Dan.
|
| posted on 22/11/17 at 11:34 PM |
|
|
Brakes that fit under 13" wheels in big power seven
Hi all,
Need to sort something out for the braking on my car...
I will be running 13" wheels, the car is stupidly over powered far well in excess of a 620R so I'd like a decent set of brakes.
What would be my best option?
The front uprights are a custom billet item yet to be made so can be flexible on the caliper mounts.
I know lots of people run solid discs to keep the unsprung weight down but will these be sufficient on a ~600kg car with LOTS of power? I'm
expecting to be braking from higher top speed than an average seven (or hoping to be) or do I need to go vented?
I've noted the wilwood calipers come with varying piston sizes what size would be best to compliment my dual master cylinder setup (0.625"
front and 0.7" rear)?
And onto the rears I am limited by Sierra mounting position... read plenty of stories about terrible hand brake mechanisms and the last thing I want
is to fail IVA on handbrake efficiency, an again the 13" wheels will no doubt be a limiting factor, will obviously run solid discs at this end
of the car.
Any advice would be appreciated chaps!
[Edited on 22/11/17 by Dan.]
|
|
|
|
|
froggy
|
| posted on 22/11/17 at 11:49 PM |
|
|
Whatever the 620 uses will most likely be pretty good but the brake set up I’ve ended up with to deal with 460 hp in my fairly heavy seven use 286mm
front discs and just sneak under a 15”
[IMG]http://i144.photobucket.com/albums/r187/froggy_0[IMG]
|
|
|
Dan.
|
| posted on 22/11/17 at 11:59 PM |
|
|
That's the thing that concerns me about 13s... but I'd really prefer to run them if I can get away with it... the car will be capable of
similar power numbers to yours... I'd guess it's at least going vented then...
Just how heavy is yours?
[Edited on 23/11/17 by Dan.]
|
|
|
sam919
|
| posted on 23/11/17 at 08:10 AM |
|
|
If it's road and track without being pure race, ( you mention handbrake), then look at the Caterham big brake kit made by AP. Irrespective of
power on the road or track day I doubt you'll get into the realms of consistent hot braking needed when running slicks for a 40 min race around
a track in a professional drivers hands to which the big brake kit performs well
|
|
|
jossey
|
| posted on 23/11/17 at 10:31 AM |
|
|
I have a Westfield running 303hp when I got her and now 269hp I fried all the standard brakes I tried but not I have a bias box and cosworth rear
discs and pads with cross drilled and grooved discs.
My fronts are midilite 4 pot with x drilled discs which are vented.
I've tried alot of different setups and this is the best I've had. But I had to dump the ap racing cylinder to get it spot on.
Good luck.
Thanks
David Johnson
Building my tiger avon slowly but surely.
|
|
|
JAG
|
| posted on 23/11/17 at 10:41 AM |
|
|
Hi Dan,
I have worked for a large brake caliper and brake system supplier and now I work for a car manufacturer. If you send me some details (U2U) I'll
happily work out what you need.
It is perfectly possible to fit suitable brakes under the 13" wheel - but with 13" wheels the limiting factor is disc diameter and caliper
clearance.
What you'll need;
1) Large Caliper piston diameters, to keep pedal forces reasonable, with a relatively small effective radius.
2) Small diameter but thick and heavy, vented discs - to keep disc temperatures reasonable.
3) Larger diameter master cylinder to provide enough brake fluid to actuate the big caliper pistons
4) MAYBE a Vacuum Servo to keep the pedal forces reasonable (kinda depends on all the other stuff)
Justin
Who is this super hero? Sarge? ...No.
Rosemary, the telephone operator? ...No.
Penry, the mild-mannered janitor? ...Could be!
|
|
|
jeffw
|
| posted on 23/11/17 at 01:14 PM |
|
|
Midilite with vented disks under 13" wheels worked on the Phoenix. If I was doing it again I'd buy a stiffer caliper from AP or someone
because you can certainly feel the flex in the caliper braking from 150 plus. I could easily melt non-vented discs and would frequently crack vented
ones.
I would use Hawk DTC-30 pads as well.
|
|
|
rdodger
|
| posted on 23/11/17 at 06:34 PM |
|
|
Have a chat with Procomp. I have seen on their Facebook page they have a kit using AP rotors and calipers.
As Jeff says although a Midilite on a vented disc should do the trick they aren't the last word in quality and do flex quite a lot. They were
good enough for my 250bhp kit but with 100bhp more I recon AP would be the way to go.
|
|
|
johnH20
|
| posted on 23/11/17 at 08:33 PM |
|
|
As JAG says a brake system has to be designed as a totality. You cannot just pick and choose parts .
|
|
|
Dan.
|
| posted on 23/11/17 at 08:43 PM |
|
|
Thanks for the feedback guys looks like 13s are an option still which is good.. just need to find some non flexing light weight calipers 
I'm not just picking and choosing parts I havee master cylinders already ideally I'd prefer to keep them and buy a set of calipers that
compliment them, I now know I have to go vented too. Just need to get callipers with appropriate piston sizes to pair well with the master
cylinders... if there are none that do them I guess I'll have to bite the bullet and change them... would have thought there should be plenty of
options when I know the ratio between i need.
[Edited on 23/11/17 by Dan.]
|
|
|
jeffw
|
| posted on 23/11/17 at 09:12 PM |
|
|
Have a look at the HiSpec Monoblocs
|
|
|
Dan.
|
| posted on 23/11/17 at 09:22 PM |
|
|
quote:
Originally posted by jeffw
Have a look at the HiSpec Monoblocs
Had already looked at the hispec options.. hear mixed reviews from hispec products though most appear to be about the lack of dust seal protection on
certain models as with most many people complain about the handbrake mechanisms on their rears.
Think the monoblocks are a bit big for my application though would never get them under 13s lol
[Edited on 23/11/17 by Dan.]
|
|
|
jeffw
|
| posted on 23/11/17 at 09:31 PM |
|
|
This one
http://www.hispeccalipers.co.uk/rx13.html
|
|
|
Dan.
|
| posted on 23/11/17 at 09:41 PM |
|
|
quote:
Originally posted by jeffw
This one
http://www.hispeccalipers.co.uk/rx13.html
They look much more suitable! Will certainly fit under the rims anyway
|
|
|
Dick
|
| posted on 24/11/17 at 09:37 AM |
|
|
Never had a Hi spec caliper that did not have the dust seals on them and trust me we have fitted lots of them , on the other hand we have seen some of
the willwood ones that dont have them fitted. Hand brakes on hi specs have been upgraded and now work. We tend to fit more hi spec than any other as
they are only in Dartford and they will help out with tricky installations and have a good back up and even offer a repair service unlike others. A
lot of the bad feed back was from people that fitted new brake kits and thought they had brought F1 technology and rubbished them off because they did
not stop the car in 5 yards.
We are not connected to any brake supplier
|
|
|
Dan.
|
| posted on 24/11/17 at 02:05 PM |
|
|
quote:
Originally posted by Dick
Never had a Hi spec caliper that did not have the dust seals on them and trust me we have fitted lots of them , on the other hand we have seen some of
the willwood ones that dont have them fitted. Hand brakes on hi specs have been upgraded and now work. We tend to fit more hi spec than any other as
they are only in Dartford and they will help out with tricky installations and have a good back up and even offer a repair service unlike others. A
lot of the bad feed back was from people that fitted new brake kits and thought they had brought F1 technology and rubbished them off because they did
not stop the car in 5 yards.
We are not connected to any brake supplier
Thanks that inspires more confidence good to hear the hand brake mechanism is improved too.
|
|
|
sdh2903
|
| posted on 24/11/17 at 08:08 PM |
|
|
I've heard lots of people say how great hi spec are if your local to them to pop in. I'm not local and only dealt over the phone with
them. Paid for a set of 4 calipers up front. Told was a 4 week lead, sweet. 6 weeks later no brakes, no contact. "They're in build now
just finishing them up".
2 weeks later no brakes. "We had a machine breakdown which stopped us making the caliper bodies" er hang on pal you said they were
practically done? "They'll be with you within the week" quell surprise nothing turned up.
Phoned up and asked what was going on to be told "they're in build" what again? How many sets have I ordered? So told them as
politely as possible to stick their calipers. "OK no probs bye" excuse me what about my refund? "You haven't paid so
there's no refund to issue!" Really. I don't think so. At this point the guy gets arsey and was basically told I have the bank
statements to prove the payment and needs to be processed asap. He put the phone down on me!
I raised a payment dispute with the bank but thankfully I got my refund a few days later.
I wouldn't trust Hi spec with tuppence ever again. They do also sell lots of calipers with no piston dust seals as well as ones that do as do
wilwoods.
I ended up chatting to rally design discussing my requirements and wheel sizes.
They were delivered the next day job done. Wilwood midilites complete with dust seals and were very very capable of stopping a 7 with 250bhp.
|
|
|
Paul Turner
|
| posted on 29/11/17 at 11:11 AM |
|
|
Got Hi-Spec Billet 4 on the front of the Caterham and they just fit under 13" wheels. They have dust seals in and offer great braking with great
feel. The supplied piston sizes matched the original perfectly thus not affecting balance but larger pistons are available. Pads are cheap (Volvo 240
origin) and are available in many different materials, I have the standard EBC ones which give more than enough braking. Use some fancy ones with big
pistons and the brakes would be mega.
Got solid discs on mine but vented were an option bit simply not necessary on a light car.
Its fair to say they took a while to arrive but it was exactly the quoted time and no problem in winter. Only issue I had was the supplied brake
flexible's, they were too short. They pretended to send some longer ones which never arrived. I modded the pipes on the car by using different
end fittings and then the flexible's were fine and after some "discussion" they reimbursed the £20 I spent.
Before I bought the Hi_Specs I bought a set of Willwoods from Rally Design with their Caterham fitting kit. On the shelf, arrived next day. The
calipers had no dust seals but since I only use the car in Summer I saw no issue. But the fitting kit was plain dangerous. The brackets were very weak
and needed spacing with many washers which also looked crap. The discs were so badly machined they failed to meet any decent engineering standard.
They refused to supply new brackets and discs so I returned the lot.
There is no comparison between the kits, I could not recommend the Rally Design stuff to anyone.
[Edited on 29/11/17 by Paul Turner]
|
|
|
