austinsFD

Just starting a few days ago when its really cold at night and I driving my car,and when I floor the RPMs get up to 4 or 5k fine when all of the sudden my rpms fly up for around a secound or two (with no extra power) and then they fall back to what the engine is really pushing what do you think it is?

thanks

austin

FormerPorscheGuy

Yup, sounds like the clutch is slipping. Time for a new one.

austinsFD

what model should I buy?

Kento

https://www.rx7club.com/search.php?s...der=descending

adam c

iTrader: (2)

Just to confirm, you do need a new clutch. You have a lot of choices. If your car is stock, and you want to keep it that way, the OEM clutch is the way to go.

If you are going to (or already have done) some performance mods, you should consider getting a light weight flywheel to install when you put in the new clutch. Most of the light flywheels are about the same quality, and are 12 lbs with the counterweight. I chose to replace my flywheel and clutch at the same time. The ACT SS clutch was my choice. It has a slightly siffer pedal pressure than stock, but is not too stiff. I have been very happy with it. I don't expect my future mods to exceed 350 rwhp, and this clutch should be good for much higher than that.

austinsFD

I will be modding this alot heavily

SNracing

what about the 9lb flywheel? is it to light for street driving/racing? and is there a big diffrence in the 9lb. and the 12lb?

adam c

iTrader: (2)

My flywheel is 9.5 lbs. The counterweight is about 2.5 lbs. That's 12 lbs. Some companies don't include the counterweight when listing the weight. A counterweight is required with a light flywheel.

Mahjik

iTrader: (1)

That's also because the counter weight isn't part of the rotational mass, so in actuality, it shouldn't be counted.

adam c

iTrader: (2)

The counterweight has to rotate with the flywheel. How can it not be considered part of the rotational mass, when it is rotating? The counterweight and the light flywheel replace the stock 19 lb flywheel. That's 12 lbs to replace 19 lbs, or 9.5 lbs + 2.5 lbs to replace 19 lbs. Its the same thing.

Some companies, like Racing Beat include the weight of the counterweight when advertising. Some, like SR motorsports don't include it.

Mahjik

iTrader: (1)

Here's a good explaination about it:

Here's the thread if you care to read it:

https://www.rx7club.com/showthread.p...hreadid=166449

adam c

iTrader: (2)

I believe that the counterweight does spin with the flywheel. Since the bulk of it's weight is closer to the eccentric shaft, it doesn't supply much inertia. However, it is still some mass that has to be rotated.

SNracing

whats the diffrence then?

here, one is steel, and the other is Aluminum.

http://66.216.67.51/product.asp?0=206&1=242&3=228

http://66.216.67.51/product.asp?0=206&1=242&3=573

steel 1 says that it includes the counter weight. so im guessing its 12lbs w/ the counter weight.

Aluminum says 9lbs w/ counter weight so isint it 9.5 w/ the counter weight?

and back to my question, if this info is correct, is the 9.5lb to light for street driving/racing.

Mahjik

iTrader: (1)

It's not too light for street driving. The only downside (if you call it a downside) that you need to slip the clutch a little more than normal to get the car going from a stop.

adam c

iTrader: (2)

With a light flywheel, the engine will slow down more quickly. This is particularly noticable from a stop. It just takes a little getting used to. Just a little more gas, and slip this clutch just a hair more like Mahjik said.

rynberg

It should be pointed out that if you are an avid drag racer or street race from a dig, a lightweight flywheel is NOT desirable. It depends on what you want to do with the car.

When I burn out the current OEM clutch, I will be going with a lightweight flywheel and the ACT S/S clutch. If you are planning on going single, you may want to get the ACT S/S clutch disk with the Extreme pressure plate instead of the heavy duty one.