looking to use the same setup I have on my ws6 on my new setup. (I would like to replicate it) The clutch is stage 2 monster and feels solid. not to hard not to soft.

It looks like factory is a 3/4"bore and the only way I got it to work is by modifying it to be adjustable.

So on my next setup I would like to step it up to 7/8"bore willwood master cylinder. using same oem clutch slave the pedal should feel stiffer and would like it to feel the same as the fbody if not softer.

I can modify the clutch pedal a bit to get the optimum ratio. but would like to know what the ratio of the stock clutch pedal ratio for the fbody is, for comparison.

Also how much stroke does a 7/8 master need when coupled with oem slave?

lastly what is the bore size of oem slave?

thank you

 

might want to consider the 13/16 bore

http://www.mcleodracing.com/index.ph...1998-2002.html

 

any particular reason why the 13/16?

and that is one pricey master cylinder.
I was thinking since I have unlimited options for master I would just go with a wildwood 7/8 master.

I had good success from previous project and its only $80

 

13/16" is just one size up from your stock size if you feel you need more volume per stroke out of your hydraulics.

The 7/8" bore will give more volume per stroke if you feel you need that much. The larger the MC bore the shorter the pedal travel is so if you go to big the clutch can become more of an on/off switch in terms of having a very short pedal throw.

If you feel the 7/8" is what you like, go for it.

McLeod uses the Wilwood compact MC. You can just buy the Wilwood either direct from them or another vendor but you would need to make a flange to mount it to your pedal assembly and get a threaded adjustable rod

 

would you happen to know the ratio of stock fbody pedal? and how much travel the 13/16" master needs?

while the on/off is a concern my main focus is to make sure I don't go to big of a master and add unnecessary pedal pressure. only way to make the best choice is to figure out some technical info.

if the 13/16 can get the job done with the available travel in my clutch pedal then I will go that route.(I measured roughly 1" max travel on the custom pedal)

 

IDK what the ratio is. Your 1" travel is on the short side for your "custom" pedal so a larger bore MC will help in dealing with that short of a distance of travel

1/16 larger will result in about 10% more pedal effort. IDK if going 1/8" larger means 20% more over stock

 

any links to the 10% info?

I did some P=F/A calculation and with the same required pressure and a chance in area the force required difference in about 17% for 1/16 and 36% for 1/8.

36% is a huge difference in effort if i did the calculation correctly.
Im sure around town this is fine but i dont know about traffic situation.

 

I was told by McLeod when discussing my Street Twin clutch and they said for the LT1 "pull" twin that required a larger bore mc over stock so they included the 13/16" bore MC in the clutch kit

and said pedal effort would be "about 10% greater than stock".

IDK the math involved in determining this but can say after installing the clutch & MC the pedal effort is "more" but not anything uncomfortable in stop & go traffic. Nothing like the old school 3 finger Borg & Beck manual linkage clutch I had in my 57 chevy which was seriously heavy clutch pedal to hold in.

Ironically McLeod recommends the stock MC bore size for the RST/RXT twin clutch