GTD brake upgrade

I'm in the process to upgrade my brakes...

First step is identification of the brakes:
Front is clear = Ford Granada MK2
Rear not so clear to me should be MK3. Disc = 252mm and solid.
Can someone confirm these are Granada MK3? see picture + hub carrier dimensions:

So for the brakes I looked into some solutions:
1- AP -> expensive but the best.
2- Hi-spec -> on the shelf solution (front/rear) but customer communication terrible and lead time problems?
3- Wilwood -> front solution on the shelf (superlite Billet 6 pot) but rear is a do-it you-self job.

So still some choices to make here......
 

Attachments

  • 20151228_161127.jpg
    20151228_161127.jpg
    59.6 KB · Views: 628
  • Hub_carier.pdf
    16.2 KB · Views: 291
I'm also interested by the answer, as I have exactly the same setup on my car ... Some added information is probably needed to choose a configuration : what size of wheels do you run ? The classics 15' rims, or bigger ?
 
Curt, you have an early GTD car with under slung rear brakes, these were changed by GTD quite early in its evolution to a different rear upright and bearing carriers with the cal operas mounted on the side. If the car is standard GTD, there are several good options of upgrade, but in my opinion this should commence by changing the pedal assembly to get a greater pedal ratio , this will be a much greater immediate benefit than just changing the brakes themselves. You will then need to consider changing the rear uprights ( and the fronts to do the job properly ) as the rear uprights you have will not carry the brakes you need. I use Tilton pedals , but others are available, with a pedal ratio of 6 to 1 ( standard GTD ratio is 3 to 1
Frank
 
A cheap and easy upgrade for the rear brakes on an older GTD are the use of the cosworth hub carriers, 273mm vented discs and calipers. The only machine work is the redrilling of the disc rotor to 5 stud.

http://www.ebay.co.uk/itm/2WD-BILLE...621659?hash=item1c583f351b:g:qOAAAOxyUfFTkYGb

http://www.ebay.co.uk/itm/Ford-Sier...557600?hash=item3f5296da20:g:mA4AAOSwMmBV3eBc

EBC Grooved Rear Vented Brake Discs Ford Sierra 2.0 Turbo Cosworth 4 x 4 (GD558) | eBay

These are two old rusty carriers just to demonstrate the extended lugs on the lower cosworth hub carrier.

 
Last edited:

Yuji

Lifetime Supporter
Agree with Frank. I've replaced with Tilton pedal boxes in conjunction with brake upgrade and it works extremely fine with me.
 

Dave Bilyk

Dave Bilyk
Supporter
Curt, my car is a DAX but used same brakes as GTD. I upgraded fronts with Wilwood 4 pot and rear with HiSpec 4 pot. The rear was tricky to get right due to the space saving of the original 1 pot caliper, but I managed to squeeze in 310mm discs with Billet 4 caliper.
see threadRear solution

For the fronts see Front solution

I looked into using 6 pot, but saw that the total piston area was really small compared to the 4 pot, and came to the conclusion that the 4 pot was a better choice for me.

Dave
 
Curt,

I have front and rear Hispec with Yellow stuff pads.
Service is ok but you need to call them.
I like the calipers but less efficient once you go on track.
As Frank said, I would go for Wilwoods.

I have also a Tilton pedal box.

If you want, I can give you a name of someone to place them (near Brussels).

Rgds
Fred
 
Curt,
I have APs on the front of mine and some Wilwood integrated handbrake Powerlite calipers on the rear. I admit though that the car has not been used in anger.

If I was doing it again, I would probably go all Wilwood. They have a nice little handbrake caliper the MC4 (that I may still have to use) and would combine with a 4 pot on the rear.

Brett
 

Malcolm

Supporter
If you are going near a race track with your car then the AP option is the best route. They won't let you down as it is what they are made for.

Your rear brakes are your weak point so at least change to the cosworth caliper scorpio disc at the rear then a 4 pot system up front will work with servos. It was a standard GTD supplied upgrade although used Alcon calipers up front. If you want 4 pots all round then you need to change your uprights.

Mick at Southern GT has a lot of this stuff off the shelf including pedal boxes depending on how far you want to go.
 
The other upside of the cosworth setup is the hub itself, if you use the drive flange off the cosworth and the wheel hub plate of the granada you can upgrade the CV`s to 108mm cosworth units which are a fair bit tougher than the 100mm granada ones , you can then keep the wheel offsets and PCD. If you dont want to change bearing carriers you can get the granada scorpio vented disc which is the same smaller diameter but you will still need the Cosworth wider caliper. I am surprised no ones mentioned overbraking of the rears and brake biasing, its all about balance or the upgrades will get you nowhere.

Bob
 
Bob,
Good point. Tilton used (may still do) have a service that you could send in the specification of what you planned with weight of car and brake setup and they would recommend master cylinder sizing.

Brett
 

Ian Anderson

Lifetime Supporter
On the rear of my DAX I have Saab 900 Turbo Front brakes. On this car the handbrake works on the front wheels so is ideal as a rear caliper

The same system I believe is used on Vauxhall Vectra

the SAAB and Vectras certainly stopped OK

Ian
 
Wow thanks for the input...
FYI I have 15" wheels which I want to keep. Use is mainly road and sometimes track day.

@Frank, Yes I also looked into the ratio issue. But at the moment I have 2 boosters installed F/R circuit. Would this compensate the lack of ratio?
However I would not know what the equivalent ratio would be to calculate cylinder size?
If necessary I would go for a top mounted pedalbox. But initially I was planning to use this
Professional Motorsport Parts, Spares & Rally Equipment from Rally Design
to add to the current pedal box. I think I saw it also here on the forum? Does someone has experiences with this?
Your rear set-up is indeed professional, completely different... Time/cost wise I would not prefer to go that far.

@Robert, thanks this was an option indeed. I'm planning to use the scorpio vented brakes as you mentioned of 272mm 20mm wide. But the plan was to go to 1 brand front/rear.

@Dave, 310mm in the rear...woow, Hi-Spec proposed a 288mm disc and this this left me 4mm play. The 6 pot is the only kit R&R design supports at the moment, that’s meanly why I wanted to go that way. But indeed 4 pot is possible if you have the brackets...

@Fred, I called Hi-spec but even then... difficult. But as you said I would prefer Wilwood.
Yes sent me the person perhaps I need assistance. I'm also looking for running road + carburettor specialist in Belgium...

@ Bred, Yes I was also thinking about the handbrake Powerlite calipers!!

@Malcon, Soutern Gt seems indeed an Interesting supplier.. Useful I would certainly go there for suspension upgrade later..

grs Curt
 

Keith

Moderator
On the rear of my DAX I have Saab 900 Turbo Front brakes. On this car the handbrake works on the front wheels so is ideal as a rear caliper

The same system I believe is used on Vauxhall Vectra

the SAAB and Vectras certainly stopped OK

Ian

You just have to be different Ian! Actually, that's a very cool combo.. :)
 

Dave Bilyk

Dave Bilyk
Supporter
Curt,

@Dave, 310mm in the rear...woow, Hi-Spec proposed a 288mm disc and this this left me 4mm play. The 6 pot is the only kit R&R design supports at the moment, that’s meanly why I wanted to go that way. But indeed 4 pot is possible if you have the brackets...

My wheels are the old spun alloy 3 piece, so the rims are only 3/32" thick, I think that is where I have the advantage on rotor size. When I did this, there didn't seem to be any complete kits, so I took the measurements, and arrived at a solution using the Hispec caliper with handbrake, along with a 310mm Wilwood disc 160-5845/6 (I couldn't find a Hispec disc to fit), and a self designed caliper bracket I got a local machine shop to make for me. Lateral space is very tight so to get the correct offset, I used universal mounting bells machined to suit. The front discs were the Wilwood 160-7705/6 with Wilwood SL radial caliper 120-8070/1.
As Bob said front/rear balance is important, and as I was ditching my so far unreliable servos, the 6 pot piston area was too small and 4 pots gave much better balance / effort.

This all works well, and the only issue I have is trusting the hydraulic handbrake, I believe they do a mechanical version now, but I always leave the car in gear with a wheel chock if on a hill, so I'm happy with that.

Dave
 
Last edited:

Tim Kay

Lifetime Supporter
One small suggestion if I may, I upgraded my original Tornado issue breaks to Willwood and if I were to do it over again I would opt for 4 pot calipers instead of 6 pot. Both function and fitment would've been better.

Tim
 

Malcolm

Supporter
Southern GT do a GTD to southern GT top hung pedal box which has a balance bar if you wish to go that route. Cheaper than tilton.

If you are keeping servos then if you have 4 pot fronts and the rear cosworth ie GTD uprated rear brakes then that is not a bad balance on the original GTD pedal box and twin circuit master cylinder. I ran that set up for 25 years and did many miles on track and in competition. And that was with Alcon calipers which would be similar to an AP set up. Alcon no longer make the caliper as recommended by GTD.
 
Back
Top