Let's talk about lightweight clutch/Flywheel combo's
10-03-2015, 09:55 AM
#21
I've got a LS7 clutch with 13lb Fidanza flywheel. If I switched to the McLeod RST with Fidanza flywheel, what changes should I expect? What part numbers would I need to use the RST & Fidanza solution? It's my daily driver, no drag racing, with some autocross & HPDE.
10-03-2015, 10:43 AM
#22
You should pick up a set of arp flywheel bolts as some people have had issues with them contacting the clutch disks on the rst fidanza combo. The ls7 unit is a tank, your car will shift light years better, have a slightly lighter pedal than you do now and the car will be much more responsive from a roll. I experienced all of those.
Also Jim, I'm pulling my rst/fidanza combo here in a few weeks if you're interested? It has about 12-13k on the whole unit and I'll let it go for a good price I just wont have a use for it. If you're interested pm me, its a complete bolt in and go deal. It's never been to the track either.
Also Jim, I'm pulling my rst/fidanza combo here in a few weeks if you're interested? It has about 12-13k on the whole unit and I'll let it go for a good price I just wont have a use for it. If you're interested pm me, its a complete bolt in and go deal. It's never been to the track either.
10-03-2015, 03:43 PM
#24
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Thanks for posting that, Scotty. I was wondering what the real world benefit of a lighter clutch would be.
10-03-2015, 05:25 PM
#27
That article is a pretty good comparison the lighter weight will add hp like there but what that test doesnt show is the way the engine will respond. Throttle response and the way the engine revs will drastically improve, much more so than just adding 7 hp. This is because the inertia the smaller clutch takes to accelerate is much less and hp doesnt account for that.
10-03-2015, 06:05 PM
#28
For me, there are a number of factors which lead me to using a stock GM clutch assembly.
1) Price. I get the GM parts 10% over cost if I mail order them - significant savings versus aftermarket units.
2) Availability. If something on it fails, it's pretty likely that I can find a replacement at a local dealership, even though the cost will likely be higher. Less down time on my only vehicle.
3) Stock drivability. I like the feel of GM OEM clutches. I don't want any side effects... no chattering, being able to slip the clutch, perfect parking lot manners, etc. I'd rather slip the clutch than shock the rear end.
4) My past experiences with non-OEM clutch companies. Back in 1999 when I first installed a McLeod clutch (it was red IIRC), it lasted a little over a year before it began slipping horribly. Switched to a SPEC Stage 2 (I think it was blue), it lasted almost 2 years before it did the same. Switched to a SPEC Stage 3 (I think it was yellow), it lasted less than a year before the disc disintegrated. Switched to a complete LS7 clutch, it never failed in 4 years. I've replaced the kit once due to preventative maintenance while the tranny was out, and later replaced the Fidanza flywheel insert once for the same reason two years later.
5) Shims. All those McLeod/SPEC units had to use shims for the proper engagement point. At that point in time the shops around here were too stupid to know how to take measurements and if the engagement point was wrong I had to pay to R&R the clutch a second time to add/remove a shim. No shims with the LS7. I don't like paying speed shops to practice on my vehicle and charge me for it. It needs to be bolt-in and go and have the engagement point working well from the beginning.
1) Price. I get the GM parts 10% over cost if I mail order them - significant savings versus aftermarket units.
2) Availability. If something on it fails, it's pretty likely that I can find a replacement at a local dealership, even though the cost will likely be higher. Less down time on my only vehicle.
3) Stock drivability. I like the feel of GM OEM clutches. I don't want any side effects... no chattering, being able to slip the clutch, perfect parking lot manners, etc. I'd rather slip the clutch than shock the rear end.
4) My past experiences with non-OEM clutch companies. Back in 1999 when I first installed a McLeod clutch (it was red IIRC), it lasted a little over a year before it began slipping horribly. Switched to a SPEC Stage 2 (I think it was blue), it lasted almost 2 years before it did the same. Switched to a SPEC Stage 3 (I think it was yellow), it lasted less than a year before the disc disintegrated. Switched to a complete LS7 clutch, it never failed in 4 years. I've replaced the kit once due to preventative maintenance while the tranny was out, and later replaced the Fidanza flywheel insert once for the same reason two years later.
5) Shims. All those McLeod/SPEC units had to use shims for the proper engagement point. At that point in time the shops around here were too stupid to know how to take measurements and if the engagement point was wrong I had to pay to R&R the clutch a second time to add/remove a shim. No shims with the LS7. I don't like paying speed shops to practice on my vehicle and charge me for it. It needs to be bolt-in and go and have the engagement point working well from the beginning.
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Coy (12-03-2020)
10-03-2015, 06:18 PM
#29
For me, there are a number of factors which lead me to using a stock GM clutch assembly.
1) Price. I get the GM parts 10% over cost if I mail order them - significant savings versus aftermarket units.
2) Availability. If something on it fails, it's pretty likely that I can find a replacement at a local dealership, even though the cost will likely be higher. Less down time on my only vehicle.
3) Stock drivability. I like the feel of GM OEM clutches. I don't want any side effects... no chattering, being able to slip the clutch, perfect parking lot manners, etc. I'd rather slip the clutch than shock the rear end.
4) My past experiences with non-OEM clutch companies. Back in 1999 when I first installed a McLeod clutch (it was red IIRC), it lasted a little over a year before it began slipping horribly. Switched to a SPEC Stage 2 (I think it was blue), it lasted almost 2 years before it did the same. Switched to a SPEC Stage 3 (I think it was yellow), it lasted less than a year before the disc disintegrated. Switched to a complete LS7 clutch, it never failed in 4 years. I've replaced the kit once due to preventative maintenance while the tranny was out, and later replaced the Fidanza flywheel insert once for the same reason two years later.
5) Shims. All those McLeod/SPEC units had to use shims for the proper engagement point. At that point in time the shops around here were too stupid to know how to take measurements and if the engagement point was wrong I had to pay to R&R the clutch a second time to add/remove a shim. No shims with the LS7. I don't like paying speed shops to practice on my vehicle and charge me for it. It needs to be bolt-in and go and have the engagement point working well from the beginning.
1) Price. I get the GM parts 10% over cost if I mail order them - significant savings versus aftermarket units.
2) Availability. If something on it fails, it's pretty likely that I can find a replacement at a local dealership, even though the cost will likely be higher. Less down time on my only vehicle.
3) Stock drivability. I like the feel of GM OEM clutches. I don't want any side effects... no chattering, being able to slip the clutch, perfect parking lot manners, etc. I'd rather slip the clutch than shock the rear end.
4) My past experiences with non-OEM clutch companies. Back in 1999 when I first installed a McLeod clutch (it was red IIRC), it lasted a little over a year before it began slipping horribly. Switched to a SPEC Stage 2 (I think it was blue), it lasted almost 2 years before it did the same. Switched to a SPEC Stage 3 (I think it was yellow), it lasted less than a year before the disc disintegrated. Switched to a complete LS7 clutch, it never failed in 4 years. I've replaced the kit once due to preventative maintenance while the tranny was out, and later replaced the Fidanza flywheel insert once for the same reason two years later.
5) Shims. All those McLeod/SPEC units had to use shims for the proper engagement point. At that point in time the shops around here were too stupid to know how to take measurements and if the engagement point was wrong I had to pay to R&R the clutch a second time to add/remove a shim. No shims with the LS7. I don't like paying speed shops to practice on my vehicle and charge me for it. It needs to be bolt-in and go and have the engagement point working well from the beginning.
Cool stories.
10-03-2015, 06:24 PM
#30
For me, there are a number of factors which lead me to using a stock GM clutch assembly.
1) Price. I get the GM parts 10% over cost if I mail order them - significant savings versus aftermarket units.
2) Availability. If something on it fails, it's pretty likely that I can find a replacement at a local dealership, even though the cost will likely be higher. Less down time on my only vehicle.
3) Stock drivability. I like the feel of GM OEM clutches. I don't want any side effects... no chattering, being able to slip the clutch, perfect parking lot manners, etc. I'd rather slip the clutch than shock the rear end.
4) My past experiences with non-OEM clutch companies. Back in 1999 when I first installed a McLeod clutch (it was red IIRC), it lasted a little over a year before it began slipping horribly. Switched to a SPEC Stage 2 (I think it was blue), it lasted almost 2 years before it did the same. Switched to a SPEC Stage 3 (I think it was yellow), it lasted less than a year before the disc disintegrated. Switched to a complete LS7 clutch, it never failed in 4 years. I've replaced the kit once due to preventative maintenance while the tranny was out, and later replaced the Fidanza flywheel insert once for the same reason two years later.
5) Shims. All those McLeod/SPEC units had to use shims for the proper engagement point. At that point in time the shops around here were too stupid to know how to take measurements and if the engagement point was wrong I had to pay to R&R the clutch a second time to add/remove a shim. No shims with the LS7. I don't like paying speed shops to practice on my vehicle and charge me for it. It needs to be bolt-in and go and have the engagement point working well from the beginning.
1) Price. I get the GM parts 10% over cost if I mail order them - significant savings versus aftermarket units.
2) Availability. If something on it fails, it's pretty likely that I can find a replacement at a local dealership, even though the cost will likely be higher. Less down time on my only vehicle.
3) Stock drivability. I like the feel of GM OEM clutches. I don't want any side effects... no chattering, being able to slip the clutch, perfect parking lot manners, etc. I'd rather slip the clutch than shock the rear end.
4) My past experiences with non-OEM clutch companies. Back in 1999 when I first installed a McLeod clutch (it was red IIRC), it lasted a little over a year before it began slipping horribly. Switched to a SPEC Stage 2 (I think it was blue), it lasted almost 2 years before it did the same. Switched to a SPEC Stage 3 (I think it was yellow), it lasted less than a year before the disc disintegrated. Switched to a complete LS7 clutch, it never failed in 4 years. I've replaced the kit once due to preventative maintenance while the tranny was out, and later replaced the Fidanza flywheel insert once for the same reason two years later.
5) Shims. All those McLeod/SPEC units had to use shims for the proper engagement point. At that point in time the shops around here were too stupid to know how to take measurements and if the engagement point was wrong I had to pay to R&R the clutch a second time to add/remove a shim. No shims with the LS7. I don't like paying speed shops to practice on my vehicle and charge me for it. It needs to be bolt-in and go and have the engagement point working well from the beginning.
Clutches have come a long way in 15 years the mcleod you tried back then isnt even close to the rst and rxt they offer now
10-03-2015, 07:34 PM
#31
Jim, you are correct about the stock drive ability on the LS7 clutch. Mine drive great on the street. At the drag strip, for me, it sucked. Especially with the et streets. Maybe it was my driving habits? Who knows. I'll never pay for a clutch that loses power ever again. My car wasn't a daily driver. I wish I did my research before I made my choice.
10-04-2015, 08:39 AM
#32
Here's a article from Super Chevy about FW weight and HP produced.
http://www.superchevy.com/how-to/eng...el-why-weight/
http://www.superchevy.com/how-to/eng...el-why-weight/
10-04-2015, 02:39 PM
#33
I was thinking and determined that maybe it would be helpful if we had some clutch weights laid out here so everyone can compare and see what might fit their bill the best.... fidanza flywheels weigh 12.5-13lbs
Stock LS1/LS6 clutch kit
12" dia. Flywheel=22lbs Clutch=31lbs Total Wt.=53lbs
Wt. with Fidanza/Spec AL flywheel=44.5lbs
GM performance LS7 Clutch kit
12" dia Flywheel=26lbs Clutch=33lbs Total Wt.=59 lbs
Wt. with Fidanza/Spec Al flywheel=46.5 lbs
Monster Clutch kits
Standard Clutch Kits
12" dia Flywheel=28lbs Clutch=28lbs Total Wt.=56 lbs
With 18lb flywheel=46lbs
LT1 C7 series
9.5" dia Flywheel=24lbs Clutch=29.5lbs Total Wt.=53.5 lbs
With 20lb lightweight flywheel=49.5lbs
Billet twin
8.5" dia Flywheel=28lbs Clutch=16lbs Total Wt.=44 lbs
With 18lb flywheel=34lbs
McLeod RST/RXT
9.5" dia Flywheel=22lbs (stock) Clutch=21.5lbs Total Wt.=43.5 lbs
With 28lb billet flywheel=49.5lbs
With Fidanza=34lbs
With Mcleod aluminum=35lbs
Mantic 7000 Track MOI plus
7.25" dia Flywheel=12lbs Clutch=12.5lbs Total Wt.=24.5 lbs
Spec Super Twin
10" dia Total weight with alum flywheel=38lbs
Spec Mini Twin
7.25" dia Flywheel=7.5lbs Clutch=12lbs Total Wt.=19.5 lbs
There are others but those are the ones I know off hand others in the same category will be of similar weight
Stock LS1/LS6 clutch kit
12" dia. Flywheel=22lbs Clutch=31lbs Total Wt.=53lbs
Wt. with Fidanza/Spec AL flywheel=44.5lbs
GM performance LS7 Clutch kit
12" dia Flywheel=26lbs Clutch=33lbs Total Wt.=59 lbs
Wt. with Fidanza/Spec Al flywheel=46.5 lbs
Monster Clutch kits
Standard Clutch Kits
12" dia Flywheel=28lbs Clutch=28lbs Total Wt.=56 lbs
With 18lb flywheel=46lbs
LT1 C7 series
9.5" dia Flywheel=24lbs Clutch=29.5lbs Total Wt.=53.5 lbs
With 20lb lightweight flywheel=49.5lbs
Billet twin
8.5" dia Flywheel=28lbs Clutch=16lbs Total Wt.=44 lbs
With 18lb flywheel=34lbs
McLeod RST/RXT
9.5" dia Flywheel=22lbs (stock) Clutch=21.5lbs Total Wt.=43.5 lbs
With 28lb billet flywheel=49.5lbs
With Fidanza=34lbs
With Mcleod aluminum=35lbs
Mantic 7000 Track MOI plus
7.25" dia Flywheel=12lbs Clutch=12.5lbs Total Wt.=24.5 lbs
Spec Super Twin
10" dia Total weight with alum flywheel=38lbs
Spec Mini Twin
7.25" dia Flywheel=7.5lbs Clutch=12lbs Total Wt.=19.5 lbs
There are others but those are the ones I know off hand others in the same category will be of similar weight
Last edited by redbird555; 10-04-2015 at 06:06 PM.
10-04-2015, 05:19 PM
#34
11 Second Club
I was thinking and determined that maybe it would be helpful if we had some clutch weights laid out here so everyone can compare and see what might fit their bill the best.... fidanza flywheels weigh 12.5-13lbs
Spec Super Twin
Total weight with alum flywheel=38lbs
There are others but those are the ones I know off hand others in the same category will be of similar weight
Spec Super Twin
Total weight with alum flywheel=38lbs
There are others but those are the ones I know off hand others in the same category will be of similar weight
10-04-2015, 08:22 PM
#37
11 Second Club
I've managed a couple 1.7's, but as you can imagine, getting off the line in a stiffly sprung, light weight car with too much camber wasn't the most ideal setup. Gonna go after 10's in the spring with less(no) camber and a taller tire.
10-05-2015, 07:30 AM
#38
The clutch performed fine. Easy enough to modulate/slip to get off the line but has never slipped while fully in gear. I think it's rated at 900ft/lb, I'm only putting down half that.
I've managed a couple 1.7's, but as you can imagine, getting off the line in a stiffly sprung, light weight car with too much camber wasn't the most ideal setup. Gonna go after 10's in the spring with less(no) camber and a taller tire.
I've managed a couple 1.7's, but as you can imagine, getting off the line in a stiffly sprung, light weight car with too much camber wasn't the most ideal setup. Gonna go after 10's in the spring with less(no) camber and a taller tire.
https://ls1tech.com/forums/manual-tr...er-twin-2.html
10-05-2015, 10:47 AM
#39
11 Second Club
I went back and looked at my measurements from the clutch install. SPEC told me the minimum distance between the face of the throwout bearing and the pressure plate fingers should be .175" min and .225" max. All of my measurements came out between .100" and .120" which, without an adjustable master, would normally lead to a higher pedal.
I'm using the stock Mazda pedals with a Wilwood adjustable master so I could put the pedal wherever I wanted.
It seems like a couple people in that thread took no measurements at all.
I'm using the stock Mazda pedals with a Wilwood adjustable master so I could put the pedal wherever I wanted.
It seems like a couple people in that thread took no measurements at all.
10-05-2015, 12:23 PM
#40
I went back and looked at my measurements from the clutch install. SPEC told me the minimum distance between the face of the throwout bearing and the pressure plate fingers should be .175" min and .225" max. All of my measurements came out between .100" and .120" which, without an adjustable master, would normally lead to a higher pedal.
I'm using the stock Mazda pedals with a Wilwood adjustable master so I could put the pedal wherever I wanted.
It seems like a couple people in that thread took no measurements at all.
I'm using the stock Mazda pedals with a Wilwood adjustable master so I could put the pedal wherever I wanted.
It seems like a couple people in that thread took no measurements at all.