LS7 Clutch + Aluminum Flywheel (Who has it??)
02-06-2007, 03:02 PM
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LS7 Clutch + Aluminum Flywheel (Who has it??) A while back before I did my TFS H/C swap I started looking at which clutch I could put in my car. I don't track race and mainly just tool around. My car's stock clutch is NOT liking my H/C configuration at all 
It's starting to slip.
I have an LS7 clutch I got from a non-sponsor. The assembly is VERY heavy and was "thinking" about adding an aluminum flywheel to the mix BUT I'm a little hesitant for the following reasons.
1. Reliability ( I heard from some people that aluminum flywheels are strange and much more finicky about allowing a good mating surface between the clutch and the flyhweel and if something goes wrong during the bedding process you're out of luck and need a new flywheel)
2. The factory LS7 motor isn't bothered by the "heavier" assembly (by a few pounds right?) but it's also nearly 100 cid bigger then my little LS1 motor.
Does anyone have any input or suggestions? Thanks!
It's starting to slip. I have an LS7 clutch I got from a non-sponsor. The assembly is VERY heavy and was "thinking" about adding an aluminum flywheel to the mix BUT I'm a little hesitant for the following reasons.
1. Reliability ( I heard from some people that aluminum flywheels are strange and much more finicky about allowing a good mating surface between the clutch and the flyhweel and if something goes wrong during the bedding process you're out of luck and need a new flywheel)
2. The factory LS7 motor isn't bothered by the "heavier" assembly (by a few pounds right?) but it's also nearly 100 cid bigger then my little LS1 motor.
Does anyone have any input or suggestions? Thanks!
02-06-2007, 09:33 PM
#2
I use a LS7 clutch assembly in conjunction with a Fidanza 13lb LS2 flywheel. I'd have to dig up my invoices, but I believe it's nearing 1 year old. I autocross one day out of the month, and went to the strip for the first time in 5 years with it. Other than that I put maybe 3-400 miles per month on the car in daily driving.
I haven't read about your first concern. The second concern seems similar to the theory that the clutch may not be able to handle the same power levels on a heavier vehicle.
The only problem I had was the engagement point. Not many had installed an LS7 clutch in an F-body when I chose that route, and one that I knew of who did it with the Fidanza. So lot's of opinions on letting it break in vs. slapping in a slave shim. I didn't want to risk damage to the tranny while waiting for it to 'self-adjust' so I shimmed mine.
I haven't read about your first concern. The second concern seems similar to the theory that the clutch may not be able to handle the same power levels on a heavier vehicle.
The only problem I had was the engagement point. Not many had installed an LS7 clutch in an F-body when I chose that route, and one that I knew of who did it with the Fidanza. So lot's of opinions on letting it break in vs. slapping in a slave shim. I didn't want to risk damage to the tranny while waiting for it to 'self-adjust' so I shimmed mine.
02-06-2007, 10:09 PM
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I have one too, and was going back and forth with jim when I first installed mine. Had a ton of problems at first, some were caused by me, and some were just working the bugs out.
I ran it with the stock m/c and the shim, and it shifted decently most of the time if I drove normal, but the pick up was low. The big problem was that it would jam on a quick shift, especially the 1-2. OEM ls2 flywheels have a low pedal too but no shifting issues.
*Short-cut through months of dropping money trying to sort things out*
I installed a new adj. m/c and took it to the shop for measurements. With the shim in place, it is within 1/16 of stock distance. After everything was said and done, it has a stock height pedal and stock feel.
You need the shim and adj. m/c for everything to work out.
I've put 10k hard street miles on it, a road race event, and about 10 passes on the clutch as well, dropping at 3.5k.
No hiccups and no slip.
1. As far as the mating surface thing, I had no issues. Just did a normal break in procedure, maybe a little more easy as I waited till over 1k miles before I started dropping it. If you somehow do burn the surface, you only need to buy the friction material, not a new flywheel.
2. ? This is why you would get the aluminum flywheel. Going steel gains 8 lbs rotating mass IIRC, great for drag racing, bad for anything else. Going with aluminum LS2 loses 2 or 3 lbs compared to the STOCK LS1 rotating mass. Not enough to have issues hooking up at the track like those who lose 13 lbs with the ls1 alum. flywheel, but enough to free up some horsepower. Perfect IMO.
I ran it with the stock m/c and the shim, and it shifted decently most of the time if I drove normal, but the pick up was low. The big problem was that it would jam on a quick shift, especially the 1-2. OEM ls2 flywheels have a low pedal too but no shifting issues.
*Short-cut through months of dropping money trying to sort things out*
I installed a new adj. m/c and took it to the shop for measurements. With the shim in place, it is within 1/16 of stock distance. After everything was said and done, it has a stock height pedal and stock feel.
You need the shim and adj. m/c for everything to work out.
I've put 10k hard street miles on it, a road race event, and about 10 passes on the clutch as well, dropping at 3.5k.
No hiccups and no slip.
1. As far as the mating surface thing, I had no issues. Just did a normal break in procedure, maybe a little more easy as I waited till over 1k miles before I started dropping it. If you somehow do burn the surface, you only need to buy the friction material, not a new flywheel.
2. ? This is why you would get the aluminum flywheel. Going steel gains 8 lbs rotating mass IIRC, great for drag racing, bad for anything else. Going with aluminum LS2 loses 2 or 3 lbs compared to the STOCK LS1 rotating mass. Not enough to have issues hooking up at the track like those who lose 13 lbs with the ls1 alum. flywheel, but enough to free up some horsepower. Perfect IMO.
02-06-2007, 10:55 PM
#4
Iv heard people say that you need to run an 01-02 adj. master cyl. w/ the LS7 clutch. Well, last time I put a clutch in, i upgraded to a McLaren adjustable mc. Will this work fine w/ the LS7 clutch?
A little off subject, i know
A little off subject, i know
02-07-2007, 07:07 AM
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Originally Posted by blackrat
I have one too, and was going back and forth with jim when I first installed mine. Had a ton of problems at first, some were caused by me, and some were just working the bugs out.
I ran it with the stock m/c and the shim, and it shifted decently most of the time if I drove normal, but the pick up was low. The big problem was that it would jam on a quick shift, especially the 1-2. OEM ls2 flywheels have a low pedal too but no shifting issues.
*Short-cut through months of dropping money trying to sort things out*
I installed a new adj. m/c and took it to the shop for measurements. With the shim in place, it is within 1/16 of stock distance. After everything was said and done, it has a stock height pedal and stock feel.
You need the shim and adj. m/c for everything to work out.
I've put 10k hard street miles on it, a road race event, and about 10 passes on the clutch as well, dropping at 3.5k.
No hiccups and no slip.
1. As far as the mating surface thing, I had no issues. Just did a normal break in procedure, maybe a little more easy as I waited till over 1k miles before I started dropping it. If you somehow do burn the surface, you only need to buy the friction material, not a new flywheel.
2. ? This is why you would get the aluminum flywheel. Going steel gains 8 lbs rotating mass IIRC, great for drag racing, bad for anything else. Going with aluminum LS2 loses 2 or 3 lbs compared to the STOCK LS1 rotating mass. Not enough to have issues hooking up at the track like those who lose 13 lbs with the ls1 alum. flywheel, but enough to free up some horsepower. Perfect IMO.
I ran it with the stock m/c and the shim, and it shifted decently most of the time if I drove normal, but the pick up was low. The big problem was that it would jam on a quick shift, especially the 1-2. OEM ls2 flywheels have a low pedal too but no shifting issues.
*Short-cut through months of dropping money trying to sort things out*
I installed a new adj. m/c and took it to the shop for measurements. With the shim in place, it is within 1/16 of stock distance. After everything was said and done, it has a stock height pedal and stock feel.
You need the shim and adj. m/c for everything to work out.
I've put 10k hard street miles on it, a road race event, and about 10 passes on the clutch as well, dropping at 3.5k.
No hiccups and no slip.
1. As far as the mating surface thing, I had no issues. Just did a normal break in procedure, maybe a little more easy as I waited till over 1k miles before I started dropping it. If you somehow do burn the surface, you only need to buy the friction material, not a new flywheel.
2. ? This is why you would get the aluminum flywheel. Going steel gains 8 lbs rotating mass IIRC, great for drag racing, bad for anything else. Going with aluminum LS2 loses 2 or 3 lbs compared to the STOCK LS1 rotating mass. Not enough to have issues hooking up at the track like those who lose 13 lbs with the ls1 alum. flywheel, but enough to free up some horsepower. Perfect IMO.
Knowing I have the 02 hydraulicswould you still suggest the adjustable hydraulics?
Also more on the shim. What depth was it and where did you get it? *(machine shop)*??
Also, do ALL LS7 clutch upgrades using the LS2 flywheel (factory or not) need a shim or do just the ones using the Fidanza flywheel?
Thanks for the input guys!
02-09-2007, 09:57 PM
#7
I had the McLeod adjustable master cylinder with my previous clutch, and the speed shop convinced me to swap back to stock hydraulics (with the line drilled) because they were having a lot of success with it even on high horsepower cars and they felt the adjustable m/c was now a bandaid.
So I bought the latest revisions of the master, slave, throwout bearing as well. If it wasn't such a PITA to swap, I'd like to try using the adjustable master again.But what I didn't like about the adj. m/c was that I couldn't get both the pedal height and the engagement point where I wanted it simultaneously.
So I bought the latest revisions of the master, slave, throwout bearing as well. If it wasn't such a PITA to swap, I'd like to try using the adjustable master again.But what I didn't like about the adj. m/c was that I couldn't get both the pedal height and the engagement point where I wanted it simultaneously.
