Major Stare
|
 posted on 16/7/10 at 10:24 PM |
|
|
2pot or 4pot.... that is the question
Currently have standard M16 2pot calipers.
Would lightweight 4pots make a difference/improve braking?
Jon "FISH"
|
|
|
|
|
ReMan
|
| posted on 16/7/10 at 10:34 PM |
|
|
Can you lock your fronts up with a reasonable pedal pressure?
|
|
|
Steve Hignett
|
| posted on 16/7/10 at 10:36 PM |
|
|
In my experience/opinion, upgrading to lightweight Ali 4 pots is only really for weight saving.
If you think they will be much better brakes than your standard ones you will be dissapointed (IMO)...
[Edited on 16/7/10 by Steve Hignett]
|
|
|
Major Stare
|
| posted on 16/7/10 at 10:38 PM |
|
|
quote:
Originally posted by ReMan
Can you lock your fronts up with a reasonable pedal pressure?
Nope
Jon "FISH"
|
|
|
ReMan
|
| posted on 16/7/10 at 10:38 PM |
|
|
If yes.
Then as per Steves reply
If not, then why not?
[Edited on 16/7/10 by ReMan]
What you cant lock them up at all?
Or it takes a good hard shove?
[Edited on 16/7/10 by ReMan]
|
|
|
Dan.
|
| posted on 16/7/10 at 10:47 PM |
|
|
Generally the best upgrade for brakes would be to change the master cylinder for a 19mm one. (fiat 126/panda ones work nicely)
|
|
|
expatkiwi
|
| posted on 17/7/10 at 05:27 AM |
|
|
I use M16 with 1144 pads. No problems. I was going to go for some 4 pots but as the car is only 500kg (ish) i figures that the change to the 1144s
will be more than enough as after all the car is only 1/2 the weight of a std car
I have decided to call my Westfeild "The Caterhammer" Hopefully it will
|
|
|
Mal
|
| posted on 17/7/10 at 06:06 AM |
|
|
There is nothing inherently better about 4 piston piston calipers over 2. Four pistons of smaller diameter, but the same total area, are better for
design packaging under the wheel space and allow the pressure concentration to be better distributed over the pad face.
When drivers change from 2 to 4 piston calipers the difference is often confused because of also changing the pad material at the same time. Badly
designed 4 piston aluminium calipers may not be as stiff as cast iron ones.
However the reduction in unsprung weight is undesputable for aluminium 4 pots.
|
|
|
adithorp
|
| posted on 17/7/10 at 08:38 AM |
|
|
How well the brakes stop you is down to pedal ratio and master cylinder/caliper ratio and the pads. The difference, as far as brake effort goes,
between 2 and 4 pot calipers is down to whether the piston area is different. So if the 4pots have a larger total piston area then you will get more
brake presure. With 4 pots the presure will also be more evenly spread across the pad.
The big advantage of ally' calipers over cast, is the reduced unsprung weight... and the bling factor!
Cheapest solution for better braking is different pads and then smaller diameter master cylinder.
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
|
|
|
cliftyhanger
|
| posted on 17/7/10 at 08:40 AM |
|
|
Hmm, double post causing some confusion...
BUT the calipers you have should be more than adequate.
I suspect some maintenance is required, maybe a £10 set of caliper seals, or new discs etc. Unless you are using cheapo pads which are
hopeless.....
Most poor braking is down to maintenance. And people are surprised that their brakes work better when they fit flash new calipers, new discs and
decent pads. Same effect as overhaul of the old stuff, but of course far pricier.
But then again, some benefit from unsprung weight...
|
|
|
RazMan
|
| posted on 17/7/10 at 09:41 AM |
|
|
I used to have standard Sierra rear disc brakes (single piston) and decided to change to Wilwood Powerlites (4-pots with handbrake). The result was
very disappointing and completely the opposite to what I was expecting. After some research I changed the master cylinder to a smaller one, changed
the pedal ratio and eventually got the same braking performance back compared to the old brakes!! 
As previously mentioned, braking performance is mainly dependent on piston sizes and the relationship between master & slave cylinders. Pedal
ratio also comes into the equation and many people don't realise that a non-servo system requires a 'longer' pedal to achieve an
acceptable braking force.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
|
|
|
Major Stare
|
| posted on 18/7/10 at 07:03 AM |
|
|
Cheers guys.
I'll keep the M16's and get some Mintex pads.
I understand about unsprung weight and the bling of nice 4 pots.... but ive read quiet a few topics on the web now and people have problems when
fitting them
Jon "FISH"
|
|
|
02GF74
|
| posted on 18/7/10 at 11:15 AM |
|
|
funnily enough I was looking at this last night - M16 caliper have 52 (or 54) mm dia psiton and the RalDes M16 cheapest replacement have 4 pot but
smaller piston area - this to me means that the pedal needs to be pressed harder to stop the car.
I have M16 calipaer but with Sierra master - 22 mm - ^^^ say put in smaller dia master - this, unless someone correct me, means less pedal pressure
but more pdeal travel - the same effect, unless someone corrects me would be achieve using calipers with largere piston area - since I would be one
hell of a job to change the master to a smaller dia, fitting relacement calipers should be a bolt on job.
|
|
|
