Aftermarket Flywheel Choices
 

Hi guys, I'd like to hear from those of you who have switched over to a lightweight aluminum flywheel. I have thought about doing it in the past but was never high on my priority list but now that I've got the engine out I figure I might as well. What brand/model did you go with? Any pros & cons from your experience. ROI factor...worth it? One thing I'm trying to avoid is the noise/chattering that's often associated with having a lightened flywheel. I've got one in my DD and I can hear it everytime I'm just taking it easy driving on city streets or coasting it's kind of annoying. I've been out of the RX-7 world for over a decade I'm sure lots of stuff have changed. Any helpful feedback would be appreciated.

[Unpopular Opinion]

The stock flywheel is light enough, an even lighter flywheel will make your car drive worse and not give much performance benefit

^ Unpopular b/c it’s not entirely accurate IMO. There are performance benefits but there are downsides. The stock FW was optimized with stop n go traffic in mind. If that’s where you drive a lot I’d keep it too. My experience cons are low speed/low gear balk, higher rev’ing standing starts which intuitively increases clutch disc wear. Pros...rpm drop between shifts with quicker accel.
For a streeted car I wouldn’t go lighter than about 11 lbs. on the FW itself. You will need a counterweight from a auto FD. Visually there’s not much difference between the FD and FC counterweights so I’d either source a new one from a reputable vendor or a used one from a knowledgeable member with a good trader score.
I bought a used aluminum SR Motorsports one locally a number of years ago that came with a new steel friction plate. No noise or issues but if I had to do it again I’d probably go with something like the ACT Street-lite.

Ok, OP, when was the last time you drove in any kind of traffic in your car?

No real benefit for a street car and you have to be really good at shifting. i have a 12lb wheel and found shifting slightly more difficult, especially 4th and 5th to 2nd. I would not go any lighter than that.

I have ACT and all of the above is true. It is quick on acceleration though. Keep the stock FW for dd.

I'm always a fan of OEM FW for traffic or city driving. If going non oem, I usually defer to steel/chromoly LWFW types to aid in drive ability some if stepping away from OEM and based on my driving location. With that said, I have the ACT 13LB FW (& matching counterweight) due to a full lightened & balanced rotating assembly. I can't imagine anything lighter without noise or a little drive ability hindering especially in traffic areas.

—-> https://www.rx7club.com/3rd-generati...-853894/page2/

I recommend keeping the stock flywheel. I had a lightened 13lb (can't remember exactly...) flywheel on a previous FD. It was good until you, as others have said, get into stop and go traffic. You will find yourself revving and dragging the clutch a bit more. My first experience with one was a friend's FD that I had to drive up a bridge in stop and go traffic because he had too much to drink that night.. LOL.

the thing you need to keep in mind is that you need the counterweight.

Racing beat prices the flywheel with it, and everyone else is without, so you need to do a little maths.

i have an ACT in mine, its not light, i think its about the same as the stock flywheel. so its pointless, although streetable.

That thread pretty much counters the feedback on this thread. Wonder if those "opinions" still prevail 10 yrs later

It's not just the overall weight, but how it's distributed

Can’t remember exact numbers but the ACT Street-Lite is probably 5 lbs lighter or so (w/counterweight) than the 22 lb stock FW. Which is significant. But like most all LWFW’s, it also moves the mass closer to center.

I have the Racing Beat AL flywheel that weighs 8 lbs without the counter weight. Next time I will go somewhat heavier.
The problem is low rpms and low speeds jerkiness under certain conditions. You need to use lower gears and higher revs to have a smooth ride under these conditions.
I run a 3.909 differential gear due to having a .806 fifth gear as the car is for the street.
Even so, it is not that difficult to start off from a stop.

Recently using the FC-Tweak software that shows how to modify the acceleration and TPS tables for the Apexi PFC,
driveability has increased tremendously.

I ran the Mazdaspeed flywheel with the ACT stage1 clutch kit early 2000's for years with no problems. Pedal effort was increased, clutch engagement was more aggressive and occured lower in the pedal throw / closer to the floor (iirc). Expect to experience some low rpm / speed jerkiness as stated above and slightly more noise. Was well worth it imo, and mostly a question of what you'll be willing to live with while 'street' driving. GL :)

I have an ACT Pro-lite and ACT SS clutch package. Revs up and down faster for sure, needs more revs to start from stop. Needs to cruise at higher revs to be smooth. Sometimes will rev down too fast and stall or near-stall before the PFC catches it but I'm sure with better tuning it can be fixed.

Drive modern sports/sporty cars with manual transmissions (the few that are left) and electronic throttle and you will realize how free revving even a completely stock FD is. The revs do drop significantly on a stock car, it free revs pretty quickly, and the stock clutch is pretty stiff.

Here are some comparison points. My recent 2017 Challenger R/T with the 5.7 Hemi and manual trans (Tremec TR6060, common newer V8's) had a lighter clutch and smoother engagement than my FD. That's years of refinement and of course a lot more displacement. My 2015 Mustang Ecoboost (with single mass flywheel) and 2019 (wife's lease car) with dual mass flywheel also have much smoother engagement. The tuning of the electronic throttles also tend to close the throttle slowly ("rev hang").

Those cars have well over 100 more lb/ft of torque and smoother engagement/smoother drivetrain vibration due to modern technology and customer expectations.

There's really not much that's soft and boulevard cruiser about even a non R1/R2 FD. The goalpost has moved a lot. The trans and clutch design of the FD really go back to the 80s with a transmission/clutch family that was shared with Ford trucks, so it's not surprising.