Let's talk about lightweight clutch/Flywheel combo's
09-13-2017, 03:30 PM
#281
There is plenty of evidence out there showing that yes lighter clutches do accelerate better weedy. It's kind of a no brainer. Especially with the over weight gm clutches.
Scotty's results aren't really whete they should be yet. Anyone trapping 118 in a fbo ls6 z06 should trade it iff on a prius to save the gasoline for those if us that know wtf we're doin.
I've seen stock c5z go 118.
Scotty's results aren't really whete they should be yet. Anyone trapping 118 in a fbo ls6 z06 should trade it iff on a prius to save the gasoline for those if us that know wtf we're doin.
I've seen stock c5z go 118.
09-13-2017, 03:56 PM
#282
Using 1320/mph as a ballpark indicator of et potential, very few here with a lightweight clutch are anywhere close.
According to the sigs/posts...
nmass399 11.29@119, comes within .2 sec
bighammer 11.5@121 + .591 sec
stevieturbo 9.85@144.75 + .731 sec
scotty2000ss 11.814@120.27 + .839 sec
hiosilver 10.90@131.3 +.847 sec
Whatever the reason, if you can't get the clutch to slip effectively your et will suffer.
Grant
09-13-2017, 04:12 PM
#284
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Flat style springs need less finger travel for release than stock style springs. When I had the Quarter Master 8.5" single disk in my RX7, I used a 5/8" bore MC. This made the pedal nice and light and increased the window of engagement (modulatability) of the clutch. In other words, it was easy to drive because the clutch wasn't an ON/OFF switch. I still had to worry about generating excess heat, so I did not slip it as much as I would a stock clutch.
With the RPS carbon/carbon, I would find out the exact diameter bearing that is required. I know they say it works with a stock TOB, but it may work much better with a radius faced bearing instead of a flat stock style bearing. RPS should also be able to give you the exact distance the spring fingers need to travel for a clean release. Using all that information you can use the appropriate bearing and MC combo to improve drivability, pedal feel, etc....
Andrew
09-13-2017, 04:32 PM
#285
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Well...not really do to lighter clutch. More of the design of the clutch and the fact that a clutch with grippier material will act like the window is smaller.
On a clutch like mine and scottys the length of the springs are much shorter also. Further reducing the amount the hydraulic release bearing has to travel for engagement.
It's not really a weight thing.
On a clutch like mine and scottys the length of the springs are much shorter also. Further reducing the amount the hydraulic release bearing has to travel for engagement.
It's not really a weight thing.
Somewhere earlier in this thread I made mention that the smaller clutches use a flat diaphragm spring, as opposed to raised finger springs on stock style clutches.
Flat style springs need less finger travel for release than stock style springs. When I had the Quarter Master 8.5" single disk in my RX7, I used a 5/8" bore MC. This made the pedal nice and light and increased the window of engagement (modulatability) of the clutch. In other words, it was easy to drive because the clutch wasn't an ON/OFF switch. I still had to worry about generating excess heat, so I did not slip it as much as I would a stock clutch.
With the RPS carbon/carbon, I would find out the exact diameter bearing that is required. I know they say it works with a stock TOB, but it may work much better with a radius faced bearing instead of a flat stock style bearing. RPS should also be able to give you the exact distance the spring fingers need to travel for a clean release. Using all that information you can use the appropriate bearing and MC combo to improve drivability, pedal feel, etc....
Andrew
Flat style springs need less finger travel for release than stock style springs. When I had the Quarter Master 8.5" single disk in my RX7, I used a 5/8" bore MC. This made the pedal nice and light and increased the window of engagement (modulatability) of the clutch. In other words, it was easy to drive because the clutch wasn't an ON/OFF switch. I still had to worry about generating excess heat, so I did not slip it as much as I would a stock clutch.
With the RPS carbon/carbon, I would find out the exact diameter bearing that is required. I know they say it works with a stock TOB, but it may work much better with a radius faced bearing instead of a flat stock style bearing. RPS should also be able to give you the exact distance the spring fingers need to travel for a clean release. Using all that information you can use the appropriate bearing and MC combo to improve drivability, pedal feel, etc....
Andrew
09-13-2017, 04:33 PM
#286
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The point i'm getting to is overall efficiency of the run- ET vs MPH.
Using 1320/mph as a ballpark indicator of et potential, very few here with a lightweight clutch are anywhere close.
According to the sigs/posts...
nmass399 11.29@119, comes within .2 sec
bighammer 11.5@121 + .591 sec
stevieturbo 9.85@144.75 + .731 sec
scotty2000ss 11.814@120.27 + .839 sec
hiosilver 10.90@131.3 +.847 sec
Whatever the reason, if you can't get the clutch to slip effectively your et will suffer.
Grant
Using 1320/mph as a ballpark indicator of et potential, very few here with a lightweight clutch are anywhere close.
According to the sigs/posts...
nmass399 11.29@119, comes within .2 sec
bighammer 11.5@121 + .591 sec
stevieturbo 9.85@144.75 + .731 sec
scotty2000ss 11.814@120.27 + .839 sec
hiosilver 10.90@131.3 +.847 sec
Whatever the reason, if you can't get the clutch to slip effectively your et will suffer.
Grant
You can't really compare full on drag race set ups to what alot of us are doin. There's more to it than a clutch but no denying a lighter clutch can accelerate faster.
If the weight in that area meant nothing you would be running steel rods.
Somewhere earlier in this thread I made mention that the smaller clutches use a flat diaphragm spring, as opposed to raised finger springs on stock style clutches.
Flat style springs need less finger travel for release than stock style springs. When I had the Quarter Master 8.5" single disk in my RX7, I used a 5/8" bore MC. This made the pedal nice and light and increased the window of engagement (modulatability) of the clutch. In other words, it was easy to drive because the clutch wasn't an ON/OFF switch. I still had to worry about generating excess heat, so I did not slip it as much as I would a stock clutch.
With the RPS carbon/carbon, I would find out the exact diameter bearing that is required. I know they say it works with a stock TOB, but it may work much better with a radius faced bearing instead of a flat stock style bearing. RPS should also be able to give you the exact distance the spring fingers need to travel for a clean release. Using all that information you can use the appropriate bearing and MC combo to improve drivability, pedal feel, etc....
Andrew
Flat style springs need less finger travel for release than stock style springs. When I had the Quarter Master 8.5" single disk in my RX7, I used a 5/8" bore MC. This made the pedal nice and light and increased the window of engagement (modulatability) of the clutch. In other words, it was easy to drive because the clutch wasn't an ON/OFF switch. I still had to worry about generating excess heat, so I did not slip it as much as I would a stock clutch.
With the RPS carbon/carbon, I would find out the exact diameter bearing that is required. I know they say it works with a stock TOB, but it may work much better with a radius faced bearing instead of a flat stock style bearing. RPS should also be able to give you the exact distance the spring fingers need to travel for a clean release. Using all that information you can use the appropriate bearing and MC combo to improve drivability, pedal feel, etc....
Andrew
09-13-2017, 04:41 PM
#287
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Here are pictures for reference:
Quarter Master 8.5" single disk. Note the flat spring.
Quarter Master tri-lite bearing installed on a T56 with radius faced bearing:
Andrew
Quarter Master 8.5" single disk. Note the flat spring.
Quarter Master tri-lite bearing installed on a T56 with radius faced bearing:
Andrew
09-13-2017, 05:01 PM
#288
9 Second Club
OEM GM bearing has a flat/radiused too ?
I've used the OEM bearing on flat faced fingers before ( and present ) without issue.
In fact, the bearing that was supplied to be used with my current clutch was a pretty ***** choice, wish I'd never even tried using it in the first place. But that's another story.
Although doubt an OEM bearing would work with that simply due to the very small diameter
I've used the OEM bearing on flat faced fingers before ( and present ) without issue.
In fact, the bearing that was supplied to be used with my current clutch was a pretty ***** choice, wish I'd never even tried using it in the first place. But that's another story.
Although doubt an OEM bearing would work with that simply due to the very small diameter
09-13-2017, 05:08 PM
#289
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That radius bearing face is interesting. I bet that partially addresses the occasional "progressive" clutch effort - where the further you push the pedal, the stiffer it sometimes gets due to the contact point moving outward - making less mechanical advantage on the PP finger.
I won't go and drop my transmission for one, but next time it's out, I'll have to take a serious look at that
I won't go and drop my transmission for one, but next time it's out, I'll have to take a serious look at that
09-13-2017, 05:45 PM
#290
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You can use a flat faced bearing with flat springs, but that is not optimal for reasons stated below.
Andrew
09-14-2017, 05:45 AM
#291
9 Second Club
OEM GM vs Nissan 350z clutch bearing on a flat fingered type clutch.
Pics are with the diaphragm uncompressed so obviously the fingers are at more of an angle than if the clutch was all bolted up, with the fingers almost flat.
So in this instance, there really is no problem using a "flat" GM bearing which does still have a radius at the outer edge vs what the clutch company wanted to use, which gave me problems.
Pics are with the diaphragm uncompressed so obviously the fingers are at more of an angle than if the clutch was all bolted up, with the fingers almost flat.
So in this instance, there really is no problem using a "flat" GM bearing which does still have a radius at the outer edge vs what the clutch company wanted to use, which gave me problems.
09-15-2017, 12:47 PM
#294
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Yea......we used a tilton 6000 series on my buddies 5gen we put a 5.5 tilton in.
I thought it would be easier because of the way it adjusted but wonce bolted up it was to far from the clutch. We made a spacer and it all worked out then.
I thought it would be easier because of the way it adjusted but wonce bolted up it was to far from the clutch. We made a spacer and it all worked out then.
09-15-2017, 04:52 PM
#295
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Tilton pay you for this R&D work?
08-10-2020, 02:14 AM
#298
I know most people here probably get tired of hearing my setup currently but I run a mcleod rst which is a 9.8" clutch (less moi than a 12) and with its fidanza flywheel it comes in at 34 lbs on the nose as a total setup. The difference from the stock clutch to that was HUGE. The engine revved so much easier going through the gears and was much quicker from a roll. Monster makes a great product and I'm not bashing them in any way. However my rst shifts every bit as good as my buddies stage 3's (he's had 2 now) and I can literally take off by just letting out the clutch, no chatter no bucking and the pedal feels jsut a little lighter than stock even with my tick m/c. I cant dream of doing that to his without it bucking or having some chatter.
Edit: SOLD. Thanks everyone!
Last edited by eb110americana; 08-12-2020 at 06:45 PM. Reason: Items no longer available.
08-10-2020, 11:44 AM
#299
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That radius bearing face is interesting. I bet that partially addresses the occasional "progressive" clutch effort - where the further you push the pedal, the stiffer it sometimes gets due to the contact point moving outward - making less mechanical advantage on the PP finger.
I won't go and drop my transmission for one, but next time it's out, I'll have to take a serious look at that
I won't go and drop my transmission for one, but next time it's out, I'll have to take a serious look at that
OEM GM T56 bearing has a flat face. There are examples of OEM radius faced bearings. Mazda used them on 2nd and 3rd gen RX7s because their clutch used a flat diaphragm spring.
You can use a flat faced bearing with flat springs, but that is not optimal for reasons stated below.
A radius faced bearing completely addresses this point because it results in a single point of contact between the bearing and the spring. A flat bearing initially makes contact with the spring fingers at a diameter closer to the input shaft centerline (spring finger tips), then as the bearing movement increases the bearing outer rim makes contact with the spring at a diameter further out from the center of the input shaft, thus increasing pedal effort (due to reduced mechanical advantage) and resulting in a non-linear pedal feel.
Andrew
You can use a flat faced bearing with flat springs, but that is not optimal for reasons stated below.
A radius faced bearing completely addresses this point because it results in a single point of contact between the bearing and the spring. A flat bearing initially makes contact with the spring fingers at a diameter closer to the input shaft centerline (spring finger tips), then as the bearing movement increases the bearing outer rim makes contact with the spring at a diameter further out from the center of the input shaft, thus increasing pedal effort (due to reduced mechanical advantage) and resulting in a non-linear pedal feel.
Andrew