RazMan
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| posted on 6/5/07 at 10:27 PM |
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We're gonna need bigger brakes
After the Stoneleigh run today I have decided that I need bigger discs on the front, but retaining the Wilwood calipers.
The present discs are vented 245mm Capri jobbies. What is the next size up with the same offsets etc and are different caliper mounting brackets
available? Cossie maybe?
Any guidance is appreciated as always 
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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pjavon
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| posted on 6/5/07 at 10:33 PM |
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damn does that mean you won't be there tomorrow raz, i was hoping to see your car in the flesh
Always keep a big hammer and a condom in your toolbox, if you can't fix it with the hammer
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violentblue
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| posted on 6/5/07 at 10:40 PM |
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you can always run softer pads, makes quite a mess, but will do the job if you need it.
a few pics of my other projects
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Peteff
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| posted on 6/5/07 at 10:55 PM |
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Try some solid brake lines 
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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saigonij
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| posted on 7/5/07 at 08:09 AM |
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are you actually running capri brakes at the front -> e.g. capri hubs, struts etc?
if so, then check out these guys -> www.caprisport.com
they allow you to mount the disc on the front of the hub. you can then use 283mm cossie 2wd discs and mondeo / granada calipers.
this gives awesome brakes.
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RazMan
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| posted on 7/5/07 at 09:57 AM |
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pjavon - Yep, I went yesterday as I didn't fancy the weather forecast for today
violentblue - That would be a good solution but I can't seem to find anything softer for my Dynalites. I've tried Greenstuff (scary) and
Hawk 'fast road' versions but it still feels underbraked. A lot of this might be due to my low pedal ratio which is 4.5:1. I have fitted
smaller m/c to reduce the pedal effort and tinkered with the bias bar but nothing seems to give me a warm feeling.
So I thought I would fit another pair of Wilwoods to the rear, replacing the std Sierra jobbies, and try bigger discs to increase the leverage effect
on the front.
Peteff, Nowt wrong with the brakelines - they are rock hard despite using flexi hoses 
saigonij - I'm using Cortina uprights with Wilwood Dynalites on Capri vented discs.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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Tralfaz
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| posted on 7/5/07 at 11:24 AM |
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Have you looked at any of the Wilwood 'Polymatrix' pads? RallyDesign has them for DL's
T
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RazMan
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| posted on 8/5/07 at 06:59 AM |
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Tralfaz - I was under the impression that the Hawk pads I tried were quite a soft compound but maybe a phone call to Rally Design (UK distributor for
Wilwood) would be a good idea to see what they recommend.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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NS Dev
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| posted on 8/5/07 at 12:23 PM |
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Found similar with those green pads myself.
presume mintex don't do pads to suit the wilwood's?
Look at that first before doing anything else, what you have now should be fine.
If not, then the suggestion of using the caprisport granny caliper upgrade is a good one, used that on a capri years ago and it is great, depsite
using "ungfashionable" single pot calipers and other std fordy bits, it works a treat and nice pads are avaialble for them at decent
prices.
(i.e. a caliper that takes mintex pads is worth its weight in cast iron! )
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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RazMan
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| posted on 8/5/07 at 05:05 PM |
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I phoned RD today and apparently the Green Stuff pads are pretty soft and they have a Wilwood 'Smart Pad' which is on the same level. I
don't think anyone does Mintex pads for my Dynalites so I'm stuck really.
I have tried the bias bar fully wound to the rear setting but I still can't get the rears to lock up - just the fronts. Consequently I have
placed an order for Wilwood Powerlites & discs (for rears) as I am sure that the std Sierra jobbies are not up to the job on my middy.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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NS Dev
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| posted on 9/5/07 at 12:07 PM |
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really daft question but are you sure you're winding the bar the right way? (I've done it before!!  )
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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ChrisGamlin
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| posted on 9/5/07 at 12:20 PM |
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RazMan, you can get Pagid RS14's to fit out of the box, but if you want to go softer still, as mentioned in my master cylinder thread you can
get RS15s in there although they don't actually sell a pad off the shelf that will fit.
The ones Ive used are actually a Subaru fitment and the two ends need cutting off with a chop saw. Sounds dodgy but myself and 3 others ordered a set
and did the mod having been told it unofficially by a Pagid distributor, and have had no problems at all, evidently this is Pagid's unofficial
way of getting RS15 pads into Wilwood / Outlaw / Bremsport calipers like ours.
Chris
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Doug68
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| posted on 9/5/07 at 01:49 PM |
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RazMan, I'm inclined to agree with you that the rear brakes may not be up to the job but reading
this then if (Wild guesses BTW):
Car weight = 2000lb
Wheelbase = 100"
Weight distribution is 40% front 60% rear.
CG Height is 20"
Then static theres 800lb of the front and 1200lb on the rear.
A 1g stop would give a weight transfer of 2000 x 20 / 100 = 400lb
Add that on to the static and theres 1200lb front and 800lb rear load.
Now if it were a front engine car with 60-40 front with all else being the same at 1g braking we'd end up with 400lb load on the rear and 1600lb
on the front.
If you run the above with your real numbers what do you come out with?
On the face of it to me you should have the same brakes on both ends of the car.
[Edited on 9/5/07 by Doug68]
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RazMan
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| posted on 9/5/07 at 04:10 PM |
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quote:
Originally posted by NS Dev
really daft question but are you sure you're winding the bar the right way? (I've done it before!! )
I checked and then double checked that the bias bar was doing what it was supposed to do (and I was wrong the first time ) However I discovered
that the washers either side were jamming on the tapped rod, which is tapered near the threads. This was preventing a little movement at each end of
its travel and I thought I had solved the problem - but no, I am still unable to lock up the rears 
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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RazMan
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| posted on 9/5/07 at 04:15 PM |
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quote:
Originally posted by ChrisGamlin
RazMan, you can get Pagid RS14's to fit out of the box, but if you want to go softer still, as mentioned in my master cylinder thread you can
get RS15s in there although they don't actually sell a pad off the shelf that will fit.
The ones Ive used are actually a Subaru fitment and the two ends need cutting off with a chop saw. Sounds dodgy but myself and 3 others ordered a set
and did the mod having been told it unofficially by a Pagid distributor, and have had no problems at all, evidently this is Pagid's unofficial
way of getting RS15 pads into Wilwood / Outlaw / Bremsport calipers like ours.
Chris
That sounds like a good dodge Chris - the Pagid specs would seem to suggest that I need RS15 pads but they are bloomin expensive aren't they! 
so I had better be sure before I hack £150 of pads up If my rear upgrade doesn't have the desired effect I will give them a try.
Thanks for the tip.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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RazMan
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| posted on 9/5/07 at 04:28 PM |
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quote:
Originally posted by Doug68
RazMan, I'm inclined to agree with you that the rear brakes may not be up to the job but reading
this then if (Wild guesses BTW):
Car weight = 2000lb
Wheelbase = 100"
Weight distribution is 40% front 60% rear.
CG Height is 20"
Then static theres 800lb of the front and 1200lb on the rear.
A 1g stop would give a weight transfer of 2000 x 20 / 100 = 400lb
Add that on to the static and theres 1200lb front and 800lb rear load.
Now if it were a front engine car with 60-40 front with all else being the same at 1g braking we'd end up with 400lb load on the rear and 1600lb
on the front.
If you run the above with your real numbers what do you come out with?
On the face of it to me you should have the same brakes on both ends of the car.
[Edited on 9/5/07 by Doug68]
Thanks for the figures Doug - I reckon you are about right. My car weighs around 800kG and has a wheelbase of 2.3m with a rough 60/40 split
(haven't a clue what the c of g height is though) but I think a rear upgrade is definitely needed - my Rally Design order should arrive shortly
so I can test out the theory soon.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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ChrisGamlin
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| posted on 9/5/07 at 07:51 PM |
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quote:
Originally posted by RazMan
That sounds like a good dodge Chris - the Pagid specs would seem to suggest that I need RS15 pads but they are bloomin expensive aren't they!
so I had better be sure before I hack £150 of pads up If my rear upgrade doesn't have the desired effect I will give them a try.
Thanks for the tip.
They are bloody expensive yeh, and when you take a chop saw to them you do question your sanity for several reasons (wear a facemask!) but they
transformed all my mate's Westies running Bremsports, the only other pad that seem to compare are Hawk Blacks, but they are carbon metallic and
create stupid amounts of metallic dust (you get a full catherine wheel effect when braking in the dark!) that corrodes alloy wheels if you dont
constantly clean them, and they eat discs, whereas the Pagid last ages and produce very little dust.
If you need to find out the exact pad, let me know and I'll find out.
Chris
[Edited on 9/5/07 by ChrisGamlin]
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flak monkey
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| posted on 9/5/07 at 08:02 PM |
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The 'polymatrix a' pads from wilwood are pretty damn snappy, and have a very high friction coefficient from cold. The wilwood site says
they are race only, but all their calipers say that on too
They are rather expensive though
You can buy discs(rotors) and centre discs/spacers from rally design, as someones probably mentioned. Should let you build a system to whatever spec
you need.
Next size up from 245mm is 260mm You could go larger though, as it looked like you had tons of room in your wheels? It all depends how underbraked the
car is at the moment. You can do the calcs to roughly work it out though.
Let me know what m/c sizes you have and which calipers and what tyres and disc sizes you are currently running and i will attempt some number
crunching. (Never guess what my dissertation was on?)
David
[Edited on 9/5/07 by flak monkey]
Sera
http://www.motosera.com
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RazMan
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| posted on 9/5/07 at 09:21 PM |
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quote:
Originally posted by flak monkey
Let me know what m/c sizes you have and which calipers and what tyres and disc sizes you are currently running and i will attempt some number
crunching.
Okay David, I would appreciate your calculations on this one
800 kg middy with 60/40 split
Front: 4 pot Dynalites (old version) 35mm pistons & 245mm discs. 0.625" m/c
Rear: Bog std Sierra single pot calipers & discs . 0.70" m/c
I have ordered the Powerlites for the rear - just typing this info down makes it pretty obvious which end needs upgrading bearing in mind it is a
middy
p.s. I nearly forgot - Polymatrix pads don't seem to be available for the old Dynalites
[Edited on 9-5-07 by RazMan]
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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flak monkey
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| posted on 10/5/07 at 03:18 PM |
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Do you know what the piston size and disc size is on the rear by any chance?
Oh and tyre size please
[Edited on 10/5/07 by flak monkey]
Sera
http://www.motosera.com
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RazMan
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| posted on 10/5/07 at 03:40 PM |
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I have a feeling that the Sierra rear caliper has one 43mm piston (sliding caliper)
My tyres are:
Front - 205/40/17
Rear - 245/35/17
I would interested in the change when I swap the rears to Superlites (34mm pistons) and 273mm discs - it should change quite radically
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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flak monkey
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| posted on 10/5/07 at 04:02 PM |
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OK from the little spreadsheet i wrote when I was doin my calcs:
Based on a 1g max deceleration, which I would think is about right on road tyres, your clamping forces that are required are:
9939N at front
7094N at rear
With your 4.5 pedal ratio, and 245mm front discs and 253mm rear discs (i beleive thats the std sierra size?) and the rest of the system as you said
then in theory you would need:
The bias bar set to 54% rear, 46% front (the front would lock marginally before the rears at this setting)
And a mahoosive 490N pedal effort to get 1G decelleration. Which to be honest is a fair bit.
I will change the numbers and see what size discs you need with a roughly 50/50 bias setting and a much lower pedal effort.
David
Sera
http://www.motosera.com
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RazMan
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| posted on 10/5/07 at 04:21 PM |
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quote:
Originally posted by flak monkey
And a mahoosive 490N pedal effort to get 1G decelleration. Which to be honest is a fair bit.
I had better do some more leg presses down the gym then
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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flak monkey
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| posted on 10/5/07 at 04:22 PM |
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OK, from my calcs, based on you using the powelites up back with 273mm discs and the dynalites up front:
To get a more reasonable pedal effort - 350N (still quite high, but I would guess about right for a non-servo car?) you would need to run 309mm discs
at the front. That would leave you with a 50/50 setting on the bias bar too (again with a marginal tendency for the fronts to lock first).
So summary:
Fr - Dynalites with 309mm OD discs.
Rr - Powerlites with 273mm OD discs.
50/50 setting on bias bar.
I have based the calcs on a CoG height of 400mm, sound reasonable?
I can send you the spreadsheet if you want to have a look?
If you are on msn it would make it easier.
David
Sera
http://www.motosera.com
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NS Dev
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| posted on 10/5/07 at 04:24 PM |
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quote:
Originally posted by RazMan
quote:
Originally posted by flak monkey
Let me know what m/c sizes you have and which calipers and what tyres and disc sizes you are currently running and i will attempt some number
crunching.
Okay David, I would appreciate your calculations on this one
800 kg middy with 60/40 split
Front: 4 pot Dynalites (old version) 35mm pistons & 245mm discs. 0.625" m/c
Rear: Bog std Sierra single pot calipers & discs . 0.70" m/c
I have ordered the Powerlites for the rear - just typing this info down makes it pretty obvious which end needs upgrading bearing in mind it is a
middy
p.s. I nearly forgot - Polymatrix pads don't seem to be available for the old Dynalites
[Edited on 9-5-07 by RazMan]
No idea how they compare, but I am using mintex 1144 pads in my raceleda/outlaw calipers. They are Volvo MGB522 Mintex 1144 pads slightly modified, as
used by a few folks I believe!!.
They need filing to allow for a retaining pin and a 3mm shim under them.
These pads are also specified by hispec for their calipers.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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