Heavy hydraulic clutch pedal

[Paul Buxe]

So I finally got the LS2 engine installed and running in the Panoz. I had installed a brand new stock Corvette clutch and pressure plate with a brand new 1400 series McLeod clutch slave cylinder and an old rebuilt stock Panoz Wilwood master clutch cylinder. Well the system work fine, except the pedal pressure is very high. Is this common with Panoz hydraulic clutch? I was thinking of seeing if i could get a smaller diameter master cylinder to trade pedal stroke for reduced pedal effort. Has anyone done this? What diameter master cylinder bore did you go to?
Comments?
Thanks

[Paul Buxe]

Does anybody know if the stock master cylinder is a 1" or a 3/4" bore?

[Gatorac]

It should be cast into the master somewhere.

[Paul Buxe]

Thanks, I'll take a look.

[Paul Buxe]

Turns out its a 1.00" bore diameter, so if I go with a .750" bore diameter I will have only ~56% of the pedal force,its an piston area thing, but also have to deal with 56% more pedal travel. I think I order one from Summit and give it a try. I went out and compared pedal force on my FFR Cobra, and the Panoz was MUCH harder, maybe 3 time the force required. So we will see how it turns out.
Or maybe I'm just a puss.

[Gatorac]

While it's likely your a puss, 1" is pretty darn big for a HTB

[Paul Buxe]

Well I guess I'm a puss, I put in the 3/4" bore master cyl and the clutch is lighter, but still way harder than my FFR Cobra is. From what I have heard, the LS2 Corvette uses a 3/4" bore master cylinder, and thats the pressure plate I'm using, so i thinking maybe the Corvette slave cylinder has a larger pistion area which would make for a lighter clutch. Or maybe I really am a PUSS.
Anybody know if the T56 slave cylinder would fit a 3550 trany input shaft? I hope I'm not a PUSS and that maybe the slave cylinder I got is too small. Any thoughts, except the PUSS thing?

[Gatorac]

Any thoughts, except the PUSS thing?

I think you solved the mystery. Kinda drawing a blank on anything else. Maybe a Miata would be better for you. :-)

Have you looked at what the hydraulic TOB manufacturer's recommend? Seems like it shouldn't be a secret. Especially with a standard pedal set up like what's in the Panoz. The clutch in my new BDR was pretty tough. I moved the pivot point for the slave pushrod and helped it a lot. I may change the MC too. What TOB did you use?

[Panoz26]

Paul, on my LSx engine - I went with this setup from Tilton:

http://www.tiltonracing.com/content.php?page=hydraulic

it's very smooth and very, very easy to depress the pedal.

Devin

[NZGTRA17]

Originally Posted by Panoz26

Paul, on my LSx engine - I went with this setup from Tilton:

http://www.tiltonracing.com/content.php?page=hydraulic

it's very smooth and very, very easy to depress the pedal.

Devin

I fitted the same unit to my car as well (new). 4 hours into our last race it let us down by developing leaks at the banjo unions. If you use this unit (which is otherwise an excllent design) ditch the banjo unions and fit solid elbows - unless you enjoy hoisting the engine out of your car!!

Kel.

[Panoz26]

Originally Posted by NZGTRA17

I fitted the same unit to my car as well (new). 4 hours into our last race it let us down by developing leaks at the banjo unions. If you use this unit (which is otherwise an excllent design) ditch the banjo unions and fit solid elbows - unless you enjoy hoisting the engine out of your car!!

Kel.

Kel, now you tell me. I am at the track this weekend - think they will hold up for first time use? Not like these were easy to get to once installed, I almost ditched them from the beginning -- solid extenstion's out the bellhousing would be most beneificial now.

Devin

[panozracing]

buy the mcloed TO unit....its durable!

[NZGTRA17]

Originally Posted by Panoz26

Kel, now you tell me. I am at the track this weekend - think they will hold up for first time use? Not like these were easy to get to once installed, I almost ditched them from the beginning -- solid extenstion's out the bellhousing would be most beneificial now.

Devin

Kinda figured you would say that Devin!! I would just see how it goes and hopefully no probs until you have the engine out next. Even then if you have had no probs it may not be worth changing. I am not sure if others will have this issue and only sussed out what the problem was when we removed the 347 due to it selling (sold within 40 mins on NZ equivalent of E Bay). Even sitting in the shed we could see the fluid leaking slowly from the banjo unions over a period of time.

Cost us 14 minutes in the 6 hour race to bleed enough fluid in and remove the pedal stop so we could keep racing. That cost us about 4 - 5 places. Ah well, guess Tilton wont want to know about it!!

I am thinking of using 90 degs hose fittings Devin so that better hose alignment is possible. Havnt put much thought into it yet as to busy with engine build.

Kel.

[Paul Buxe]

I also have the Mcleod slave cylunder. They recommend a 3/4" master cylinder, but its still much harder than my FFR Cobra. I just got a 5/8" master cylinder, that should reduce the lead force by 40%, I hope that will fix it. I also hope the clutch will still have enough travel. I'll let you know.
Paul

[eric1h]

i have a 1" MC and its fine, but i have legs like tree trunks! :-D