the right braking system

H.J.Bayer

Supporter
Hello,
I'm just thinking about the brake system of my project.
I want to use 15" wheels.
The car will only moved on the race track.
I would like to install a powerful brake system.
Could you help me a little with your experience?
The issue of brakes can be quite a jungle ....:rolleyes:
 

DaveM

Supporter
I would go with the largest calipers you can that fit under 15" wheels. 11.75" rotors are probably as big as you can get under those wheels. I have 4 pot Wilwoods all round and still feel I could use more brake on track days. You might be able to use 6 piston Wilwood Superlite front calipers and still get them under a 15" wheel. Would depend on the wheel and what Wilwood says. Wilwood has aggressive pads for track use, but I've heard better results from Carbotech pads.
 
May be way overkill, but nascar has 15” wheels and substantial brake hardware to slow the 2 ton beasts. Take off parts are often on eBay too.
 

H.J.Bayer

Supporter
I've been drawing with Wilwood brake calipers.
At AP I didn't find anything that fits.

Now I used Wilwood DP6A Calipers -six piston- max. what fits in.

Disc Diameter 11.00 / 279 mm
Disc Width 1.1 / 28 mm

So it gets pretty tight, only 1.3 mm space at the ends
 

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On the subject of brakes.

The front caliper is in a trailing position but what about the rear?
Looking at various images of the SGT cars it looks like PaulBav has got them trailing but the Keith Baker car has them leading!
 
Application of logic would have to suggest that it's you then Paul.

Based on the following :-
1) You've provided an image with both the main and the handbrake caliper in situ
2) Your AP caliper is definitely the right way up
3) Having the handbrake caliper trailing just adds length to the cables and adds potential complications of being behind the driveshafts
4) It would be logical to have commonality of caliper type on front and rear axles if possible
5) I didn't see you advertising a pair of "incorrect orientation" AP caliper on e-bay :mad:

So can you add a bit more clarity and confirm?
 

Eddy McClements

Supporter
Yebbut....imagine if PaulBav removed the entire upright & brake assembly and moved it to the opposite side of the car. The caliper would then be in the leading position, but still correctly-orientated with bleed nipple at the top. Granted, the handbrake cable would need to be longer and routed differently, but other than that it's still a viable option. I think these cast uprights have lugs cast-in for mounting the calipers on either side (in other words, the uprights aren't "handed" for left or right).
 
Yebbut....imagine if PaulBav removed the entire upright & brake assembly and moved it to the opposite side of the car. The caliper would then be in the leading position, but still correctly-orientated with bleed nipple at the top. Granted, the handbrake cable would need to be longer and routed differently, but other than that it's still a viable option. I think these cast uprights have lugs cast-in for mounting the calipers on either side (in other words, the uprights aren't "handed" for left or right).
In theory I would agree. However .......

The AP calipers used have four options - 10S4 (RHT), 11S4 (LHT), 12S4 (RHL) and 13S4 (LHL).
The permutations are based on left / right hand and leading / trailing.
If you could just rotate them around then there would only be two options needed.

I think you're spot on with the rear uprights not being handed.
The fronts are similar in that they only become handed once you've attached the steering arm or stub-axle.

I'm sticking with Pauls being correct particularly as Mr Winkworths car also seems to have the rear calipers in trailing formation.
 

Eddy McClements

Supporter
In theory I would agree. However .......

The AP calipers used have four options - 10S4 (RHT), 11S4 (LHT), 12S4 (RHL) and 13S4 (LHL).
The permutations are based on left / right hand and leading / trailing.
If you could just rotate them around then there would only be two options needed.

I think you're spot on with the rear uprights not being handed.
The fronts are similar in that they only become handed once you've attached the steering arm or stub-axle.

I'm sticking with Pauls being correct particularly as Mr Winkworths car also seems to have the rear calipers in trailing formation.
Ah...of course. My description only works of the calipers have same-sized pistons. If you're using calipers with differently-sized pistons then they have a leading/trailing orientation. Smaller piston at the leading side, to combat uneven pad wear. Silly me.
 
In this case the piston sizes are the same.
However, the difference is the offset position of the pistons in relation to the caliper centre line.
 

H.J.Bayer

Supporter
Hello, Paul and everybody,
many thanks for the info and the pictures.

In fact I forgot the C5040 brake calipers.
I only tested the CP6600 and CP9441 in CAD.
The CP5040 fit really well with a 295mm/11.60" brake disc in the rim.

Now I have 2 options:
1. AP 4 piston brake calipers with brake disc 295mm diameter and 25,4mm width

or

2. Wilwood 6 piston calipers with brake disc 279 mm diameter and 28 mm width

What would work better now?
 

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