PDA

View Full Version : Power brakes and power steering



Makgecko2017
03-02-2017, 08:52 AM
How difficult is it to install these? I'm debating if I should do this or regret not doing it later.

Mike

edwardb
03-02-2017, 09:35 AM
Two separate discussions. With power brakes, first question is which pedal box? The Wilwood pedal box, probably the most common used now, is designed to be manual. It takes mods to the Wilwood pedal box and you lose the separate master cylinders and built-in front/back balancing capability if you go to either vacuum or hydroboost power. If you're using the Wilwood pedal box, my personal recommendation is use it as is. The pedal will be a bit harder than boosted, but you will have solid braking. Different pads can be used to get even more braking if necessary. For power steering, I've had both and wouldn't have one without power steering. This is my standard response: Power steering discussions seem to almost always center around reducing effort. Then it turns to not hard while cruising (true) and don't want to overboost and loose feeling (also true). But steering while at low speed or parking is really stiff and not fun. Trust me. Boost can be properly managed. And the rest of the story is front end alignment can have double the caster which translates into much improved centering and overall straight line stability. The difference is really significant. Plus if you plan to track or autocross the car, power steering is just about mandatory.

In both cases, they can be added later. But it's way harder and you will end up taking out perfectly good parts and buying some things twice. Best to install whatever you decide during the build.

DadofThree
03-02-2017, 01:07 PM
If you have a sn95 pedal box and are thinking of adding the power brake booster;
I'd suggest to do it now. Modification needs to be done to the pedal box (small trimming so it doesn't interfere with the flange bearing), and you'll need to enlarge the hole in the front driver side steel plating. You'd also need to cut the frame to make room for the booster.

https://c1.staticflickr.com/4/3725/33168872846_453d9a7da2_z.jpg

Power Brake Mod Day 1 (http://buildacobra.blogspot.com/2015/12/started-power-brake-mod.html)

Power Brake Mod Day 2 (http://buildacobra.blogspot.com/2015/12/whitby-power-brake-nightmare-cont.html)

Dave

Feen
03-02-2017, 03:34 PM
I'd do both now. Modifications with the WW pedal box are minor and probably not mush different than what Dadofthree describes, but you will lose functionality that edwardb described. As for power steering, few different ways to go. Probably the easiest and cheapest route is to follow the Jeff Kleiner method with autozone rack.

JRL16
03-02-2017, 04:12 PM
The only thing that you have to make for power steering are the hoses. Breeze has all you need for those. No modifications to the car. Power brakes are another thing. I went with the Whitby booster and have no regrets. You will have to make modifications but taken one at a time it is not as bad as you first think. At first it can be a little overwhelming. It will never cost less and be easier than it is if you install while you're building. I have power steering and brakes in my MK4 and would not want to have added those after the build. Price is another issue, neither are cheap but not many things are in these cars.

michael everson
03-02-2017, 05:15 PM
If your not using a hydraulic clutch then lose the Wilwood pedal box and get a mustang one. Then just add the booster and spacer along with the described mods to the frame. Very easy t do now and very difficult to do later. There are literally thousands of Cobras using the Mustang pedal boxes. They work great. I fI was doing power steering, I would look into some of the electric units people have been using. No hoses, no pump and no leaks. Plus you can use the FFR supplied rack.
Mike

skidd
03-03-2017, 08:30 AM
My brakes are still being finalized (custom reservoirs).. So I can't comment on the effect.. but.. FWIW.. Here is what I did to get vacuum Power Brakes installed.
- SN95 Pedal box, Fox brake booster, 1993 Cobra Master Cyl
- Enlarged center hole for booster clearance through footbox wall.
- Installed steering steady-bearing on inside of footbox wall.
- Enlarged bolt holes on.. I think 2 of the holes if I recall.
- approx 3/8" - 1/2" spacers on the 4 bolts between the footbox wall and the booster.
- Installed foam rubber between booster and footbox to prevent any hot-air seeping into footbox when driving.
- 2x aluminum remote reservoirs
- Clearance Dimple in wheel-well aluminum for master, it sticks forward about 1" into the aluminum piece.

Hope that helps some.

mcwho
03-03-2017, 09:00 AM
I decided early on to do both. No Regrets !

I have the complete MK4 kit w wildwood pedal box.

Power streering: Using the Whitby P Brake kit

Power Brakes: using a powered rack from Breeze with a HEIDTS valve for for adjustability.

hydraulic Clutch: Also have a hydraulic Clutch. (Modern Driveline) Decided on this while attending the build school and experiencing the stiff clutch.

AC Bill
03-04-2017, 04:19 AM
Now those subjects have been debated many a time over the years. No right or wrong answer, just a personal choice.:)

I have neither, and never regretted it.
The cars are light, easy to steer. Disc brakes stop them just fine without having to pull groin muscle. You could get higher ratio steering racks for easier cranking during parking, or just eat your Wheaties.. I also like the lack of hoses, p/s pump and brackets. Tidier under the hood, more like an original.

JJ in Cbus
03-06-2017, 07:07 AM
I just got my MK3.1 on the road with both manual. When I remove the body for paint I plan on adding power steering and possibly power brakes. I am looking at the Prius electric steering column. Still having a lot of fun in it's current config, but power steering would make it more comfortable.