Is a rear BBK unnecesary for tracking?

[HBspeed]

I'm looking into purchasing a stoptech BBK for my z4m and I keep hearing that I only need to go all out on the front, that the stock rear calipers are plenty. What does everybody think?

[Crimson92]

Personally I believe there should be balance.

If you get bigger brakes in front you throw off the braking balance without doing the rear

check out stoptechs website...last i checked they had a good explanation.

[DerekSelmanRacing]

Will this be your first track experience? If so, you will not overdrive your brakes.

We regularly track an '05 3.0 with upgraded fluid, pads, and oem sized slotted discs. These aren't the best and can be overdriven, but you're starting out a lot better.

Where are you tracking the car and with which group?

[HBspeed]

I have tracked once so far at Buttonwillow (config 13), but in the future it is most likely to be willow springs or Fontana speedway. I tracked with Speed Ventures. The brakes were ok, but after a few laps and especially towards the end of the day they were noticeably fading to the point I had to drive quite cautiously (also probably partly due to the crap oem conti sport contact 1's). I may be new but i think i put up a respectable best time of 2:22.921 for a bone stock Z4M coupe.

[DerekSelmanRacing]

Not bad especially for your first trip.

My best recollection is that I ran about 2:12 to 14 and Derek (excellent driver with race experience) ran around 2:08 in the 3.0 with stock engine and susp except ft camber plates and dot-r tires. We run NASA (nasaproracing.com) almost exclusively and Derek's generally about 6 seconds quicker than me. Driving ability makes a HUGE difference. I would expect your stock car should be capable of running under 2:05 with tires.

Might be fun to get together sometime.

Joel

[pbdm4k]

If you're on a budget, I think the front BBK's are enough and just get a more aggressive pad for the rear with slotted rotors.

I have a set of Brembo BBK's myself in the fronts and I'm running Hawk pads in the rear.

I'm also using Ate Typ200 brake fluid. Makes a big difference over the OEM fluid to keep the brakes from going spongy.

[JCz04Bimmer]

With proper fluid (ie Motul RBF600) and proper bleeding, you'll have very little need for a BBK to be honest. The calipers that come on our cars, even the non-M varieties, are very capable. The most I would recommend doing is upgrading your pads to something with more bite. I highly recommend Ferodo DS2500s. They have phenomenal bite and don't have a cliff-like fall off when they exceed their rated temperatures and don't destroy your rotors too quickly with street driving. I know a lot of track junkies who run DS2500s on the street and then swap in DS3000s in the front when they hit the track.

The only real benefit of a BBK is heat dissipation. Well that and the look frickin pimp!

[silversprint]

Originally Posted by HBspeed

I have tracked once so far at Buttonwillow (config 13), but in the future it is most likely to be willow springs or Fontana speedway. I tracked with Speed Ventures. The brakes were ok, but after a few laps and especially towards the end of the day they were noticeably fading to the point I had to drive quite cautiously (also probably partly due to the crap oem conti sport contact 1's). I may be new but i think i put up a respectable best time of 2:22.921 for a bone stock Z4M coupe.

I did a 2:09-2:10 in a stock Z4M coupe at that same track configuration with stock tires and brakes. You may be also overusing the brakes or kicking in DSC too much overheating the rear brakes. But a BBK on a Z4M is overkill.

I don't think the Z4M needs a big brake kit. The fade you were feeling were the stock pads. Get a set of Performance Friction or Carbotech race track pads and change the brake fluid to motul. The stock BMW fluid is not too bad but motul is better.

Trying better brake pads might be a better before dumping $2K on a BBK that you don't need and won't make your lap times better.

I drive many events with speedventures either in the white z4m or MR2 spyder race car. Drop by and I'll take you out for a spin.

I've driven Cal speedway, SOW, Buttonwillow with better brake pads and never had major brake fade, even coming off the Roval banking at 150+mph.

When is your next event with Speedventures?

[terryltl]

i did 2:10 last year, and last track evnet was 2.16,cuz rear tire only have 20% the rest off,will try new set up for my z4mc next track event at 9/26

[Jaku]

check with your brake fluid, brake pads, tire temp before spending money on BBK

you can improve as much as 12~16s by spending those money on track seat time with bone stock Z4M

[HBspeed]

I'm planning on getting moton club sport's and lighter wheels (advan rs 18x8.5, 18x9.5) with nitto NT-01's (245 & 275) along with some sort of brake upgrade. How do you guys feel about the stock suspension vs aftermarket suspensions on our car in your experiences?

[silversprint]

What is you driving experience level?

What exactly are you trying to get out of the car? Are you interested in the fastest lap times or want it to have bling too.

The right aftermarket suspension well make the car faster on the track. But you have to know how to set up the car. You have to be a fairly consistent and competent driver to tell what that car is doing so you can make suspension adjustments. Making the wrong adjustment just makes the car hard to drive or dangerous. The car pretty easy to drive with stock suspension.

With all those mods you will have a very fast track car but only with the right driver.

I see people put coilovers on the z4M but never even take the interior trim out to adjust dampening on the rear for different tracks. So they are barely faster than a stock car.

I know it sounds cool to throw mods on a car. I'm guilty of that too. But what makes the car really fast is a fast driver. The same money invested in a SkipBarber driving school would improve lap times more that a BBK.


As far as the mods the biggest improvement can be made with sticky tires and coilovers.

The Z4M is a very good car. The limit of the car is hard to reach by most drivers. I say track the car 5-10 times with slight improvements each time and see how you and the car improve. You will become more comfortable in the car and know exactly what needs to be improved.

The most common path taken for a track car is:

1)Brake pads and fluid first
2)More Aggressive alignment
3)Tires and maybe wheels
4)suspension

[DerekSelmanRacing]

Agree with silversprint.

The only obvious problem with our '05 3.0 w/sport suspension is understeer which was cured with camber plates. The Z4 will run with an ex-Grand Am Cup Z3 Cpe with 197 rwhp. The Z4 suspension is stock except for the camber plates-the Z3 has ft coilovers, camber plates, and motons.

The Z4 brakes do require a little more care than the full race Z3. Incidentally, the Z3 brakes are stock except for pads and fluid because THAT'S ALL GRAND AM WOULD ALLOW. This car used to do 3 hour races.

[DerekSelmanRacing]

Incidentally, doesn't everybody turn off DSC for track work? I've found the traction aids on the '05 3.0 way too intrusive for any serious tracking.

[HBspeed]

Well my tracking experience is minimal since I have only gone the one time, but I am looking to get more serious as soon as I can get at least some better tire and braking capabilities. I am looking mostly for functionality in my mods but I may throw on a few less necessary pieces after the car is set up such as a lightweight battery, CF roof, oem CF rear spoiler, oem sideskirts, etc. As far as driving school I agree that's very important. For now Chris at BMS is going to come out to the track and teach me the ropes so I should have that base covered

[Jaku]

i really don't want to go straightforward and hurt your feeling, but trust me, whatever mods you put on your car won't improve your laptime by 12~16s like i said, more seat time is the only way to achieve that

if a pro-skilled driver goes to dealer, picks up a Z4M and goes straight to BW, he can do 2'08 or even better (since no amatuar driver has ever done it, let's say 2'08 is a very conservative estimate even tho i believe it should do faster than that)

for the money you spend on that LONG list, you can become a much faster driver and clock faster time without spending any money modifying your car, maybe just some miantainance cost

if you can't even do 2'10~2'12 on factory bone stock Z4M, i don't see any seriousness you are really showing for track driving and no consistant driving to be able to use stuff like Moton

maybe you should spend money on a data logger and see where you should improve your driving, i bet it's the mod that improves your laptime most

[HBspeed]

ok Jaku... the long list is stuff I may do at some point was a response to silversprint's post. and yes i know that was not an amazing stock time but like I said it was my first time out at a track ever a few weeks ago, and I am going to be going regularly once I get at least tires and brake pads/fluid upgrade. i don't understand why you would be sitting there quoting me lap times either. I am merely asking for opinions on brake set ups and now suspension set ups, and only posted my times because people were asking how I did and what group I ran. I don't expect any of these mods to cut significant time off my lap initially, but I am going to be having help from experienced guys who are going to help me adjust the suspension and teach me how to do it myself as well. I appreciate your opinion, but i don't understand why you would sign up for zpost, not even owning a z4, just to give a negative response.

[Jaku]

i think i signed up just to give you a very positive response, i also gave you such response mainly cos you are new to track driving, i'm not turning you down, i'm pointing you to a better, correct direction of getting fast laptime & being a faster driver since you said you are very serious about tracking or you meant serious about modding your car?

not only that, i think i'm trying to save you a bunch of money, not just a little, and i don't even make money out of you, those shops do!

you gonna drive 9/26 or 9/28?

[HBspeed]

I agree that it isn't the cheapest set up but I'm getting it at a well discounted price. I also agree experience will lead to much larger improvements in lap times than any mods, but since the right opportunity has presented itself I will probably be doing both. Not going to be ready in time for those events because I am in the process trying to find a buyer for my WRX before getting the work done, not to mention one of those days is my girlfriend's b-day

[silversprint]

BMS is running a business. They just want to sell you stuff. But we are somewhat impartial here and want to point you in the right direction. Im sure BMS is a great shop but no one can teach you drive in a day. You would need many tracks days in the car to become comfortable.

Getting something for a discount that you don't really need is not really a great deal. Do you really NEED what they are selling?

There is a BMWCCA driving school at Cal speedway in september. It would be a great way to see what the car can do and improve your driving. You don't need to do anything to the car just drive it stock.

http://www.bmwclubla.org/index.php

I'll probably take the school myself because I can always improve.