Any tyre has only a finite amount of grip it can give which is based on its coefficient of friction. Everyone seems to know this when it relates to lateral grip (i.e. going around corners) but it's exactly the same amount of grip (friction) that you've got for accelerative and braking traction. So, if your new brakes have more friction than your tyres have with the road, then instead of locking up the wheels (as seen in F1), the ABS kicks in, to prevent the tyres from losing their grip with the road thus allowing the car to brake at the limit of the tyres grip. I would suggest that unless you also upgrade your tyres, a BBK is overkill because the tyres are now the weakest link.
First track day on ap racing brakes (snetterton 300)
- Thread starter alanhasanicez4m
- Start date
alanhasanicez4m
Member
What tyres are you running then beedub? There is only so far you can go for road tyres right
alanhasanicez4m
Member
woah, they would want to be good, over 300 quid a corner. How would you rate them? Have you got a good base for comparison or did you add them at the same time as the breaks?
Beedub said:
The OEM brakes on my Z4MC are far better than the OEM brakes on my Z3MC, but I bring on the ABS with the Z3MC with Falken 452s at Wehrseifen at The Ring when braking downhill, but I didn't experienced the ABS on the Z4MC with OEM Contis there. From this I deduce that the OEM Contis have a higher coefficient of friction than the Falkens.
alanhasanicez4m
Member
I didn't have a temp gauge, they were really quite hot at one stage. I dropped the pressure to 30 during the day.
To be honest, for what I have learned here I would say it was mainly lack of bedding in. I'll have to do that. Would love to upgrade the tyres too, but will wait until these ones are toast.
The OEM brakes are good, however by the end of a day on the track they go soft and start making ticking sounds and the likes.
To be honest, for what I have learned here I would say it was mainly lack of bedding in. I'll have to do that. Would love to upgrade the tyres too, but will wait until these ones are toast.
The OEM brakes are good, however by the end of a day on the track they go soft and start making ticking sounds and the likes.
Exdos, I agree with your comment about tyres. However, the benefits of a BBK extend beyond reducing braking distances (if the brakes are the weak link). Better heat dissipation makes braking more consistent. Also, I chew through pads (EBC Bluestuff) really quickly on track with OEM discs and it's getting expensive!
BMWZ4MC said:
I'm certainly not knocking BBKs at all. But I think a lot of owners base a good part of their decision on the fact that they want a BBK for the bling as much as for their use. As you know, I use brake ducting for cooling as I describe here: http://www.z4-forum.com/forum/viewtopic.php?f=24&t=38775 you can't see it (and it's best that you can't!) because it certainly has no bling factor. It's dirt cheap to do and most importantly: it works. If it's all down to the difference in stopping distance between the OEM brakes and a BBK, then I bet there's hardly anything in it, and if it's down to duty cycle, then brake ducting will make it a match. Have you tried ducting yet?
I also use solid brake bushings which I've also described here: http://www.z4-forum.com/forum/viewtopic.php?f=24&t=45293 which improves the feel of brake modulation. At the end of the day, we all have different priorities/needs, and my first big spend on the car was on replacing the OEM suspension
If you come across a nice AP Racing BBK for sale at about £250, I'll take it off your hands though.
alanhasanicez4m, I don't think you mentioned this, what brake pads are you using? If you've got something with a higher friction coefficient than stock it's normal to be activating the ABS quicker than before until you learn the new limits of your brakes/tires.
If i mash the brake pedal now with my Stoptech brake kit and Pagid RS29 it'll very easily activate the ABS, i needed to re-learn how to use them properly.
If i mash the brake pedal now with my Stoptech brake kit and Pagid RS29 it'll very easily activate the ABS, i needed to re-learn how to use them properly.
Exdos,I knew about your brake mods and certainly plan to give them a try before spending thousands on a BBK. However, I'm very hard on brakes I suspect because I mostly frequent short circuits with fast straights and tight hairpins. As such they get really very hot and I consume pads at a very high rate. I suspect a BBK would improve things but at great cost to my supercharger fund!
Edit: Thanks for re-posting the links by the way - I've copied and pasted them into my 'to do' list in the brakes section!
Edit: Thanks for re-posting the links by the way - I've copied and pasted them into my 'to do' list in the brakes section!
alanhasanicez4m
Member
The pads that come with the kit, heres a code CP2340D51-APF404, it just says pad kit. But I recon your right, it does take some getting used to
I've said this before at other similar threads, the main reason i wanted a big brake kit is because i simply didn't want to worry about brakes AT ALL. Not that the fluid will boil, that the pedal will turn to mash, that the pads will stop stopping. The BBK does exactly that. Solid, repeatable performance, lap after lap. Money well spent in my opinion.
Beedub said:
I understand this - in the ///M I've not yet found that I've put my foot on the brakes at the end of a straight and the pedal has sunk to the floor (I have in other road cars), but I found less of a response than expected on one occasion (which turned a corner that was intended to be 9/10ths into 10/10ths and distinctly messy). I think I'll try the cheaper options first then think more about a BBK if I don't find that to be enough......unless I see a bargain I can't resist on the meantime
