Brake Pedal Travel

[v8robert]

Before getting thrown off the track at Bedford Autodrome for being too loud I did notice the travel in the brake pedal become very long.

I have standard xj6 front brake discs. The brakes did remain effective and keep their bite however there is a very marked difference between road and race use. Is this simply temp related and nought to worry about til the bite does fail or would it be sensible to get discs that dissipate the heat better and upgrade my brake fluid to race spec ? Any suggestions

Also running michelin piolet sports which are tremendous however rears are close to a change so looking for stickier tyres more dedicated to the track but need to be road legal ? Again, a little help ?

Cheers big ears
Rob :thumb:

[nbracken]

Rob I believe if your pedal travel is increasing with heavy use it is most likley you have some air somewhere (even tiny amount) in the system and that is then expanding. Even with vented and cross drilled fronts I have managed to get silicone (dot 5) fluid to overheat ,primarily I believe through overheating in board rear discs which are not vented and which get very little natural air flow. When I change my diff I will probably upgrade to vented rear discs (several kits available).

On tyres I've not experience of Pilots but I've used Toyo Proxes T1S for several years and am really impressed with the way they perform when you get them warmed up on the track. Have just replaced with the latest design (T1R) and they are supped to be similar (no experience yet).

HTH

[snake_bitten]

hi rob

A friend of mine ha sa dedicated set of track tyers which are road legal and awesome on track they are yokahama a032r's 'tweeks' are quite cheap for tyers

http://www.demon-tweeks.co.uk/catalo.../M1657010A032R

[v8robert]

Cheers lads

Have invested in a set of ebc turbo groved discs for the front and will prob replace brake fluid with race spec. What's the deal with it not being legal ?

As for my rears overheating i have already changed them to outboard xj40 discs so don't think thats the prob

Will look into the Yoko ao32r tyres, i have had my eye on them for a while, anyone else have any experience of them ?

Laters
Rob :thumb:

[nbracken]

Rob I was not aware with silicone not being legal? The company who sells it (cannot recall their name just now and am away from home) does not mention it and my car did several MOTs when it was in the UK with no problem. I cannot think of any reason why it would be illegal either.

Re the brakes themselves, I would have thought it a pretty major job to changeover to the outboard XJ40 type. Did you do teh conversion and was there much to it?

One other thing that I looked at after my silicone fluid overheated was to fit a set of the glassfibre air ducts that Gerry Hawkridge sells (replicas of originals of course at GBP84 per pair) which channel air from the front openings to the front discs. I havn't yet bought them though.

[v8robert]

Nigel

If the truth be known, the previous owners of the rear axle (don't ask) changed the inboard to an outboard discs for that reason, overheating on track days, so i don't know how much work went into it.

Re the brake fluid, yeah, god knows why race fluid might not be legal on the roads, its just heresay, so if anyone knows if this is true and why let me know ?

Will look into the ducting thing, cheers

Rob :thumb: