Brembo on a budget! Let's make x5 great again :)

[tlow]

Originally Posted by dentprotony@gmail.com

Porsche front 6 piston caliper piston diameter is 33/34mm all same , rear seems to be 27/28mm dia

Good info. Thanks. So next question becomes where do the center of the pistons sit relative to the center of the hub? Meaning if they sit in the same spot as say the M5 calipers, having the bigger 400mm rotors won’t be much of a gain (at least on the street)

[dentprotony@gmail.com]

Originally Posted by tlow

Found this on bimmerfest:
Comparison is based on 5M brake:

OE Front 4 pot: 42/42mm (27.7 cm^2)
OE Rear single floating: 42 (13.9 cm^2)
Piston area ratio: 67/33 (%)

RB Front 6 pot: 32/34/36 (27.3 cm^2)
RB Rear 4 pot: 30/30 (14.1 cm^2)
Piston area ratio: 66/34 (%)​

OE front pad (D1429) with a dimension (Length x width) of 124x90mm
RB front pad (D1666) Same as Mustang GT500-162x65mm

Full reply: https://www.bimmerfest.com/threads/b...2/post-9336273

I doubt the stopping power of the 4 vs 6 piston fronts is all that different if the areas are about the same. I mean if we’re getting technical the bmw x5m and M5 is a two piece caliper (less movement) and pistons spread across the pad better. But if the pistons center points aren’t different relative the centerline of the hub (aka the braking level arm). Again I doubt that much difference. Also, unless you take it to the track…no one on this forum is using either brakes to their full potential. Ya I get the safety and slowing down sooner aspect.

I just replaced my pads on the f85 (m5 rotors/pads upgrade), so i have pictures of pad comparison between my pads that come with porsche 6 piston vs f10 m5 pads. I was pleasantly surprised how close they are in size lol. I am trying to figure out how to post pictures on here from my phone vs loading them up on my laptop and then posting in here

[notslow]

I'm guessing the pistons weren't out during measurement. The faces usually measure a little under actual diameter. I found these specs.
The Porsche rear calipers I have are 32mm as well.

It seems that the piston diameters are much larger than the f85 or 50i. Using the whole system from the Porsche would likely feel balanced if the smaller diameter 350mm rotors were used in the rear.

The 50i uses a slightly larger piston (34mm) rear caliper. With the 345mm rear rotor, this should work well with the F85 Front calipers and larger 395mm rotors. Best bang for the buck would be just upgrading the front brakes to F85 calipers and rotors. The from to rear bias would stay close to stock. Cosmetically, not so great with the single piston floating caliper in the rear.

With the larger F85 or F10 rear rotors, it would be optimal to use the smaller piston F85 rear caliper or a 30mm Porsche caliper if one exists.

Due to the smaller surface area of the F85/F10 6 piston calipers, using a 32mm 4 piston rear caliper will reduce front bias quite a bit. It would start making sense to use Porsche front 6 piston calipers at that point to keep forward bias.

Panamara and VW Toureg:
Front 36mm 6 piston
Rear 32mm 4 piston
Front rotors 380mm
Rear rotor 350mm


Next big question, is there a 30mm 4 piston caliper out there?

996 Porsche have a 28mm/30mm rear, but that increases front bias when used with the F85 Front caliper. Front bias would be similar to the MPB which is heavily Front biased.

30mm really is the sweet spot for the rear caliper.

[tlow]

IMO I wouldn’t worry about rear pistons/rotors being too “big”. I doubt one can notice the difference in front to rear braking performance change. A very easy solution would be to run very conservative/harder pads in the rear. We do this on racecars all the time without changing the “actual” bias. Also I’m assuming when you say “bias change” you referring to coding the computer. Just changing pads/rotors won’t change the bias unless you get into the abs.
Only way to change bias from what I know about this car when not in the abs would be to code it into the computer

[notslow]

Originally Posted by tlow

IMO I wouldn’t worry about rear pistons/rotors being too “big”. I doubt one can notice the difference in front to rear braking performance change. A very easy solution would be to run very conservative/harder pads in the rear. We do this on racecars all the time without changing the “actual” bias. Also I’m assuming when you say “bias change” you referring to coding the computer. Just changing pads/rotors won’t change the bias unless you get into the abs.
Only way to change bias from what I know about this car when not in the abs would be to code it into the computer

Correct me if I'm wrong, but everything I've ever learned about brake systems says that installing a proportionately large brake rotor and caliper on one end of the vehicle is going to increase bias (brake balance) at that end. The RB brake system you referenced earlier is a great example of components that keep the ratio close to stock. Stop Tech systems have piston diameters matched to individual vehicles as well instead of using one size fits all calipers. I don't know if it's changed more recently, but Brembo GT brake kits used to mostly use the same off the shelf calipers. For many applications, the front and rear calipers were the exact same. This was not optimal for most vehicles and required adjusting bias by a proportion valve. This may be okay for track cars, but not optimal for street use. Back in the day I drove quite a few first generation NSXs with different brake upgrades. The Stop Tech system was awesome.
The Brembo systems on just the front were well balanced, but the front and rear Brembo systems would lock the rear wheels first at threshold breaking or trigger Abs way too early, not good in a turn.

I'm sure these modern BMWs are more forgiving with all the computer controls keeping the wheels from locking.

[dentprotony@gmail.com]

Originally Posted by tlow

IMO I wouldn’t worry about rear pistons/rotors being too “big”. I doubt one can notice the difference in front to rear braking performance change. A very easy solution would be to run very conservative/harder pads in the rear. We do this on racecars all the time without changing the “actual” bias. Also I’m assuming when you say “bias change” you referring to coding the computer. Just changing pads/rotors won’t change the bias unless you get into the abs.
Only way to change bias from what I know about this car when not in the abs would be to code it into the computer

Very true, you can do minor adjustments with different pad compound. Also, vehicle this large, one has to do something really major to notice the bias, i doubt 98% of f15 owners take their vehicle to the track and push it to the limit to ‘feel’ the brake bias

[tlow]

Well it depends on your definition of brake bias I guess. Without going to deep into the weeds, we don’t have a great way to measure braking force or braking torque (some cars or racecars have torque sensors on the axles but that’s a topic for another day). So typically when you say brake bias we are referring to line pressure. On ABS cars, line pressure is typically fixed unless you get into the ABS. On some cars and almost all GT3 racecars now, you have both a brake bias adjustment knob as well as an ABS map knob. So the driver could adjust both fixed bias as well as how the abs responds when the driver does get into the abs. Then add in different styles/brands of rotors/pads, calipers etc.
In either case, the question becomes how do you slow the car down the fastest? On a street car, it’s actually harder to optimize bc of varying brake temps. For example, it’s totally silly to have carbon or carbon ceramic rotors/pads. On the street, you will never keep them in the proper operating window (unless you just want the weight out of the car, unsprung mass is another topic for another day)

Hope that helps. Again, we’re not on the track so other than driver “feel” I doubt any of the combos in this thread are night and day better compared to each other.

Originally Posted by notslow

Correct me if I'm wrong, but everything I've ever learned about brake systems says that installing a proportionately large brake rotor and caliper on one end of the vehicle is going to increase bias (brake balance) at that end. The RB brake system you referenced earlier is a great example of components that keep the ratio close to stock. Stop Tech systems have piston diameters matched to individual vehicles as well instead of using one size fits all calipers. I don't know if it's changed more recently, but Brembo GT brake kits used to mostly use the same off the shelf calipers. For many applications, the front and rear calipers were the exact same. This was not optimal for most vehicles and required adjusting bias by a proportion valve. This may be okay for track cars, but not optimal for street use. Back in the day I drove quite a few first generation NSXs with different brake upgrades. The Stop Tech system was awesome.
The Brembo systems on just the front were well balanced, but the front and rear Brembo systems would lock the rear wheels first at threshold breaking or trigger Abs way too early, not good in a turn.

I'm sure these modern BMWs are more forgiving with all the computer controls keeping the wheels from locking.

[notslow]

For anyone who has installed the F85 front calipers. Did you change the dust plates and brake lines? I know that the f85 has different part numbers, so not sure if my 50i pieces will work. Sometimes the dust covers are a negligible difference, but want to be sure for this application.

I'd like to order parts this week. Already have the calipers. Just need pads, rotors and maybe dust plates and brake lines.

[dentprotony@gmail.com]

Originally Posted by notslow

For anyone who has insurable the F85 front calipers. Did you change the dust plates and brake lines? I know that the f85 has different part numbers, so not sure if my 50i pieces will fit work. Sometimes the dust covers are a negligible difference, but want to be sure for this application.

I'd like to order parts this week. Already have the calipers. Just need pads, rotors and maybe dust plates and brake lines.

Yep you will need x5m dust shields, they are larger than 50i

[notslow]

Thanks, I compared some photos and it definitely looked a lot larger diameter. I also found out the brake lines for the 50i are an inch too short for the X5M calipers.

[classic_erik]

Question - are the caliper guide pins and caliper bracket bolts the same between stock 50i and the ones that come with the MPBK? Before I start taking apart my brakes I want to make sure they are the same since I can't find the original stock hardware.

https://www.pelicanparts.com/More_In...41-M4&fc=Y

https://www.pelicanparts.com/More_In...4-BOE&fc=Y

[classic_erik]

Originally Posted by classic_erik

Question - are the caliper guide pins and caliper bracket bolts the same between stock 50i and the ones that come with the MPBK? Before I start taking apart my brakes I want to make sure they are the same since I can't find the original stock hardware.

https://www.pelicanparts.com/More_In...41-M4&fc=Y

https://www.pelicanparts.com/More_In...4-BOE&fc=Y

I confirmed the front caliper guide pins are different for the MPBK, while the rear are the same as stock. The MPBK comes with the 4 front guide pins needed.

The bracket bolts are the same as stock.

[Chrislife]

Originally Posted by notslow

Thanks, I compared some photos and it definitely looked a lot larger diameter. I also found out the brake lines for the 50i are an inch too short for the X5M calipers.

Can anybody else confirm that the brake hoses are too short and need changing?

[Seanjordan20]

Originally Posted by Chrislife

Can anybody else confirm that the brake hoses are too short and need changing?

No they are not too short. If you’re coding performance brakes then opt for braided lines

[Seanjordan20]

Originally Posted by dentprotony@gmail.com

Yep you will need x5m dust shields, they are larger than 50i

Anything special to change out the front covers or is it just remove the rotor to get to them

[classic_erik]

Originally Posted by Seanjordan20

Anything special to change out the front covers or is it just remove the rotor to get to them

Just remove the rotors to access the dust shields. They are secured by a few small bolts.

[dentprotony@gmail.com]

Sole of our recent work 👍👍👍👍

[rmacgurn]

Originally Posted by mcaesar

Just installed brake upgrade and want to say thanks to Tony for offering these 6 piston front 4 piston rear brembo brake caliper kits. In my case I wanted to improve the braking overall of my 2018 f15 3.5D especially for occasional trailering. As we all know the OE brake set up can be marginal at times. Compared to what is available his kit is very reasonably priced ~ $2,500 which includes refurbished front and rear calipers w/custom brackets and pads. They are beautiful and powerful. Figured if this same set up is OE for a Porche Panamerican it’ll be a improvement over the X5’s OE and save $’s. BTW Tony was also super helpful with selecting the appropriate rotors (rock auto) and braided brake lines.

hello mcaesar I would like to know how to contact Tony to purchase the same as you did but min is X6 3.0d with m pack, has a few suspension bit from M but stock brakes (yellow pots).
thanks in advance.
Richard

[dentprotony@gmail.com]

Originally Posted by rmacgurn

hello mcaesar I would like to know how to contact Tony to purchase the same as you did but min is X6 3.0d with m pack, has a few suspension bit from M but stock brakes (yellow pots).
thanks in advance.
Richard

You can either email me at dentprotony@gmail.com or text me directly at 6016181023, ill get you a set 👍👍👍

[Maverik259]

Originally Posted by rmacgurn

Hi Tony it's Richard, you replied to an old post asking how to contact you but mcaesar already put me in touch with you and I communicated with you at 601-618-1023 on 12/31. I was using my phoenix cell phone number then (480-406-xxxx) last we texted you said they were going out for paint this week or last sat. and you would give my a 7-10 day heads up so I could release the SS brake lines and the disks you sent me to buy from Rockauto.com.

are we getting close now? I want to make sure it all arrives close together in Florida.

thank you and let me know the final amount to pay with shipping to the below address.

Nath/Premier Global
8548 NW 72Street
Miami, Fl 33166
ph 786-800-9991

thanks again

Richard

Why wouldn’t you put this in a PM vice on the open forum?

[R4ndy]

Hi all, recently did a full retrofit on a BMW X5 F15 using F85 X5M BBK parts, 6 pot front callipers, 395mm rotors etc.. rears seems just rotors are bigger and callipers are the same.

I noticed no difference, actually performance felt worse and I had bled the brakes twice. Feels really soft on pedal.

Do I need to code anything? There is an option to code m performance brakes as a retrofit, would this improve? Thanks

[classic_erik]

Originally Posted by R4ndy

Hi all, recently did a full retrofit on a BMW X5 F15 using F85 X5M BBK parts, 6 pot front callipers, 395mm rotors etc.. rears seems just rotors are bigger and callipers are the same.

I noticed no difference, actually performance felt worse and I had bled the brakes twice. Feels really soft on pedal.

Do I need to code anything? There is an option to code m performance brakes as a retrofit, would this improve? Thanks

Yes, coding is required. All the info you need is here on this thread.