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Technical Rear disc conversion

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Technical Rear disc conversion

nogin said:
locking your car up at the rear is in no way a bonus, or at the front, as soon as you lock a wheel up you loose control, so if you lock your front wheels up and your back ones what you going to do other then slide into them, chinqs dont need disks at rear they are way too light
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I have rear discs, and a hydraulic handbrake. I also have a balance bar and no servos.

The only time I want to lock the rears up is for handbrake turns, which are an important element of autotesting.

I fitted the rear discs and the vented fronts top ensure consistant brakes over longer sections.

Doing 20 miles of twisty stuff, followed by a time control, then another 20 miles, the standard brakes would overheat. The problem is not with the drums, but the shoes. It is almost impossible to get uprated material for cento shoes.

Cheers

D
 
So braking through a corner you can take at 70 or maybe 80mph into a corner that's about 30mph is slower than braking to 30mph for the faster corner? I think not... so does everyone else that drives that corner configuration.
 
this caption below is saying you push the chinq brakes quite hard and on the road i persume which is not a good idea, traffic light racing is not a safe form of motor sport.

While cornering drums get grabby and lock up easily, discs are less prone to this. As long as the bias remains in the right area, a manually adjustable bias valve isn't necessary and balance can be done with a front disc upgrade, it helps to maintain car stability during cornering under braking.

the whole point of the car being set up for more braking up front is two fold, lots of weight goes that way while braking, and as to stop the rear brakes locking up which is a realy bad situation, im not disagreeing that there no good or not an improvment but on a road going chinq they are overkill and a hazard, if you use your front upgraded brakes to the point you need to go to rear disks you are a danger on the road, eg recless driving, keep it on the track

just so you dont think i doint know what im on about i drive a turbo mini with 170 brake and i dont need rear discks on mine to stop
 
Not need, prefer them, it's yet more safety margin when balanced, I agree putting Punto GT discs on a 'cento with stock front brakes is slightly crazy.

I've seen people lose it on a roundabout trying to brake cause some moron has pulled out on them with way to little space for the car coming round the roundabout. Under those conditions I prefer to have as much going for me as possible and a more progressive rear braking system then is a bonus.
 
Disc brakes looks better ;) And the Fiat drumbrakes sucks. So why not an upgrade.

only with the original cento brakes at the front I should choose for Uno brakes 228mm.

And if you've got GT brakes 257mm ventilated) the 240mm are better and you can use your old fronts at the back :)
 
Well after going round Castle Combe, one of the fastest tracks in UK in Jamie's Cinq turbo, I can report that there is absolutely no way of locking up the rear brakes when fitted with Punto GT fronts, and thats leaving in place the rear biased valve as fitted as standard below the master cylinder. And they do work hard, hard enough that after 4 1/2 laps you would have melted your fingers if you were daft enough to touch the disc :)

And yes I agree with TurboCinqy they look so much better than drums, no sexy car would be seen dead with drums at rear, especially bright painted ones (oh controversial) :D

Tho if you have a wheel design that doesn't show them off, then i wouldn't bother even tho the handbrake is fantastic, you can with some effort get the drums handbrake to work, just needs maintenance to keep it like that.
 
All well and good having rear disc brakes, but the cinq does all its braking with the front discs. All it needs is uprated fronts. Anyone with rear discs who live with them long enough will tell you that they tend to seize up [ a fiat weak point ], either one side or both.
With a little modification, cinq/sei drums can be made to work very well indeed. Drums are reliable, and work much better over a longer period.

Andy.:)
 
sumplug said:
All well and good having rear disc brakes, but the cinq does all its braking with the front discs. All it needs is uprated fronts. Anyone with rear discs who live with them long enough will tell you that they tend to seize up [ a fiat weak point ], either one side or both.
With a little modification, cinq/sei drums can be made to work very well indeed. Drums are reliable, and work much better over a longer period.

Andy.:)
Click to expand...



Got to disagree with you Andy,

all cars brake from the front more, so that statement is a universal statement and not specific to Cinqs/Seis, and having been round Castle Combe in a turbo Cinq with rear disc's set up they do work hard, very hard, hard enough top generate a lot of heat from them, that to touch would burn you.

The rear drum set up is very poor on Cinqs/Sei needing constant maintenance to get it to achieve there full potential, read the amount of cars failing MOT's on poor handbrake's. I have lived with rear disc's sets up on all my cars over last 12 years never had one seize on me, thats Renault's , Peugeot's, Lancias, VW's etc and all have performed much much better than any drum set up, with no need to maintain them except for pad changes, unlike drums which need the adjusters removed and cleaned up and lubricated or replaced, leaking or seized wheel cylinders replaced etc Fiat callipers are not made by Fiat, but by Bendix/Girling etc same as any other manufacturer so don't seize anymore than any other car.

Drums in principle work as well as disc's, in fact can have more power, but they will never ever dissipate heat as well, hence they can fade badly, putting more pressure on fronts to work harder so they do and then they fade. They also have more of a tendency to lock up more than disc's.

But each to there own, my discs look so much better than a nasty drum, especially if the drum has been painted a bright colour and not just black :yuck: :D

Aaron.
 
SkinzCinqSporting said:
Have to agree wit Aaron, the drums are ****e, If i could afford the disc conversion I would, sick of the drums sezing on me :bang:
Click to expand...

Thing is I'm not saying discs are faultless, they are not, but they do offer an improvemnet over drums otherwise no car would have them fitted on the rears, we would make do with discs front/drums rear.

The drums on Cinqs/Seis do work, and can work well, but do sometimes require effort & time to achieve this, I've managed to get Cinqs through MOT's 1st time, but took time beforehand to ensure this, whereas I've dropped off old R5GTTs to pass 1st time no effort.
 
If you modify the adjuster on the drum and use a Sei cable with twin adjustments on it, the handbrake works perfect.
As i say again, the Cinq is light weight, and is designed to brake on the front, so why change the rears? If you are driving on your brakes on the road, you are a crap driver.
If you are track driving, that is a totally different matter, and you need track brakes, simple as that.
Oh, rear calipers on Fiats have been a weak point since the Fiat 124 and effects all modern Coupes. Only way to stop it is to liberally grease brakes every month. Handbrake is notorious to seize too.

Andy.:)
 
sumplug said:
As i say again, the Cinq is light weight, and is designed to brake on the front, so why change the rears? If you are driving on your brakes on the road, you are a crap driver.

Andy.:)
Click to expand...

Because there is a thing called brake balance and you need to keep it at the original state.

If you put GT brakes at the front and get 60% higher front brake force, you need to do the same at the back too, or the car gets more front bias braking, which might lead to easy front wheel locking, rear end rising, caster angle moves towards negative values, car tends not to brake in a straight line, camber gets more negative while nose diving, tyre contact surface becomes smaller, you loose traction and tend to stop further than you could...
 
sumplug said:
If you modify the adjuster on the drum and use a Sei cable with twin adjustments on it, the handbrake works perfect.
As i say again, the Cinq is light weight, and is designed to brake on the front, so why change the rears? If you are driving on your brakes on the road, you are a crap driver.
If you are track driving, that is a totally different matter, and you need track brakes, simple as that.
Oh, rear calipers on Fiats have been a weak point since the Fiat 124 and effects all modern Coupes. Only way to stop it is to liberally grease brakes every month. Handbrake is notorious to seize too.

Andy.:)
Click to expand...

What modification is needed to be done to the adjusters on the drums, im fed up of my handbrake being terrible.
 
pranksta said:
What modification is needed to be done to the adjusters on the drums, im fed up of my handbrake being terrible.
Click to expand...
To make the shoes clamp harder with the handbrake, you need to modify the handbrake arm by cutting a recess in it. It also needs a coupe of welds. You need to deasemble the drum lever and see how it moves to see what iam going on about. Basically it starts to clamp before the arm runs out of movement.
The Sei handbrake cable has an adjuster at the handbrake handle and 2 adjusters on the cable. This needs to be adjusted right. It can be done with a little bit of thought.

Andy:)
 
Asteris said:
Because there is a thing called brake balance and you need to keep it at the original state.

If you put GT brakes at the front and get 60% higher front brake force, you need to do the same at the back too, or the car gets more front bias braking, which might lead to easy front wheel locking, rear end rising, caster angle moves towards negative values, car tends not to brake in a straight line, camber gets more negative while nose diving, tyre contact surface becomes smaller, you loose traction and tend to stop further than you could...
Click to expand...
Well myself and Stu fitted 257mm discs and calipers to Emms Turbo Sei from an Alfa 155 and it just brakes a lot sooner and in a straight line. Brakes are now excellent. It has standard rear Drums!

Andy;)
 
Braking in a straight line on a flat road hardly is a test of the braking and chassis stability, what you need to find is a nice piece of weird ass road that's doing the wrong thing in terms of surface camber/gradient.
 
Ok, so i will be doing the 257mm fronts soon, I have the calipers already.

I am also going to get 240mm rears to reuse my discs and pads from the front.

Barchetta 95-99 same as Punto GT 93-97
Barchetta 99- same as Punto GT 98-99
Click to expand...

So either of the above would fit? Are there any differences between the ages?

I looked HERE for all applications for the 240mm disc. There are many models listed under RR (rear) so do you think most if not all of those RR cars would be suitable for the conversion?

If so that would make searching for parts easier!

Where is the best place to buy? i presume the breakers is the only real option due to the variety of parts needed?



Been asked before but a bit unclear, I need:

Rear calipers (240mm variety)
Cinq/Sei Rear hubs (reuse them but fit new nut)
Cinq/Sei front discs and pads
A custom caliper mount
Handbrake cable
Flexy hose

Is that it?

Using the cinq hub and disc I won't need any spacers, just the mount?

Rallycinq, what do you think the problem is with the mounts posted?

Also, is it best to have a splash guard?? I don't have a larger one for the front :( But could poss get one for front the same time i get the rears.

Cheers,

Kristian
 
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