b14wrc
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 posted on 4/12/11 at 12:32 AM |
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Brake development work
Hi all,
Some of you may have read my posts in the summer about Brembo brakes and what size disc can be used with a 15" wheel. I had 305mm discs from my
coupe, but couldn't tell if they were too big initially. Well after some drastic mods, ruled this out. The zetec s wheel I have didn't
fit.
Any way, went to the scrap yard on Friday, I had researched on the net (APEC brakes online catalogue) to determine what I needed. Pug 406 283mm disc
was what I was after. Found one, and after a bit of work today it's now mated to the Cortina mk5 hub.
As you can see from the back. 
The calliper will fit fairly well, just need to make a braket, thinking I will make a fibre glass mock up and then get one machine in steel. Overall
very happy, it's a big disc conversion and utilises the 4 pot callipers.
If any one else is interested in this, I would be more than happy to help with details. The bracket will be the next step then it is compete. The disc
did require some work to fit to the back of the hub. But looks like it was meant to be there now. Comparing it to a vented Capri disc, it's
massive!
Rob
20vt powered rear engined locost
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ashg
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| posted on 4/12/11 at 07:58 AM |
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i had a coupe and as i remember the brembo callipers are stupidly heavy. would it not be better to sell the brembo callipers to a coupe nut for a few
hundred and put your money towards a set of light weight callipers like willwood or high-spec which weigh about 1kg? if i also remember correctly on
the coupe brembos the pistons in the front and rear of the calliper were different sizes which made the discs prone to warping under heavy use.
not trying to be negative about doing something different but thought i should say there are better options out there.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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big-vee-twin
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| posted on 4/12/11 at 10:44 AM |
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How close is the caliper to the wheel, if you get a stone or pebble thrown in there, it may get stuck and make a mess of the wheel and caliper?
Duratec Engine is fitted, MS2 Extra V3 is assembled and tested, engine running, car now built. IVA passed 26/02/2016
http://www.triangleltd.com
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bertie_bas205
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| posted on 4/12/11 at 12:20 PM |
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quote:
Originally posted by ashg
i had a coupe and as i remember the brembo callipers are stupidly heavy. would it not be better to sell the brembo callipers to a coupe nut for a few
hundred and put your money towards a set of light weight callipers like willwood or high-spec which weigh about 1kg? if i also remember correctly on
the coupe brembos the pistons in the front and rear of the calliper were different sizes which made the discs prone to warping under heavy use.
not trying to be negative about doing something different but thought i should say there are better options out there.
I'd be inclined to agree....
The brembos are well over kill for the weight of the car...
But if its what ye wanna do, get on n do it, good on ye for trying something different....
Theres a few Peugs that run 285mm discs, later HDI's, 306 Rallyes, GTi6's.....
I run the GTi6 set up on my 205 turbo and are more than fit for the job....
Bertie.
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thefreak
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| posted on 4/12/11 at 12:22 PM |
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That's the problem I've noticed when designing brake kits. The Brembo calipers are big and chunky and do add a decent amount to the
unsprung weight of the car. Adding that to the heavier turning feel means yes they might feel good when you're stamping on in a straight line,
but when you're trying to be quick and nimble through the twisties you feel like you're trying to turn an oil tanker.
Those Brembos are perfect for a 1500-2000kg car with it's power steering and big wheels, but stick them on a 600kg kit and you'll know
about it, even the discs will be significantly heavier as they're vented.
They do look good behind the wheels, and if you're going for the look then perfect, but I think you might find them a little chunky on a
lightweight kit.
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v8kid
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| posted on 4/12/11 at 01:03 PM |
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More info here http://www.zyworld.com/caprisport/1_brakes.htm
With a bit of forethought you can fit 300mm discs under 13" rims but it necessitates using split rims.
I machined off the lugs on the ford hob to save a bit of weight but did not really notice the difference.
Changing to 13" wheels with unvented discs did make a difference to the ride however which was obvious in retrospect as I had shaved a few Kg
off the weight.
Main reason was tyre availability though.
Cheers
You'd be surprised how quickly the sales people at B&Q try and assist you after ignoring you for the past 15 minutes when you try and start a
chainsaw
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b14wrc
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| posted on 5/12/11 at 12:35 PM |
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Hi All,
Some mixed views on that subject then. I basically wanted to show people that there are good upgrades for the Cortina set up other than expensive
break kits. I am going to use the Brembos as I have them and believe they are good brakes. Just sharing my experience and backing up theory with
actual prototyping, thought that was the locost way of doing things…….
Why would Mitsubishi use Brembos on the Evo??
I take the comments on car weights, however I do need good stopping power as I am running a powerful engine. But my question is how heavy? I mean, if
we are comparing apples with apples – how much more does the Brembo alloy four pot weigh to the standard iron two pot Cortina calliper? Which would be
my standard alternative. I would guess not much more….. I will weigh them and post it. In terms of cost effectiveness, if the Brembos provide twice
the braking power over the Cortina ones – I say that was cost effective. As it hasn’t cost me any thing, £2 for a disc to mess around with.
By the way, I believe Evo’s warp discs too, couple of my mates have had them, and the 5 which had Brembos was better (less warping) than the 4 which
didn’t. Just depends how hard you use them, in a lightweight machine you would not need to use them as hard and hence less likely to warp?
Aesthetics is high on my list too, and think they look hard core! There is about 6mm between the rim and the Calliper, I expect you could get a little
more clearance if you used an aftermarket wheel, such as a Team dynamic Pro Race 1.2 as I intend too.
Caprisport – endorse the use if you read the blurb on their web page…..
Cheers, Rob
20vt powered rear engined locost
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thefreak
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| posted on 5/12/11 at 01:01 PM |
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The Evo is a completely different beast to anything the kit car market comes up with. It's a 1500kg, 4wd, 300bhp saloon. So it needs something
to slow down that weight when it's tanking around a track.
Most kits are easily 1/2 that weight, so wont need something as big and heavy so stop the car. It wont be throwing anywhere near as much heat through
the discs as a 32mm thick disc is designed to cope with.
The standard cast calipers will be a similar weight to the brembos yes, but probably 2-3 times the weight of a dynalite caliper so the savings on
unsprung weight will be significant as you wont need to run a 28mm thick disc, you can drop down to 25 or 21mm, or even just go for a solid if you
wish.
I've made a kit for the MX5 using dynalite calipers and 2 piece 280x20.6mm discs. The standard discs are 256x20mm and weigh 4.3kg, the same
weight as the 280mm 2 piece discs, so gaining extra and extra 24mm diameter for free.
The standard cast calipers with carriers are 3.7kg, the Wilwoods with brackets and fixings are 2.3kg.
I dont know the weights for the Brembo calipers, but the last set I had came in around 4.5kg each and those Pug 283x26mm discs are 7kg.
Also, what's your thoughts for the rear, as something that big up front will need something to balance out the back
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v8kid
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| posted on 5/12/11 at 04:43 PM |
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There are loads of spreadsheet programmes to work out balance of brakes front/rear. If you work out at 1.4g braking the answer is not so far away from
perfect.
Watch out with using vented discs for a few reasons - suspension weight is only one. as our cars are lighter they dissipate less kinetic energy as
heat when they stop. With a vented disc's cooling coupled with the thermal capacity (proportional to weight) the disc probably will never get up
to working temp. This is important for most sporting pads which do not work so well when cold.
So for our cars lighter discs are a win/win situation. If you feel flush or are handy having a disc mounted on an ally center or bell pushes this idea
a bit further but is more hassle.
Merc SL rear brakes are cheap and unbelievably light for the money and if re-drilled for 4 studs fit perfectly on sierra rear hubs positioning the
callipers nicely for mounting block adaptors.
Nice thread Rob
Cheers!
You'd be surprised how quickly the sales people at B&Q try and assist you after ignoring you for the past 15 minutes when you try and start a
chainsaw
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MikeRJ
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| posted on 5/12/11 at 05:04 PM |
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quote:
Originally posted by ashg
i had a coupe and as i remember the brembo callipers are stupidly heavy.
I stripped mine down a couple of weeks ago and I was surprised just how light they were for such a large caliper. I would agree that they are way OTT
for a Seven though, and they have a nasty habit of corroding and of squealing in their original fitment. On top of that they are IMO pretty mediocre
brakes with a disappointing amount of pedal feel.
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bertie_bas205
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| posted on 5/12/11 at 07:16 PM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by ashg
i had a coupe and as i remember the brembo callipers are stupidly heavy.
I stripped mine down a couple of weeks ago and I was surprised just how light they were for such a large caliper. I would agree that they are way OTT
for a Seven though, and they have a nasty habit of corroding and of squealing in their original fitment. On top of that they are IMO pretty mediocre
brakes with a disappointing amount of pedal feel.
I rate the Brembo's on my coupe....... They are dam good!!!
Yes they squeak like a pig on a hot BBQ, i can live with that for the return in braking efficency they provide....
If I had a spare set sitting on the shelf, I would be fitting them too....
Money saved to spend somewhere else......
Ye can fit them under 15" wheels, ye need to mill the disc's down to 295-300 (cant remember exact size)...
The problem is the huge hub offset required to stop the wheel scuffing the caliper, we used 18mm hub spacers...
Not ideal but worked well....
Bertie.
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iank
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| posted on 5/12/11 at 08:09 PM |
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quote:
Originally posted by b14wrc
I take the comments on car weights, however I do need good stopping power as I am running a powerful engine.
Physics says the amount of kinetic energy you need to lose approximates 0.5 * m * v^2 (plenty also being lost by the poor aero on most 7's)
Evo's weigh 3-4 times as much as your car should and can they go 30-40% quicker (max speed not point to point speed). They also have 4 seats so
that's an additional 200kg of passenger they may have to deal with, plus luggage, plus the possibility someone will put on a towing eye and a
caravan  so the manufacture have to put on big brakes to ensure their car is always safe.
So fit them if you want them, but on a lightweight car you'll probably end up either restricting the pressure through fiddling with master
cylinders/bias bars or locking up the fronts really easily. Bigger/thicker disks are good for preventing fade, but on a 7 with the brakes out in the
breeze and no weight most seem find getting up to temperature more of a problem (as v8kid says).
[Edited on 5/12/11 by iank]
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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b14wrc
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| posted on 5/12/11 at 11:11 PM |
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Right Chaps,
I have been out in the garage quickly tonight and using my spring balance (not sure how accurate, it's a fairly decent one!) have weighed all
the above parts.
1. Pug 406 283mm disc, 5.6kg
2. Brembo Caliper with pads and all fittings, 3.1kg
3. Cortina hub, 2.0kg
4. Upright, 3.0kg
5. Capri vented disc, 240mm, 3.4kg
6. Fiat Coupe 20v turbo disc, 305mm, 7.2kg
7. Fiesta Zetec S alloy, 15", 6kg
These are estimates as you have to judge the gauge, going to buy a digital scale later on in week, so will update if necessary.
Calipers are lighter than thought.
Rob
20vt powered rear engined locost
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b14wrc
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| posted on 5/12/11 at 11:14 PM |
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Oh and wrt rears, I am running fiat hubs but plan to modify to fit ford discs.
Not sure, maybe something in the region of a 260mm solid? Brembo twin pot would be nice but expect that would be " over kill". 
20vt powered rear engined locost
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b14wrc
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| posted on 7/12/11 at 05:10 PM |
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Update:
Calipers with all parts fitted, complete unit weighs 3752g.
My spring balance is more accurate with heavier things on. So guessing the disc is about 6.2kg not 5.6 as thought.
Still, I am very happy with that, power per £ and looks the nuts!
Ok, so that's a real figure. What weights are other peoples lighter weight options and what are the specs??
Just keen to compare, I am going down my route because I beleave it's the best for my car and fits my budget. Can't afford to splash out
on a pair of Alcons or AP ones.
Rob
[Edited on 7/12/11 by b14wrc]
20vt powered rear engined locost
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thefreak
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| posted on 7/12/11 at 05:20 PM |
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So 3.75kg for caliper, bracket, pads and bolts yes?
Disc weight is 6.2kg too yes?
total 9.95Kg.. or have I missed something?
Wilwood 4 pot Dynalite caliper, with pads and bracket/bolts weight 2.3Kg
280x20.6mm vented 2 piece disc with aluminium bell weight 4.3Kg
Total 6.6Kg.
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tomgregory2000
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| posted on 7/12/11 at 05:25 PM |
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quote:
Originally posted by thefreak
So 3.75kg for caliper, bracket, pads and bolts yes?
Disc weight is 6.2kg too yes?
total 9.95Kg.. or have I missed something?
Wilwood 4 pot Dynalite caliper, with pads and bracket/bolts weight 2.3Kg
280x20.6mm vented 2 piece disc with aluminium bell weight 4.3Kg
Total 6.6Kg.
But i wonder which one will cost more?
Keep up the good work, i like it and they will look sweeeeeet 
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thefreak
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| posted on 7/12/11 at 05:37 PM |
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Using a 1 piece disc, the weight of the disc goes upto 5.7Kg (Brembo aftermarket values, the same site that suggested the Pug discs are 7Kg not 6.2Kg)
So the weight would then go up to 8Kg.
If you went for solid discs, the weight would be around the same as 2 piece setup. (A 280x10 BMW 1 series disc is 4.4Kg)
Pricewise... I think the 2 piece setup cost me around £7-800, and the 1 piece with vented discs is around £450 for the complete kit. Those are retail
prices too, you can take a few quid off if you can machine the brackets yourself as you're only paying for material.
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b14wrc
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| posted on 7/12/11 at 10:31 PM |
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Cheers tomgregory2000. 
My set up cost me £0.00 for the Calipers (which actually was -£250 ish) because I made a profit on the braking of the donor car from what I paid for
it.
£2.00 for an old disc, to develop the design, which now I will go for a groved after Market version, bit lighter and reduce pad glazing, say around
£60 a pair. (eBay)
The bracket, hummmmm planning to make a fibre glass mock up, then get a steel one ( something a bit fancy - NQ1 maybe?) machined at work. Cost again
£0.00...
Sorry, but at this stage 3kg weight saving isn't going to convince me to spend an extra £700.... You seen what engine I'm running? Fiat
20v turbo.... These arnt light, so the extra 6kg up front will help balance it out! Lol
Plus, I like the more custom build. No one else will have the same design.
Rob
20vt powered rear engined locost
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thefreak
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| posted on 7/12/11 at 10:40 PM |
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Like I said, if you can do the machining yourself, it helps with the cost.
If you're buying second hand parts that also brings the cost down. I make and sell brake kits, so looking at it that way my kit cost nothing too
But if someone was going out to buy the parts, and paying an engineer to design and make them for your kit you're looking closer to £500.
I've got a good contact for discs if you're wanting a set of grooved ones too
[Edited on 7-12-11 by thefreak]
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b14wrc
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| posted on 8/12/11 at 07:55 AM |
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Might take you up on that, thanks.
20vt powered rear engined locost
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b14wrc
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| posted on 11/12/11 at 01:20 PM |
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[IMG]http://i1126.photobucket.com/albums/l603/b14wrc/7bb0afb9.mp4[/IMG]
It's almost there.
20vt powered rear engined locost
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ashg
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| posted on 11/12/11 at 03:36 PM |
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my willwood power lite callipers front and rear which weigh 1kg each with 270mm front and 240mm rear solid discs my 7 is running a +200bhp saab
engine and i havent found the limit on the brakes yet even being silly out on track
its nice to see people doing something different and i take my had off for posting it up but if your going for maximum braking vs weight there are
lots of better solutions. evos have brembo brakes because mitsubishi could get them for the right price at the right time and the math in terms of
required braking worked out.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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b14wrc
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| posted on 11/12/11 at 07:41 PM |
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Thanks,
But no, I am going for maximum braking for cost. Can't afford anything else. So the brembo's will have to do. I actually like the look of
them too, my old Celica GTfour had some nice four pots on it, but they were heavier than the brembo's.
I am not really that bothered about the weight, as long as the whole car ends up under 600kg I will be happy, should be running at least 300bhp.
Rob
20vt powered rear engined locost
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b14wrc
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| posted on 12/12/11 at 11:01 PM |
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Hi all,
Tweaked the design; running nice now.
Mock up bracket....
Rob
20vt powered rear engined locost
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