Technical Standard Abarth brakes

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Technical Standard Abarth brakes

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Quick question, and I'm asking it in the Abarth section even though I own a 500 TA.

I smoked my front brake pads twice the other evening when enjoying a 'sprightly' drive, so am thinking I'll swap over to vented discs (and the wider calipers) - something I'd been planning for a while. Naturally, I'm thinking go for the Abarth 'standard' discs and calipers (284mm), but wonder whether these will fit under the 14" steels (for winter tyres). I'm thinking not?
 
Doing some searches, I've found that people say 15's are a tight fit over them, so 14's are going to be a no go.

I *might* put the bigger brakes on, and sell the 14's and get another set of wheels to put winters on..
 
Pretty sure they won't. What size front discs are yours? The same as the 1.4? Or the smaller 1.2?

I think my 1.4 Lounge is on 257mm discs. I found that stainless hoses, Castrol SRF fluid, EBC vented grooved and dimpled discs and, oddly, Ferodo 1500 pads are the best setup. That configuration handled 4000 miles, 2 hours around Spa-Francorchamps, 20 laps of the 'ring including 6 in a row, the drive back home and another 2000 miles before the pads needed doing. No fade, no horrible burning smells, no squeaking or screaming.

If you do fancy trying your 14"s though, I've a spare 1.4 front strut at home with caliper, disc, hub, etc. I've also got an Abarth caliper and a set of Abarth discs kicking around if you want to prototype without pulling your car to bits.

cheers
Jason
 
TA has 257mm solids on it - so the size is there (and they do work), but fade like mad when pushed very hard.

I suspect it's probably best just to chuck 1.4 calipers and vented discs on it, and then the fade problems will go, as the actual braking power is fine.
 
Also, your post rang a bell with me. I went rummaging on another forum and found this thought I had from a year ago when I had time to contemplate such things and do the maths and research to make sure it was a sound idea:

I've been mulling over the 500's front brakes. I'd like them to be:

- slightly bigger
- much lighter
- 4 pot calipers that take a variety of easy change pads (yellows for track, etc)
- fit under 15" alloys because I love the way she handles on 15"s

To start the process off I bought a 500 1.4 front axle/hub/brake/upright assembly from Lewey so I wouldn't have to pull Isabella to bits measuring stuff up. After much procrastination and more thinking and measuring I think I can get away with 10.5 inch disc rotors like these:

ul-hp-straight-vane-rotor-lg.jpg
That's 267mm in new world measurements which is 10mm bigger than the standard discs. These bolt on to these ally bells:

images


This solves a couple of problems, slightly bigger brakes so more efficient, yet at the same time they're a lot lighter than the standard cast discs due to the alloy bells in the middle. Offsets are variable. Just need to pick the right one or blanks that suit and do a lot of machining.

For the calipers I'm looking at Wilwood midilites. They're aluminium 4 pot calipers, very light and good for cars up to 1300kgs in weight. The body of the caliper is reasonably small and the range of pads is awesome. Everything from EBC and Hawk and Ferodo is made for these and quite cheaply. Also the pad change is as simple as pull a W bracket out by hand and pop the old pads out and new ones in.

I've measured the surface area of the standard caliper with the pi x r squared formula and then trawled the range to find a midilite that's got marginally bigger surface area than the standard caliper (taking into account the multiple pistons vs single in the standard). This should be an ideal fit, given that the standard master cylinder will cope with 20% increase before the pedal feel is affected according to Fiat.

Interestingly the surface area of this 4 pot is marginally bigger than the Brembo GT kit advertised for the 500/Abarth 500. Also, interesting side note, the master cylinder for both 500 and Abarth 500 are the same.

Then machine some brackets from blanks which are surprisingly cheap. My initial thought is to convert the measurements into an mdf template then take it to a mates garage and borrow his milling machine to mill them out of some alloy blocks. I haven't done this bit because work has been a nightmare. But for giggles, here's a progress shot from a bracket I'm making for something else:

Brake-Bracket-Damons-Proposal-M.png


Once I've got it all together I'll need new stainless flexi lines made, Fiat 500 at one end and wilwood fitment at the other which isn't that expensive. Then fit them, flush through with new fluid and test.

As regards cost:

To give you an idea of costs:

2 x Calipers = £279
2 x brackets = £30 (ally blanks)
2 x Ally bells = £120
2 x disc rotors = £120
2 x brake hoses = £50
Pads = £65
================
Parts Total = £664

That's before we take into account:

- Machining the 4x98 and centre bore into the ally bells
- Machining the brackets
- Brake fluid
- Bolts and washers
- Labour to install it

So realistically, some faffing about and about a grand. But you'd get a very nice setup that would fit under 15" wheels such as the pro race 2's I'm running on Isabella now.
 
Do like the sound of that, if nothing else, removing some unsprung mass is always a good thing. Alloy calipers and alloy bells for the discs will save a couple of kg I would have thought - which is going to give the suspension a lot of help..
 
TA has 257mm solids on it - so the size is there (and they do work), but fade like mad when pushed very hard.

I suspect it's probably best just to chuck 1.4 calipers and vented discs on it, and then the fade problems will go, as the actual braking power is fine.
I told you the TA had rubbish brakes in comparison with the 1.4! The braking power on the 1.4 is noticeably better than the TA so I think those ventilated discs make quite a difference, along with the discs at the rear.
 
No, there's plenty of braking power as the brakes are identical in size to the 1.4. What I'm saying is that under repeated and sustained braking, the solid discs can't dissipate enough heat (or do not have enough material, and thus heat capacity), and cause brake fade.

I dare say if I changed the pads for something better (rather than OE), they'd be better.

The discs at the rear make no difference at all. I can promise you that.
 
What about trying MTec drilled discs? They are only £69.99 so not much to lose if not that good. Maybe these combined with EBC red pads? It's a cheap enough option that may improve fade.
 
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What about trying MTec drilled discs? They are only £69.99 do not much to lose if not that good. Maybe these combined with EBC red pads? It's a cheap enough option that may improve fade.

I'd rather just buy a set of vented discs, calipers and pads to suit. I know what the issue is, and how to circumvent it.

Tbh, the standard brakes are perfectly adequate and only suffered fade when being pushed ridiculously hard (for the road). I just want to engineer in a little more margin.
 
I'd rather just buy a set of vented discs, calipers and pads to suit. I know what the issue is, and how to circumvent it.

Tbh, the standard brakes are perfectly adequate and only suffered fade when being pushed ridiculously hard (for the road). I just want to engineer in a little more margin.

I find the brakes pretty good on the TA too.
I'll soon be ready for discs and pads so thinking of getting the setup I mentioned above. Of course your option is a better solution but a bit more ££
 
I find the brakes pretty good on the TA too.
I'll soon be ready for discs and pads so thinking of getting the setup I mentioned above. Of course your option is a better solution but a bit more ££

Indeed - the initial bite and braking ability is fine.

A set of calipers from a breakers won't cost a huge amount, a new set of discs and pads (which I will need anyway as they're consumable) and some brake fluid for bleeding. Well worth it IMO.
 
No, there's plenty of braking power as the brakes are identical in size to the 1.4. What I'm saying is that under repeated and sustained braking, the solid discs can't dissipate enough heat (or do not have enough material, and thus heat capacity), and cause brake fade.

I dare say if I changed the pads for something better (rather than OE), they'd be better.

The discs at the rear make no difference at all. I can promise you that.

But how come i felt that the brakes of the 1.4 were better than the ta?
 
TA has 257mm solids on it - so the size is there (and they do work), but fade like mad when pushed very hard.

I suspect it's probably best just to chuck 1.4 calipers and vented discs on it, and then the fade problems will go, as the actual braking power is fine.

Have you tried other pads? I've got standard Brembo pads and they're much better than standard. Obviously some even racier pads would be even better.

Obviously depends if you've got pad fade going on or if the fluid is boiling as well.
 
But how come i felt that the brakes of the 1.4 were better than the ta?

Difficult to tell, but if the TAs brakes had been abused, they might not be working as well as they should. As they're *exactly* the same (apart from being vented), on initial bite, they'll be just the same as the 1.4s. And the rear drums, if anything, will bite harder.
 
Have you tried other pads? I've got standard Brembo pads and they're much better than standard. Obviously some even racier pads would be even better.

Obviously depends if you've got pad fade going on or if the fluid is boiling as well.

Definitely not fluid boil - as the braking came back as good(ish) as before after a minute or two of driving along without applying the brakes. Whereas once you've boiled the fluid, you'll need to bleed the brakes to get full braking efficiency back.

As I say, I'll just go to vented, it's a bolt on job.
 
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