I have been reading thread after thread on lightened flywheels and I was just curious if anyone has any regrets after having gone with a lighter setup.

I am about to drop my tranny (throwout bearing) and I was contemplating the swap. I am interested in the ACT streetlite flywheel.

I am currently sitting at a little over 360 to the wheels now, but that will increase once I get my streetport done. I do not drag my car (at least not yet) and my car is not a daily driver. Has not seen the track either (contemplating it).

Any useful input would be greatly appreciated...

 

if you are going to drag race, stay away from it. if road racing is what you want to do the lw fw would be better suited for that

 

Here's my take on lightweight flywheels.

First off, I've only driven FC's with light flywheels. But, everything that applies to an FC should apply to an FD as well, if not moreso.

The big problem with light flywheels are they cost a good amount of money (around $300ish), are a big job to install (pull tranny), and really give you about $50 worth of "cool". You will most likely not notice any difference in power itself with the light flywheel - the only advantage it really has is making the car rev much faster.

People who have installed the heavier steel flywheels felt gypped - it's just not enough of a difference, considering the amount of money spent and the effort involved. Definitely get an aluminum flywheel. I've driven both, and you just don't get the bang for the buck with the steel.

I taught an old girlfriend of mine how to drive stick on my old TII. It had a VERY heavy ACT clutch, a street port, and a light flywheel. She didn't have any trouble after she got generally used to it. If you've driven a stick for more than a month, you will not have any problems driving the car with the aluminum flywheel.

Now, if you do stop and go bumper to bumper traffic uphill both ways every day, I might reconsider. That could get old, as you do have to give it a bit more gas when starting out. Otherwise go for it. This is definitely a mod to consider "while you're in there".

The biggest benefit is for rev-matching and heel/toe downshifting. If you can drive a stick well, you'll really enjoy it. That's where you'll feel the difference - the engine will rev up so easy to revmatch on downshifts. Again, don't expect the car to be way faster or anything.

Again, I have FIRST HAND EXPERIENCE with MANY cars on this one. You'll see a lot of people simply parroting what they read on Mazdatrix's website. This is my experience, and opinions from the RX-7 guys around here.

Dale

 

the last paragraph of your post reads like a disclaimer. i guess u need one of those these days.

 

I installed an Exedy 13lb flywheel on my Subaru Impreza (non-turbo, 165hp 165tq). The original flywheel was about 30lbs, so there was a very noticeable difference. I loved it, it didn't take more than a day to get used to the difference. At low RPM's (below 2500), the lightweight flywheel makes you feel like you're driving a car with a smaller engine: you need to give it more gas to get moving. Above 3000 RPM's, the car accelerated noticeably better. Upshifts were faster, because the engine decelerated to the proper speed more quickly. Downshifts were smoother, even when you didn't get the rev-matching exactly right; the engine had less inertia, so it wouldn't upset the balance of the car as much.


From what I've read, the RX-7 has a pretty light flywheel to start with. Dropping 5 lbs from the flywheel isn't going to make the same difference as dropping 20lbs. As Dale mentioned, I wouldn't bother replacing it unless you're already in there. Another thing to consider: a well-designed flywheel will have low inertia in addition to light weight. Look for a flywheel with minimal material on the outer edges, for instance the ACT prolite as opposed to the ACT streetlite.

http://www.rx7.com/store/rx7/fddrivetrain_flywheel.html

^^After reading this page, I'd like to know the weight of the Exedy twin-plate combo.

-s-


edit: don't forget engine mounts while you're in there.

 

My FD will have a light flywheel but I wont finish the car until the end of the month or so. My old n/a FC had an aluminum flywheel, my friends GSL-SE had an aluminum flywheel on his TII engine and my brother has one in his n/a FC. Ive driven all of these cars alot so my "review" is firehand experience like Dale's. All of these are daily drivers as well but none have a heavy clutch.

I didnt have a problem driving my FC after the flywheel install. It was my daily driver and I didnt think it needed much effort to drive around town. Same thing with my brothers and friends car. They both loved the flywheel and said it was one of the best mods done to the engine. They never complained about it being a pain to drive around town or uphills. All of these were aluminum flywheels using stock-like clutch setups.

I dont have any personal experience with FDs & lightened flywheels but the results should be the same. Im sure I'll love my flywheel once the car is back together.

 

A 9lb flywheel is a 9lb flywheel, whether its made of steel or aluminum. Right??

Also $300 is cheap for an FD part

 

i like my aluminum flywheel. it is a bit harder to start from stop though like dave says you need to rev up a little higher.

 

I think he is saying that the steel flywheels are heavier than the aluminum flywheels.

$300 is cheap for an aftermarket part for the FD.

 

if you decide to go for it, I have a brand new ACT street-lite that I don't need. pm me and save some $

 

Yep, I have the ACT 9.5lb and LOVE IT! Don't be scared. It does take a minor adjustment in driving style to get started, but I would never go back.

 

I agree with Dale. Their OK. Not exactly worth the $ or trouble unless you are already doing a clutch job and have some extra cash. If you do get one, go with the 9.5 lb aluminum.... I would if I HAD to do it again.

 

What if I track, autox, drift and drag? (preference in that order) I've been considering the ACT Prolite.

 

You'll love it at the track and drifting since both of these require lots of rev matching. I dont know much about about drag racing but my friend said he liked his car with a heavier flywheel for drag racing. I personally wouldnt take everything apart just to install the flywheel but I wouldnt think twice about installing one while doing a clutch job or any other time the tranny is apart from the engine.

 

i have lightweight flywheel...it def makes a difference in the rev...definately....revving in neutral will shoot up to redline before you can blink...it is def a pain though in stop/go traffic, when letting out on the clutch, about half way out, the car feels like a normal stick shift and starts to move foward, then after about half way if your not aware of the lw fw it will buck and stall, it requires extra gas about half way through the clutch

 

If you're gonna do it, look at the Racing Beat or SR Motorsports ones. They have a replaceable friction disk that can be replaced for ~$80 vs. having to buy a whole new flywheel if something were to happen down the line.

 

I'm running the SR Motorsports 11 lb aluminum unit. I do like the feel of the car with it and it does make downshifts easier. However, I guess that I will go against the status quo a bit and say, for a pure street-driven car, I would stay with the stock flywheel. This goes double for a car used as a daily driver.

 

Ive installed both types for myself and customers.

I have never heard a regret from someone who got the ~12lb steel setup unless they ran a solid hub clutch.

I have heard regrets from people who got the ~9lb aluminum setups, *especially*when running an agressive clutch (any kit using an organic disc is not very aggressive).

I personally hate a 9lb setup though it is tolerable. But if you add a 6 puck clutch on top of that it becomes intolerable, to me. I dont like looking like a jackass or a clutch newbie at redlights, and I dont like having to rev to 1800rpm and make the drivetrain shudder to take off smoothly.

My personal favorite combo is the act streetlite with the act SS clutch. This combo will rev faster than stock and launch well, and hold 450rwhp+, yet it is 100% driveable in the city.

Keep in mind I live in hilly Tn and my driveway itself is a big hill that I have to climb to get to the road, so people in texas might have a different opinion.

 

not all of Texas is flat, just like not all of tenn is imbred

As for the 9lb flywheel and 6puck setup, I will be able to relay firsthand experience of that setup very soon. Didn't want the 6 puck but thats all I could get that wouldn't of taken weeks to get.

 

I'm running the 9lb flywheel and the ACT 6puck unsprung. It grabs no other but does suck when taking off from a stop on an incline. Its tolerable to me. But when it comes time for a clutch job, I'll try using a sprung 6 puck.

 

Dale, with all due respect, I disagree w/ you wholeheartedly.

I actually drove my car for several thousand miles in various conditions w/ the stock setup, then I put a lightened flywheel on. The difference was NIGHT AND DAY IMO. Night and day. Not only was the car incredibly quick to rev match, but I felt a LOT more power in 1st and 2nd. My FD was *noticeably* faster after the flywheel. That's my subjective part. As far as objectivity goes, Rynberg posted a report by Max Cooper from a while back w/ testing results from a regular to lightened flywheel.

From back in '03 (https://www.rx7club.com/showthread.p...7&page=2&pp=15)

50hp TO THE WHEELS in 1st, and 16 in 2nd!!! That's 99.99% of the reason why my FD was pulling SO damn hard w/ a dead tired motor w/ 91K original miles, 9 inHg vacuum, and dying stock turbos

~Ramy

PS: I do agree w/ Dave though that for a daily driver, in stop and go traffic, or getting stuck on a bunch of hills (if you actually DON'T want to ride your clutch), it essentially sucks lol.

 

Ah, don't be a sissy. I daily drove my FD for 3 years in texas with a light flywheel, not to mention removed a/c, and didn't mind one bit

If you are performance oriented, the light flywheel is a no brainer. If you own an FD, you are performance oriented. 'nuff said. [disclaimer: this excludes those who constantly launch their FD]

 

Haha, we all know you're a masochist, Rich.

Anyone willingly removing the A/C while living in Dallas is a few seals short of a good motor.

 

you can rev match just fine on a stock flywheel.

 

No one said you can't do it. But doing it w/ a lightened flywheel is a COMPLETELY diff experience.

I remember when I first had the flywheel installed, I had trouble coming off the line, b/c I'd be up to 4K rpm or so immediately overreving, b/c the flywheel was now MUCH lighter than stock!