Downloadable PDF's:



Application Guide

Spline listing

Clutch Install. Instructions

Hydro-MAX Install. Instr.

Reverse Mount Starter
Installation Instructions

Crank Walk

PowerTrain Technology
Flywheels, Flexplates & Reverse Mount Ring Gears

Chevy SB V-8 Early Model ('85 & earlier)
& V-6, 153T

also available for:

Chevy SB V-8 Late Model ('86 & later) 153T
and Ford SB V-8 157T


Low Moment of Inertia (M.O.I.) flexplates are a way of getting a lightweight racing clutch mounted on your racecar, while using a starter located in the stock location, turning a stock diameter ring gear. These flexplates are used in combination with a lightweight button style flywheel that is approximately the same diameter as the racing clutch being mounted. The flywheels are called button style flywheels due to their small `button-like' size. Button flywheels & low M.O.I. flexplates are lighter than a one piece flywheel. They are lighter in price as well. If your rules dictate a stock diameter ring gear, this set-up has a high level of performance and a lot of `bang for the buck'.

PTT's Low M.O.I. Flexplates are engineered to make the most of lightweight racing clutches. These flexplates vary slightly by application, but all of them have reduced thickness, premium quality, and hardened ring gears. The reduced thickness translates to lower rotating weight & faster acceleration, while still offering great reliability & long life. They are robotically welded to a steel center plate made from a high tensile, fatigue resistant alloy that is perfectly matched to high r.p.m. racecar use.

Flexplate, RM-RG & Flywheel Catalog - PDF file 238K


Reverse mount ring gears (RM-RG) mount onto the clutch cover with the clutch bolts. They are used with a reverse starter mount bellhousing instead of a flexplate. The RM-RG's for the 5.5" and 4.5" clutches have a scalloped adapter that reduces static weight and greatly reduces M.O.I.

Flexplate, RM-RG & Flywheel Catalog - PDF file 238K


Lightweight button style flywheels are a way of getting a lightweight racing clutch mounted on your race car. They can be used in combination with a lightweight flexplate (if using a starter in the stock location with a stock diameter ring gear), or with a reverse mount ring gear (if using a reverse starter mount bellhousing).


PTT also offers custom manufactured flywheels. If you have an engine or chassis combination that you would like to install a racing clutch into, please feel free to contact the engineering department at PTT for a high performance solution that is right for you.

Flywheel shown: Mitsubishi, 7.25", 2.0 ltr., I4, 106t, 2 pc., 6 bolt

7.25" Racing Clutches Catalog - PDF file 757K

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