Wedge Rear Disc Brakes for TR7

[Delmon]

There was a post about installing rear disc brakes on a TR7. Can anybody point me in the right direction, because I cannot find it again.

 

[NutmegCT]

Maybe this will give you some help?

https://www.britishcarforum.com/bcforum/ubbthreads.php/ubb/showflat/Number/431484/

 

[WedgeWorks]

Delmon-Looking for something like this?

 

[tr8todd]

There is no kit available that I know of. One could be made up without a ton of work. I recommend you start with a caliper that has a built in e brake attachment. I converted my BMW 2002 over to rear discs using a VW Golf caliper. Most people looking for rear discs on a 7/8 usually install a modified Ford 8.8 rear end, that way you get rear discs and a posi in a bullet proof package. The rear end Michael shows in the picture above is from his rally car reproduction. He had to have brackets custom made to locate the calipers, but I'm sure it can be reproduced.

 

[WedgeWorks]

The parts I have in my conversion are Ford Taurus SHO rear calipers with a spacial adaptor plate, spacer plate to replace the old rear drum mounting/backing plate, I think ford Tempo brake rotors mounted on a stock TR7/8 5 speed rear axle. It does not change the rim spacing but you cannot use the stocxk steel or alloy TR7/8 13-inch rims. You need to use an aftermarket 13-inch rim such as panasport, minilite, superlite, etc. I do not have an ebrake cable set up yet but someone will eventually.


Components to the conversion

 

[tdskip]

<span style="font-weight: bold">Way cool</span> - but short of racing does it make a difference on the street? Again - WAY COOL.

 

[WedgeWorks]

Oh it is a huge difference. You can dial the proportioning to the rear discs with a proportioning valve. Plus no more once every year or two years to worry about changing leaking wheel cylinders. You will have or can achieve a 50-50 braking and not a front nose dive with rears locking up and praying you make it!
Here are the calipers typical 1989-ish Taurus SHO with the small springs for the ebrake lever are even with the outside edge of the caliper. If the springs overhang then they will hit the rear coil spring of the suspension.

Below is the Works Rally raer calipers which are a 4-piston arrangment. They also use a hydralic master for the e-brake.

 

[DNK]

Mike on the top diagram there is a "angle 45 degree"
What gets angled?

 

[WedgeWorks]

It is the degree for the angle of the chamfered edge ajacent to the .47-inch ID hole.

 

[DNK]

Was leaning that way.
So that doesn't help with the e brake deal. Does a rally car need an e brake?

 

[WedgeWorks]

The e-brake is very important in Rallying for swinging the back end around on hair-pin turns.

 

[WedgeWorks]

Plenty of room with a 13-inch aftermarket rim.

 

[tr8todd]

Modern rally cars actually use a second rear caliper for the ebrake. It is a hydraulic unit. When you pull up on the hand brake, the other end of the handle pushes against a slave cylinder that pushes fluid to the secondary caliper. It is much easier to modulate compared to a cable driven caliper. Now that's way cool!

 

[tdskip]

Good stuff guys - thanks for the info!

 

[DNK]

Modern rally cars actually use a second rear caliper for the ebrake. It is a hydraulic unit. When you pull up on the hand brake, the other end of the handle pushes against a slave cylinder that pushes fluid to the secondary caliper. It is much easier to modulate compared to a cable driven caliper. Now that's way cool!

Like this

 

[Delmon]

Yes, this is what I was looking for. Thanks much.

 

[Delmon]

Yes, this is what I was looking for. Thanks a lot.