So, having measured the GTV6 front discs that I pulled off my wreck, they are under minimum thickness. Quick look at the DBA catalogue shows no vented disc listed for the alfettas, but does show one for the 75 which I thought may fit. Seems to be no option for slotted discs though.
So the question is, what brakes do people run on their track cars with GTV6 front brakes? I believe cross drilled is bad rather than good, due to fracturing around the holes, so I imagine a set of slotted discs would be the go, and I was thinking EBC yellowstuff pads might be good (apparently they don't need warming up to work, so should be pretty good on the street also). Any experiences/combinations appreciated. Not in a huge rush to do anything, but like to plan out my setups ahead of time.
Hi, the DBA 75 disc does fit and I have used them successfully. You can have them grooved if you like. I have used them in conjunction with EBC yellow in the front for Road Rally, hill climb motorkhana and club sprints. They are very good ,working from cold to hot in my GTV6. Kind to the rotors too. EBC yellow are much more expensive than good old Lucas, which would only just last three hot laps of my late braking. Lucas are awsome value for money, are a good starting point and still good for road use. I use Lucas in the rear. Cheers
How much are you talking when you say expensive, with the Yellowstuff pads? I did come across a pommy site selling them for about 50 pounds, which I didn't think was too expensive, although shipping might be the killer....
I am sourcing Lucas front pads at about $65 and EBC yellow about $170 locally.
How many track days would you get out of these EBC Yellows?
$170 is probably pretty comparative to the UK price then I guess, shipping would probably eat up the $50 saving....
Why do you want slotted rotors? It doesn't help cooling, what it does is take a skim off the brake pads. This works for some pads where refreshing the surface helps and not others. The best thing you can do is work on cooling. The easy things are open spoke-y wheels & to remove the dust cover from the inside of the disc. The harder way is to duct air to the centre of the disc. Vented discs don't pump air very effectively, they really need air delievered into the centre of the disc. My GTV6 has a cuff that fits on the inside opening of the disc within 1mm. Temperature for me is no issue at all. The rears are still a bit of a drama, but less so after I fitted vented rear rotors.
I started off with Howard Reynolds (Race Brakes) RB74 pads. These are nice pads with good feel and good grip, but lack initial bite. At Howard's suggestion I went to RB192, which just doesn't seem to want to play with the GTV6 disc material. Then I tried Hugh's pads, but I don't like the feel. Many guys like them - but not me. Then I moved to DS3000 at the front band DS2500 at the rear. This is fantastic. They sqeal and are not very road friendly when they are cold, but really good on the track and the pedal feel is identical for every brake application. However, now I can lock front wheels at any speed and I was looking for something with slightly less friction. I was going to go to DS2500, but while I was getting RB74 pads for the Montreal, Howard has talked me into Endless spec R. These aren't on the car yet.
Doug Gould
Doug, could you explain this "cuff that fits on the inside opening of the disc within 1mm" further please. I can't quite visualise what you mean.
Would also appreciate more detail on the disc cuff, as brake cooling is definitely on the list of mods.
Interesting view on the slotted discs - I was under the impression that they created a bit of an air pocket to pass the pad and assist cooling. I was aware they tended to chew pads up though. If as you say, they don't assist in cooling then it makes sense to run a standard surface disc to have the maximum contact area with the pad.
You are right about the air pocket theoiry - although we're getting firmly into black magic territory. My memory on its a bit dim, but it may also be to do with pads that emit gas and allowing the gas to escape. Apart from Heroes like Jim Neilsen I don't think the rest of us are in this territory. Doug
Sheldon , I would typically get about 5 track days out of a set of yellows, depending on the rack, with minimal rotor wear.
Doug I agree with the comments on DS2500, have tried Formula ferrodo ( DS2000) which are similar but both not good from cold and not suited to Road Rally/ motorkahna/hillclimb. Where did you get the DS3000's from?
Grooved discs are to allow gas escape from the pad/disc interface, but do accelerate pad wear
I agree with Eddy. I used to use EBC yellow stuff and had problems with initial bite, wear rate and cracking. I could wear a pair out in a weekend of racing in under 2L sports sedans (in the giulietta which at the time was using GTV6 Brembo calipers). I am now using the Lucas pads that eddy talks about (though in Mazda RX7 rotors). The Lucas pads last much longer - on may car probably 10 - 20 times longer. The are a lot less expensive because of this - as well as there base cost is less. The only problems that i have had with the Lucas pads are that (a) they can be pushed into fading in an event like the 6hr - whereas the EBC yellowstuff pads never went into fade on my cay (I cured this problem with the simple addition of 100mm drake ducts from the front splitter) (b) I have to warm the pads up to get the best out of them, on my car that has small rotors and no powerbooster. But in this regard they are no worse than the EBC yellowstuff pads. I'd try the Lucas pads first as its a low cost experiment. I use them front and rear.
jim.
Well, I just went to order myself a set of DBA discs (nothing fancy, just stock replacement) today, only to find out that apparently DBA aren't making them anymore - which I find hard to believe, considering they're in the 2007 catalogue, and will have to chase up further. So now i have the option of standard discs at twice the price, or finding another alternative.
So, does anyone have any suggestions for disc suppliers that may be cheaper than standard? The manufacturer and a rough price guide would be helpful...
Further to this, can anyone tell me who supplies Lucas pads, and for that matter DS2500s?
Having now driven with the V6 brakes, I'm wholly unimpressed - I think the fact that the pads are low and discs well under minimum thickness has a lot to do with it, as it does stop ok, just the pedal is pretty shocking (compared to how I think it should be with stainless braided brake lines and the V6 front brakes).
Hello there
I have a new pair of GTV6 disc which I was going to use but have no time or car for it at the moment, so if you are interested in buying them, email or call me, neil_choi@optusnet.com.au or 0433 11 66 47
Also got some EBC reds for the rears which I wouldn't be needing for a little while.
Neil
Neil, email sent re discs.
Now I'm hopefully just down to front pads - anyone got helpful suggestions on where to find the Lucas parts, and what the current part number is? I notice that Meridian Motorsport carry the DS2500s, but not to sure on how they are for the road use I'll be spending much time doing? I'm a pretty heavy braker, but I don't know whether it's heavy enough to keep heat in race pads or not, especially since I only use them for very short duration most of the time....
I'm running QFM 750 degree pads in the Alfasud (only 900 odd kilos). Highly recommended, they have much more friction than the DS2500s I was running, although maybe take a little longer to come up to temperature. Possibly a little extreme for a street car, you might try one of their other pad materials. I still think they're better than the DS2500s, and cheaper too.
Bruno at Maranello Motors supplies them 9386 9650.
If you are after a serious Front Brake Set Up for Competition Work see Bruno at Marranello for a set up similar to my 75 Twin Spark (same as a STD GTV6 from Factory).
Bruno has made adaptors from old disc rotors and fitted 156 Rotors with 4 Spot Volvo Calipers and Braided Brake Hoses.
The 156 Rotors are about 10-12mm larger in diameter than the GTV6/75 Rotors and slightly thicker.
The set up works very well, at the 6 Hour we used QFM Pads and they are less than half worn after over 2 Hours on the Track with two drivers.
We use 100mm Brake Ducts from where the Fog Lights used to be at 6Hour events and remove them for Sprint events.
If you want to get really serious have a look at the Outboard Rear Brakes on my Car they came from Alan Goodall's sadly missed GTV6 Race Car.
Rob Dale.
Call Howard at Race Brakes for professional advice - his no. is 03 9326 6088 He has a range of compounds depending on application - as Jim pointed out what may be good for a 6 lap sprint may not be great for the 6 hr. web site - http://www.racebrakes.com.au/
Or Hugh at Monza's - he has his "secret" compounds that work a treat as well as the usual brands and has a lot of experience (and the proof is how quick he is) 9720 4442
If you are doing a lot of road use then some of these pads are not going to be the way to go - they need heat and in most cases are not going to be suitable for the road - noisy and will lack bite till warm. I would buy a set of race pads and a set of road pads and swap.
Forums are great for getting some opinions and research but for this I would go and talk with the pros about your particular curcumstances and application.
If it's brake feel your after pad compound, brake line and discs will make a difference but make sure you don't overlook compliance (flexing) in the brake pedal, linkages and master cylinder, particularly for alfettas which have a shocking mount for the master cylinder/booster to the firewall.
Quotebut make sure you don't overlook compliance (flexing) in the brake pedal, linkages and master cylinder, particularly for alfettas which have a shocking mount for the master cylinder/booster to the firewall.
This is definitely on the list too, I'm contemplating the difficulties of lathing up aluminium bushings to replace the rubber ones around the bar that crosses over from the pedal to the booster, and checked the freeplay in it the other night. I'm guessing that the other thing to do is reinforce the firewall where the pedal box and the booster mount to? I have also noticed that the Brembos seem to flex quite a bit when the pedal is pushed (like when bleeding brakes), not sure what to do about that other than possibly the 156 disc/volvo caliper conversion (which at this stage I'll leave until the V6 brakes prove themselves not up to the job).
QuoteI'm running QFM 750 degree pads in the Alfasud (only 900 odd kilos). Highly recommended, they have much more friction than the DS2500s I was running, although maybe take a little longer to come up to temperature.
Thats a good thought too, I was wondering whether QFM did race pads, as we buy a lot of pads off them through my work. Idle thought comes to mind that they may come up to temp quicker in the 1100 kilo Alfetta than the Sud?
QuoteI have also noticed that the Brembos seem to flex quite a bit when the pedal is pushed (like when bleeding brakes),
This probably looks worse than it is with the wheel off the car as the disc may not be pulled up hard agaist the hub