brakes Tii Big brake kit pros and cons

[Pstegner]

Thanks for all the info! So, Lars, if I understand correctly the turbo and too spindles are the same, bearings are the same, so I should be able to run turbo rotors with turbo hubs on my Tii struts?

[LarsAlpina]

so I should be able to run turbo rotors with turbo hubs on my Tii struts?

 

Yes, just like that. BUT: Keep in mind that new turbo hubs are in no way cheap, they´re near 400EUR at the moment here in Germany - EACH, not a pair. And you will of course need to widen your tii calipers with spacer kits or buy a set of turbo/E3/E9/E12 front calipers for vented rotors.

 

if you intend to buy E3/E12 be careful: At least for EURO spec cars BMW in appr. 1976 switched the brake pad thickness from 15mm to 19mm. Along with that the calipers got a little bigger which may cause space issues in 02. Black caliper is for 15mm, silver caliper is for 19mm:

 

 

You can distinguish the 15mm calipers from the 19mm simplest by checking how the caliper halfs are put together. 15mm do have bolts with nuts, 19mm have bolts, too, but instead of nuts there are threads machined directly in the material of the one caliper half.

 

Best regards, Lars.

[Preyupy]

Lars, I stand corrected I went and looked at the turbo hubs and Tii hubs on my shelf. The Turbo hub has a different mounting height but I believe the difference is a machining difference and that it should not be difficult to modify and Tii hub to work.

[LarsAlpina]

Well, now my limited skills in English language keep me from exactly writing what I want to write. I´ll give it a try:

 

For all turbo hubs I had in my hands the hub part marked red on the photo was some 10 or 12mm (don´t remember the exact number at the moment, would have to look that up in my documents if needed) deeper than on a tii hub. I don´t really see how one can add up length there by machining?

 

 

Regards, Lars.

Edited January 31, 2015 by LarsAlpina

[kbmb02]

I am planning on going with the big brake kit that Ireland sells. (E21 rotors and hubs, e24 calipers). I have a Tii. I have already purchased the rotors. Today I called Ireland to to ask if I use e21 bearings or Tii bearings and was told to use my Tii hubs with the e21 rotors because the Tii had bigger bearings. I was super excited at this point. Less money spent, bigger bearings, with bigger brakes, and no hubcentric stuff to worry about. First thing I did when I got home was remove my Tii hubs from the Tii rotors and attempt to install the new w21 rotors on them. I quickly des covered that this does lot work. Now I am wondering if it's worth it to give up the larger bearings of the Tii hub for larger e21 brakes. Is there any way to keep Tii hubs and have larger brakes?

 

OP: I believe I have a pair of early e21 hubs on the shelf ... send PM, I'll check over the weekend. -KB

[Pstegner]

I would love them, if you want to sell /-)

[Paul Taffa]

On 31/01/2015 at 11:49 AM, Preyupy said:

Lars, I stand corrected I went and looked at the turbo hubs and Tii hubs on my shelf. The Turbo hub has a different mounting height but I believe the difference is a machining difference and that it should not be difficult to modify and Tii hub to work.

 

I am attempting to do this conversion on my '73 tii. I have a lathe and the skills to do this machining. I have purchased new Turbo discs from W&N, and had the spacers made on a 5 axis CNC machine, and the calipers have been done. Could you please measure the hubs and post here with  the differences you have found?

It would be greatly appreciated.

Thanks.

[Paul Taffa]

Sorry for resurrecting an old thread, but I can definitely confirm Turbo discs will NOT fit to ti / tii hubs. Turbo discs and hubs are different to ti / tii.

 

For my big brake conversion on my 1973 tii, I used E21 323 hubs and discs. These were a popular model in Australia, and though now harder to get, they still sometimes turn up at wrecking yards. This a bolt-in, as the 6cyl E21 cars used the same big bearings as ti / tii (and the E12 / E9.)

 

For the calipers, I made a pattern to widen the tii calipers, and then had the spacer manufactured on a CNC machine. I have the pattern and the shop has retained the CNC program on the machine. I can have more made on a phone call.

 

To fix the now widened caliper halves together, I used high tensile (grade 12.9) socket head cap screws (allen bolts) in 3/8 in UNF. The standard bolts in a tii caliper are 9mm dia, which is not a standard size and not commercially available.

3/8 UNF measure 9.5mm diameter, and the bolt holes in the caliper are 9.2mm. Thus, a 3/8in reamer takes out only 0.3mm of metal on the diameter, or only 0.15mm on the radius, and you get fitted bolts which adds strength and stiffness to the caliper. Given the mass of cast iron in the caliper, the loss of 0.3mm is of no consequence.

I used over length bolts, (as in long plain shank bolts) and shortened the thread section to have around only 3mm or so of thread in the hole.

The O rings to seal the caliper halves are standard over the counter items from any bearing or engineering supply shop.

 

I purchased a Turbo caliper pin and pad retainer kit from Walloth Nesche to retain the pads.

 

The pic shows the modded caliper fitted to the hub. New discs were fitted, the ones shown are the wrecking yard items, which already had been machined.

 

Please email me if you a set of spacers for the ti / tii caliper. I have a Facebook page under my name to send me a message.

 

Hope all this helps.

 

Cheers.

 

 

 

[Conserv]

Going back to @JohnS’s question from 2015: I’m assuming that adding turbo hubs, rotors, and calipers eliminates the possibility of fitting stock 5 x 13, ET26, steelies or early OEM 5 x 13, ET26, alloy rims?

 

The turbo used 5 1/2 x 13, ET18, steelies, and I’m guessing that that offset, 18 mm., was necessary to mount the stock steelies with the turbo’s brakes.

Thanks and regards,

 

Steve