[JohnnyK]

I will check and get back, thanks!

 

[JohnnyK]

I just checked.. I'm using basically the stock mounting points in the firewall and the pedal support. Had to drill a new bottom one I believe..

My pedal support is in the correct place, right? As I recall it bumped the cowl, but that is probably due to the fact I welded in a new one and the contour is off.. I don't see a hole in the firewall for the bottom hole that you see in that picture, but that top hole that nothing is going through seems to line up, so I assume thats correct. And as I said, I didn't drill any new holes in teh top for the booster.. What gives here?

 

[66emberglow]

Any chance you could measure how long the pushrod is from the back of the booster to the pedal? Just from the inside of the firewall to the center of the hole would be close enough of course.. And for arguments sake, anyone have another 67-68 booster they could do as well? It's driving me frikkin insane. Thanks!

Pedal pin measures 4.5 inches from the firewall with booster/pushrod installed. Pedal looks to be in normal position, but the pedal pin was repositioned by MustangSteve to give a better power ratio.

 

[JohnnyK]

hmm.. Ok, so it is the longer fox body pushrod.. I'm wondering if they drill 4 new holes and mounted the booster lower on the firewall, instead of just drilling the 1 or two new bottom holes.

 

[ultrastang]

I just checked.. I'm using basically the stock mounting points in the firewall and the pedal support. Had to drill a new bottom one I believe..

My pedal support is in the correct place, right?
As I recall it bumped the cowl, but that is probably due to the fact I welded in a new one and the contour is off.. I don't see a hole in the firewall for the bottom hole that you see in that picture, but that top hole that nothing is going through seems to line up, so I assume thats correct. And as I said, I didn't drill any new holes in teh top for the booster.. What gives here?

Johnny,

I see that what I thought MAY be the problem IS in fact the problem.

Your booster is mounted too high on the firewall. Go back to the photo I posted earlier and look where the top booster stud is in relation to the pedal support vs. where you have yours located.

This would put your input rod higher up on the pedal's upright, and reduce the distance of the fulcrum point. It would force your pedal way back, and that would in turn make it sit very high when at rest (when not being applied).

 

[JohnnyK]

It does indeed appear that yours is lower.. So is yours mounted lower than the stock booster would be mounted? As I said I just used 3 of the 4 stock mounting holes for both the booster nad the pedal.. I dont see any of the stock holes in your pedal support though? Is that custom, or did you weld them up to close them? Also as you can see in my picture, i only have about 1/4 or slightly more of the middle hole to lower the booster.. Did you enlarge that hole? Err, basically what I'm asking, is, did you drill 4 new holes to mount the booster lower to make up for the longer input rod? Thanks!

 

[ultrastang]

It does indeed appear that yours is lower.. So is yours mounted lower than the stock booster would be mounted? As I said I just used 3 of the 4 stock mounting holes for both the booster nad the pedal.. I dont see any of the stock holes in your pedal support though? Is that custom, or did you weld them up to close them? Also as you can see in my picture, i only have about 1/4 or slightly more of the middle hole to lower the booster.. Did you enlarge that hole? Err, basically what I'm asking, is, did you drill 4 new holes to mount the booster lower to make up for the longer input rod? Thanks!

This photo shows a side-by-side comparrison of an unmodified '67/68 pedal support (on the left), and the modified pedal support (on the right).

This isn't a custom support. I just didn't like the unused stock holes left in the support, so I welded them up. http://www.ultrastang.com/Images/Scanned/Sept2002/12.jpg

You'll notice on the modified pedal support that the holes are lower compared to the ones on the unmodifed support. You can also see that pretty much the bellows of the Fox booster would be centered between the "diamond" stampings that you can see on the support.

 

[JohnnyK]

Aha.. Seems to be about an inch lower on there.. So does that mean you welded up the stock holes on the firewall for the booster, and drilled new ones about an inch lower? (All 4 holes?)

 

[ultrastang]

Aha.. Seems to be about an inch lower on there.. So does that mean you welded up the stock holes on the firewall for the booster, and drilled new ones about an inch lower? (All 4 holes?)

Johnny,

Yes, I welded up the stock mounting holes in the firewall and drilled new holes for the Fox booster. I also enlarged the big center hole where the rubber bellows of the Fox booster goes in through the firewall. I used an electrician's 2" Greenlee knockout --used to pop holes in junction boxes, termination cabinets, etc. for running conduit into those type of enclosures.
The 2" knockout makes perfectly round 2-3/8" diameter holes, which is exactly the diameter needed to clear the diameter of the Fox booster's pushrod boot; http://img239.imageshack.us/img239/5559/greenleeknockoutpo4.jpg

This is a plate/template I made. I layed out the pattern with this and then welded this plate onto the mounting face (front) of my pedal support prior to installing the pedal support in the car.
http://img237.imageshack.us/img237/1794/foxbrakeboostertemplatewv6.jpg

 

[JohnnyK]

Thanks for the reply man. Yes, it seems i would have to drill some new holes to make it work with the extended pedal rod.. I won't be drilling into my new firewall anymore I don't think.. Has anyone tried the metro booster? Apparently the pushrod is adjustable, but.. who knows

I'm really trying to think of a way to shorten the fox boosters input rod. The only problem is it's inside of a 1.5" (approx) wider plunger.. I could cut it, but it would be hard to get a good weld in there. Plus I dont know if I really trust a weld on that piece.. and it would be almost impossible to get a piece of tubing overtop of it to weld in there.. I'd ideally like to thread it, but there would be no room to get a tap (die, whatever) in there.. at least of the 1.5" round variety. Is there any other type? Plus I'd have to find a way to hold the rod from spinning.. Open to suggestions once again.. Man, it'd be great if the original boosters weren't so frikkin pricey.

 

[JohnnyK]

http://static.summitracing.com/global/images/prod/large/sum-760125_w.jpg

Take a look at that apparatus on the left.. I, since I have come this far, am thinking of chopping the end off my booster, threading as far down as I can, and installing something like that. Then drilling a hole in the pedal. Does anyone see a problem with this? Not going to buy this kit, but just going to find something in a local hardware store, or build it.. If I Could find something like the threaded things to the right, that would work as well..

Hey Ultra, you know how you lowered the booster? If I'm not going to do that, just shorten the input rod, am I going to have any clearance problems with anything? It's below that 'seam' where the cowl welds to the firewall.. Maybe the brace or something, but besides that? Did you lower it because of the longer input rod, or for clearance (5.0 booster).. Thanks!

 

[JohnnyK]

Welp, chopped the end off.. threaded as far down as I could go, which really, wasn't that far.. Found a 'yoke' or something like I stated in that previous picture from an industrial supply place ($20.. Sheesh.. For a tiny piece of forged steel).. Anyways, it clocks in at about 3.75 or 4" now, which is still a good inch shorter. about .5" longer than a stock booster rod. Only problem now is getting the original pin out of the brake pedal.. Can't seem to drill it, and an 11 ton press just bend the pedal.. Guess I'll try a grinder tomorrow.. Looks like it should work out nicely though. I'm sure I ruined the booster in the process though..