Technical punto gt brake upgrade

[J333EVO]

Re: I've fitted Punto GT callipers/disc's!

more pics showing differance in size of discs

Aaron.

 

[mase]

Re: I've fitted Punto GT callipers/disc's!

aaron: are those the maxtorq discs from rally design?

wats pads u suggest u use with those?

 

[J333EVO]

Re: I've fitted Punto GT callipers/disc's!

aaron: are those the maxtorq discs from rally design?

wats pads u suggest u use with those?

Yes MaxTorq form Rallydesign, I use Mintex M1144 pads which are very very good, but expensive, Emma runs standard Bendix pads which were great value at £17 local car shop and have more than enough bite for what she needs. TBH any decent pad will work well as the extra diameter of the disc offer so much more stopping power than a Cinq/Sei calliper disc could ever muster.

You have to be careful if ordering on line as someplaces do not offer the two pad designs, your callipers are same as mine so you need to ensure the pads are for 97-99 Punto GT not 94-97 like emma's are as pads are very different.

Aaron.

 

[CinqyAbarth]

Re: I've fitted Punto GT callipers/disc's!

Im looking at Red Dot pads with mine and standard discs until i get some more money.. do standard discs come vented, as lukes were solid iirc but mine are vented like the ones in the pics..
Oldschool does the pads for £37 (rrp £46) and discs for £88 (rrp £110)

and btw what is that on the top of your GT disc on the first pic? looks like someones sctratched it or something..

and how the hell did you get those calipers so smooth? mine are lumpy as fook as theyve been a bit rusted...

Craig

 

[GhostWKD]

Re: I've fitted Punto GT callipers/disc's!

finger prints on the disc grease or de-greaser i'd imagain, std GT discs are vented too

 

[CinqyAbarth]

Re: I've fitted Punto GT callipers/disc's!

Cheers Alex

 

[LanciaMad]

Re: I've fitted Punto GT callipers/disc's!

Dunno if its been mentioned yet but these are the same calipers and discs also found on bravo/bravas 1.8 and upwards, Im sure theres a few more of those in scrapys than GTs!

 

[mase]

Re: I've fitted Punto GT callipers/disc's!

your callipers are same as mine so you need to ensure the pads are for 97-99 Punto GT not 94-97 like emma's are as pads are very different.

Aaron.

good lad, that was goin to be my next question as im lookin at gettin new brakes in the coming months.

 

[foxyemx]

Re: I've fitted Punto GT callipers/disc's!

and how the hell did you get those calipers so smooth? mine are lumpy as fook as theyve been a bit rusted...

Craig

Alot of preparation went into getting them smooth as possible, when i got the calipers they were red, so all that had to come off with paint stripper, then wire brushed, oh and a wire brush grinder was used too, also the quality of caliper paint used helped, i went for Folia Tec in blue http://www.rtecshop.com/index.php?p=browse&category=45

emz

 

[Badger_Benji]

Re: I've fitted Punto GT callipers/disc's!

Just fitted mine, the pedal feel has improved now the pads have bedded in, but the pedal is longer and softer, but this helps modulate the increased power that there is. Im running mine with 12 groove discs as thats what my calipers came with, its really noisy when I stand hard on the pedal, but it really stops the car now

 

[J333EVO]

Re: I've fitted Punto GT callipers/disc's!

Just fitted mine, the pedal feel has improved now the pads have bedded in, but the pedal is longer and softer, but this helps modulate the increased power that there is. Im running mine with 12 groove discs as thats what my calipers came with, its really noisy when I stand hard on the pedal, but it really stops the car now

Ensure that you have bleed them correctly as mine were firm staight out if the box as were Emmas, no further peddle travel at all, if anything less peddle travel, tho in both cases new s/s braided brake lines were fitted, and in my case new Castrol Response Plus fluid was used as well.

As an aside, in Emma's pics you can clearly see the standard Fiat 10mm spacers and stud conversion as supplied with Sei Abarth wheels as I know many people ask about these.

Aaron.

 

[Badger_Benji]

Re: I've fitted Punto GT callipers/disc's!

They have been bled, but the piston is alot bigger than the standard piston, so there will be a slightly longer pedal as a result. I have stainless brake lines, but just need to fit them, but im about to drop the arms out and the engine, so was going to do it then, and replace the rigid brake pipes all at the same time.

 

[Liam]

Re: I've fitted Punto GT callipers/disc's!

Hmmm, great posts and pics Aaron, new rims and brakes await me, my wallet and my poor knuckles!

Liam

 

[Duncan]

Re: I've fitted Punto GT callipers/disc's!

You have to be careful if ordering on line as someplaces do not offer the two pad designs, your callipers are same as mine so you need to ensure the pads are for 97-99 Punto GT not 94-97 like emma's are as pads are very different.

Aaron.

Is there any benefit to the different calipers?? Are both a straight swop?

 

[LanciaMad]

Re: I've fitted Punto GT callipers/disc's!

Is there any benefit to the different calipers?? Are both a straight swop?

Both calipers are just 1 pot so its more the difference in size 240mm to 257mm and the new discs are vented....

 

[mase]

Re: I've fitted Punto GT callipers/disc's!

Both calipers are just 1 pot so its more the difference in size 240mm to 257mm and the new discs are vented....

and the piston in the gt calipers is bigger, so not only do you get more surface area for the pads to press against, but the pressure pressing down in them is increased!

and i can tell u right now, when coupled with stainless hoses, u can outbrake and suprise an aweful lot of bigger / faster cars with them :slayer: defo a worth while mod!!!

 

[J333EVO]

Re: I've fitted Punto GT callipers/disc's!

Is there any benefit to the different calipers?? Are both a straight swop?

TBH i don't really think there is much difference in the two types of Punto GT callipers, ok there must have been a reason to change but as they are both considerably bigger than the cinq callipers and as pointed out allow the fitment of the bigger vented disc going to be a big improvement.

The earlier ones are actually slightly easier to fit as they do not foul the dust sheild unlike the later ones which require the dust sheild to be bent slightly.

Aaron.

 

[arseofbox]

Re: I've fitted Punto GT callipers/disc's!

and the piston in the gt calipers is bigger, so not only do you get more surface area for the pads to press against, but the pressure pressing down in them is increased!

Fraid not mate!!

For the same pressure, if the area the force is being applied on increases (eg a larger piston diameter), the force will decrease!!

Its all to do with the pads...

 

[Liam]

Re: I've fitted Punto GT callipers/disc's!

I'll add something to this thread that will help anyone fitting discs.

I was told that the discs when manufactured are coated in a substance that stops them surface rusting whilst sitting on shelf or in damp places, to remove this you wipe the discs with a clean rag and white spirit, this lets the discs bed in that bit better once fully running.

On another matter, is there any truth that runnning in new discs with old pads speeds up the process?

Liam

 

[Asteris]

Re: I've fitted Punto GT callipers/disc's!

Fraid not mate!!

For the same pressure, if the area the force is being applied on increases (eg a larger piston diameter), the force will decrease!!

Its all to do with the pads...

Fraid not too mate. A pressure that is applied at a point of a liquid, is equally delivered to the rest of the liquid. That's the Pascal's principle. Pressure stays the same, force multiplies by the areas ratio.

Check this site: http://hyperphysics.phy-astr.gsu.edu/Hbase/pasc.html

At the hydraulics press calculation, enter r1= 0.5cm (footbrake pump piston area), r2= 5cm (Punto GT I/II caliper area) and F1 (foot braking force) = 10N. Result is 999 N of force at the caliper end.

Do the same with r2 = 4.6cm for the cento caliper and 5.4cm for the GT III (year 97-99) caliper and see the results for yourself (846 and 1166 Newtons respectively).

Braking power is also bigger at the 257mm disk because it is applied at bigger distance from the center (braking is actually a torque as it is a force applied at a distance from the rotation axis, so it obays at T = F * R, so T is relative to distance appplied).

Brake pad surface is the third parameter that benefits at the 257mm disks, bigger surface gives bigger friction.

Vented disks are the least our light car needs, but it's not bad to have. Vented disks is also heavier than solid ones by a kilo and a half and this adds to the weight of the suspension (along with heavier wheels/biger tyres), which is always bad to happen...