Suspension & Brakes E46M platform.

[Tbonem3]

What year is the car? Post 09/02 is mk60? Go for it! If it's a 2001-2002 car, sell the car before upgrading anything. I kid I kid. Sort of. Sell the car.

[repoman89]

Hi guys,

I don't want to open a new thread and hope continuing this thread is ok.
I am thinking about replacing my brake system aka BBK. However after reading and researching I've read a lot that the stock brakes are not bad compared to a lot BBK "upgrades".
My initial plan was fitting BMW F30 Brembo 4-pot calipers with CSL rotors in the front and 996 calipers in the rear. Even though the brake bias will only slightly shift to the rear by 1.36 % (F 65.51 % R 34.49 %) I am worried about loosing stopping power. Total piston area in the front will decrease about 11 % which also leads to a decrease in torque of about 11 %. For the rear I will loose about 5 % in total piston area which therefore leads to a loss of 5 % of torque. Total decrease in piston area/torque is about 16 %.
I am not an expert nor have I any experience with that, I was just playing around with the calculator and trying to understand what the outcome numbers will mean in the end. Can someone explain if these 16 % loss in total piston area/torque will bring me 16 % less stopping power?

What that means is that with the pedal on the floor, you will be supplying 16% less torque to the rotors. In practice, ABS will be preventing you from locking up your tires well before pedal to the floor, so what you will have is longer pedal travel for a given brake torque. I find this to be a good thing with my 996 setup .. heel/toe is easier at the ABS threshold on track and to me, modulation and feel is improved.

Total stopping power by moving bias rearward will probably improve slightly but either way 1-2% won't be enough to notice.

[m3_sancho]

Hi guys,

I don't want to open a new thread and hope continuing this thread is ok.
I am thinking about replacing my brake system aka BBK. However after reading and researching I've read a lot that the stock brakes are not bad compared to a lot BBK "upgrades".
My initial plan was fitting BMW F30 Brembo 4-pot calipers with CSL rotors in the front and 996 calipers in the rear. Even though the brake bias will only slightly shift to the rear by 1.36 % (F 65.51 % R 34.49 %) I am worried about loosing stopping power. Total piston area in the front will decrease about 11 % which also leads to a decrease in torque of about 11 %. For the rear I will loose about 5 % in total piston area which therefore leads to a loss of 5 % of torque. Total decrease in piston area/torque is about 16 %.
I am not an expert nor have I any experience with that, I was just playing around with the calculator and trying to understand what the outcome numbers will mean in the end. Can someone explain if these 16 % loss in total piston area/torque will bring me 16 % less stopping power?

[tnord]

The travel is sufficient, so long as you tailor your ride height to it. People who try to go higher or lower than is optimal really ruin them fast…

… which was initially exacerbated by them being designed for euro spindles, so they didn’t work at any sort of reasonable ride height with US spec spindles (3DM now makes/sells spacers to address that issue).

I may swap the spindles also, I haven't looked into it much yet. From what I remember of the initial discussion on the old board about them, they increase castor but otherwise have no drawbacks? I think it needs a new wheel bearing also, do they need to be pressed in?

[02_lsb]

car use: mostly weekend, good weather only.

Suspension: I had stock->ST (not a fan) and now TCK DA, they’re fantastic.

Brakes: I have 996 brembos. Given my driving style, they’re just bling.

[Obioban]

I've searched and read a bunch on this subject, but I'm still left with a specific question or two.

Yes, I know the Ohlins have very limited front bump travel. What I don't see is what scenario you run out of travel. For a dual purpose setup, I believe you need the most travel when using curbs on track, which shouldn't be an issue for me. If I take it to the track, I can avoid curbs.

"but if you're not taking it to the track why not just get TCK, or why even spend the money and just stay stock?"

well, I kind of agree with that, but when I looked at even the SAs they cost the same as the Ohlins, and I can't help but think they're more capable and better built. Also, I bought the car in 2010 and it came with Konis and H&Rs. I'd like to try something other than the H&Rs, the koni bodies are severely corroded and need replacing, and the "lifetime" rear top mounts I got from bimmerworld seem to make a lot of noise when it gets cold. So there's a bunch of stuff that needs to be replaced anyway.

I have 245 front PSS right now, and will replace with same size PS4S in the spring, so the packaging of the ohlins isn't as much of an issue. If my guess is right, that my use case really won't run into bump travel problems, and they cost the same, is the TCK SA really still the better option (understanding the different people have different definitions of "better")?

The travel is sufficient, so long as you tailor your ride height to it. People who try to go higher or lower than is optimal really ruin them fast…

… which was initially exacerbated by them being designed for euro spindles, so they didn’t work at any sort of reasonable ride height with US spec spindles (3DM now makes/sells spacers to address that issue).

[Obioban]

You have to remember that with the Ohlins purchase you need to also get camber plates. So that brings the price closer to $3k. I'm in a similar situation as I need to replace the factory stuff soon so might as well upgrade. I ran Ohlins on my Audi and loved them for a street car but the M3 I am thinking of moving over the the Fortune Auto stuff.Their prices are much more reasonable compared to Ohlins and KW. They come with with camber plates too.
They have a lot of options and can upgrade as you move down the road. A lot of the M3 guys around me are now running them. One of them even moved from KW Clubsports to the Fortune set up.

Sorry for going way off topic but maybe it will help.

If he’s not tracking, no benefit to camber plates.

[lvm3sm46]

You have to remember that with the Ohlins purchase you need to also get camber plates. So that brings the price closer to $3k. I'm in a similar situation as I need to replace the factory stuff soon so might as well upgrade. I ran Ohlins on my Audi and loved them for a street car but the M3 I am thinking of moving over the the Fortune Auto stuff.Their prices are much more reasonable compared to Ohlins and KW. They come with with camber plates too.
They have a lot of options and can upgrade as you move down the road. A lot of the M3 guys around me are now running them. One of them even moved from KW Clubsports to the Fortune set up.

Sorry for going way off topic but maybe it will help.

[tnord]

I've searched and read a bunch on this subject, but I'm still left with a specific question or two.

Yes, I know the Ohlins have very limited front bump travel. What I don't see is what scenario you run out of travel. For a dual purpose setup, I believe you need the most travel when using curbs on track, which shouldn't be an issue for me. If I take it to the track, I can avoid curbs.

"but if you're not taking it to the track why not just get TCK, or why even spend the money and just stay stock?"

well, I kind of agree with that, but when I looked at even the SAs they cost the same as the Ohlins, and I can't help but think they're more capable and better built. Also, I bought the car in 2010 and it came with Konis and H&Rs. I'd like to try something other than the H&Rs, the koni bodies are severely corroded and need replacing, and the "lifetime" rear top mounts I got from bimmerworld seem to make a lot of noise when it gets cold. So there's a bunch of stuff that needs to be replaced anyway.

I have 245 front PSS right now, and will replace with same size PS4S in the spring, so the packaging of the ohlins isn't as much of an issue. If my guess is right, that my use case really won't run into bump travel problems, and they cost the same, is the TCK SA really still the better option (understanding the different people have different definitions of "better")?

[K-Dawg]

What's up guys. So after catching up on the forum and reading these posts again. Did i totally mess up on getting B4 with dinan springs? Is there no travel for spring to strut? Smh. I still have my h and r springs if that still works better than dinan. I think they may be dropped a bit more than the h and r.

I'd think you're fine. It's the monotube B6 damper that has limited travel.

Are you experiencing some trouble?

[Drewrivera]

Thanks for the tip. I guess I'll have to open things up again and see what's feeling off. I can't remember if i pressed the spring down onto the strut. 🤔. I feel like i didn't need to.

[Obioban]

What's up guys. So after catching up on the forum and reading these posts again. Did i totally mess up on getting B4 with dinan springs? Is there no travel for spring to strut? Smh. I still have my h and r springs if that still works better than dinan. I think they may be dropped a bit more than the h and r.

H&R springs drop the car significantly more than Dinans. The dinans and eibachs have the least drop of any springs for the chassis.

[Drewrivera]

What's up guys. So after catching up on the forum and reading these posts again. Did i totally mess up on getting B4 with dinan springs? Is there no travel for spring to strut? Smh. I still have my h and r springs if that still works better than dinan. I think they may be dropped a bit more than the h and r.

[zzyzx85]

Thank you! I'll adjust my expectations to getting Brembos in the future then.

You were talking about the AP Racing kits from Essex Parts, right? The folks at Essex were helpful on making sure I got the right stuff when I bought a set for my STI.

[eXpensiveGears]

They can work on the street but they will likely be noisier and need to be bled more often since they lack dust boots to keep the brake dust out of the brake fluid. The selection of street compound pads might not be as wide as what's available for other calipers as well.

Thank you! I'll adjust my expectations to getting Brembos in the future then.