Single circuit master brake cyl

[Pastelblue'02]

Just now, Hans said:

Don't E9 rotors have 5 holes? So many questions!

Ha! Correct. I had to drill the accurate pattern into them so that they could be bolted to the backside of the hub, just like on an 02.

[Pastelblue'02]

1 hour ago, Hans said:

As far as I can see, E21 master is just over 20mm. CS single circuit (your last pic) is 23. 6mm or so.

Doing some technical reading on master cylinder bore, I believe a smaller bore increases line pressure and results in stronger braking, not weaker. So that would then explain why the braking performance is strong!

Edited October 6 by Pastelblue'02

[Hans]

On 10/5/2024 at 8:05 PM, Pastelblue'02 said:

Doing some technical reading on master cylinder bore, I believe a smaller bore increases line pressure and results in stronger braking, not weaker. So that would then explain why the braking performance is strong!

Sounds good. Are there not any 4 bolt vented rotors out there? E30?

[66m10]

No need to make something.

This is the vented E9 rotor made with the 4 bolt pattern

Bremsscheibe Neue Klasse 272 x 22 mm belüftet Satz NEU !

SHOPWARE.BMW-OLDTIMERTEILE.DE

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Bremsscheibe (1 Satz) belüftet 272x22 mm passend für BMW Baureihe Neue Klasse 2000 2000Ti Tii Tilux 2000 C CS , 2000/1,8 Für Umbau auf belüftetet…

 

You need these rotors and either E23 calipers for 27x22mm rotors if you want to keep the single circuit brakes or E9 CSI/ 02 Turbo calipers if your car has dual circuit brakes.

[Pastelblue'02]

33 minutes ago, Hans said:

Sounds good. Are there not any 4 bolt vented rotors out there? E30?

Nope. At least not while using the factory hubs. All later rotors attach to the front side of the hub, throwing off the offset and spacing for the caliper. Someone in Germany did a group buy for vented NK rotors a while back, but they are all sold now. They were just vented e9 rotors with a different bolt pattern! lol 

[Pastelblue'02]

Just now, Pastelblue'02 said:

Nope. At least not while using the factory hubs. All later rotors attach to the front side of the hub, throwing off the offset and spacing for the caliper. Someone in Germany did a group buy for vented NK rotors a while back, but they are all sold now. They were just vented e9 rotors with a different bolt pattern! lol 

Turns out those rotors are still available! I stand corrected. They are 50 euros more per rotor. It was worth 100 euros for me to use my free drill bits, lol.

[66m10]

Well i don't know how much the E9 rotors are in the US, but by my math the pair of vented rotors is 30 euros more than a pair of standart non vented rotors. 

[Pastelblue'02]

2 minutes ago, 66m10 said:

Well i don't know how much the E9 rotors are in the US, but by my math the pair of vented rotors is 30 euros more than a pair of standart non vented rotors. 

Last I checked, Walloth is offering e9 vented rotors at 107 euros a piece. Making a pair about 160 euros cheaper.

[Hans]

On 10/7/2024 at 10:41 AM, 66m10 said:

Well i don't know how much the E9 rotors are in the US, but by my math the pair of vented rotors is 30 euros more than a pair of standart non vented rotors. 

 

On 10/7/2024 at 10:44 AM, Pastelblue'02 said:

Last I checked, Walloth is offering e9 vented rotors at 107 euros a piece. Making a pair about 160 euros cheaper.

I'm back. 

thanks for ideas. Those 272x22 rotors are available but shipping doubles cost. Yikes.

My main objective is to at least get dual circuit brakes. Currently running on single circuit with things rebuilt about 35 years ago. Always used Dot 5 silicone fluid.

Option 1 is to convert to later dual circuit system. I have two tii size rebuilt calipers in storage. I think I could use those if I could find a master cyl. at a reasonable price.

Option 2 is to do 320i master, E31 calipers and vented rotors. That starts to get pricey.

I have some early single circuit caliper rebuilt kits but they have been sitting for a while.  Also have a tii master cyl kit but again, its been sitting for decades.

I suppose I could just bolt on 320i master and at least have dual circuit in case something blows.

Thoughts??

[Pastelblue'02]

43 minutes ago, Hans said:

 

I'm back. 

thanks for ideas. Those 272x22 rotors are available but shipping doubles cost. Yikes.

My main objective is to at least get dual circuit brakes. Currently running on single circuit with things rebuilt about 35 years ago. Always used Dot 5 silicone fluid.

Option 1 is to convert to later dual circuit system. I have two tii size rebuilt calipers in storage. I think I could use those if I could find a master cyl. at a reasonable price.

Option 2 is to do 320i master, E31 calipers and vented rotors. That starts to get pricey.

I have some early single circuit caliper rebuilt kits but they have been sitting for a while.  Also have a tii master cyl kit but again, its been sitting for decades.

I suppose I could just bolt on 320i master and at least have dual circuit in case something blows.

Thoughts??

What are you concerns with single circuit brakes? Most modern cars use a single circuit setup. Of course, there is extra insurance with the dual circuit setup, but if you have a new master cylinder, new brake lines and rebuilt calipers, what is there to stress over?

 

someone may no better, but I believe with the tii calipers, you would also need to use tii rotors, which have a smaller diameter. So while you’re gaining dual circuit, you may lose braking power. Might be marginal, I’m not sure.

 

if you went the e31 route, you would at minimum need 15” wheels. Additionally, you’d be installing brakes intended for a vehicle that weighs nearly twice of an NK, so you may never use them to their potential, or might be very unbalanced with the rear brakes. Additionally, you would need e31 hubs (no clue if those would even adapt to NK spindles?). E31’s are also ABS cars, no clue if that would hinder anything.

 

if you want to do dual circuit, I would think your easiest adaptation would be later dual circuit NK brakes, or e23 745i brakes, as they are also dual circuit.

[Hans]

19 hours ago, Pastelblue'02 said:

What are you concerns with single circuit brakes? Most modern cars use a single circuit setup. Of course, there is extra insurance with the dual circuit setup, but if you have a new master cylinder, new brake lines and rebuilt calipers, what is there to stress over?

 

someone may no better, but I believe with the tii calipers, you would also need to use tii rotors, which have a smaller diameter. So while you’re gaining dual circuit, you may lose braking power. Might be marginal, I’m not sure.

 

if you went the e31 route, you would at minimum need 15” wheels. Additionally, you’d be installing brakes intended for a vehicle that weighs nearly twice of an NK, so you may never use them to their potential, or might be very unbalanced with the rear brakes. Additionally, you would need e31 hubs (no clue if those would even adapt to NK spindles?). E31’s are also ABS cars, no clue if that would hinder anything.

 

if you want to do dual circuit, I would think your easiest adaptation would be later dual circuit NK brakes, or e23 745i brakes, as they are also dual circuit.

I misspoke. E23 calipers, not E31! I believe tii and later NKs used the same master and calipers - NK had larger 272 rotors. So path of least resistance is to rebuild what I believe is old Bavaria master and use tii calipers. I'll have to inspect bore.

[Pastelblue'02]

48 minutes ago, Hans said:

I misspoke. E23 calipers, not E31! I believe tii and later NKs used the same master and calipers - NK had larger 272 rotors. So path of least resistance is to rebuild what I believe is old Bavaria master and use tii calipers. I'll have to inspect bore.

Realoem should be able to verify that for you, if you haven’t already checked! Seems like a good way to go.