ACT prolite flywheel or ACT streetlite flywheel
 

Can someone tell me what the difference between the two are and what the advantages and disadvantages of each are? I've searched and found nothing explaining the difference.

i'll be in the market for a new clutch soon and i'd love an exedy twin but money just wont allow it with a baby on the way. I'll mostlikely be getting an ACT xtreme to go along with some sort of green or 50trim setup (undecided) and want to know you guys opinions on the flywheels.

I currently am running ACT's HDSS model andafter 21k miles and no more than 40 launches, it's getting ready to go. I only make 3 passes at the track each time i go. so i'm definitely not over doing it there. never back to back either. my 60's always range from 1.73-1.78 so they are rough launches. on the street i launch maybe 1once every other month. i do a LOT of highway runs though so thats probably where the clutch has taken the most abuse (just a guess. im no expert).

the clutch has low miles but under high rpm's shifting to 3rd, or 4th or 5th (6speed) are very tough. not notchy and never grinding but after i shift, the clutch pedal doesn't come back up all the way anymore. only halfway (if i shift hard) so im figuring it's the clutch.

I have a TRE 6speed in here at the moment with about 15k miles on it so i highly doubt it's the transmission.

maybe after i do the clutch, i'll do shifter bushings, ss clutch line, solid motor mounts and a torque dampener just to make sure i dont have anymore issues with shifting.

anyhow im not sure about the flywheels or how they differ. can someone please educate me on that :)

you have to be kidding me. all of you guys are just as clueless about flywheels as me?

They are both very close in weight, Its always nice to free up as much weight as possible on the clutch set up, it will help with high rpm shifts.

The ACT Prolite is 10.1 lbs, the Streetlite is 13.1 and is close to stock in terms of the weight. The Streetlite has the weight removed from the outside of the flywheel so even though the weight is similar to stock it still feel lighter upon acceleration.

I would say that if you do a lot of drag racing the Streetlite would be the way to go because the weight makes it easier to launch/modulate the clutch. I've driven cars with both and the Prolite's weight can make it bit more difficult if you live in a hilly area or drag race often to take off, but not impossible.

The obvious advantage of the Prolite is that it weighs less and as such will have more of an effect on the cars acceleration/deceleration. The advantage of the Streetlite is that it is close enough in weight to stock, but thicker than the OE (from what I've read and is therefore resurfaceable and less likely to warp from overheating). I think ACTMAN said that both were thicker than stock so that should be an advantage on either weight. Other than that I think the only other factor would be the price. The Prolite cost a bit more than the Streetlite.

I dont find any problems with lauching cars with prolite flwheels, The Exedy twin in my car weighs less then a act clutch/prolite combo and i also have no problems with that. I never understood why people say they have a problem launching cars with lighten flywheels.

well then that makes things much easier. i have the streetlite in mine. being strapped for cash and knowing that it's resurfaceable makes purchasing the clutch much easier now

I would think that the prolite would be better for drag being that the shifts are very quick. I use the streetlite and it is very similar to the stocker.

I had the ACT MB7 HDSS clutch with the prolight flywheel on my BR350 IX and loved it. Smooth as stock on take off,quieter,better clutch pedal feel,etc.The car launched like a rocket with no clutch smell at all when done right,and the revs came up much quicker (obviousely) with the prolight. I saw no drawbacks at all using the prolight instead of a heavier one like the streetlight or the gruppe-s flywheel.I was told this and that about using the PL about it being to light for great launches and how the revs would come down to fast in between shifts,etc. I found none of that to be true. The car shifted smooth as glass in every gear whether upshifting or downshifting at any rpm right up to 7800 rpm,s. I highly recommend it.

The actual clutch weight makes for faster better shifts not the flywheel weights. A street disc with springs is gonna be the slowest and also the hardest to shift at high rpms. A carbon without springs or a 4 puck with no springs is gonna be the best for fast high rpm shifting.

What I said was it was harder, but not impossible. All of which is subject to the driver and his/her ability to launch the car in the first place.

That is correct. The lighter flywheel will help the car to accelerate faster because their is less weight for the crank shaft to turn, but the ability to shift faster is related to the weight of the disc.

I have heard that you may lose a bit of low-end torque when switching over to a lightweight flywheel. Any truth to this?


Also, Kee1, TTP will modify the ACT HD clutches so they won't lock you out at high rpms...

well i guess ill hit scott up about a clutch then. i just bought something from him last night. maybe he'll help me out :)

well since your saying that your clutch isnt coming up all the way anymore could it be your clutch master cylinder, slave master cylinder or both?

That's not quite the right way to put it.

A heavier flywheel stores more energy than a light one. What this does is help the car get moving from a stop. As soon as the car is moving, there is no more advantage, as the greater mass of a heavier flywheel requires more power to accelerate. A heavier flyweel just makes stop-and-go driving a bit easier for a relatively heavy car with a small motor. It also tends to be easier on the clutch, because less slippage is required.

thanks, Ted...


so, with a lightened flywheel, will the acceleration difference actually be measurable? i.e. better ET's, traps, etc...?