Light flywheel question

[MvM]

I have what might be a dumb question or questions.

If I would want to install (or rather: have installed) a light flywheel, could I still combine this with a stock OEM clutch ?? The car in question is a 1994 so the clutch is a twin-disc unit.
Also, are there any specific issues that my mechanic should know of when installing a lighter flywheel.
Last, if I have a non-OEM flywheel installed, can I later combine this with any of the available aftermarkt clutches like the ACT or RPS-clutch??

Thanks in advance for your input of course.

 

[DutchBlackNsx]

If I would want to install (or rather: have installed) a light flywheel, could I still combine this with a stock OEM clutch ?? The car in question is a 1994 so the clutch is a twin-disc unit.

Yes no problem, i run a light flywheel with a stock clutch. Might be flywheel specific though.

Also, are there any specific issues that my mechanic should know of when installing a lighter flywheel.

No, just make sure they follow the manual step by step when they putting the clutch back on. Make sure to place the white dots correct, and initialize the middle plate. Make sure they put a new, or maybe used top-bearing in the flywheel, thats a commonly forgotten item.

Last, if I have a non-OEM flywheel installed, can I later combine this with any of the available aftermarkt clutches like the ACT or RPS-clutch??

Depends on what clutch you are going to use, not familiar with ACT or RPS, i have seen setups which could be used stock/aftermarket but i have also seen setups which come as a package, and is not compatible with the stock flywheel.


FYI, i found the light flywheel a good mod.

hth

 

[MvM]

Hi Michel :smile:

Thanks very much for the (quick) reply.
You are right, I forgot you had one of those mods as well. Nice to see a reply from someone close.

 

[TURBO2GO]

FYI, i found the light flywheel a good mod.

hth

Do you feel any drawbacks? What feels better exactly?

 

[DutchBlackNsx]

Do you feel any drawbacks? What feels better exactly?

Con:
- Idle not so smooth
- More revs to take off
- More carefull when shifting

( i have noticed with the stock flywheel and the long gears, that if you shift rapidly, youre rpm's fall back to exactly the rpm's you need to have)

Good:
- Faster engine response
- Acceleration in lower gears *feels* faster (no backup data)
- Weight savings

 

[Larry Bastanza]

You can combine the lightwieght flywheel with the OEM setup. I think the ACT is a stock twin disk rebuild, but check to be sure. Will not work with the RPS. The RPS is a complete setup and it is different, very nice too, if you are OK with the stiffness. I got used to it in about 20 miles of driving and really liked the direct hookup.

One thing is that the lightwieght flywheels do not come with the three 6mm pins that are required. You must have those removed from the heavy fylwheel and have them pressed into the LW. It is not a big deal, but nice to know going in.

I just went through this and you need to be careful removing the pins from the original fylwheel. If you grab them with a vise grip you will gouge them and that is not good. I took the fylwheel to my machinist and he drilled a small hole from the back behind the pins, then he knocked them out with a drift. They were not damaged at all, and it cost me US $12. Pressing them in was easy.


This was a Fidanza flywheel mounted with a Centerforce rebiuld with NEW resurfaced disks. Finished up yesterday and was quite surprised the feel it gave to the car. Very Nice. The car is a 1997 with stock 16/17, and the customer is going 18/19. I figure that will cancel the gain from the flywheel and the car will have relatively stock acceleration.

Regards,
LarryB

 

[CarCrazed4Life]

The car is a 1997 with stock 16/17, and the customer is going 18/19. I figure that will cancel the gain from the flywheel and the car will have relatively stock acceleration.

Regards,
LarryB

You becha ya!!! Those SSR GT3s will be heavy compared to the stocks

Can't wait to get her back lol

 

[Cameron]

lighter flywheels are good for peak horsepower and revving more freely, but rob torque. good for track, not so much for street, hence the higher revs at take off.

 

[Larry Bastanza]

lighter flywheels are good for peak horsepower and revving more freely, but rob torque. good for track, not so much for street, hence the higher revs at take off.

Please expalin technically why this is so. Based on the fact a given engine with a lightened flywheel accelerates faster, I was under the impression that torque used to spin up the heavy flywheel was then availble to go directly to the wheels, resulting in better acceleration.

Torque = Work, no??

Thanks,
LarryB

 

[AutoVation]

Please expalin technically why this is so. Based on the fact a given engine with a lightened flywheel accelerates faster, I was under the impression that torque used to spin up the heavy flywheel was then availble to go directly to the wheels, resulting in better acceleration.

Torque = Work, no??

Thanks,
LarryB

I think he might be referring to the inertia that a heavier flywheel generates during takeoff on the street. It's easier to launch faster using a heavier flywheel but once engaged, the lighter flywheel puts more torque to the ground. Many drag cars do not use lw flywheels because of this. In their case, the relatively small peak hp gains are not worth the missing hundredths of a second at launch. On a street car like the NSX, it would be worth it (at least to me).

 

[mystican]

I just did short gears with a JUN lite flywheel...very quality piece of machined Cro-moly...JUN very well known in the Nissan world...

Noticable difference in revving...engine more eager to move...

Starting the car...increased "screeching"...probably from the starter engaging the flywheel teeth...

otherwise excellent setup...

 

[stevenlee]

Two weeks ago my Clutchmaster Stage 4 went out with only 5K miles.

I replaced it with an RPS clutch that has a lightened flywheel. The lightened flywheel revs so much faster that it took a couple of days to learn how to take off from a stop. I would always overrev the first few times I drove it because the engine revs so much faster. Without enough revs, the engine stalled. It took only a few days to learn to launch the car from a stop. It takes a little more concentration and precision but I love the RPS clutch and the light flywheel. I do have the low gears and R&P.

I don't think the light flywheel would reduce the launch time any because the NSX has sufficient power to spin the wheels and one could (with the proper skill) increase the revs to prevent bogging the engine. My car does accelerate noticably faster with the light clutch/flywheel which could be due in part to the new tune.

BTW, it held 528 RWHP on the dyno with no problem.

 

[1BADNSX]

I wish everybody would preface their comments saying the engine revs so much faster “when not in gear”. While accelerating in gear, the engine is directly connected to the drivetrain and the amount of revving is limited by the power to accelerate the vehicle (which can’t be felt, except for maybe in first gear).

The energy it takes to spin a rotating mass is proportional to the RPM squared divided by the amount of time it take to change RPM. While accelerating, the NSX changes RPM fast enough in first gear for this possibly to be felt, but above that it would be very small.

Bob

 

[OLDMNSX]

Something to keep in mind when you get in to do clutch work change the rear main seal. Even if it isn't leaking now it probably will before you have to do the clutch again. I change the front main seal when I do a timing belt just for the same reason. If you do it yourself remember to use a awl to poke a hole in the face of the seal and then remove it with a small slide hammer. Don't use a drill, it may nick the crank surface. Pretty cheep preventative maintenance. I hate oil leaks!!!

 

[sahtt]

Good advice on the rear main seal. A lightened flywheel should not effect your idle. You could un-bolt the transmission entirely and your idle should be the same. You may think your idle is different if you are not used to the engagement point of the drivetrain compared to stock when taking off. Lightened flywheels do not 'rob' your engine of torque. This has no bearing mechanically. It is less intertia in the spinning components of your drivetrain. Similar to getting a lightened driveshaft but the change is more pronounced since it is over a broader area and is closer to where the engine actually produces power [depending on how technical you want to get, we'll say the crankshaft is the original instrument of force to the transmission/ds/rear end/wheels etc.].

When pairing a clutch to a flywheel, you must make sure the materials of both units will work in conjunction. Many strong 6-puck clutches will eat weaker flywheels into mush after a few launches. I have always replaced oem flywheels with lighter aftermarkets when replacing the clutch to a performance unit.

There is some bearing on the weight of a flywheel and drag racing. On very powerful cars with huge slicks, you need a heavier flywheel for maximum acceleration. It has to do with the inertia of the drivetrain pre-launch. Otherwise it is not useful. If that doesn't apply to you, get a lighter one and enjoy it!

FYI, I had a 400whp+480rtq+ 300zx on a light, 'weaker' aluminum flywheel that withstood heavy abuse. Also, flywheel/clutch ratings are mostly based on tq figures to determine the limit of their structural integrity, so NSX's get a break there.

 

[cuts1200]

Check this out. It might help answer some questions about torque and horse power.http://science.howstuffworks.com/fpte4.htm