front brakes

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bones
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front brakes

Post by bones »

hi all, abit of advice on the front brakes, ive got a mk1 escort the struts are off a 2.8i capri, the engine going in is a 302, the wheels are 7x15, what i need to know will the capri brakes and discs be ok, or should i go for the big discs and wilwood calipers, this might be a stupid question but i dont want to waste the my money,or do i just spend the £400 on the big disc kit,advice needed once youve stopped laughing, :D rich,



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Post by kiwicar »

I think with a 302 in there you will need bigger brakes, even though you are starting with 2.8i bits. I would start with the bigger discs first, as surly you can do this but just remount the 2.8i calipers. See if this is adaquate. If you then find this is not enough then add the willwood calipers. Before you go to big four or six pot brakes I would make sure you are getting the best out of your existing set up though, correct master cylinder, matched servo (if fitted), in full working order, good quality flexable lines and good condition hard lines with top quality clean brake fluid, only then add £500-£700 of calipers!
I think the guy in PPC with the 302 capri runs big discs with Princess calipers, but I think all his problems have been bodged installation and dodgy servo/ vacuem feed.
Best of luck
Mike
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Post by ian.stewart »

For me the first plan of building a car is to get the brakes sorted, in most applications, build the brakes far in excess of what you expect you will need,
Depends where you want to use the car, if the car is purely a drag race car, 2.8s with decent pads will be fine, as the brakes dont have a severe duty cycle and are probably lighter than most big discs, What people expect from capri brakes is better brakes than what was on the car originally, if you have 245mm discs now there will be NO improvement on what you have, with the same dis disc, same size pad, same swept area the brakes are no better in fact, just the same as the originals, but because they are vented, they are less prone to fade,
I run big brakes on the front of my cortina, 310x28mm in 6x15s. Porsche/Bembro Callipers and Green stuff pads, which works very well, I had allready gone the 2.8i route, then 285mm discs, princess callipers, [but very heavy] which again worked well, but the bigger version I have now is about the same but better feel and a lighter set up, for me the main thing about bigger brakes is not the better stopping, but the better feel of the pedal, and the ability to control the car better without the problems of locking up, obviously the brakes are less prone to fade from gassing or boiling due to the larger area to dissipate heat,
Another factor of the braking system that is regularly overlooked is the tires, Traction is everything, no grip, no brakes, as soon as your wheels lock, 50%++ of your braking effort has been lost, Good Grippy tires are also about stopping the car,
Ian
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Post by bones »

thanks for the replies, the car will be street n strip use, would the willwood forged dynalite 4-pot caliper and 285x21 discs be ok, and what is the verdict on mounting a remote servo under the wheel arch as the space in the engine bay is limited,sorry to be a pain just dont want to go the wrong route again wasteing money, all the best :D rich,

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Post by kiwicar »

As above, I would go with the 285 discs (if you can get 310 discs under those wheels I would go for those) use the calipers you have and remount them, get some good pads, fresh clean break fluid (and thoroughly flush out the plumbing) fit good flexible lines (earls or similar), make sure you have the right master cylinder and break pedel ratio. If you are drag racing there is a need to dissipate alot of energy once, then time to let it cool, the four pot ally calipers will be of minimal advantage in this case, and you are not really bothered about unsprung mass (the other main reason for these calipers being used on cct cars, also the alluminium will transfer the heat more rapigly to your break fluid), you want alot of disc surface area to get rid of heat from high speed breaking, and can make use of the bigger mass of the standard calipers as you can then let them cool after stopping, the bigger diamiter discs will also give you more instantanious stopping power. I think the Dynalite series are track/race calipers and as such will not have dust seals, no good for road use as you will be rebuilding them every other week in the winter, for the use you describe, street/ strip, they are all wrong. I would think a big heafty caliper like the Jag 4 pot (or what you have) would be much better, lots of power, good and strong, and a good amount of mass so you can dissipate alot of energy without boiling your beak fluid.
Hope this is some help
Mike
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Post by bones »

thanks Mike, as for know i have no servo or pedals or master cylinder, so im starting from scratch with the brakes,rally design do a kit for £400 which uses the midilite caliper and 285x21 vented discs ,the caliper is fully dust sealed. Although i realise that isnt the end price for them as i think i have to buy the hubs and brake pads.so all the advice is very welcome, all the best :D Rich

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Post by ian.stewart »

As Kiwicar said the dust seal thing with Willwoods is an issue, and I think Willwood do offer some callipers with dust seals, If your car was to be a daily, I would suggest looking for sealed callipers,
Most "Toys" are driven with a very limited mileage. and not used in the winter, so you have plenty of time to give the callipers a quick wipe down. so if you keep on top of it the seals should not be a problem,
Why do you want a servo? all servos do is reduce pedal pressure, they have no other benifical advantages, They do not improve braking, and after you spending the time and effort of putting bigger discs and beter calipers why do you want to fit something that takes away 90% of the feeling in the brake system, a servo is essentially a damper in your braking system, The other problem with a servo you will find if you are using a Big cam is the engine will not produce enough vacuum to charge the servo.
Servos are for GIRLS
And by now you have probably guessed I HATE SERVOS in performance cars,
Ian :D :D
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Post by kiwicar »

Hi
midilight sounds a better caliper than the Dynalite, if you are starting from scratch then go that route, for street strip I would still go for as big front disc as you can, a twin master cylinder pedel box would be a good investment if you are fully from scratch, and don't bother with a servo(that is if you use 310 discs), use decent size coppernickle or stainless steel hard lines and as Ian said consider tyres carfully, if you are using drag radials on the back then consider upgrading the rear to discs aswell and ballancing it with the twin master cylinder pedel box (kit car market is a good place to look for them, robinhood, carbuilder solutions and many others oh! and rally design). try and remember what use the breaks are to be used for, cct and rally cars are very different beasts to street strip cars, for cct racing (and to a larger extent rally work) it isn't about stopping the car, but ballancing and setting it up for the next corner (and maybe taking off 10 to 15mph) so you put in small amounts of heat very often so you design the set up to get up to working temperature and stay there (also a very big design consideration is unsprung weight). For a drag car you want the thing to stop from 130mph or more under your control as quickly as possable and without boiling the brake fluid and starting with cold discs and pads. The calipers and discs are going to get a hard time for about 10 seconds then you let them cool off but while standing still! :shock:
Best of luck
Mike
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Post by kiwicar »

I'm sorry I have got to say it, for this use I would go for Cast iron over ally every time, and a fairly heafty caliper at that. An ally one will boil your breakfluid, you wan't somthing from a heavy pasenger car or a road sports car (928 porsche or rears off a 911, 7 series BMW jag somthing like that)
Sorry had to say it :oops:
Mike
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Post by ian.stewart »

Mmmm, Cast steel v Ally, Ally has better conductivity heat over steel, and I realise the main route for heat to get into the callipers is thru the pistons then into the fluid, which is why most callipers have cupped pistons so the heat transfer is periphial and will transfer into the calliper rather than into the fluid, and hopefully dissipate faster in ally than steel.
When getting into race callipers its a different game with brake fluid recirculation systems, and water cooled callipers, and prices to match, a friend of mine was quoted 7k for a set of water coold brakes from AP a little while age. and that was not even the ultimate spec ones!!!!
For me it would be ally every time, I have had no problem with my Porsche Bembros boiling fluid, even standing on the brakes from 140+ to 0, ok the pads smoked a bit when I looked, but there was NO FADE, I have my callipers painted, not in calliper paint but engine enamel, which is rated temprature wise to about 300 degs C, and I think I am right in saying all brake fluids boil above that point, and as yet, there is no sign of my paint starting to discolour or peel indicating excessive heat,
I think most the hi performance saloons now use ally callipers, I know my 5 series does. I also had a set of callipers off a supercharged jag which were ally Bembros as well
Mike, I am not having a dig at you just airing my opinions :rolleyes
Ian :D :D
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Post by kiwicar »

No dig taken Ian
the use of ally in modern sports and salloon car brakes is IMO a matter of fassion and not best material for purpose, the fact that they use so much of it I think validates my case! have you seen the size of a set of audi A6 SR calipers, dont tell me they are built that size other than to give them some heat capacity. I would expect your brembos have no problem at all stopping your car from 140 as they are designed to stop a car weighing another half ton from 180mph I am sure your set up will be briliant on his car too. I do however think that a set of calipers designed a lightweight car like a seven to go on the street and circute racing as the wilwood ones are are not ideal for stopping a car from 130 with a ford 302 in the front. The thing is going to weigh at least a ton more than a seven and those calipers are designed to get up to temperature fast and stay there not the same as what Bones is after. I am just trying to stop the guy spending £400 when he will get a more suitable set up out of a scrap yard by hunting around, the wife has an xk8 with sliding twin pot calipers on the front, they stop it from 150 like you would not believe and you can get them for £35 each off ebay.
Mike
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Post by ihatesissycars »

Don't forget to check if any of these will clear the inside of your wheel.

Imo i would do what ever it takes to get some 4 pot brembos fitted to your car as they look sooooooooooooooo good and are priceless in the pub crap talk stakes!

Ian, got any piccies of your setup?
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Post by kiwicar »

Gav I think you may have the real point here, on that front the Hispec six pots are even more bling in the pub for not unreal money.
Mike
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Post by chodjinn »

Well if we're on pub talk the Tarox 10-pot callipers are prob the biggest bling factor!

My 2 pence; I was considering shelling out some serious money on new brakes until I did the maths (cost vs. performance benefits etc)

My MGB uses (*I think*) Jaguar XJS 4-pots on the front with drilled/vented discs, and Sierra Cossy single pots on the rear with Mercedes discs. They're pretty beefy and although I've not used the car much in anger yet, they certainly do the job. Someone told me the front ones looked like Ford calipers, but I've yet to see any Ford with brakes that big! For what I intend to use the car for (fun, bit of drag, bit of track, but mainly road) the current brakes are fine, just need to add some fast road pads.

The only bling bit I have is the custom alloy twin reservoir & brake bias, now that does look good!

As people have mentioned, you can shell out a fortune on bling brakes or monster track spec stuff, but if you're only gonna use it on the track occassionally then its simply not work it, unless you're minted, or just daft. :lol:

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Post by bones »

thanks for all the replies, i did use a x-drilled vented jag disc and xj12 4-pot jag calipers on my rover sd1, had some spacer plates made up for it,ok Ian no servo that saves me putting that in and getting one. the car will be used on the road at weekends and strip action. the twin master cylindar pedal is fine, the rear axle has drums as the axle is a ford 8" item, The front disc should be a min of 285 but 310 is better and the midilites would be ok, thanks again all for the help and advice, :D rich.

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