My 1988 LFX F40 build. (Page 64/66)
Rickady88GT DEC 02, 09:38 PM

quote
Originally posted by Joseph Upson:


I used an OE new first design clutch master cylinder because it was the most dependable for me of all of them made for the Fiero, and simply spaced it off the mount surface a bit and never had a problem.



Do you loose travel in the slave cylinder?
I do not have this in my car yet, but one of these days I will put the F40 in and bench the automatic. When that happens, I think the correct cylinders working together should give the best pedal feel and travel for the set up. I believe the original F40 had a dual mass flywheel? And may have required more travel than the Fiero F40 system? My goal is to get my hands on some parts and see first had how it all works together.
I really appreciate the documentation and advice. Thanks everyone
Daryl M DEC 03, 02:22 AM

quote
Originally posted by Joseph Upson:


I used an OE new first design clutch master cylinder because it was the most dependable for me of all of them made for the Fiero, and simply spaced it off the mount surface a bit and never had a problem.



How heavy was the pedal? My setup with the Fiero master is way more than I want to deal with. Way heavier than the stock 87 GT I sold a couple of months ago.
Joseph Upson DEC 03, 04:13 AM

quote
Originally posted by Daryl M:


How heavy was the pedal? My setup with the Fiero master is way more than I want to deal with. Way heavier than the stock 87 GT I sold a couple of months ago.



Loosing travel to deal with the hydraulic volume was the goal, only the pedal didn't feel any different to me. The adjustment was not an extreme amount, possibly 1/4". My initial install used the stock dual mass and clutch. The motor was turbocharged and I noted a slip at some point on what should have been a solid setup. That's when I discovered via email to the flywheel manufacturer that dualmass flywheels (theirs) are torque limited to about 10% above the engine it was rated for.

It was all custom after that, solid flywheel, kevlar disc and modified heavy duty stock GM 2.8L pressure plate to about 2500 lb clamping pressure. The pedal was a bit stiffer, but not what I recall some V8 pedals being. In stop and go traffic in Atlanta it was a workout at times, but I imagine it would have been regardless given the number of times the pedal had to be pressed. The first design master cylinder is a bit more unique
compared to the others and it always delivered a firm feel. I always had trouble with the cast iron and steel tube models almost immediately upon putting them in use as remanufactured units.
Daryl M DEC 18, 05:08 PM


This is my solution to the clutch master cylinder piston being too big. After considering modifying the stock master cylinder, I decided to go with the Saab unit that matches the F40 clutch. Now I just have to do something with the pedal linkage end.

[This message has been edited by Daryl M (edited 12-18-2021).]

Daryl M DEC 19, 07:15 PM


Yes, the Saab master cylinder is in and bled. It feels much lighter. I still have to mount the reservoir and get some hose clamps, but I really like the pedal feel now. Although the wiring prevents a real test, with the pedal depressed, the clutch does seem to completely disengage.
Rickady88GT DEC 19, 10:35 PM
Not trying to rush you or anything.......BUT sound clips, dyno specs, burnouts and such.......
Thanks for the updates
Daryl M DEC 20, 12:05 AM

quote
Originally posted by Rickady88GT:

Not trying to rush you or anything.......BUT sound clips, dyno specs, burnouts and such.......
Thanks for the updates



Yes, I get it.

Will DEC 21, 01:46 PM

quote
Originally posted by Daryl M:



Yes, the Saab master cylinder is in and bled. It feels much lighter. I still have to mount the reservoir and get some hose clamps, but I really like the pedal feel now. Although the wiring prevents a real test, with the pedal depressed, the clutch does seem to completely disengage.



That's pretty cool!

What does the pedal end look like?
Daryl M DEC 21, 05:55 PM

quote
Originally posted by Will:


That's pretty cool!

What does the pedal end look like?



I cut the end from the stock Fiero unit and made a sleeve to splice the old end to the Saab rod. I epoxied it with West Systems Epoxy and their 404 high density filler. The stuff is indestructible.

reinhart DEC 25, 05:38 AM

quote
Originally posted by Daryl M:


I cut the end from the stock Fiero unit and made a sleeve to splice the old end to the Saab rod. I epoxied it with West Systems Epoxy and their 404 high density filler. The stuff is indestructible.



Good idea. I made the stock banjo adjustable by cutting it and then welding in some threaded rod and adding a coupling nut.