Pedal box for road racing FD3S
 

Hi group, has anyone installed an adjustable pedal box such as a Tilton 72-607 in an RHD FD? Keen to know your experiences regarding fitment etc.
We are rebuilding the car which currently runs XYZ 6 piston fronts and XYZ 4 piston rears, both with 330mm rotors.
The car was running the standard FD 15/16 bore master cylinder and factory ABS (3 channel).
We are also entertaining installing either continental or Bosch motorsport ABS
All feedback welcome

No experience installing one in an RHD car, but what I'm planning on doing with my pedal assembly (the tilton overhung variant) as soon as the roll cage is fabricated is having two pieces of flat bar stock (perhaps 0.250"/6.35mm) bent and welded to the dash bar and the firewall with reinforcement plates and mounting holes to locate the pedal assembly. IMO that would likely be easier to make work if you don't already have the firewall mount variant on hand.

I don't know how you car is packaged, but if you're planning on mounting the ABS unit in the interior, overhung would probably work better because you won't have to go back through the firewall from the master cylinders to reach it.

Interested to hear how the motorsport ABS implementation works for you. Have been strongly considering it.

All the tilton equipped cars I've seen locally have been floor mount, which needed mods to the firewall as well as the floor to fit.

DIYman(?) in HK did have a Revolution overhung set-up with a few pictures on here I believe - I think he must have sold the car as he's disappeared for several years and into rx8s last I saw. I made something similar using the stock box, with a tilton balance bar, but changed the pedal ratio and had to use 60 degree AP masters to make it fit....and also didn't trust a welded stock pedal or an aluminium tube for the balance bar to bear upon and remade it all in steel.

Might be telling you how to suck eggs, firewall reinforcement would be good!

i think i could come up with a pic of the Revolution setup, if needed,
and that was easy, Revolution Online Catalog / AP?????????????

it kind of looks like there is a pillow ball in the pedal to be the pivot?

By coincidence, looking under images, appears there's a second hand one for sale at the moment https://www.croooober.com/en/item/cp...5BRX-7-FD3S%5D. Looks like the urethane brake switch stop has rotted out as usual. Possibly only a 1/8"/3mm reinforcement plate used - if I had to guess.

A interesting bit of the detail of the balance bar is shown, definitely aluminium welding in the Revo cattle dog above ^^^, this one appears to be a shrink fit(?) steel insert with the balance bar sleeve tacked inside.......saving the pictures for posterity
https://cimg1.ibsrv.net/gimg/www.rx7...28930104c8.jpg
https://cimg2.ibsrv.net/gimg/www.rx7...bbee90adff.jpg
https://cimg5.ibsrv.net/gimg/www.rx7...6a0d485cd0.jpg
https://cimg7.ibsrv.net/gimg/www.rx7...c6ae52d26d.jpg
https://cimg0.ibsrv.net/gimg/www.rx7...a69eb6effc.jpg
https://cimg1.ibsrv.net/gimg/www.rx7...8384c25f57.jpg
https://cimg3.ibsrv.net/gimg/www.rx7...0d4b0298d1.jpg
https://cimg5.ibsrv.net/gimg/www.rx7...a60f3e5f8e.jpg
https://cimg6.ibsrv.net/gimg/www.rx7...c7ec07d70f.jpg
https://cimg1.ibsrv.net/gimg/www.rx7...fcc71b92b5.jpg

This information is like gold, Interesting to see if it is LHD or im guessing RHD, and their choice of master cylinders. One would need a seperate fluid reservoir for the clutch master cylinder too :-)

the other interesting thing is that the AP cylinders seem to be the same bolt pattern as the booster, which is super convenient

It will be the usual 2 1/4" spacing on the masters. Didn't keep a list of the stock dimensions, but probably looking at ~ 60mm vertical spacing and you'd also have some wiggle room with an 8mm bolt in a 10mm hole (iirc?).in both the pedal box tubular mounts and masters.

Looking at that modern version again, it's very fuzzy, there might actually be a thin wall sleeve pressed inside?

With Up Garage selling it and the bend to the right, it's going to be RHD. The usual default 5/8, 3/4 master arrangement there, which probably isn't a bad starting spot really. For the clutch reservoir, I just made a clamp and moved one AP tallish thin reservoir to the right of the brake ones for better heat isolation - you probably could use a remote with dual outlet to replicate something close to a stock set-up too.

The AP catalog has the Balance bar in it, i can't tell if tis the HD unit or not
i mean its still easier just to let Revolution make you one, but if say you owned an FC....
i like this setup, its so simple i never would have thought of it

https://cimg4.ibsrv.net/gimg/www.rx7...200770fd94.jpg

I have been in discussion with Bosch Motorsport in regards to their M5 Motorsport ABS kit and its imperitive that the master cylinders need to be ABS compatible, ie a special bleed to minimise the high pressure fluid oscillations damaging the master cylinder "O" Rings when in operation. Somthing I didnt even think about

Did find the vertical measurement, 58mm for the booster v 57.15 for the masters, so an easy match. From memory the horizontal was more critical, I used a discontinued 2.75" bar here, but with the change in pedal ratio and mods to the pedal box anyhow, it wasn't a significant factor.

Those AP balance bars, 32 nominal for the standard sleeve, 33.4 for the HD, spherical in the standard is ~ 23.....and assume that's the same in both.......smaller there would be better to allow more meat in the pedal where the force is translated.

Quote:

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Originally Posted by garethb

I have been in discussion with Bosch Motorsport in regards to their M5 Motorsport ABS kit and its imperitive that the master cylinders need to be ABS compatible, ie a special bleed to minimise the high pressure fluid oscillations damaging the master cylinder "O" Rings when in operation. Somthing I didnt even think about

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There are a couple of FDs with the MS ABS installed locally, the last guy with it I had any personal contact with sold his about 4 years ago though. Some sort of spring loaded valve to stop backfeed, I think I've seen something similar on OEM masters from donkey's years ago??

I didn't reply because I was under the assumption you wanted a full on professional pedalbox. But if the construction like the crooober pictures is an option you would consider, go look at CompBrake.com

Just had it installed on my FC but still need to fully test the setup and potentially test other master cylinders.

https://cimg1.ibsrv.net/gimg/www.rx7...2bbe35aa43.jpg

As expected, the price is completely unreasonable.

i have run manual brakes on my FD since 2010 and it is one of my favorite mods. the leverage on my setup adds to the pedal ratio so braking is easy on the leg. during my typical 37 minute SCCA race i would adjust my brakes at least once towards the end of the race as 80 pounds of fuel was burned off and the track rubbered in. cockpit adj.

https://imagizer.imageshack.com/v2/1...923/hyANlk.jpg
https://imagizer.imageshack.com/v2/1...924/OjUHIg.jpg

https://imagizer.imageshack.com/v2/1...923/r8GzE7.jpg

How much did that setup cost?

"How much did that setup cost?"

don't recall exactly. i bought it off a forum member (Damian)... around $500. i did buy new master cylinders as a refresh and of course did a bit of brakeline work primarily relating to ditching the lousy ABS.

the mechanism might be something for someone to duplicate as there might be a market for it. one of the keys is the additional leverage that makes it very street friendly. it is awesome on a roadcourse.

So it looks like quite a few vehicles share the same mounting hole spacing where the booster is affixed to the pedal (I believe it was 60mm x 80mm, please correct if not), and there are manufacturers that offer solutions for other platforms that could very likely work given you have the requisite depth forward of the firewall and size your master cylinders accordingly. If I were reusing the OE pedals for my application, it is likely that I would have done that or something very similar.

i think the pattern is an SAE standard, certainly after 1977 every Mazda, Ford, Subazerati and many others are the same

https://www.compbrake.com/product/ma...ylinder-kit-a/

Pretty reasonable, IMO!

MAZDA RX7 BRAKE BIAS SERVO REPLACEMENT PEDAL BOX KIT – HYDRAULIC DUAL AP CYLINDER

WOW, what a find, very similar to mine but doesn't look quite as home built... although mine works perfectly. i am going to check availability and swap for it.

One of these two kits appear to be the ones to get as they include the lever to increase pedal ratio since we are ditching the booster. Can't tell from the pictures if it would bolt up to the stock pedal.

https://www.compbrake.com/product/ma...inder-kit-a-2/

https://www.compbrake.com/product/ma...inder-kit-b-2/

I purchased one of the compbrake units from a forum member (the one that 1badFB posted) a little over two years ago and can attest that it does appear to be a quality piece, though I never got around to using it. I would suggest trying to see if it is possible to purchase sans master cylinders as the sizing of which will be contingent upon your desired pedal effort, caliper piston diameter and rotor diameter among other aspects.