LT1 T56 master/slave worth upgrading?
Thread Starter
Joined: May 2011
Posts: 1,241
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From: Conshohocken, PA
LT1 T56 master/slave worth upgrading? Putting this in the LT1 section because these clutch setups are pretty unique.
Who has had good luck with the stock master/slave cylinder and high horsepower or RPM setups?
I know the hydraulics are a wear item that should be replaced when fresh pressure plates are installed. I had to replace my factory master/slave when I did a clutch job about 15-20k miles ago because the engagement was too far down the pedal. A new pre-bled AC Delco setup from the dealer did the trick and I've never had a problem shifting at 6300 in my car.
Fast forward to today... my new build entails revving to 7k RPM and a lot of horsepower. The clutch in question is a Spec 3+ and I'll end up replacing the hydraulics again for peace of mind. All of the Spec pressure plates should have the same clamping force but I wonder if the added RPM and more aggressive disc are going to beat the **** out of the Delco master/slave.
Who has gotten away with the OEM style stuff?
Who has had good luck with the stock master/slave cylinder and high horsepower or RPM setups?
I know the hydraulics are a wear item that should be replaced when fresh pressure plates are installed. I had to replace my factory master/slave when I did a clutch job about 15-20k miles ago because the engagement was too far down the pedal. A new pre-bled AC Delco setup from the dealer did the trick and I've never had a problem shifting at 6300 in my car.
Fast forward to today... my new build entails revving to 7k RPM and a lot of horsepower. The clutch in question is a Spec 3+ and I'll end up replacing the hydraulics again for peace of mind. All of the Spec pressure plates should have the same clamping force but I wonder if the added RPM and more aggressive disc are going to beat the **** out of the Delco master/slave.
Who has gotten away with the OEM style stuff?
Thread Starter
Joined: May 2011
Posts: 1,241
Likes: 25
From: Conshohocken, PA
Even with north of 600whp?
That's what I was thinking. It seems like the disc friction material will be doing all of the hard work if the Spec plates are pretty much unchanged between different stages. I know the Stage 3 has .040" milled off of the surface because the disc is thicker but the clamping should be the same.
(flame suit on) The Spec PP should be stamped with the same C70043 as the OEM style PP that's in my car currently. I have no problems with shifting.
That's what I was thinking. It seems like the disc friction material will be doing all of the hard work if the Spec plates are pretty much unchanged between different stages. I know the Stage 3 has .040" milled off of the surface because the disc is thicker but the clamping should be the same.
(flame suit on) The Spec PP should be stamped with the same C70043 as the OEM style PP that's in my car currently. I have no problems with shifting.
My stock setup at 140k was bleeding off pressure if I held the clutch down for more than 2 seconds, it would start to engage and roll forward. Replaced the slave, same issue, ended up getting a stock master and slave prebled kit from rockauto and it was genuine gm parts, exactly like OEM. Everyone from tick and alot on this board kept pressing me to drop $300 on an aftermarket, but it's not needed unless for some reason you need the adjustability. The principle is the same, fluid doesn't compress and it pushes out the slave as you press the clutch. Doesn't matter the hp level.
Seems like those chinese PP's are showing up more and more. As said, an aftermarket MC is only for adjustability. The stock LT1 hydraulics are better than the stock LS1 setup, so there's less need for aftermarket. That said, I have a McLeod adjustable that I really like because of the short clutch pedal throw. I never liked the clutch pedal being so high.
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Joined: Apr 2008
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McLeod offers 2 size MC for LT1 F-body applications the 13/16"(.81) MC pushes more fluid than the stock .75" size for more stroke. Typically needed for twin disc clutch. They are also adjustable so pedal height can be adjusted as well as the throw length tuned for disengagement
for single disc clutches I never had a problem with the sealed OEM one. I found the "replacement" one at O'Rileys (assume other places as well) were exactly same make as OEM.
SPEC claims they "modify" PP to give greater clamp loads...not saying this is fact but their rep went into some detail claiming they did. would not say what they did but just said they made adjustments to it....the picture they sent me showing a machine and a digital readout was supposed to show it measures a higher clamp force. I contacted the maker of the equipment and they advised it was a rivet press....so again I can't verify if in fact anything is done to their PP for LT1.
every PP I have seen as a replacement LT1 regardless of whose name is on it is the same "clone" ones of the original Valeo units. My McLeod Twin is the clone and FWIW McLeod did state they do nothing to increase clamp load on single or multi disc LT1 PP. There are other clutch companies claiming they do though...
McLeod part # for the .81 (13/64") MC is pic below. Made by Wilwood. McLeod makes the adapter part and adjustable rod for many vehicle specific applications. The Wilwood MC is from their "compact" series.
for single disc clutches I never had a problem with the sealed OEM one. I found the "replacement" one at O'Rileys (assume other places as well) were exactly same make as OEM.
SPEC claims they "modify" PP to give greater clamp loads...not saying this is fact but their rep went into some detail claiming they did. would not say what they did but just said they made adjustments to it....the picture they sent me showing a machine and a digital readout was supposed to show it measures a higher clamp force. I contacted the maker of the equipment and they advised it was a rivet press....so again I can't verify if in fact anything is done to their PP for LT1.
every PP I have seen as a replacement LT1 regardless of whose name is on it is the same "clone" ones of the original Valeo units. My McLeod Twin is the clone and FWIW McLeod did state they do nothing to increase clamp load on single or multi disc LT1 PP. There are other clutch companies claiming they do though...
McLeod part # for the .81 (13/64") MC is pic below. Made by Wilwood. McLeod makes the adapter part and adjustable rod for many vehicle specific applications. The Wilwood MC is from their "compact" series.
