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01/30/07-Assembling Transmission/Brake Booster Modifications


Thursday: Begin assembling transfer case.

Friday: Complete transfer case and reassemble transmission. The total savings was a substantial amount of room and about 30lbs of ROTATING mass.

Here are pics of the completed transmission.

Saturday I began trying to solve the next major hurdle... The brakes. I tried a few things, looked at various brake boosters and master cylinders... What I found to be the most space efficient was a civic master cylinder and booster. I feel confident that this setup will be fine for the street. The car weighs less than a civic EX in full trim, and had plenty of stopping power on layzie's turbo hatch. (In fact, it's layzie's old unit) While this setup isn't exactly track-able, it will do for now. I didn't want to blow hundreds of dollars on a tilton setup just yet, because I don't even know the fate of the car, as yet... but I digress.

Without modifying the civic brake booster at all, I probably could have fit it in place, but the clearance would have been tight. The bolt pattern on the civic unit is a wide rectangle. (3.5 inches wide X 2 inches tall). In order to get the mounting studs to clear the clutch pedal bracket, I would have to cheat the master cylinder almost an inch TOWARD the motor. Also, the studs on the driver's side of the car would be floating in midair, as they passed through the center hole of the old unit. That's no good.

however, if I rotated the booster 90 degrees, the bolt pattern became a tall rectangle (2 wide X 3.5 tall). In this configuration, both of the above problems were solved. The new bolt holes required in the firewall landed on sheet metal (albeit, not a lot) and not only was I able to "re-center" the booster, but was now able to cheat it about an inch AWAY from the motor. Holla.

The next step was to drill the new holes, and clearance the firewall for the snout of the booster. I'm a bit ashamed at how this turned out... I measured twice, carefully drilled the firewall, then tried to fit the booster. What I failed to notice was the clearance for the brake pedal mounting bracket interfered with the studs on the booster, so the whole assembly needed to be shifted around slightly. I was a bit frustrated at this pint, and probably should have called it a day, but I attacked the firewall with a die grinder until it fit.

Pic = YUCK!


Well, now that we had fit the booster at 90 degrees, it was now necessary to rotate the master cylinder BACK 90 degrees. Since the booster is a sealed unit with a rubber diaphragm, welding and/or drilling it was out of the question. My answer to this problem was again the machine shop. Using some 3/8 6061, I fabbed up these brackets in about 3 hours. They allow the master to be mounted at exactly 90 degrees from it's original position.

Still a bit embarrassed about my lousy firewall job, I fabbed up this close-off plate out of 11GA 304SS. The picture is deceiving, but all the edges are perfectly square and all the holes are clean.

Of course, even without the plate, when everything is installed, you can barely see any of the "hack job", but it's there for my personal peace of mind. As for structural integrity, the brake pedal support, which you cannot see, provides all of the support for the booster assembly. The firewall, even in stock form, provides very little support.


The last step, since the booster (and thus, the actuation shaft) moved OUTBOARD 1", the pedal needed to be modified. I don't have a before picture, but perfectly enough, the OEM pedal actually had a 1" extension INBOARD. I simply cut this off and welded it back on @ 0" extension.

After I bolted everything back together, I tested for smooth feel and travel. Success!

We spent the time afterwards relaxing, chilling out and just talking about our feelings.

I also performed some preliminary radiator and intercooler fitment analysis...

The entertainment of the night was watching Gary (deviousTSi) manhandle his 1G DSM with 4 seized brakes into the shop. It was manly as hell.


I have no idea where that close-off plate is.  I hope it’s still somewhere with the brake booster…  I hope I don’t have to do this twice…


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