Clutch master cylinder size and willwood brake master question

[Storm_X]

Ok i was going to keep my original clutch master and modify a brake master beside it, but they will just interfere with my Plenum.

I would just like to know what is the size of the clutch master ? as i am going to purchase this http://www.ebay.com.au/itm/370603496989?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_795wt_932

Also i want to purchase this
http://www.ebay.com.au/itm/350557166335?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_500wt_715
But i am unsure with what size brake masters i will need, i want to use two masters and the brakes i am going to use is Nissan GTR or possibly z32 to fit inside a 15" wheel- front and rear.

Does anyone know what sizing brake masters i should use ?

Thanks Chris

[Fylnn]

I am using dual 3/4" master cylinders with my pedal box using standard rear calipers and Mazda RX7 4 piston fronts.  All inside 15" wheels.  The braking is firm but not excessive.  Depends a lot on pads and the like as well.  I have thought about going down to 0.70" to give me a little bit more stroke and slightly less pressure, but using it in anger (dirt rally car) I have not given it a second thought. 

[BradGTV]

the wilwood floor mount pedals wont fit the floor, they bring the pedal to far back, and u cant mount the mc's on the outside of bulkead as chassis rail is their. (assuming guilietta floor pan is the same as gtv) im using the swing mount pedals.

[Storm_X]

I am a bit hesitant about the flor mount pedal box assemble , I am hoping someone Out there has dOne it or has tried. With the swing pedals seems like they won't fit around the steering Collum .

Brad I know what u mean about them not fitting but I could cut out the floor but yes the shasis rail? Is in the middle in the way .

[BradGTV]

yep chassis rail is right their, i have looked at cutting / reinforcing but it is simply not possible.

swing mount will fit, u need a custom firewall / bulkhead with a flat box section ressed in this is where the mc's will mount out into the engine bay, then u need rhs rails under the dash for the pedals to bolt onto, u will need to make a new mount for the steering coloum to mount to and reinforce the new firwall area to ensure no flexing. not and easy job  (download the drawings of the wilwood website and do some measuring)

[Storm_X]

I've sen the ones with the MC on the inside but that's stupid, I like tO rest my heel on the floor , using top Of my feet on the pedals

[Storm_X]

Cut out the left side of the shasis rail for the clutch and then leave a gap where the shasis rail is then cut Out the right side for the break ? If that makes any sence ?

[Tristan Atkins]

Hi Storm,

It might be easier to modify the existing pedal box. I've seen a few GTV's that have had the pedal box widened to accommodate twin master cylinders.  The advantage of this setup is that you can delete the brake booster and the massive bar that its associated with. I'm sure you could get the cylinders angled to fit under the intake plenum and run remote resevours to facilitate packaging. Most people retain the original hard line and run a flex line from the cylinder.  I'm believe most of the Group S guys run this setup.

I consider looking into this solution myself but I'm sure the fabrication wouldn't be cheep. However, if a few guys are interested a batch order it could reduce the cost. Let me know if your keen to proceed down this route.

Alternatively, if you keen for a floor mount setup you can mount the pistons vertically to improve packaging. Picture here: http://www.facebook.com/photo.php?fbid=10150726459585456&set=o.185745901446670&type=3&theater 

Pg 44 has an exploded diagram of the design Monash uses on their FSAE car. http://flipflashpages.uniflip.com/2/33833/114787/pub/index.html

Regards,

Tristan

[BradGTV]

Alternatively, if you keen for a floor mount setup you can mount the pistons vertically to improve packaging.

interesting idea, i had not thought about, howver by the time you were to modify your pedals / make up a frame to house the linkage / pivot arm your might as well just use swing mount forward facing imo

chris can you post a picture (looking down) on the clearance between your plenum and pedal box? fabricating / modifing your orginal pedal box is easy, i wish i had that option for $$ sake, but my engine is to far back 

[scott.venables]

A guy near me is building a Sports Sedan Mk1 Golf and he's using a pedal box from here:

http://www.obpltd.com/obp-shop/race-car-pedal-boxes/track-pro-vw-ford-peugeot-etc

It's designed to sit on the angled floor pan so it might suit the Alfa.  The BMW E30 pedal boxes look like they would sit on an angled floor pan too. They also have pedal boxes with the master cyl. under your heel. 

Thanks for the link to the article Tristan.  I haven't had a good look at M11 yet, I missed the competition last year and now the cars been shipped.

Scott

[Storm_X]

Scott they seem all to be the same ones I loOked at on eBay .

Brad I haven't modified my plenum to fit yet nor have I tried testing it with the motor, but I know  it will hit on the brake master , clutch should be fine

[Storm_X]

Wish I could borrow a pedal bOx to test fit