AP 300mm Rear Brake upgrade

AP 300mm Rear Brake upgrade

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Discussion

Matthew Poxon

Original Poster:

5,329 posts

172 months

Wednesday 28th September 2016
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Good afternoon gents.

The rear brakes on my Griff are in need of replacement, I have completely worn out on of my rear pads and I now have metal on metal. As such i need to replace the pads and discs, I believe the rear discs are original anyway as they are quite heavily corroded on the outside so ideally need replacement anyway.

I already have the Alcon 4pot upgrade on the front of my Griff which I really like and fits under the 15" wheel. I am thinking as I need to replace the rear pads and discs anyway I could go for a cheeky upgrade. I am looking at the Reyland 300mm AP rotor upgrade keeping the existing callipers which I will probably look to get refurbished. Does anyone have any experience or opinions on the upgrade? It will apparently fit inside an OE 16" Estoril wheel:

http://www.reyland.co.uk/tvr/


ClassiChimi

12,424 posts

148 months

Thursday 29th September 2016
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Very nice Matthew, can't say as I have any experience of these but if the adaptor bracket is a simple bolt on affair and the centring is ok it should be easy enough to fit them. smile

You mention the age of your old ones, that's a clue,,,
If you do invest, these should last donkeys years.

I suppose the obvious question will be if these add rear braking power how's this going to effect brake balance?
Does the griff have a rear pressure valve, can't remember how it works on the Chim either scratchchin

They look like really good quality smile

jesfirth

1,743 posts

241 months

Thursday 29th September 2016
quotequote all
ClassiChimi said:
I suppose the obvious question will be if these add rear braking power how's this going to effect brake balance?
Does the griff have a rear pressure valve, can't remember how it works on the Chim either scratchchin
the griff does have a pressure valve tucked away above the diff. I added a variable adjuster to mine with a new knob - ooh err - by the handbrake

griffdude

1,819 posts

247 months

Thursday 29th September 2016
quotequote all
jesfirth said:
ClassiChimi said:
I suppose the obvious question will be if these add rear braking power how's this going to effect brake balance?
Does the griff have a rear pressure valve, can't remember how it works on the Chim either scratchchin
the griff does have a pressure valve tucked away above the diff. I added a variable adjuster to mine with a new knob - ooh err - by the handbrake
I swapped out the brake proportioning valve for an adjustable tilton one from demon tweeks which is behind the driver's seat, underneath the 'whaletail'.

http://www.demon-tweeks.co.uk/motorsport/brake-pro...

Matthew Poxon

Original Poster:

5,329 posts

172 months

Thursday 29th September 2016
quotequote all
I am working on the basis that I replaced the front brakes with 4pot callipers and bigger discs so I have increased the front braking power so a minor upgrade to the rear should keep it balanced.

What situations do you use a manual brake balancer, it is something that you set and leave or is it something that you would adjust depending on a circuit?

ClassiChimi

12,424 posts

148 months

Thursday 29th September 2016
quotequote all
A biase valve makes a small adjustment, most drivers I know get a balance and pretty much leave it at that and don't really change it track to track!
As you say Matt you have bigger fronts already. Maybe fit the new rears and see how it feels first.

It's only a bit of extra copper piping added into the rear line going through the valve ( knob) inside the car Easy enough to do.

I'm not sure about the legality using one on a road car, if it's legal I'd look to do it but only if I thought the brakes were becoming unbalanced.



Bluebottle

3,498 posts

239 months

Thursday 29th September 2016
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Matthew Poxon said:
I am working on the basis that I replaced the front brakes with 4pot callipers and bigger discs so I have increased the front braking power so a minor upgrade to the rear should keep it balanced.

What situations do you use a manual brake balancer, it is something that you set and leave or is it something that you would adjust depending on a circuit?
Like others above i have an adjustable brake bias valve behind my seat, with the bigger anchors up front it was necessary but even with it set max bias to the rear the balance isnt quite where i want it. I am thinking i could do with bigger discs on the rear to fine tune it.
The kit you listed above includes stuff you probably don't need so you could get it for less as you only need the two piece disks and the calliper adaptor mounts...assuming you already run the 500/cossie calipers,braided hoses and DS2500 pads? My only concern is i keep hearing that 2 part rotors are prone to warping? and i'm heavy on brakes does anyone have experience with them?

WinstonWolf

72,857 posts

238 months

Thursday 29th September 2016
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I'm running this on the rear with a front upgrade.

http://www.compbrake.com/product/ford-sierraescort...

If the AP kit is the same as mine (which it looks like it is) you probably won't need to alter the bias at all. Mine feels more planted under braking since the upgrade.

One thing to be aware of, the original pads won't sweep the whole rotor. Not a problem but the inner part of the rotor goes a bit rusty over time.

WinstonWolf

72,857 posts

238 months

Thursday 29th September 2016
quotequote all
And conveniently I have already done the maths for you biggrin

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Matthew Poxon

Original Poster:

5,329 posts

172 months

Thursday 29th September 2016
quotequote all
Thanks for the feedback Rob, it certainly looks like you put more thought into the upgrade than me, loving the calculations.

The bell looks slightly bigger on the Reyland kit so I am wondering whether that will resolve the pads not sweeping the whole rotor minor issue.

Did you have these running with Estorils or was the kit fitted after you had the Compotive MO6s? (correct me if I am wrong) fitted?

WinstonWolf

72,857 posts

238 months

Thursday 29th September 2016
quotequote all
It may well do, it's just something I noticed over time.

I've only ever had it under the MO6's so I wouldn't know if it will go under the standard wheels.

The maths have stood the test of time, even under heavy braking she feels balanced since I upgraded the rears thumbup

griffdude

1,819 posts

247 months

Thursday 29th September 2016
quotequote all
Matthew Poxon said:
I am working on the basis that I replaced the front brakes with 4pot callipers and bigger discs so I have increased the front braking power so a minor upgrade to the rear should keep it balanced.

What situations do you use a manual brake balancer, it is something that you set and leave or is it something that you would adjust depending on a circuit?
I found I was running out of brakes on some of the quicker sprints with high speed, heavy braking into tight corners. I changed the front brakes to 4 pots with 283 discs which were great on track but because of the amount of fluid moving to front, the balance was all wrong, so fitted a proportioning valve.

Andav469

957 posts

136 months

Thursday 29th September 2016
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Something I am just about to do myself, if you call them and speak to the owner, he is very knowledgeable.

From the measurements he has given me, this will easily fit within a 16" Estoril

Matthew Poxon

Original Poster:

5,329 posts

172 months

Thursday 29th September 2016
quotequote all
I did contact Martin and he did say he thought they would fit. I have 295mm discs inside the front 15" estorils so I would imagine 300mm would fit nicely inside 16". Good to hear you are looking at the same kit and have measured it, that was the next step for me so you have saved me a job. thumbup

Pupp

12,205 posts

271 months

Thursday 29th September 2016
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So, which bit of that kit is AP Racing?

I use the same kit, made by Reyland, and it's spot on... I use it with a 330mm AP Racing 4-pot set up on the front (OEM rear calipers) and the balance is absolutely fine in my experience (if the brakes are on properly, the rears are petty well unweighted anyway) - even with 283/4 pots on the front I would not be concerned but accept Howard will have used that set up harder...

Matthew Poxon

Original Poster:

5,329 posts

172 months

Friday 30th September 2016
quotequote all
Thanks for the feedback Gary. Good to hear you are happy with it. The rotor is definitely AP, and possibly the bell. The brackets are billet items made by Reyland and as you have mentioned the kit uses the OE calipers (4x4 cossie iirc)

Having seen the way Howard drives on the sprint courses I can see how he would have found the limits. As long as the brake balance is roughly right I think it will be fine for my modest needs.

Matthew Poxon

Original Poster:

5,329 posts

172 months

Friday 30th September 2016
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Just ordered this kit from Martin at Reyland if anyone else is interested might be worth getting in soon as the price of the kit is due to increase from £425 to £450.

eff eff

754 posts

203 months

Friday 30th September 2016
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Matthew

I've got an AP 330 4-pot set up on the front and Sagaris 298 discs and calipers on the rear with standard plumbing.
They feel great and work well no lock ups or any other issues that I can detect. My rears are one piece
discs, I like the look of bells and rotors and they do reduce the un-sprung weight so nice solution and a reasonable price

Matthew Poxon

Original Poster:

5,329 posts

172 months

Friday 30th September 2016
quotequote all
Hello Frank, good shout on the Sagaris discs, nice solution being an OE part from another TVR as those parts should always be available. The result is very similar to what I am about to do with mine so many thanks for the feedback. The 2 part discs are certainly a Brucey bonus.

I am going to get my rear callipers refurbished at the same time as I believe one of them is sticking and they are original anyway so probably in need of some attention.

V8Bart

788 posts

189 months

Friday 30th September 2016
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Evening Matthew ,
I have the later tvr calipers on the front (Tuscan/t350) and large 2 piece with original calipers rear.
Works a treat, but you have to think along the lines of better front than rear for a nice balance. I've never need to adjust the bias.

Hope that makes sense, I'm down the pub lol