he liked it very much. Transmission rattle was never mentioned.

[-=Jeff=-]

So for a stock HP set-up If I needed to swap the dual mass I would do the 22# flywheel with sprung hub disc. That way I have some Dampening

[XfireZ51]

Originally Posted by -=Jeff=-

So for a stock HP set-up If I needed to swap the dual mass I would do the 22# flywheel with sprung hub disc. That way I have some Dampening

That's what I have been using w my Fidanza. It's a Camaro LT-1 sprung hub disc.

[Jitse]

The # 18 single mass flywheel ( sold too the europe customer).
Is running smooth, just a little bit noise, but not something which is irritating. The idle is moved up to aprox. 850 rpm.
The guy and I am happy with it, can recommend it. My own Z has the fidanza, but if I ever need a new one its gonna be the #18 from Jerry.