Small Brakes on Novas (front end, competition use)

[novarally]

I'm talking about modified brake set-ups (not the solid discs on your OHV Nova!).

Everyone fits big stuff, but I want to hear from anyone who's used small diameter and/or solid discs at the front end of their Nova (or other FWD VX), especially with a lightweight caliper.

Anyone know of anything? Maybe some drag race Vauxhalls have something interesting to save on weight?

[Gareth_C]

Hi Colin I use the wilwood setup from rally design. It runs a 256mm disc but the calipers only weight about 2kg iirc and they stop on a 6pence

[Novasport]

What about VX220 AP 2 pot calipers? Should fit a 256x24 disc

[Stuart]

What about VX220 AP 2 pot calipers? Should fit a 256x24 disc


They arent exactly light though :s :(
They run on 288*24/5mm discs and should cope on 256, maybe even down to 236 at a push but you might overhang the pad a lot.

[Novasport]

Got to be lighter than an ATE caliper.

[Stuart]

once you add in a bracket to adapt, I reckon its gonna be close to the ATE.

Hactually..... Colin, just use the 1.2 corsa ATE 236*10 calipers and fit some lairy as feck pads (carbon Lorraine or PFB ) and air vents to the discs, job done.

[Novasport]

How effective do they need to be? Motorbike ones sufficient?

[Mark]

http://img.photobucket.com/albums/v11/CorsaNova/NovaSaloon/utf-8BSU1HMDA0ODYtMjAxMDA1MTctMDgxM.jpg

1.66kg for my Wilwood 4-pot caliper and bracket (Just a standard carrier weighs twice that let alone the caliper too)

[Iain]

Drop this guy a PM, not sure what he's running behind 13" Wellers on his race car:

http://www.pngclub.com/forum/showthread.php?110730-smallblock-race-car&highlight=

[novarally]

OK, I'm talking about needing to be very lightweight, my current Wilwood 4 pots are pretty light (under 1.5kg), but I want lighter still.

I've had 2 attempts at getting motorcycle calipers sorted, but have had to admit defeat now due to difficulties in making mounting brackets beefy enough.

What I'd really like to try is the MMC (Metal Matrix Composite) brake disc as found on the early Lotus Elise, but these are almost unobtainable now, and have to be run with special pads. I'm also not sure how lightweight the calipers are.

Hence I was wondering if there were any other ultra-lightweight solutions out there.

Massive heat is not an enemy for me, due to the short duration races I run, so solid discs are ok.

[Stuart]

weigh up some of the 236mm ATE's, if they come in lighter then happy days.

Getting alibelled discs made isnt hard nor that expensive especially the low impact style you want.

MMC's will be 288*24ish, and as you say nearly impossible to buy (I can ask some contacts when I'm back in the office working on a project we have with Lotus) and need silly pads.

[novarally]

weigh up some of the 236mm ATE's, if they come in lighter then happy days.

Getting alibelled discs made isnt hard nor that expensive especially the low impact style you want.

MMC's will be 288*24ish, and as you say nearly impossible to buy (I can ask some contacts when I'm back in the office working on a project we have with Lotus) and need silly pads.

I've already had a set of lightweight solid discs custom made, which I may or may not use. I was seeing if I could find something that had been tried and tested already really, to avoid a lot of custom fabrication.

But despite that, I'd be very interested to hear about the MMC stuff, cheers.

[Novasport]

What about a 2 pot rear caliper off something like an Impreza? Should be small enough and suitable for a solid disc.

[Stuart]

What about a 2 pot rear caliper off something like an Impreza? Should be small enough and suitable for a solid disc.

98% the same caliper as on the VX/Elise :)

[Novasport]

Willwood 2 pot Dynapro caliper...
http://www.rallydesign.co.uk/images/DynaPro%20Single%20Product.jpg

Dragster caliper too small?
http://www.rallydesign.co.uk/images/kartjr1.jpg

[Stuart]

those dynapros do weigh next to nothing, CP runs them as rears on his

[Novasport]

Dynapro's are cheap too, only £80 each plus vat

[gary_126]

works nova spec A.P 4 pots, with alloy bells and seprate disks, light and fit under 14"s. My mate uses them on his corsa b rally car, immense bit of kit

[Stuart]

works nova spec A.P 4 pots, with alloy bells and seprate disks, light and fit under 14"s. My mate uses them on his corsa b rally car, immense bit of kit

I'd wager not light enough for mr smiths desires lol

[mowgli]

its a pity the bike calipers couldn't mount..

not to sound like a stuck record, but what do the mini racers use?

[novarally]

its a pity the bike calipers couldn't mount..

not to sound like a stuck record, but what do the mini racers use?

The top Minis all use KAD stuff. Most of them are using this 6-pot caliper, some with solid discs, some with vented;

http://www.kad-uk.com/mini-parts/KAD-Mini-Brakes/mini-calipers?product_id=1

I did have a set of these 6-pots, plus some 8.4" alloy-belled Mini discs (very light), but once again construction of the mounting bracket for the caliper proved to be a problem. The Mini uses a different design to the FWD Vauxhall as the drive flange sits way outboard of the brake.

With the design of the Nova upright, I think it's going to be easier to work with a slightly larger diameter disc, hence looking into the MMC ones.

[novarally]

works nova spec A.P 4 pots, with alloy bells and seprate disks, light and fit under 14"s. My mate uses them on his corsa b rally car, immense bit of kit

Yes, good equipment, but way over the top for my needs, I'm only need to stop something about half the weight of that Corsa.

[novarally]

Thought it might help to post up some photos to demonstrate the problems I'm up against in trying to adapt the motorcycle calipers to work on the front of a Nova.

This is the solid disc (247mm x 7mm) which I've had custom made;

http://i285.photobucket.com/albums/ll66/hillclimbescort/001-31.jpg

http://i285.photobucket.com/albums/ll66/hillclimbescort/002-66.jpg

And these are the Yamaha R1 calipers I would like to use (note they are RADIAL mounted, not lug mounted);

http://i285.photobucket.com/albums/ll66/hillclimbescort/003-69.jpg

http://i285.photobucket.com/albums/ll66/hillclimbescort/004-59.jpg

And this is how they trial fit;

http://i285.photobucket.com/albums/ll66/hillclimbescort/005-49.jpg

http://i285.photobucket.com/albums/ll66/hillclimbescort/006-51.jpg

http://i285.photobucket.com/albums/ll66/hillclimbescort/007-44.jpg

As you can see, there is very little distance between the mounting points on the Nova hub, and the fixing points on the caliper. This is always going to be an issue when using a small diameter disc, as it's meaning the caliper moves in closer to the centre of the hub (of course!). And with a radial mounting the bolts for mounting the caliper and the bracket are wanting to dissect one another.

There's no point in using a larger diameter disc, as that defeats the object of the exercise, so Thought 1 was that the disc could be spaced out a bit from the drive flange, to give a bit more room for a bracket.

But that means the wheel is also moved out correspondingly, and puts more stress on the wheel bearing. It also means that the wheel centre spigot no longer locates onto the hub, so all the forces are acting on the wheel studs, which I don't fancy at all.

Thought 2 is to give up on the idea of using the R1 calipers, and adapt the mounting bracket of my current Wilwood Dynalites to suit the solid discs;

http://i285.photobucket.com/albums/ll66/hillclimbescort/008-38.jpg

http://i285.photobucket.com/albums/ll66/hillclimbescort/009-37.jpg

http://i285.photobucket.com/albums/ll66/hillclimbescort/010-36.jpg

I'm not so keen on this idea as the Wilwoods with their mounting brackets and hardware weigh in at roughly 2.5kg each. The R1 calipers (without any mountings) are about 800g each, so offer a good weight saving.

I've only got as far as Thought 3 so far, and that one is to find a more suitable lug-mounted caliper, which is lighter than the Wilwood Dynalite, and might be easier to fit. That will be an exercise I indulge in at the Autosport show in a couple of weeks' time.

In the meantime, if anyone has any inspired thoughts on other solutions, I'm all ears...........

[Stuart]

How far 'offset' can you mount the R1 caliper from the upright bolt holes? IE not mount the caliper with its centre line inline with the centreline of the uprights.

[MK999]

space out the disc, or use an adapter that mounts on the other side of the upright, and comes round to meet the holes in the bike calipers, like a sort of C shape.

[Stuart]

yeah, rotate the caliper round and add bracket to suit (ideally down for an underslung caliper)

[novarally]

space out the disc, or use an adapter that mounts on the other side of the upright, and comes round to meet the holes in the bike calipers, like a sort of C shape.

That's worth looking at Mark, good suggestion, thank-you. It makes the design of the bracket more complex, but it could work. I'll mock it up tomorrow.

Stuart - we did look at mounting the caliper off-centre, but keeping the position of it sensible my CNC-man reckoned it still didn't give us enough room to work with.

[novarally]

yeah, rotate the caliper round and add bracket to suit (ideally down for an underslung caliper)

My expertise runs out here, wouldn't that give problems with bleeding the system, if the caliper was mounted at the bottom of the disc?

[Stuart]

keep the bleed nipples a little bit above the horizontal ;)

[MK999]

right at the bottom yes, at 80 degrees upright, or slightly less you should have no problems though.

[novarally]

keep the bleed nipples a little bit above the horizontal ;)

Thanks, there's another option to experiment with.

Definitely more entertaining than other New Years Eve activities!

[Lewis.]

I'd stick with the bike brakes, but just look at different calipers. for example the 6 pot tokico's found on GSXR's, hayabusa's etc are lug mount, as are fireblade calipers (4 pot nissin's)
pair's can be had for about £150 which isn't bad really. stealth clicky (http://www.ebay.co.uk/itm/CBR900RRY-FIREBLADE-CBR900-929-CBR-900-BRAKE-CALIPERS-/200663720463?pt=UK_Motorcycle_Parts&hash=item2eb87d620f)

[novarally]

I'd stick with the bike brakes, but just look at different calipers. for example the 6 pot tokico's found on GSXR's, hayabusa's etc are lug mount, as are fireblade calipers (4 pot nissin's)
pair's can be had for about £150 which isn't bad really. stealth clicky (http://www.ebay.co.uk/itm/CBR900RRY-FIREBLADE-CBR900-929-CBR-900-BRAKE-CALIPERS-/200663720463?pt=UK_Motorcycle_Parts&hash=item2eb87d620f)

I did have some lug mounted 'Pretech' motorcycle 6-pots last year, and those were also a pain to fit, which was why we looked at radial mounting.

I'm looking at the Autograss machines for inspiration, as a lot of them use motorcycle calipers. The Sleaford Mini Centre are heavily into it, and have a Mini with Yamaha R1 calipers on it, so I need to go and see them.

In fact I'm now wondering whether I could fit an Autograss brake disc directly to the drive flange on the Nova (it would probably have to be mounted on the reverse of the flange, inboard of the wheel);

http://www.berrisford.co.uk/index.php?cPath=42_48&osCsid=m4315e2s87ugidtr4qit5qutk6

That would definitely save weight as it wouldn't need a mounting bell for the disc. Unfortunately on their website they don't give the diameter or PCD of the disc, so it's hard to do a mock-up.

I know there are some Grass Racers on PNG, so any photos/specs of these types of brakes (or others) would be very welcome, please.

[mowgli]

colin, to be honest, any decent engineer with a cad milling machine would be able to knock up a caliper bracket. or the other option is to get the lugs cut off & a flat piece of steel welded in place to take the calipers... you might just have the odd hub to prototype with.

[Mike]

Dynapro's are cheap too, only £80 each plus vat

Im a GM rear disc fitment or just in a generic fitment??

[Southie]

Probably a silly thought and will get laughed at but what brakes are used on Go-Karts? Or am I being a tard in suggesting looking into this avenue lol

[novarally]

colin, to be honest, any decent engineer with a cad milling machine would be able to knock up a caliper bracket. or the other option is to get the lugs cut off & a flat piece of steel welded in place to take the calipers... you might just have the odd hub to prototype with.

Modifying the hub was something we considered, but as it's cast, there was a bit of doubt as to whether welding it might weaken it. It's not a preferred option as obviously if a hub ever needed replacing it would need another one modifying.

I think with a bit of relocation of the caliper the problem can be solved more easily.

[novarally]

Probably a silly thought and will get laughed at but what brakes are used on Go-Karts? Or am I being a tard in suggesting looking into this avenue lol


I also looked at kart brakes, generally they are 200mm diameter, so probably a bit too small! There are other sizes in use, which are essentially the same sort of thing as the Autograss ones I posted the link for above.

[Southie]

I was thinking the horsepower on your car would possibly burn the go-kart brakes out quickly though more than the size.

[Lewis.]

I did have some lug mounted 'Pretech' motorcycle 6-pots last year, and those were also a pain to fit, which was why we looked at radial mounting.

I'm looking at the Autograss machines for inspiration, as a lot of them use motorcycle calipers. The Sleaford Mini Centre are heavily into it, and have a Mini with Yamaha R1 calipers on it, so I need to go and see them.

In fact I'm now wondering whether I could fit an Autograss brake disc directly to the drive flange on the Nova (it would probably have to be mounted on the reverse of the flange, inboard of the wheel);

http://www.berrisford.co.uk/index.php?cPath=42_48&osCsid=m4315e2s87ugidtr4qit5qutk6

That would definitely save weight as it wouldn't need a mounting bell for the disc. Unfortunately on their website they don't give the diameter or PCD of the disc, so it's hard to do a mock-up.

I know there are some Grass Racers on PNG, so any photos/specs of these types of brakes (or others) would be very welcome, please.

looking at the picture of your radial mount calipers, I'd imagine if they were lug mount a bracket would be quite easy to machine to fit it, or were there other fitment issues?

They're good guys over at Sleaford Mini Center, what is this mini of theirs built for? autograss? (also, why is Sleaford Mini Center in Heckington? lol)

[novarally]

looking at the picture of your radial mount calipers, I'd imagine if they were lug mount a bracket would be quite easy to machine to fit it, or were there other fitment issues?

They're good guys over at Sleaford Mini Center, what is this mini of theirs built for? autograss? (also, why is Sleaford Mini Center in Heckington? lol)

I've been to see them once before, and they were very helpful.

It's an Autograss Mini they've got with the Yamaha brakes. I too was confused as to why they weren't actually at Sleaford, maybe they were there once, and moved?

[deanwilko]

might be worth signing upto locostbuilders.co.uk and putting a post up on there as a couple of people are using bike calipers and might be able to help.

[mowgli]

colin, roughly how far away from hinckley are you?
i could to do a road trip to try & help you out on this.. i'm sure you've got something i might need for my nova too..

mk999 is actually onto something about mounting the calipers lower, & a bleeding procedure would be quite easy by unbolting them & putting them in the 'right' place with a 7.5mm spacer in between the pads..

[MK999]

Only time you'd have to take the calipers off to bleed is if they're literally right on the bottom of the disc, as long as there's some sort of 'uphill' direction to the bleed nipple it will be fine.

[mowgli]

unless you need to mount one upside down... which might have to be an option...

[MK999]

Or just mount it on the opposite side of the disc and see if there really is any performance difference between brake positions, that'd be an interesting test lol

[mowgli]

mk, these calipers are for bikes, which have fixed position hubs, so all options need looking at..

[novarally]

might be worth signing upto locostbuilders.co.uk and putting a post up on there as a couple of people are using bike calipers and might be able to help.

Yes, I've looked on there before and there are a few threads on the subject, not much really useful information, although someone did mention that Stuart Taylor kit cars have used motorcycle calipers. They're also commonly used in Formula Student race cars, so I'm confident they can be made to work on something as lightweight as my Nova.

[mowgli]

i take it these are 2 calipers on the front wheel of a bike.

i suppose if 1 each side isn't enoughdo you think you might manage to fit 2 per side on the nova to get enough breaking?

[deanwilko]

http://www.bici.co.uk/Shop/Parts/Brake-Calipers/27494-Brembo-Goldline-Rear-Brake-Calipers.html

would these be any use to you, being as the mounting lug is 84mm and novas are around the same 85 of top of my head

[novarally]

http://www.bici.co.uk/Shop/Parts/Brake-Calipers/27494-Brembo-Goldline-Rear-Brake-Calipers.html

would these be any use to you, being as the mounting lug is 84mm and novas are around the same 85 of top of my head

Interesting, thanks, but as they're designed for the rear of a bike, I would doubt they'd be adequately sized for the front of a car.

[novarally]

colin, roughly how far away from hinckley are you?
i could to do a road trip to try & help you out on this.. i'm sure you've got something i might need for my nova too..

Thanks Mike, much appreciated, I'm 80 miles from Hinckley.

However, for the moment I've left the Sleaford Mini Centre guys with a Nova hub, the R1 calipers and a front wheel so they can ponder the possible ways forward. They have the facilities to laser-cut a brake disc, and have done a few conversions on other cars, so they seem to be well placed to advise.

[Gazza808]

in all honesty mounting that caliper you have posted to that nova hub/disk combo is easy.
i've done some thing simliar, started with a solid block and milled slots out to sink the hub mounting points in, then milled an angle on the block for radial mounted caliper and off set the mounting points?

worked fine. sure matey is still used them now. and this was 4ish years ago. wasn't a bike caliper though.

[Gazza808]

like this
http://www.migweb.co.uk/forums/welding-fabrication-painting/437257-latest-ken-tattie-item.html
but with the bracket sunk onto the hub lugs and of course radial mounted caliper offset say 10degrees.

[novarally]

in all honesty mounting that caliper you have posted to that nova hub/disk combo is easy.
i've done some thing simliar, started with a solid block and milled slots out to sink the hub mounting points in, then milled an angle on the block for radial mounted caliper and off set the mounting points?

worked fine. sure matey is still used them now. and this was 4ish years ago. wasn't a bike caliper though.

Interesting, thanks for the reply.

Are you in Peterborough, Cambridgeshire? (I'm guessing not)

[Gazza808]

yup peterborough cambs, well there and in stamford, lincs,
I would offer to make them but I'm now on the service team so rarely near the machine shop :(

[novarally]

yup peterborough cambs, well there and in stamford, lincs,
I would offer to make them but I'm now on the service team so rarely near the machine shop :(

Get back to the machine shop then please, you sound like you'll be a useful man to know. And localish too.

[boffer8]

Having a ponder over what has been discussed throughout this thread and looking at that picture you have posted of that disc on the hub you have had made with the caliper on, plus knowing for this idea that disc would be redundant, would it not be possible to have that disc made so that it sat closer into the standard mounts, thus pushing the mounts from the caliper to the inboard side allowing for the caliper to be mounted lower and also easier? if you get my thinking?

On our formula student car we used some old Aluminium calipers that don't seem to be in production anymore by anyone, but the only model i can find with a similar size and specification is THIS (http://www.alcon.co.uk/download/alcon-catalogue/2-piston-radial-mount-caliper.pdf) and weighing in at 1.35kg is light and with the weight of your nova, should have no problems (the FS car weighed in at 212kg and the front braking force was far to potent, even though our calipers were smaller than this in piston size, pad area and external dimensions)

Personally, with the type of motorsport that you compete in, i don't see the need for 6 piston calipers, after doing the calculation for surface area requirements for braking force for a couple of projects, a car in the region of your cars weight does not require that amount of piston area to provide sufficient enough breaking at the speeds and also the duration that you will be breaking, you wont be getting the amount of heat build up that would create braking issues for you in the time that you are working the brakes to the maximum potential.

[Stuart]

I was under the impression that pad/piston area was irrelevant when working out stopping forces as the pad area is for longevity and piston size is pArt of the overall system pressure maths with the master cylinder taken into account etc.

[mowgli]

pad area must have some bearing on the calculations.

[MK999]

pad area must have some bearing on the calculations.

Not really, Force = Pressure/Area, so you either have a high amount of force digging into the disc, or a large area digging in less so but either way it's the same pressure, which is defined by the master and slave cylinder and the force applied to it (brake pedal length is a major factor)

Piston area is massively relevant though Stu, as thats your slave cylinder and the master to slave ratio is where all the force magnification comes from.

[mowgli]

so surface area & thus surface pressure of the pad has no bearing on braking??? cobblers.....

i know i'm probably about to start another row here, but pad area is massively important to braking.

[joshy]

"but pad area is massively important to braking"

Correct, But it dosent increase braking force.

It can help a brake assembly maintain a cooler working temp because of the extra area in contact with the disc, And It can sometimes increase feel and predictablity due to the force being exerted being much more stable in use.

But all things being equal, A large pad offers no braking force benifits over a small pad. over 330mm disc's and their required large calipers and pad are a waste of energy on any car IMO, be that road or competition

[Stuart]

As per my braking article, you could have a pad the size of a pin head and a pad the size of an A4 sheet of paper... Both will apply the same stopping force BUT the A4 size one will last thousands of times longer than the pin head one.

Piston area is to be considered with the rest of the system, rather than simply fitting the biggest/smallest possible and then hoping it all works (that was my point)

[MK999]

If you want working proof of the small pad thing have a look at most 4 pots, wilwood AP etc some of the pads are half the size of most OEM one's, and smaller than OEM rears even.


As per my braking article, you could have a pad the size of a pin head and a pad the size of an A4 sheet of paper... Both will apply the same stopping force BUT the A4 size one will last thousands of times longer than the pin head one.

Piston area is to be considered with the rest of the system, rather than simply fitting the biggest/smallest possible and then hoping it all works (that was my point)

Good point badly made lol But fair enough.

[novarally]

Just acquired these 240mm x 6mm (1.7kg) discs with alloy bells which I may be able to utilise;

http://i285.photobucket.com/albums/ll66/hillclimbescort/003-71.jpg

http://i285.photobucket.com/albums/ll66/hillclimbescort/004-60.jpg

http://i285.photobucket.com/albums/ll66/hillclimbescort/005-50.jpg

[stt]

did you manage to get brackets made up to mount the r6 calipers?