Question about the brakes

[gchassapis]

Does anyone know how much power the stock Z4 35i brakes can handle? I'm shooting for a power upgrade to around 400-415 HP and I don't know if the stock brakes can handle that. Any thoughts?

Separate Question: What is generally perceived to be the better flash tuner for the ECU?

Thanks!

[teog60]

IMO you haven't to upgrade the braking system if your car will not improve max. speed or the weight... There's no technical reason.
Are you interested to exceed 250 kph?

[gchassapis]

Well I'm doing a flash tune which removes the top speed governor so I don't know I can't predict the future. On public roads, never. I do plan on replacing the brake pads though for less brake dust...

[nicknaz]

If you got a low dusting pad I suspect it would overheat at the track.

My current point of view is that the stock stuff is ok for casual track usage and there are many people with a tune and a bolt on or two (~400 crank hp range) who don't upgrade brakes.

I would have expected that you would go the other way, and get a pad that has a higher max operating temperature as opposed to a pad that prioritizes low dusting.

[army_men]

What do you recommend as a decent pad upgrade from the 35i car? I'm looking at pads myself and don't have much experience with the different brands. Thanks!

[gchassapis]

I'm not going to track the car. That's just not necessary, and I'm trying to build a fast street car, but as for the pads, since I have 293 style rims, they're annoying as hell to clean so I figured go for pads that stop all of that dust from getting onto the rims so I wouldn't have to wash them every 2 days. I guess the general consensus on the breaks then is don't change them unless I go past 400ish hp?

[ChuckB]

Originally Posted by gchassapis

... I guess the general consensus on the breaks then is don't change them unless I go past 400ish hp?

you haven't increased the amount of work the brakes have to do, the stock brakes should be fine, HP doesn't really figure into the equation, only raising the top speed [which you haven't - you may have removed the speed limiter, but you are still speed limited by the gear ratios and the max RPM of your engine, and BMW has already taken this into account, nor have you increased the weight of what you are trying to stop. Can't help on the pads, as of the last time i checked, EBC still has not cleared testing and obtained T.U.V. approval for street usage on any E89 in Germany.

[Z4-35i]

Originally Posted by gchassapis

Separate Question: What is generally perceived to be the better flash tuner for the ECU?

Thanks!

I've been running the ESS map II for 6 months and it transforms the car, better low speed pick up, 911 humbling acceleration and will still return over 30mpg when at a sensible cruise speed on the motorway

[gchassapis]

I believe it! Did you do any modifications to better cool the engine?

[ChuckB]

the supplemental water cooler is increased to a 10 row cooler under hard use [like the Ring], there is a 10 degree [Celsius] drop in engine temperature.

[ChuckB]

[EDIT] the supplemental water cooler is increased to a 10 row cooler under hard use [like the Ring], there is a 10 degree [Celsius] drop in engine temperature.

Photos courtesy of "dwz8" at http://www.zroadster.com

[jannisa]

This is an additional WATER cooler, dear ChuckB.
And it's not aftermarket at all, all parts stem from the performance package of the E9x and the 1M, you will additionally have to order another RIGHT plastic fender liner just to get the part with the grilles.

Yes, it does exactly what you are stating.

Merry Christmas btw.

[ChuckB]

Originally Posted by jannisa

This is an additional WATER cooler, dear ChuckB.
And it's not aftermarket at all, all parts stem from the performance package of the E9x and the 1M, you will additionally have to order another RIGHT plastic fender liner just to get the part with the grilles.

Yes, it does exactly what you are stating.

Merry Christmas btw.

My bad, was trying to translate this without any help, apparently my technical German skills still need some polishing, thanks for jumping in.

[Auraraptor]

Originally Posted by ChuckB

While most things in the engine box are well able to handle the additional power, the German tuners pretty much across the board replace the stock oil cooler (in the left front fender just in front of the wheel) with something a bit bigger, I'll get the details on the specifics from Marcus and pass them on shortly.

Euro cars also have larger factory brakes then the USspec 35 (same as our 35iS).

[ChuckB]

Originally Posted by Auraraptor

Euro cars also have larger factory brakes then the USspec 35 (same as our 35iS).

The is what I was able to put together when I was researching a brake upgrade on my Euro Spec 30i:

sDrive23i [Euro & non US]
Front Caliper 34 11 6769091 [L]/ 2 [R]
Front Carrier 34 11 6769095
Front Rotor 34 11 6772669 [300x24]
Rear Caliper 34 20 6786057 [L]/8 [R]
Rear Carrier 34 20 6786046
Rear Rotor 34 21 6782605 [300x20]

sDrive30i [both US & Euro model] & sDrive35i [US model]
Front Caliper 34 11 6769093 [L]/ 4 [R]
Front Carrier 34 11 6769097
Front Rotor 34 11 6782601 [330x24]
Rear Caliper 34 20 6786057 [L]/8 [R]
Rear Carrier 34 20 6786046
Rear Rotor 34 21 6782605 [300x20]

sDrive35i [European Model]
Front Caliper 34 11 6773201 [L]/2 [R]
Front Carrier 34 11 6773203
Front Rotor 34 11 6782593 [348x30]
Rear Caliper 34 20 6786067 [L]/8 [R]
Rear Carrier 34 20 6786069
Rear Rotor 34 21 6782607 [324x20]

sDrive35is [Both Euro & US]
Front Caliper 34 11 6773201 [L]/2 [R]
Front Carrier 34 11 6773203
Front Rotor 34 11 6782593 [348x30]
Rear Caliper 34 20 6786067 [L]/8 [R]
Rear Carrier 34 20 6786069
Rear Rotor 34 21 6782607 [324x20]