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m_john_m

What Brake Set Up And Tyres Are You Using On Fast Road/track Car?

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wicked

surely, layman's terms, say your doing 60mph and you slam the brakes on and the wheels lock up.... Its not your brakes that you need to improve?

 

No the driver.... :P

If you just slam the brakes ignorantly, you should buy a car with ABS.....

 

Locked up tires give way less friction than braking on the edge of locking up.

Edited by wicked

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m_john_m

Thanks for the info! I'll get some GTI6 brakes then, with some decent pads and disks.

 

The fella who sells them said he's got a few sets with grooved disks, need to find out what disks and pads they come with. Iv already bought stuff off him before so I can get them quite cheap.

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Batfink

I'm not sure on that equation. You have to remember there are two systems in play. The hydraulic forces and how your foot applies force, and the frictional forces between the tyre and the road with the variables which affect that friction. I dont understand how the position of the caliper from the fulcrum can have any effect on the tyre. It however will affect how quickly maximum pressure can be achieved, so there will be variances in braking distance though I think not massively significant.

 

Changing to bigger calipers and discs make it easier to apply a greater pressure but that maximum pressure is limited by other factors. Primarily big discs are about heat dissipation, and multi-pot calipers give a greater force plus better contact patch with the pad. Big pads disipate heat better and have lower pad wear in general.

 

I've run heavy brakes on 205's and moved to original calipers in the end as I can control heat in other ways such as choosing a decent pad. You can make greater improvements on stopping distance by lowering the weight of the car and controlling weight transfer forward under braking.

 

As for grooved discs - they wont really do a massive amount either other than cost you a lot more vs a plain disc. The grooves increase pad wear to de-glase the pad surface should you over heat the pads, but with a correct pad choice and your management of the braking system by not overloading the brakes with heat you shouldnt get to this stage..

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Batfink

I didn't exactly think my red 205 handled worse for having bigger brakes! It will defenity be quicker around a track due to the extra stopping force.... Without spending a lot of money on pads alone.

 

Them pads do look pretty awesome though, for now i dont fancy paying out 350 just for pads..... Maybe in the future when I start taking it a bit more serious

 

Race brake pads are not cheap but a set of CL brakes front pads start at £145 for the front 1.9 caliper and over a few laps will outperform a car with GTI6 calipers and road pads. I've got customers racing hot hatches who do 20 odd laps flat out on standard discs with no issues. Rear pads are less important but by upgrading the rears you keep the braking balance the same though you have to be more wary about the temperatures generated as some race pads dont work from cold.

 

I noticed the difference in how the suspension reacted with my old rallye when it had 1.9 calipers. I downgraded to standard calipers and discs as well as moving back to steel wheels (from speedlines) and the car was brilliant in comparison.

 

GTi6 calipers work to a point but im not a fan.

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m_john_m

the car is going to be built it over time. i think im going to put 306 brakes with some decent pads and disks and see how it copes.

 

in the future i will be looking for some race pads. for now i will be happy with it stopping well like in my red 205. if i can upgrade the calipers to 306 then when i come to buy race pads it will even better...... i hope, all be it a bit more expensive.

 

funds are a bit low at the moment with buying the car, wheels, cage and new sump etc for it..... still need to service it, think im going anglessey on 1st may which is 3 weeks away so not got long.

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wicked

@Batfink, indeed there is more to it than only this equation. I just put this one in on to challenge the statement that only tires determine the stopping distance.

This equation gives the max braking for before the tires lock up.

Key is indeed how your foot applies the force. If you just slam the brakes, there is no point in getting bigger brakes. If you build the pressure the right way, you can increase the dynamic mass and thus max force you can apply on the tires.

 

Indeed drooved discs etc only improve braking if you have pads that generate a lot of gas during braking (fi red stuff) and would give fading because of that on plain discs. Good quality plain discs will do with gti6 brakes. Rather put money in decent pads than grooved discs.

Edited by wicked

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petert

Like I said Endless. You don't hear much about them on this forum, which is strange considering their European connections. I think I'm running N40S on the front. A good website with plenty of info on pad material and setups.

 

http://www.endless-brake.info

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m_john_m

the fella i bought the car off said he think it was yellow stuff pads. but the brakes arent very good, not sure whether a piston is seized. i thought they needed bleeding but on the day of the track day they seemed better...... only by a bit though.

 

GTI6 brakes just seem a cheap temp solution. the fella im buying off sais he has grooved disks he can sell with them...... grooved is better than not right?

 

i will look for some decent pads. i want to get this first track day out of the way first! i done a short one recently at the three sisters in wigan (£20 for 10 laps) and i dont 3 stints. everything was fine apart from brakes and tyres.

 

Im sure anglessey will put the car through its paces!

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petert

You're not listening. New non-grooved discs and quality pads are better than 2nd hand grooved discs.

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Batfink

the equation for maximum braking force before the wheel locks is:

Fa = Madyn.g.Ur

 

Fa = the total possible force on the axle

Madyn = dynamic axle mass

g = acceleration due to gravity

Ur = Co-efficient of friction between the tyre and road

 

You can work out the maximum clamping force of a caliper and disc setup with a separate equation but this will be higher than the maximum force for the equation above.

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welshpug

Like I said Endless. You don't hear much about them on this forum, which is strange considering their European connections. I think I'm running N40S on the front. A good website with plenty of info on pad material and setups.

 

http://www.endless-brake.info

 

 

I've heard of them, but who in the UK stocks them? European connections don't mean a lot in the UK :lol:

 

Had a little hunt about, nobody in the uk seem to list them whatsoever.

Edited by welshpug

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welshpug

none of them list anything :(

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Batfink

Think you're right....

 

consider yourself out-geeked!

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m_john_m

sorry petert I missed your post..... I'll have a look!

 

I'm just looking at the best cheapest option at the moment.... If such a thing exists lol

 

But surely buying 306 brakes and buying some decent pads and disks will be better than standard brakes with the same disks and pads? Or am I missing something.

 

May see what he wants for just the calipers themselves and source disks and pads myself! I am liking the look of some of your suggestions!

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Batfink

you probably wont like the price of Endless pads.

 

The 306 setup will run cooler as it is a bigger caliper, bigger pad and much larger disc. You dont run gti-6 calipers with standard discs. New you are looking at around £60-80 for a set of discs and pads so add that to your price for the calipers and you can start to work out what might be best.

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m_john_m

Yeah but once I have the calipers the. I have them for good. I can then upgrade disks etc as and when.

 

I have been looking at decent disks and pads. I'm surprised at the amount of oeople running standard brakes, I expected everyone to be running the 306 or 406 set up.

 

I need to decide pretty quick as the car has to be sorted within 3 weeks :/ hopefully sort it by next weekend ski can bed them in

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m_john_m

you probably wont like the price of Endless pads.

 

The 306 setup will run cooler as it is a bigger caliper, bigger pad and much larger disc. You dont run gti-6 calipers with standard discs. New you are looking at around £60-80 for a set of discs and pads so add that to your price for the calipers and you can start to work out what might be best.

I know you wouldn't run them with the standard disks, what I meant was:

 

 

The brakes will be better if I bought the 306 calipers and used say tarox disks and ds2500 pads

 

Than if I used standard calipers with tarox disks and DS2500 pads......

 

Like for like as it where......

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petert

Here is my last contibution to this topic. Buy a good set of brake pads (eg Endless N20J) for your standard calipers and buy new rotors. Guarantee you won't be disappointed. A better overall result than GTi6 + DS2500.

Edited by petert

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tomcolinjones

standard caliper wont ruin your handling due to increased unsprung weight. Spend your money on ds3000, new discs, decent brake fluid and then get the best tyres you can afford :)

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m_john_m

Ok I will do that then!

 

I really am surprised that larger calipers will ruin the handling! Oh well! I'll get some ordered this week!

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welshpug

added unsprung weight and rotational mass, roughly 4 kilos a side.

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m_john_m

I have a set of compomotives for it, they seem a lot lighter than the speedlines! I'm hoping it will grip even better with these on and decent tyres! Probs Michelin PE2s as you advised!

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welshpug

not likely to be any lighter, they're rally wheels so built to be strong, original wheels are around 8 kg.

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