Upgrading the brakes

[StephenH]

Thank you very much. That was exactly the information I needed. I will order the Banks vented disc kit.

It's an easy upgrade although you could engineer a better solution if you want to invest the time.

Be aware than the Banks front brake kit can be had for both the standard and GT6 stub axles, I never checked which was actually in my car and now have a spare set of aluminium hubs for the standard axles sitting around.
Also suggest you may want to order without the wheel studs fitted, or with a specific size pressed in, as you probably want to change the standard versions for something that better suits your use and wheel combo.
I've gone to 12mm on mine mainly for availability rather than strength, Richard claims the standard 3/8inch are strong enough and I think he would know.
My car isn't a race vehicle so the extra weight doesn't concern me compared to the additional safety margin.

[Mecky]

I have ordered the vented disc kit just today. Hope to receive it still in this month. I'll check, if I use the alloy hub, or my original one. If the alloy hub works with M12 x 1,5 mm studs, I'll use this one.

Now, I'm checking on my best options for the rear disc brakes. As I have already changed the rear wheel bearings, hub carrier, hub, stub axles and rims to BMW 2002 ti spec (to fit the drum brakes with Ø230 mm), I'm searching for solid brake discs, which fit to this existing configuration as good as possible. BMW 2002 brake discs are not ideal, as the discs have a different PCD than the wheels.

But as my PCD is 4 x 100 mm, I'll check, if Opel (Vauxhall) brake discs, which are unbelievably cheap in Germany, can fit. I found a front disc of an Opel Kadett D, which has Ø236 mm and the matching PCD. They should fit into the 13" rims and my plan is to machine the centering of the disc to BMW spec. Then I'll just need to engineer an adapter plate for the caliper. I'm convinced that it can work, but I will have to measure the existing configuration in detail before I buy the Opel stuff.

Below you can see my actual brake configuration, which worked not very well at my most recent race outing. I guess, the reason was the front brake pads. I was 5 seconds faster at the same track in 2014, thus it was a real step backwards. I'll report on the race weekend in the Paddock section of this forum soon.

[Rosco5000]

As everything is a compromise and it might not get the best feel or the best brake performance but could you bias your brakes more to the front so you last a race on the rear brakes?  Not an ideal solution but like I said a compromise to stay in the running.
Ross.

[Clifton]

Can you get a race compound for those rear calipers?

Dorman used to have a pdf file of every brake rotor by make and gave offset, width, height, ect but my link for it is dead now.

[EuropaTC]

This is what I used when looking for my discs.

Brian

[Mecky]

Can you get a race compound for those rear calipers?

Dorman used to have a pdf file of every brake rotor by make and gave offset, width, height, ect but my link for it is dead now.

Yes, I checked for the availability of the Opel brake pads, and there is plenty of choice from different manufacturers and compounds for road and racing use. I will start with the Ferodo DS3000, which I had good experience with. And I'm curious, which racing pads Banks will deliver with the vented disc kit. But availability for this kind of pads is even better than with the Opel stuff.

Today I will pick up an Opel Kadett (front) brake disc and caliper from the local scrap yard and check, if it fits my rear axle configuration. If yes, I'll buy a new set of Opel brakes and the racing pads tomorrow to convert my rear axle ASAP to discs.

I analyzed my brakes yesterday and could find what I expected: the rear brake shoes are gone and the front pads have been extremely hot and the surface is mirror-like smooth. With that, there is no braking to be expected.

[Mecky]

Yesterday I fitted the Opel brake discs for my rear disc conversion and it works out well. I also held the caliper (from the scrap yard, new ones to be delivered) in place. It will be a little bit tricky to design the adapter plate correctly, as there is only a small corridor behind the custom-built hub carrier, in which the caliper will fit. But it will work, when I measure everything properly. Feel free to comment.

[Clifton]

I know you want to keep this light weight. I don't know if you know but Wilwood makes calipers for 3/8" rotors with many different pistons sizes. They have detail dimension drawings on their site too.

[Mecky]

I have raced, track day’d, and road driven using the Banks front vented kit for the last 21 years now and it is more than up to the job tbh. I’ve never had any fade or overheating issues and have run a variety of different pad materials. - have even used standard road compound pads for track days (when I had the additional weight of screaming passengers in the car) without issue.

The caliper is from a relatively modern road car and there are no issues regarding their strength or suitability. - there are also plenty of different options of pad compounds readily available too and at reasonable prices.

It all fits onto the original front upright, the caliper mounting bracket is different to suit the mounting bolts of the caliper and the vented disc can be fitted to the original hubs or you can go for the aluminium versions should you wish. The kit was designed to fit inside a 13” wheel.

I also have the Banks rear discs and their balance bar pedal box - all fitted when I built my car and I raced on that set up for a good few years before retiring it to track days.

Hey JR,
I have now made the first experiences with the Banks front vented kit on track and it works fine. No fading or anything. Only the delivered competition brake pads (manufacturer: Juratek) wear like hell. That's why I have already bought new pads as replacement. The new ones are significantly more expensive (manufacturer: Ferodo) and I hope the compound (DS3000) is a more durable.

But my question is: Is it necessary to grind down new brake pads in order to fit them into the caliper together with the ventilated disc? Unfortunately, I didn't measure the thickness, before I installed them, but the old ones (supplied by Banks) fitted. Now, even after pushing the piston as deeply back as possible into the caliper, the two new pads (18 mm each) don't fit in. It seems like this caliper/pads combination is intended to be used with thinner discs (alternatively: thinner pads). I have already opened the fluid cylce to push the piston further back, but it didn't work. Not even without hydraulic pressure inside the lines.

Thus, either I have completely overlooked something, or Banks didn't tell me that detail.

[jbcollier]

Some racing pad applications are available in different thicknesses.  Can't comment on whatever pad the Banks system uses.

BTW, pad wear is a normal in racing applications.  Any car driven at speed on the track will do the same.  Except street applications will quickly overheat and fade.  The fact your brakes are working well and not fading shows that everything is working properly.

[Mecky]

Okay, I have now checked the photos from back when I bought the Banks vented disc kit. From the picture, I could measure from the pic that the pads delivered by Banks were only ~12,5 mm thick, but new ones from the internet are 18 mm thick ( I have double checked it with the exact article number from Banks's pads). That means that Banks must have grinded the pads down, before sending them to me.

This is not a big deal, but why do they not communicate this important piece of information? I have now bought new pads and did question everything, because they would not fit. I even drained the hydraulic cycle, because I thought, there was a problem with the piston. Now, I have to grind down all the freakin' pads by 3 mm, before I can use them. Not a very nice work to do.

@jbcollier: I know that it's nothing bad, when the pads wear. But I have thought that the pads wore down from 18 mm thickness to 10 mm thickness (5 mm is the back plate) in an hour of driving. And this seemed a little but too much to me. But now that I know that the pads started at 12,5 mm instead of 18 mm, it's a big difference. It means that the pads will last at least one hour more without any problem, maybe even more.

[europa88]

I really cant see Richard and the guys at lotus Supplies grinding down brake pads. If you look on their page they have a good variety of pads for the vented disc setups including race options. I would be interested to know though, if they are having them specially made for future reference. Next time I speak to Richard I'll ask the question.

Edit: Sorry Mecky,I hadn't realised you already bought competion pads from Richard.

[Mecky]

Yes, please ask. I'd be happy to learn, if thinner pads could be sourced without grinding. As I'm located in Germany, I'd prefer to buy them not from GB, as the Brexit customs tax is expensive.
But I'm quite sure that they grind them down. I searched the article number of the competition pads delivered by banks and they are described with 18 mm thickness on the website. And this simply does not fit.

[JR73]

I’ve never had to remove any pad material from the pads in order to make them fit, I have purchased them from many different suppliers too. - just checked a spare set I have and they are 18mm thick.
I can see that your calipers are actually different to the ones I have, probably sourced from a more modern car due to availability.
I generally used Mintex 1144 pads.

[Mecky]

Hey JR, thank you for checking the details on your car. Very interesting that 18 mm pads fit into your calipers. But on the photo from inside the caliper, which I attached to saturday's post (taken before installation of the ventilated disc) you can clearly see that the pads delivered by Banks are thinner than the 18 mm ones. The pack plate of the pads is 5 mm thick and the friction surface is ~1.5 times that. That equals around 12.5 mm.

Do you maybe know, from which exact car your caliper was taken? I guess it could be much easier for me to just change the calipers instead of grinding 3 mm off every brake pad from now on. Maybe they are easier to source here in Germany.

The comparison between a newly delivered and a ground down pad shows the difference between 18 mm and 14.5 mm thickness. This thickness should be enough to fit the pads into my caliper.