some advice on brakes please

[EXI Turbo]

Hi, I am building the turbo version and would like some advice on the brakes. Currently all I have is the rover Servo and master cylinder so need to buy the rest of the braking system.

Any recommendations ? I will be using the car mainly on the road but plan on a few track days.



Thanks

Nick

[Jon@JNRacing.co.uk]

you could fit wilwood dyna pro calipars 4 piston, they are a radical mount but marlin use these on the factory race car with sports disks, they are ok but i cant say how well they work as i haven't drivin a car with them on or will be as we have our own GT kit being made. Sadly ourkit will only fit honda 5 type r hubs.

Cheers Jon

[EXI Turbo]

Marlin suggest std rover 216 discs front and rear, would I notice the difference with the Wilwoods on a road car as I presume they are more expensive ?


Cheers Nick

[Jon@JNRacing.co.uk]

you can buy standard rover disk as thats what i have on my rover 200 which is my road car, you can buy sports disks from any motor factors, EBC do sports brake which are vented like the rover disks, and are drilled and grooved a small amount, they are the same price as standard disks but do stay cooler and you get a better brake, i have done 3000 miles in a rover 214 bubble on the road ive had replace the disk and pads after this as the disks were blue with the heat, so ive gone to the sports disks and they are great.

Some people I think may have looked at it not sure, the Wilwoods are just a more even brake there for dont lock as quick, as a more progressive brake.

If you drive slow and steady then normal brake wil be fine but if you enjoy the car a bit then you may fine the brakes are a bit weak.

Not sure what marlin will charge i now they have a set of brand new wilwood calipars and rover vented disks that i gave back to them, not sure if they have gone now as this was January I gave them back.

Rally design charge 119.50 +vat (link below) I think this is the ones Marlin use but i would check.

http://www.rallydesign.co.uk/catalog...oducts_id=8317

If you want to spend a lot of money there is aways AP Racing and Brembo.

Regards Jon

[Jon@JNRacing.co.uk]

Just had a thought and the MG TF has 4pot calipars if you could find ones of these in a scrap yard you could use those calipars and I think they would fit straight onto the car.

Maybe worth a look.

[EXI Turbo]

Thanks for speedy response. Price wise I do not think there is anything in it between rover parts I have been quoted for and the Wilwoods so I think I will go for the Wilwoods. A couple of dum questions. Do these just fit into the Rover front and rear brake carriers without any modification ? and are they the same for the front and rear ?

[Jon@JNRacing.co.uk]

well to be fair ive never seen a standard Marlin front hub so dont know what calipar mounts you have, if you look at some of the pictures in the progress at last thread then you will see how they fit, on our race car it is a basic mount a tube welded onto the hub. There are also pics of the rear already on our car,they are bigger disks at the back though, but this does not effect the way they are mounted.

If you interested in fitting these to your road car then contact Marlin on the help line in the week and ask if it can be done, I cant see why there would be a problem.

I will mention it to Mark on monday when I see him that your thinking about it so he may look into it before you call.

Jon

[MikeN]

Just one thing to remember when comparing braking systems that were designed for a standard production car (Rover 200/25) against the Marlin, is weight!

If the R25 is 1300kgs and the Marlin is less than half that, then the standard brakes are going to be pretty good on the road, under normal conditions. On a race car then a different set of parameters obviously come into play.
I am using stock Rover 25 discs all round on my build (VVC 160BHP). I will see heow it goes after it has been on the road for a bit.

Just food for thought.

Cheers guys.

Mike

[Jon@JNRacing.co.uk]

I saw the which kit car 5exi yeturday that has a massive servo and abs, mark took it around castle combe and said how much better the brakes were as it had this massive sero rather than just 2 master cyclinders, but you dont to get as much feedback through the pedal.

Its all down to driver style and what you like and what you dont, the wilwood brake may be good powerful if you dont run abs as there is not alot of wieght in the front of the car to get the grip on the tyres.

The main reason that we are having bigger brakes is due to the fact I drive a rover 214 on the road with vented ebc sports disks and they are good but from 50-0mph it does take a fair distance to stop. Even though we have half the wieght in our race car we also have double the power of my road car, so upgrading the brakes on our car was a must.

Jon

[limpabit]

I've used the standard turbo calipers I got from the coupe turbo donor. Got drilled and groved disks and EBC green brake pads. Stops on a sixpence and locks the wheels!

[alackofspeed]

The standard brakes I saw on a Caterham CSR the other week were pretty small - certainly no bigger than 260mm.

The main issue I can see with the standard Rover setup, is the front/rear bias. With a relatively unloaded set of front tyres, I would imagine the front calipers will tend to grab and lock unless the pedal is progressively loaded as the weight shifts on to the front.

I'm expecting to need to run the larger rears with the standard 260mm front discs to get the balance correct.

I'd be wary of drilled discs, as they have a tendancy to crack on track. I destroyed a set of front drilled discs very recently, and cracked discs aren't much fun on track!

http://www.johndry.com/gallery/main.php?g2_itemId=8457

[craig]

Whats the crack with the proportioning valves???

I have been told not to fit for sva but not really given any reasons?
Does anyone know why one can't be fitted now?
I have also been advised that I could fit one now, only if for sva it is somehow locked into position and can't be adjusted.

I currently have (but may change again.....) 282mm fronts and 262mm rears which are not drilled but dimpled and grooved for the very reason of cracking

[limpabit]

Originally Posted by alackofspeed

I'd be wary of drilled discs, and they have a tendancy to crack on track. I destroyed a set of front drilled discs very recently, and cracked discs aren't much fun on track!

http://www.johndry.com/gallery/main.php?g2_itemId=8457

Thanks for that John. Did not realise.

[alackofspeed]

Originally Posted by craig

Whats the crack with the proportioning valves???

I have been told not to fit for sva but not really given any reasons?
Does anyone know why one can't be fitted now?
I have also been advised that I could fit one now, only if for sva it is somehow locked into position and can't be adjusted.

I currently have (but may change again.....) 282mm fronts and 262mm rears which are not drilled but dimpled and grooved for the very reason of cracking

I don't know the official answer, but I think the problem with the proportioning valves is that at the SVA they test the brakes as presented. If there's a device on the car that can change the car from what was tested, then from the perspective of VOSA you could theoretically make your car "unsafe".

[bigrich]

Hi...

I'm runinng stock 216 discs and pads (non vented solid discs front and rear)...and these work fine for road use. To be honest even the non vented discs can lock easily on the front if you panic and stab the pedal.....best value for money solution I'd say would be a brake bias valve after SVA to get the front / rear balance better.

Not done track so cannot comment.

Rich

[BIG_Fella]

The brake set up i have gone for is 262 vented and grooved fronts and 260 solid grooved rear

Just got to find the H shaped pad spring for the rear calipers now

[Ric H]

I've been doing a lot of thinking about brakes recently too. I decided to go for standard rover disc size (262 & 239) but have splashed out on some pimp Mintex Ctech discs; what can I say - they're blue Special order on 3 weeks delivery though so I'm waiting...

I went for the Wilwood front caliper option and got Marlin to swap my standard uprights for some radial-mount ones to take the new calipers. To be honest this was all about unsprung weight rather than braking power - I think the car is light enough for power not to be a problem. I was unhappy about the weight of the standard caliper whereas the Wilwoods weigh, erm, nothing really!

Same problem on the rear but I didn't want the Wilwoods there because of handbrake concerns. I've bought some alloy "Hydramech" calipers from RallyDesign http://www.rallydesign.co.uk/catalog...ducts_id=10563 which are pretty light, though still sliders (which is a shame). I'm waiting for my rear discs to see what mods I need to do to fit these to the uprights, but I think it should be straightforward.

All good fun it is too! These are the best bits I think - making the car your own.
Richard

[alackofspeed]

What are the dust seals like on the calipers you've bought?

[Ric H]

The Wilwoods or the Hydramechs? The Wilwoods have no seals and the hydramechs have a typical convoluted rubber jobby. Photo gives some idea:

[alackofspeed]

I was wondering about both. I thought Wilwoods have no dust seals, didn't know about the hydramechs, and the lack of decent dust seals is what put me off going that route.