MakeEverything
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| posted on 30/3/10 at 08:54 AM |
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Which Sierra Calipers
Hi All,
Ive got normal sierra calipers on solid discs on the kit car, and the mechanical handbrake ones on the rear.
I want to upgrade to four or six pots for more braking efficiency, but i dont know which ones will fit straight on.
Anyone done this before? I dont want to keep buying bits that dont fit, then have to sell them on!
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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cd.thomson
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| posted on 30/3/10 at 08:57 AM |
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No doubt it will ignite a debate but I am under the impression that the £200+ 4 pot calipers (like the kits from rally design) are all about weight
reduction rather than significantly higher braking efficiency.
What about changing to the larger cosworth front discs and mintex pads as a more affordable option? 
ETA - of course, fit 4-pots if you like! I plan on doing that as an early winter upgrade once its on the road but mainly for bling factor 
[Edited on 30/3/10 by cd.thomson]
Craig
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ChrisW
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| posted on 30/3/10 at 09:10 AM |
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The XR4's, 4x4's and Cossies had 260mm front discs instead of 240's on standard Sierras. They're a bolt on upgrade, and
reasonable cheap to do.
With some decent pads that should be plenty for a Seven-type car. If you need better pedal feel, why not think about a servo?
Chris
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iank
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| posted on 30/3/10 at 09:14 AM |
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If you have braking problems with those discs putting on 4-pots is unlikely to improve braking. (Unless your car is going faster or is significantly
heavier than a sierra).
If you are having problems then it's probably because the master cylinder is the wrong bore, pedal pivot isn't in the right place, racing
pads that aren't up to temperature, or you simply aren't used to the feel of servo'ed brakes.
Can you lock up the brakes if you push hard enough?
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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MakeEverything
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| posted on 30/3/10 at 09:18 AM |
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For Brakes, im not too worried about the weight (within Reason), but want them more for their efficiency etc.
Larger discs will only prevent overheating, which will require larger wheels.
My kit car isnt a seven type car, so behaves differently. I already have a servo, and as said, its not hte feel, but the efficiency that im after.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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MakeEverything
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| posted on 30/3/10 at 09:19 AM |
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quote:
Originally posted by iank
If you have braking problems with those discs putting on 4-pots is unlikely to improve braking. (Unless your car is going faster or is significantly
heavier than a sierra).
If you are having problems then it's probably because the master cylinder is the wrong bore, pedal pivot isn't in the right place, racing
pads that aren't up to temperature, or you simply aren't used to the feel of servo'ed brakes.
Can you lock up the brakes if you push hard enough?
Im not having problems, i just want better braking efficiency because im going from 130hp to over 230.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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iank
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| posted on 30/3/10 at 09:32 AM |
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quote:
Originally posted by MakeEverything
quote:
Originally posted by iank
If you have braking problems with those discs putting on 4-pots is unlikely to improve braking. (Unless your car is going faster or is significantly
heavier than a sierra).
If you are having problems then it's probably because the master cylinder is the wrong bore, pedal pivot isn't in the right place, racing
pads that aren't up to temperature, or you simply aren't used to the feel of servo'ed brakes.
Can you lock up the brakes if you push hard enough?
Im not having problems, i just want better braking efficiency because im going from 130hp to over 230.
But will you be going any faster? If not it makes no difference*. i.e. road car. On the track you might need better brakes as your speed will be
higher, but the callipers won't help the efficiency much - bigger diameter discs will (you get a mechanical advantage with the pads pressing at
a greater radius). As you say thicker discs just reduce the tendency to fade.
* Brakes convert kinetic energy to heat in order to stop you. Your kinetic energy is 0.5*mass*velocity^2.
[Edited on 30/3/10 by iank]
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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MakeEverything
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| posted on 30/3/10 at 09:44 AM |
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quote:
Originally posted by iank
But will you be going any faster?
Errrr.... a bit....
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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iank
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| posted on 30/3/10 at 10:30 AM |
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quote:
Originally posted by MakeEverything
quote:
Originally posted by iank
But will you be going any faster?
Errrr.... a bit....
So it's on the track you are looking at? On the road your acceleration will be better, but it's only speed that makes the
difference to the brakes. It's a common misconception that big bhp requires expensive brakes.
My point is purely that bhp means nothing to the brakes except indirectly. If you don't break the law (or only break it sanely) then on the
road it will make no difference if you are already happy with their current performance.
In either case calipers won't make the difference you're looking for, it's really only pad material and brake diameter count.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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Brommers
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| posted on 30/3/10 at 11:45 AM |
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Assuming the brakes aren't getting too hot to work properly (in which case you need vented discs or better brake cooling) there are three things
which affect the efficience of a braking system:
1. Disc diameter
2. Pad compound
3. Whether the pad is operating in its optimum temperature range
Changing the calipers will have next to no effect on overall braking efficiency. If you can tell the difference in braking efficiency from just
changing the calipers, and you're not a top-level professional racing driver, then you're in the wrong job...
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MakeEverything
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| posted on 30/3/10 at 01:07 PM |
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quote:
Originally posted by iank
quote:
Originally posted by MakeEverything
quote:
Originally posted by iank
But will you be going any faster?
Errrr.... a bit....
So it's on the track you are looking at? On the road your acceleration will be better, but it's only speed that makes the
difference to the brakes. It's a common misconception that big bhp requires expensive brakes.
My point is purely that bhp means nothing to the brakes except indirectly. If you don't break the law (or only break it sanely) then on the
road it will make no difference if you are already happy with their current performance.
No, im not looking for track performance.
The existing calipers need overhauling, so i see that as an opportunity to upgrade.
Yes, they (once overhauled) are probably enough to stop the car, but by upgrading to four pot, or even six pot, then there is a greater surface area
of the pad touching the disc, giving greater efficiency with less effort.
I didnt really post for a debate on what it is people think i want. I KNOW what im after, i was just wondering what other people had done to achieve
it.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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cd.thomson
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| posted on 30/3/10 at 01:13 PM |
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quote:
Originally posted by MakeEverything
I KNOW what im after, i was just wondering what other people had done to achieve it.
Other people with lightweight sierra based kit cars achieve better braking efficiency by fitting larger discs and different compound brake pads.
I'm not sure what more it is you're after.
If you specifically want 4-pots for the weight reduction and bling factor than rallydesign do a sierra kit at an affordable price. Be aware that
people do experience quite a lot of brake squeal with them.
Craig
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MakeEverything
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| posted on 30/3/10 at 01:20 PM |
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OK, Thanks. Ive heard that the six pots from Rally Design are squeaky, and that the handbrake mechanism isnt too clever, so was thinking about itenms
fitted to existing road cars.
The bling factor does come into play, but primarily, if im going to overhaul calipers then id rather overhaul a better set than i have currently.
The accelleration speed will be improving, so i want the Decelleration speed to improve with it. Of course, its all relative to traction.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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turbodisplay
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| posted on 30/3/10 at 02:53 PM |
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The bore size of the caliper will affect force applied, larger bore more force on pad for givenline pressure.
Darren
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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MakeEverything
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| posted on 30/3/10 at 03:13 PM |
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quote:
Originally posted by turbodisplay
The bore size of the caliper will affect force applied, larger bore more force on pad for givenline pressure.
Darren
Correct, though the more combined surface area of all four pistons equals a greater force on the pads Vs the two cylinders, increasing the efficiency
without increasing the bore of the line or the master cylinder.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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iank
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| posted on 30/3/10 at 03:35 PM |
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quote:
Originally posted by MakeEverything
quote:
Originally posted by turbodisplay
The bore size of the caliper will affect force applied, larger bore more force on pad for givenline pressure.
Darren
Correct, though the more combined surface area of all four pistons equals a greater force on the pads Vs the two cylinders, increasing the efficiency
without increasing the bore of the line or the master cylinder.
Sorry it changes the braking effort (if you don't have a servo) but does nothing for the braking efficiency. If you can lock the brakes on your
current setup you'll just be able to lock them with less force on the pedal with the new callipers.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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Mr G
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| posted on 30/3/10 at 04:28 PM |
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Cossies run 280mm
My XR4i front upgrade thread
quote:
Originally posted by ChrisW
The XR4's, 4x4's and Cossies had 260mm front discs instead of 240's on standard Sierras. They're a bolt on upgrade, and
reasonable cheap to do.
With some decent pads that should be plenty for a Seven-type car. If you need better pedal feel, why not think about a servo?
Chris
Normal is getting dressed in clothes that you buy for work and driving through traffic in a
car that you are still paying for - in order to get to the job you need to pay for the clothes
and the car, and the house you leave vacant all day so you can afford to live in it.
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MakeEverything
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| posted on 30/3/10 at 06:42 PM |
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quote:
Originally posted by iank
quote:
Originally posted by MakeEverything
quote:
Originally posted by turbodisplay
The bore size of the caliper will affect force applied, larger bore more force on pad for givenline pressure.
Darren
Correct, though the more combined surface area of all four pistons equals a greater force on the pads Vs the two cylinders, increasing the efficiency
without increasing the bore of the line or the master cylinder.
Sorry it changes the braking effort (if you don't have a servo) but does nothing for the braking efficiency. If you can lock the brakes on your
current setup you'll just be able to lock them with less force on the pedal with the new callipers.
Making the effort exerted, more efficient????????
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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iank
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| posted on 30/3/10 at 06:53 PM |
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quote:
Originally posted by MakeEverything
quote:
Originally posted by iank
quote:
Originally posted by MakeEverything
quote:
Originally posted by turbodisplay
The bore size of the caliper will affect force applied, larger bore more force on pad for givenline pressure.
Darren
Correct, though the more combined surface area of all four pistons equals a greater force on the pads Vs the two cylinders, increasing the efficiency
without increasing the bore of the line or the master cylinder.
Sorry it changes the braking effort (if you don't have a servo) but does nothing for the braking efficiency. If you can lock the brakes on your
current setup you'll just be able to lock them with less force on the pedal with the new callipers.
Making the effort exerted, more efficient????????
Unless your measure of efficiency is leg effort no. Brake efficiency is a measure of rate of conversion of kinetic energy to heat. Pedal pressure
doesn't come into it - that's brake feel.
By all means spend your cash on aluminium 4 pots, they will make the car handle a little better and look very nice. But don't fool yourself
that they will dramatically reduce your braking distances.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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MakeEverything
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| posted on 30/3/10 at 06:57 PM |
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quote:
Originally posted by iank
Unless your measure of efficiency is leg effort no. Brake efficiency is a measure of rate of conversion of kinetic energy to heat. Pedal pressure
doesn't come into it - that's brake feel.
By all means spend your cash on aluminium 4 pots, they will make the car handle a little better and look very nice. But don't fool yourself
that they will dramatically reduce your braking distances.
Im not. Thats why im looking at something already fitted to a road car.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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Brommers
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| posted on 30/3/10 at 07:20 PM |
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quote:
Originally posted by MakeEverything
The existing calipers need overhauling, so i see that as an opportunity to upgrade.
Yes, they (once overhauled) are probably enough to stop the car, but by upgrading to four pot, or even six pot, then there is a greater surface area
of the pad touching the disc, giving greater efficiency with less effort.
Actually, pad area has nothing to do with braking efficiency. As confirmed by the Wilwood's technical pages. Force = area times
pressure'n'all - a larger pad means a lower pressure per area on the disc for an equivalent amount of force.
quote:
I didnt really post for a debate on what it is people think i want. I KNOW what im after, i was just wondering what other people had done to achieve
it.
Oh, in that case I just went to Rally Design's website and spanked some cash on a set of Powerlite kits all round. Luvverly.
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gazza285
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| posted on 30/3/10 at 07:31 PM |
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quote:
Originally posted by MakeEverything
Making the effort exerted, more efficient????????
Making a longer pedal.
DO NOT PUT ON KNOB OR BOLLOCKS!
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MakeEverything
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| posted on 30/3/10 at 08:21 PM |
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quote:
Originally posted by Brommers
Actually, pad area has nothing to do with braking efficiency. As confirmed by the Wilwood's technical pages. Force = area times
pressure'n'all - a larger pad means a lower pressure per area on the disc for an equivalent amount of force.
Exactly my point.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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MakeEverything
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| posted on 30/3/10 at 08:22 PM |
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quote:
Originally posted by gazza285
quote:
Originally posted by MakeEverything
Making the effort exerted, more efficient????????
Making a longer pedal.
Not gonna happen. Car is finished in that sense, and the pedal is as long as it can be with the space i have.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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boggle
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| posted on 30/3/10 at 09:21 PM |
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parachute?????
just because you are a character, doesnt mean you have character....
for all your bespoke parts, ali welding, waterjet, laser, folding, turning, milling, composite work, spraying, anodising and cad drawing....
u2u me for details
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