I was wondering if anyone here has done this mod and had there RX-7 dynoed after. I know a flywheel won't add horsepower to the motor but it should allow more power to be transferred to the rear wheels with the lower inertia. Any comments, especially from members with second gen NA's, would be greatly appreciated.

 

i heard it makes your redline higher too

 

There is no increase in redline, but there is a huge amount of difference in reving and power "feel" There is really no more power per say, but you get to your power faster, making it feel like more. It frees up centrifugal weight so you get the more power feel. I had the lightweight steel, but I am going to the AL 9lb'er since I want maximum potential out of our Project 86 engine. The AL flywheels are definately streetable unlike some people say. Heavy traffic would probably suck though

 

Dave,

For Dave's Project 86, yeah Aluminum is the right choice considering what its being built for. As many horses to the rear wheels as possible.

However, loosing inertia in the fly wheel means more slip clutching to avoid stalling the engine. So, if you go Aluminum in your daily driver, expect to have a shorter life in your clutch disk, will have to turn your flywheel with each clutch job (not a bad idea anyway) as your bound to build up heat spots from the clutch slipping, AND it WILL totally suck in stop and go traffic.

Its all tradeoffs, and each person has their own situations that determines which type of flywheel is best. My vote, lighten steel as it is best compromise.

However, I reallllly am interested in the dyno readings for Stock, lighten steel, and Aluminum. Anyone out there with that experience??

 

The guy that sold me my car put a lightweight steel flywheel in my TII. I could not witness the change that it made, but it is perfect for a street/strip car.

 

whats the stock weight?

 

After hearing about the stop and go traffic, I am defenitely going to go with lightened steel rather than aluminum. Stop and go traffic is already enough of a pain in the *** as it is.

 

I had a lightened aluminum flywheel and swapped it for a steel one instead. The alum. one dint get along with my clutch (clutch kept slipping REALLY badly). I think I went with the 17 pound steel flywheel. I like it. Its good for daily driving. I say go for it

 

how about stop and go on a hill? is it easy to control?

 

Stock flywheel is 30#

 

I have the 9.5# flywheel with the ACT heavy duty pressure plate and clutch disk. So far slippage has not been an issue. Less rotational inertia has made it easier to stop the flywheel in it's tracks. Stop and go traffic (Seattle has some of the worse in the U.S.) has not been a problem. Even on some of the hills in downtown in heavy traffic haven't been too bad (but a bit trickier than before). This is a first hand account of what life is like with the 9.5# flywheel. It's better than stock. It makes the engine feel alive, like a sports car should be. The idle isn't smooth like it used to be, but it isn't all that bad either. It feels like my car has lost a few hundred pounds on the top end. Energy that was spent trying to spin the stock flywheel is now put to the pavement. If you are going to go through with the effort and expense of putting a different flywheel on your car, go for the 9.5# one. It takes a little getting used to, but it's well worth it.

jerk_racer@hotmail.com

 

I have the same setup as jerk-racer and agree with his comments. It didn't take long at all to adjust, in fact it's really no big deal. The top end improvement in 1st, 2nd, and 3rd is VERY noticeable. The car drives like it's about 200-300lbs. lighter. The first time you get into it you'll about crap your pants at what it does for the car - it's a nice upgrade.

My idle is solid, by the way.

Personally, now that i've been driving this setup for 2 years I would think a light steel flywheel would be sort of doing things half-assed.

 

each pound of rotational weight you can remove from the end of your crankshaft/Eshaft should be worth 1 HP.

so if you lose 13 lbs off your flywheel, you should see a 13 lb gain at your rear wheels...theoretically speaking.

couple that Aluminum 9 lb'er and some UR/RP pulleys, and see how THAT Feels!!!!

chris