21 replies to this topic

[dw1]

It got me thinking when Subseamac just posted this in another thread... "I am running Plans AP295 aluminium belled discs and pagid RS42 on standard calipers and the expense of jumping to the full 4 pot kit doesn't seem to be justifiable unless you get into endurance racing and hour-long track sessions where you need extreme fade resistance? Could really do with an honest assessment - we've all bought kit in the past, failed to notice much difference, but tried to convince ourselves it was a justified expense. What's your verdict?" I've had the AP big brake kit for about 5 months and I actually question whether I should have bothered. It's a shed load of cash and it seems that by doing a few simple brake upgrades or a few heavier ones like the above, and you would have an awesome brake setup that's very unlikely to overheat even with track use and is half the price of the big brake kit. The reason I went for the BB Kit is its about the most extreme brake upgrade you can do and supposed to be the best. I just wanted it sorted once and for all without having to go through half way stages that weren't totally effective at preventing brake fade for my track use. So I thought sod it, I'll throw money at the problem. I was previously on Camskill disks and 1144s. For road driving they were superb and I found the bite and stopping power of the 1144s really strong (what must Pagids be like!). The let down was that on track I found I got brake fade. It could be the tyres I'm on (Hankook RS2s) but the stopping power doesn't feel as good as my original setup. I find it easier to lock the front wheels up - now this could be a combination of my bad braking technique and the increased power of the 4 pots meaning I shouldn't press so hard?? People say that the 4 pots give you more feel, perhaps I'm not a good enough driver but I haven't noticed a significant difference. I'm still not 100% happy with the setup, perhaps the Ferodo pads are a bit shite and I should change them - but they have a lot of life left so don't want to spend more dosh just yet. I not sure I could say if I've wasted my money but I can't help feel at the moment that I should have gone for the Subseamac approach, plus it would have given me the option to add 4 pots later on if I still got brake fade.

[Guy182]

i too havent noticed a difference however i havent been on track yet which is where my standard brakes were a big let down and i had no confidence in them. to be honest most the money ive spent this year apart from the traction control has been a waste. lol awaits the 'ferodos are sh*t get some pagids' etc the ds2500's were great in my clio 182

Edited by Guy182, 22 April 2008 - 09:04 AM.

[Pidgeon]

You can't argue with the physics (greater swept area, increased piston area), but I can't disagree with

For road driving they were superb and I found the bite and stopping power of the 1144s really strong

I can only think the pads are the defining factor.

[techieboy]

It could be the tyres I'm on (Hankook RS2s) but the stopping power doesn't feel as good as my original setup. I find it easier to lock the front wheels up - now this could be a combination of my bad braking technique and the increased power of the 4 pots meaning I shouldn't press so hard??

Isn't easier locking up of the fronts to be expected with the greater clamping force of the 4 pots and it's a case of learning to modulate your breaking?

I've got the same Plans setup as Subseamac and it's more than enough for me. Copes really well on all of the trackdays I've done and came in for a real hammering on the training day last Sunday. Not a hint of fade and they were taking some serious abuse on the tight circuit we were using. I really can't see me ever needing more stopping power than they provide.

[Muncher]

I must say my RS14s all round with standard discs and a bit of extra cooling give ferocious stopping power and great feel, no hint of fade either.

[subseamac]

Extremely useful feedback. I like the look of 4 pots but I just couldn't bring myself round to spending another £1.5k just for looks on top of the perfectly good plans setup with 295mm ali belled ap discs. I even thought about keeping my discs but finding some 4 pot AP calipers to match the 295mm ap discs, but I don't think I'll bother as I'm totally happy with my setup I think that braking efficiency is down to a combination of factors that all need to be right, including tyres (grip), suspension (dive+maintaining max tyre contact patch), pads and discs and finally calipers so maybe you need to have all other factors up to the standards of the AP 4 pot before you can notice any real difference? For the guys who've got them and reported no big improvement, are you running r888/048, nitrons etc?

[burnerblowout]

Think you were right about holding off on the AP 4 pot kit. Brake fade can be for many reasons and not just based on the 2 or 4 pot set up. Maintenance, pad and fluid choice are also critical. A set of 4 pots with DS2500s on old DOT 4 fluid could be more susceptible to fade than the AP 2 pots with fresh Pagid RS14s and some good quality DOT 5.1. The 4 pots will have better heat dissipation, reduced unsprung weight and increased stopping power due to slightly increased swept area but you would need to exhaust the 2 pot potential with pads/fluid before making the investment. Another misconception is the thought that a simple pad change is going to dramatically increase ‘stopping power’. A look at the differences in coefficient of friction indicates otherwise. You will gain with a higher temp threshold and tolerance leading to a greater fade margin, but you are still running the same rotor/pad working swept area with the same caliper input force.

[danger7]

On Sunday it was the first time I've ran my VXT on the track in anger (dust's himself down blows the cob webs off his lid) in its current set up. AP Racing BB kit. (No front duct cooling) Pagid RS14 pads all round. Braided hoses, and race fluid. Single Nitrons. (fast road set up) Lotus Sport Adj ARB 16/17" OZ racing wheels Toyo TR-1's ABS disabled One hour track session Nice warm sunny day, corned beef sandwiches and pop (orange dilute) Circuit Zolder - A real brake test circuit, three slow chicanes leading to and from fast sections. Comments Brakes were ok for the full hour with a lot of abuse, no hint of fade only the tyres let go a few times under braking causing lock ups and a few hairy moments. RS14's stood up well and once up to temp the braking zones were getting shorter by several metres. The VX's balance under braking was helped enourmously by the combination of Nitron/475 springs and a Lotus Sport ARB helped reduce dive under hard braking. I ran with the Ferodo's and they were quickly replaced with the RS14's the transformation was like day and night. Hope the above is useful. Cheers Ian

[Guy182]

how much are a pair of rs14 fronts to fit the AP 4 pots and a pair for standard rears? and do they squeel during normal driving/are they sh*t when cold?

[MAXR]

It’s great to hear genuine constructive comments on an expensive upgrade. I have been toying with upgrading to an AP 4pot BB setup for some time now. My current setup is Plans AP front discs, standard front & rear callipers with Pagid rs14’s all round. I regularly stay on the track for up to an hour (yes I know ,not clever) & have no problems except that after 20mins of hard braking, the initial retardation is not as good, with a metal to metal sounding squeal when wiping big speeds off. In fact It feel like my rears sometimes seem to lock up, as the rear squirms around sometimes when full on braking at above 120mph, but neither the fronts or backs ever locks up fully! It’s not really a complaint, but I just wish I could maintain the initial big reduction in speed on the first hard contact throughout the session. I have had several conversations with Jon at Plans & he seems to think that he has a more suitable set of race pads that will be more to my expectations & that I probably would not see any noticeable improvement from my current setup if upgrading to the AP BB setup. Personally, I would rather ditch 30-40 kg’s from my car and keep the brakes as they are now... That’s what I probably will do! Max

[burnerblowout]

On Sunday it was the first time I've ran my VXT on the track in anger (dust's himself down blows the cob webs off his lid) in its current set up.

AP Racing BB kit. (No front duct cooling)

Pagid RS14 pads all round.

Braided hoses, and race fluid.

Single Nitrons. (fast road set up)

Lotus Sport Adj ARB

16/17" OZ racing wheels

Toyo TR-1's

ABS disabled

One hour track session

Nice warm sunny day, corned beef sandwiches and pop (orange dilute)

Circuit Zolder - A real brake test circuit, three slow chicanes leading to and from fast sections.

Comments Brakes were ok for the full hour with a lot of abuse, no hint of fade only the tyres let go a few times under braking causing lock ups and a few hairy moments.

RS14's stood up well and once up to temp the braking zones were getting shorter by several metres. The VX's balance under braking was helped enourmously by the combination of Nitron/475 springs and a Lotus Sport ARB helped reduce dive under hard braking.

I ran with the Ferodo's and they were quickly replaced with the RS14's the transformation was like day and night.

Hope the above is useful.

Cheers
Ian

Danger 7,

Get those semi slicks on.

[Winstar]

It’s great to hear genuine constructive comments on an expensive upgrade. I have been toying with upgrading to an AP 4pot BB setup for some time now. My current setup is Plans AP front discs, standard front & rear callipers with Pagid rs14’s all round.

I regularly stay on the track for up to an hour (yes I know ,not clever) & have no problems except that after 20mins of hard braking, the initial retardation is not as good, with a metal to metal sounding squeal when wiping big speeds off. In fact It feel like my rears sometimes seem to lock up, as the rear squirms around sometimes when full on braking at above 120mph, but neither the fronts or backs ever locks up fully!

It’s not really a complaint, but I just wish I could maintain the initial big reduction in speed on the first hard contact throughout the session.
I have had several conversations with Jon at Plans & he seems to think that he has a more suitable set of race pads that will be more to my expectations & that I probably would not see any noticeable improvement from my current setup if upgrading to the AP BB setup.

Personally, I would rather ditch 30-40 kg’s from my car and keep the brakes as they are now... That’s what I probably will do!

Max

With regards to the rear end squirming there's abit of info in my post in this thread that may be of some use. clicky

[siztenboots]

Anybody running RS15's ? The initial grab on the pagids RS14 inspires confidence, although I do not run them in the winter, as they are a bit too snatchy, so keep mine for trackdays, and run SBS Protrack for road use.

[subseamac]

re 1 hour sessions, Pagid do yellow (endurance) versions of the RS14. Might be an avenue to explore If Performance friction pads are advised, I would urge caution. I have used them in the past and they chew through discs at an alarming rate and nicely deposit rusting disc deposits on the wheels and sides of the cars. Had PF97 on a clio cup before and swore never to use pf97 on any other car.

[Guy182]

re 1 hour sessions, Pagid do yellow (endurance) versions of the RS14. Might be an avenue to explore

If Performance friction pads are advised, I would urge caution. I have used them in the past and they chew through discs at an alarming rate and nicely deposit rusting disc deposits on the wheels and sides of the cars. Had PF97 on a clio cup before and swore never to use pf97 on any other car.

and create sparks.. lol

[VIX]

came in for a real hammering on the training day last Sunday. Not a hint of fade and they were taking some serious abuse on the tight circuit we were using. I really can't see me ever needing more stopping power than they provide.

I was the same on EBC discs and 1155's but although we were going from flat out to hard braking without much in between, I wonder what our max speed was. I really have absolutely no idea as there just wasn't time to look. Was it more than 70mph? - was it on Ben's data logger? I guess it was a lot less than pulling up at the end of the Bedford main straight at 120+ mph. And although the brakes got a lot of abuse on Sunday without getting the chance to cool off, perhaps they weren't actually working that hard. Dunno, just a thought.

Edited by VIX, 22 April 2008 - 04:19 PM.

[MAXR]

All your comments have been very useful. AP 4 pots BB system is now off my list of mods to do.(for now at least) I’m going to change my Brake fluid more often too starting with a change tomorrow as mine have been there for 11 track days to date. Also, I will try and get some more aggressive pads soon, I don’t mind replacing the Plans front AP discs and the standard rear discs every 12-15 months or so. I know there has been much talk in previous threads about brake cooling ducts, but has anyone introduced better underside air intakes for the engine area? I couldn’t find any info. Cheers!

[dw1]

Isn't easier locking up of the fronts to be expected with the greater clamping force of the 4 pots and it's a case of learning to modulate your breaking?

Your logic is faultless and something I hadn't thought about before buying so numnuts here got suprised when the fronts started locking up very easily. Numnuts is currently focusing on learning to brake better and modulate properly You really don't have to nail the pedal and it locks so much more easily compared to previous (until I've learnt how to brake!). The upside is that this upgrade is forcing me to become a better driver.

Extremely useful feedback.

I like the look of 4 pots but I just couldn't bring myself round to spending another £1.5k just for looks on top of the perfectly good plans setup with 295mm ali belled ap discs. I even thought about keeping my discs but finding some 4 pot AP calipers to match the 295mm ap discs, but I don't think I'll bother as I'm totally happy with my setup

I think that braking efficiency is down to a combination of factors that all need to be right, including tyres (grip), suspension (dive+maintaining max tyre contact patch), pads and discs and finally calipers so maybe you need to have all other factors up to the standards of the AP 4 pot before you can notice any real difference?

For the guys who've got them and reported no big improvement, are you running r888/048, nitrons etc?

If you've already got most of the components it wouldn't cost you £1.5k to go to the 4 pots, probably under 1k temptation. They do look sweeet
I'm running one way nitrons, 16/17" Hankook RS2s. I'll probably get even worse lock-up on 888s when I get them.

Any ideas:
How much is it to replace the AP discs for the BB kit?
How much are RS42s for the BB kit?

[subseamac]

I think that once you have the bells of the AP kit like me, you can change the rotors from 295mm to 304/308mm to go with the cp7621 4 pot calipers. The saving would be not having to buy the bells, so approx £1.2k vs £1.5k . I've been thinking about using cp5000 or cp7600 series calipers on my 295mm AP discs, but as debated in the thread above, there are better ways to spend £1k. I think that my setup (and Max's) with extra brake cooling would definitely do the job

[alain]

I have now the BB kit with RS15 Pads. What a great improvement !!!! A few months ago I had no brakes at all (zero pressure) after 6 laps at Zolder with standard discs with RS14 pads . Yesterday it was 28° C and no problem at all with the BB kit from AP Racing How hotter they are how later you can brake !! For trackday use I can only advise it , its a really good investment !!!! Alain