RotorMotor

iTrader: (5)

hey i was wondering what the stock FW weighs? if anyone has one lying around and could weigh it that would be awesome. im trying to break down the weights of the various components as im considering buying teh exedy twin plate clutch/FW setup for my 20b project... but id like to keep the rotating mass to a minimum. also if anyone knows the weight of the ENTIRE stock clutch assembly (FW, pressure plate, clutch disk, etc etc) i would be very interested. i also need to know how much the auto tranny counter weight weighs so i can add it to the weight of whatever clutch assembly i decide on.

also if anyone has used any of the twin plate clutches and can compare them to a single plate clutch with a lightweight flywheel... id be very interested in what you have to say. thanks, heath friedland

adam c

iTrader: (2)

As I recall, it is 19lbs, with no counterweight.

Mahjik

iTrader: (1)

20lbs

adam c

iTrader: (2)

19 lbs ............. noob

Improved FD

if anyone needs a stock flywheel in excellent shape let me know

t-von

iTrader: (8)

oops

poorboyracing

Mahjik

iTrader: (1)

https://www.rx7club.com/showpost.php...22&postcount=7

RotorMotor

iTrader: (5)

gotham is WAYYY off then:
http://www.gothamracing.com/catalog/...roducts_id=505

does anyone know what the rest of the bits in the stock clutch assembly weighs?

RotorMotor

iTrader: (5)

^

adam c

iTrader: (2)

https://www.rx7club.com/showthread.p...70#post5464270

RotorMotor

iTrader: (5)

but does anyone know what the REST of the parts in the stock clutch weigh? im trying to figure out if im going to be gaining weight by using a twin plate clutch setup on my 20b.

KevinK2

I measured weights at ups scale:

20.00 stock fw
13.50 RB steel fw
4.00 cw
12.55 stock pp
12.50 new pp

the driven disc was light, bring a scale to a napa store.

I also determined inertia values. The RB fw with cw, vs stock fw, had 12.5% less weight, and 31% less inertia.

The stock pp had 50% of the stock fw inertia. The pp contributes a lot to the total inertia of rotating engine mass.

RotorMotor

iTrader: (5)

thanks very much kevin... just the info i was hoping for, and then some! so the old and new pressure plates were nearly the same weight but you determined that the differences between the two were quite significant? im wondering why this is? did you factor in PLACEMENT of the rotating mass? there would be a discrepency in the momentum of two flywheels (for instance) that weighed the same but had more of the weight placed closer or further to the center of rotation correct?

while some of these twin disc clutch setups have light flywheels with minimal mass toward the outer edges, the sandwitch of discs etc seem like they would greatly add to the rotating mass of the entire assembly. is there anyone out there who is using one of these twin disc setups, and could comment on how it feels/how the motor responds when compared to say an aftermarket single disc with a lightened FW? sorry i hope that made sense. -heath friedland

KevinK2

I measured inertia values using the compound pendulum frequency technique, and then did the related calculations. This covers mass distribution.

Yes, similar fw weights, but the oem fw includes a 4.6 lb ring of mass just inboard of the ring gear. Doesn't exist on RB fw.

Check supra forums for twin dic fw experience. The multi discs are smaller dia's, and the pp is compact and lighter construction since lower clamping force is needed. I've seen some hard core tilton units in pegasus.