1 1/8" Master Cylinder Bore Size

[Mieser3]

Was wondering if anyone is using the Wilwood aluminum master cylinder with the 1 1/8" bore without a booster and how the pedal feels. I originally planned on running a booster with this master cylinder and D52 calipers at all 4 corners but have decided to clean the firewall up by not running the booster. Does anyone foresee any problems with the 1 1/8" bore and no booster?

Thanks

[lolife99]

I can't answer your question "from experience",... but I think you will have ALOT of "pedal effort" with a 1-1/8" bore M/C and no booster.

Most run a 7/8" or 1" bore when running without the booster.

[68c10airstream]

I was a dealer mechanic for a long time and i will throw this out, think of the times your vehicle died on the road and after you pushed the pedal a few times and exhausted the booster, the pedal got rock hard and didn't stop well. Yes it was designed there but still a huge boost non the less. Also think of the surface area that the booster has multiplied by the vacuum forces and it adds up. As another idea to clean up the firewall, some truck if remembering correctly ran a 90 degree pedal assembly maybe under the dash, or a hydroboost under the dash. Fun stuff on a blank sheet. Good luck, Brian F.

[CC69Rat]

I have a CPP booster and Wildwood MC on my GMC and the pedal feels really firm but not hard .. ( if that doesn't sound contradictory) Difficult to explain but I would suggest a booster with 1 1/8 .. if no booster do 7/8.
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[screaminchevypickup]

I run the 1" bore on non power brakes.. Pedal is firm but they have always stopped well.
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[wraprail]

Originally Posted by 68c10airstream

I was a dealer mechanic for a long time and i will throw this out, think of the times your vehicle died on the road and after you pushed the pedal a few times and exhausted the booster, the pedal got rock hard and didn't stop well. Yes it was designed there but still a huge boost non the less. Also think of the surface area that the booster has multiplied by the vacuum forces and it adds up. As another idea to clean up the firewall, some truck if remembering correctly ran a 90 degree pedal assembly maybe under the dash, or a hydroboost under the dash. Fun stuff on a blank sheet. Good luck, Brian F.

Thats funny, you really think an exhausted booster on a power brake system has the same pedal effort as a properly sized and installed manual brake system?

Manual brakes you would use a smaller master cylinder bore size (smaller bore=higher pressure right?) and a larger pedal ratio (again, larger pedal ratio=higher pressure)
So to make that comparison is just ridiculous.

I use a 24mm master which is slightly smaller than 1", Non power, 4 wheel disc and have for 13 years.
Stops excellent. Light pedal effort.
I wouldn't use a 1 1/8 master on manual unless you got pretty agressive on the pedal ratio. 6to1+
A lot easier to go smaller bore.
With your single piston calipers you should be fine.

[Mieser3]

Thanks for the information guys. I may just go ahead and run the booster since I've already purchased a polished stainless one and the Wilwood master cylinder.

[PaPaStewySnipes]

Doea it fit up to a stock booster without mods?