Caterham brake upgrade

[en6jwrs]

Following the installation of my Zetec engine (other thread running) I was hoping to get some advice from you knowledgeable lot.

I feel I should be upgrading the brakes to handle the significant increase in power / speed. Current set-up is standard S3 (car is circa 89).

I have had a look round and there appears to be the following options (in ascending order of expense):

Replace pads with Mintex 1144's
Replace master cylinder (along with above)
Hi-Spec (sp?) big brake kit
Wilwood 4 pot callipers
AP Racing callipers

I should mention that I am running 13 inch Revolution wheels (which I don’t want to change) on narrow track geometry (which I don’t want to change).

Does anyone have any thoughts on the options above (or another that I hadn’t considered) or any real world experience of the options?

I have had a read through blat chat and there seems to be advocates and opponents of all of the above.

Thanks in advance.

ETA: I did try the PH search but it didnt seem to work / return any results.

[Aeroscreens]

After my Zetec conversion I'm still using standard front brakes, Mintex 1144 and a AP race master cylinder. This is the same set-up that I was using on my 140bhp x/flow.

Zetec on twin 40s is now producing 170bhp and the brakes are still pretty effective. No real issues this year when sprinting

Just my 2p...

[Supra Chewie]

I'm running a 2.0 Zetec and quite happy with the standard stoppers. They're good for anchoring a 790 kg Triumph Spitfire so should be good for a 500 kg Caterham. Not sure I really need to fit my AP Racing calipers. Just adds more unsprung mass.

[BertBert]

Out of interest, what does the "race m/c" do? Is it just a bigger piston diameter to change the ratio? In which case apart from making the pedal move less and be firmer, does it actually improve the braking ability?

Bert

[Dave J]

AP calipers are lighter than STD calipers

[mickrick]

BertBert said:

Out of interest, what does the "race m/c" do? Is it just a bigger piston diameter to change the ratio? In which case apart from making the pedal move less and be firmer, does it actually improve the braking ability?

Bert

I would think it would have a smaller piston dia. to give more hydraulic pressure for less pedal pressure.
There is a calculation for master cylinder piston area against caliper piston area.
Can't remember what it it now, but off the top of my head 5:1 rings a bell.

[Red Seven]

The AP "race" master cylinder has a larger bore than the standard one, and gives a firmer pedal, requiring more pedal pressure for the same stopping power.

Standard M/C is 5/8" bore and the AP one is one is 13/16" bore, requiring something like 1.6 times the pedal pressure, but with 1.6 time less travel. However, the AP M/C also has less free travel before it starts to act than the standard M/C, so it feels like the AP M/C has even less travel.

It's possible to fit a belled washer under the standard M/C to reduce some of the initial movement, and reduce the difference between the standard and AP M/C's.

Whilst the AP calipers are lighter than the standard Triumph calipers, the big vented disks are much heavier than the standard Triumph ones.

Both Hi-Spec, and Wilwood make calipers that are significantly lighter than the AP calipers, and can be used with either standard disks or slightly larger but solid disks, giving an overall lighter weight package.

[BertBert]

Cheers, so it has no more stopping power, just works better in a race environment with less travel and firmer.

There are also 2 ratios of brake pedal on the Caterham. The low ratio pedal with the 5/8 m/c and "AP" big fronts is really squidgy! The high ratio pedal is good.

Bert

[mickrick]

Interesting So as usual, what you gain in one area, you lose in another.
I didn't have much luck with Hispec when I was looking for calipers, a bit like dealing with Mike Barnby. Plus I hear they flex a bit being three piece design.
I found BDG very helpful http://www.bgdevelopments.co.uk/ they make some nice alloy disc bells for not a lot of money considering the quality.
They actualy do a lot of the machining for AP.

[en6jwrs]

As I suspected, there are differing opnions on what to do.

Aeroscreens said:

After my Zetec conversion I'm still using standard front brakes, Mintex 1144 and a AP race master cylinder. This is the same set-up that I was using on my 140bhp x/flow.

Zetec on twin 40s is now producing 170bhp and the brakes are still pretty effective. No real issues this year when sprinting

Just my 2p...

I am interested to hear this, as I have experienced a similar power change.

I am wondering perhaps if there is a more fundamental issue. The pedal is always fairly spongy (despite numerous bleeding attempts).

I guess it would make sense to change the pads first (as it is the cheapest option).

[Aeroscreens]

From memory I think my pedal always felt a little spongy with the standard m/c which is why I changed to the race m/c as I prefer a more solid pedal 'feel'.

[BertBert]

I cured my spongy brakes by changing to the high ratio pedal. Similar effect to the race MC apart from being cheaper and easier to change (no bleeding)!
Bert

[en6jwrs]

Thanks chaps.

Any chance of part numbers Aeroscreens and Bert Bert (to avoid any confusion).

Must admit I am still a bit concerned about dissipating all that additional energy with standard (old) brakes. However will take the advice offered so far and start at the lower cost end of the "solutions".

Did either of you find problems with heel and toe after messing around with the MC or pedal ratios?

[Aeroscreens]

AP master cylinder from Caterham. Part no. 77176 but it is £189.12! Must say that I was fortunate enough to pick up a new one for just £80 2 years ago otherwise I may not have bothered.

Not sure of the cheapest place for Mintex 1144s now. I bought mine from Questmead but they only seem to deal with trade nowadays. Part no. was MGB533M1144.

Personally, I find H&T easier now....

[BertBert]

Here's the "high effort" (!) pedal
http://www.caterhamparts.co.uk/product.php?id_prod...
Costs £24.45!
Bert

[number2]

BertBert said:

Here's the "high effort" (!) pedal
http://www.caterhamparts.co.uk/product.php?id_prod...
Costs £24.45!
Bert

It costs £55.44 now .

This thread came up when I was searching for 'high effort' brake pedal and I found seeing the old cost interesting!

I'll be fitting one shortly so thought I'd search here and Blatchat for any tips.

[BertBert]

Inflation on it's own would make that £34.62 today, ouch!

[number2]

Same as the cars - doubled in price!

I did the Academy in 2010 and the car/package cost about 22k... now I think it's in the 40s!

Anyway, if anyone has any tips on fitting the pedal and shims, let me know .

I know DPR only use a few washers and I'm sure they did my last car and it seemed okay, but I feel like I should attempt this properly (and I've bought the bits!)

[AinsleyB]

If the weight of the car doesn't go up it wont require more braking.
I bet you can lock the brakes now, so do you need more braking ?

Sure, on track you may want to avoid fade, but for the road I'm not sure spending money on upgrading the brakes will be necessary just because you have more power.

[number2]

I'm just changing the pedal (for the high effort version) rather than the whole disc/caliper setup.

Although, I've not managed to lock my brakes yet and I've given them a pretty good shove... I've only used it on the road so far though. I'll look at the pads when I change them for the mintex. It's a new and they might have become glazed. Doesn't feel like there's air in the system, but i want more bite, feel and shorter travel.

I had a high effort pedal and mintex pads in my roadsport car and the brakes were awesome so I'm hoping to get back to that!