badhoopty

i've been searching the board reading up on ls7 clutch swaps. one thread i found mentioned that the ls2/ls7 combo is somewhere around 8lbs heavier than the stock ls1 flywheel and clutch. but then again there is alot of posts with conflicting comments...

if thats true, does it noticeably rev any slower on a stock ls1? i'm not talking just about banging thru the gears, i'm also talking being abnoxious at a stop light and the like. seems to me like putting in a heavier than stock flywheel is the wrong way to go, even for a heavy car +8lbs seems like alot.

call me vain or stupid, but i'd hate to put one in and have it rev noticeably slower than stock, even if it only did so in neutral.

thanks in advance for any replies.

MeentSS02

iTrader: (11)

If people have had one complaint about it, it is that. There are some that have said they felt it reved slower, and it was enough for them to notice. I've only driven one car like that, but it was too hard to tell because it was a H/C car compared to my stock internals. I can tell you that dropping 20 lbs from my previous clutch (Ram HD) to my RPS WAS noticeable.

The 8-lbs isn't the problem so much as it is the fact that it is an inertial load on the engine (since it has to spin it). Rotational mass has a greater impact than regular mass (like the weight of any stereo equipment, extra passengers, etc.).

Blk97WS6

iTrader: (19)

when i first put mine in, i thought there was a difference under normal acceleration, but then after getting on it, i could hardly notice it.

Bryan28

I haven't noticed it one bit! Especially when I turn on the juice it hits 6500 rpm fast as I can blink!

JBsZ06

I have the LS7 clutch in my vette and I wouldn't replace it with another one when the time comes.

Your right...the car feels and drives a bit differently. The added mass changes the car a bit so to answer your question...

Don't go for the ls7 clutch....

JMO

Good luck..

Vintage Iron55

It is a trade-off between better launches (heavy wheel) and better performance at the big end of the track (lighter wheel.) Back when my dad was racing guys used to drive gutted out 57 Chevys with 292 and 301 inch small blocks with 50 lbs flywheels a stiff grabby clutch and whatever gears they could find for the pontiac olds rear. The flywheel mass served to keep the car from bogging off the line. Also made a small inch, rough idleing, torqueless wonder of an engine a little easier to roll off nicely from a stop light or drive in traffic. I like a 40 lbs wheel for street driving with 3.50 gears and a muncie.

Now days people f bodies with nice torquey fuel injected roller cammed motors with automatics with high stall converters and go faster. Current thoughts on manual trans cars are to use lighter flywheel with lower rear gears and a sintered iron clutch with a light pedal adjustable long pressure plate for strip only cars or a street diaphram with a metalic high-friction disk. Six speeds allow very low gearing but its interesting to see most guys runing 4.10s and 4.56s. to match the rpm they want at the end.

The heavier flywheel may be a good thing if you have trouble launching the car with slicks, but you will pay the price at the big end where free horsepower is king and it takes more to turn that flywheel.

In the spirit of full disclosure, I still drive a car much like the first one.

Henry

BIG_MIKE2005

iTrader: (116)

I can tell a little difference but not enough to worry about. I actually feel that the extra rotating mass make the higher RPM shifts easier. With my stock set-up I used to have problems sometimes with high RPM shifts, now it feels like it holds the RPM better when shifting up high.

ChevyWeatherman

iTrader: (2)

I was thinking about using an aluminum flywheel when I swap an LS7 clutch in, I guess this thread made up my mind.

SladeX

I noticed a difference after swapping the ls7 in, it revved a bit slower and while I had less bog off the line, it just felt "slower"

I fixed that by adding a LS6 intake with a ported throttle body.

I'll take better launches and a harder grabbing clutch anyday over a little rev slowness.

badhoopty

thanks for all the responses.

i'm most likely going to go with the ls7 clutch and use an aluminum flywheel to offset the wieght gain.

vader99

iTrader: (4)

So, would an ls7 clutch with an aluminum flywheel be a good combination then? The best of both worlds????

badhoopty

i went ahead and ordered an ls7 clutch, but with an aluminum ls2 flywheel.

from what i've researched it should behave very very close to the stock ls1 setup, but with the improved ls7 holding power. it wont rev any faster like you think an aluminum flywheel would, in this case the alum flywheel just drops the weight more or less back to what the stock ls1 clutch/flywheel weighs.

again, thats just what ive gathered from searching the boards so i'm just going off what other people have experienced. the last time i actually touched a clutch was about 8 years ago.