Massive E30 Dual MC bracket (booster delete)

[JehTehsus]

A little while ago I received and installed Massive Lee's twin master cylinder booster delete kit for the E30 (https://www.facebook.com/17841744226...8798889228905/).

Overall, I am very happy with it. Installation was seamless, despite my initial apprehension about the directions being on facebook, they are fine and all you need.
The kit is definitely smaller than the booster, but a bit larger than a single MC booster delete. That said, I plan on tracking this car, and I am absolutely not comfortable running a single circuit MC with proportioning valve (like from Chase Bays).

Currently I have twin Tilton 0.625" MCs installed right now, this is running to the factory brakes. Eventually these will be swapped for something more suitable, but for now I wanted the car drivable on the street. Which it definitely is! Braking is comfortable. Certainly a bit more effort than the boosted brakes, but not excessively so (my partner had no problems driving with them, although she did note they felt 'a little weird', which I attribute to the old pads/rotors and the fact that the manual brakes do definitely feel different than boosted).

Pedal travel is a bit more than I would like, at least for a track car. In terms of comparison to stock, I would say it is roughly the same (or at least feels that way, I did not measure). This is not an issue with the kit though, it comes down to cylinder size selection, which I will need to change when redoing my calipers. As it is the options in the bracket leave me a lot of flexibility, so I have no doubt I will be able to make something work, and work well, by adjusting the cylinder sizes.

Here are a few pictures of it installed/being installed:

[digger]

Thanks for the writeup, i am going to mount mine flipped with pivout on bottom and reservoir near shock tower to maximise room, currently have dual 3/4".

What did you do with the lines,and proportionate valve?

Where did you get fittings?

[JehTehsus]

Thanks for the writeup, i am going to mount mine flipped with pivout on bottom and reservoir near shock tower to maximise room, currently have dual 3/4".

What did you do with the lines,and proportionate valve?

Where did you get fittings?

This is actually a good point, I currently have mine mounted 'up' and with the tilton res there is not really enough room. It is fine at the moment while I focus on other things but next time I am in there (and certainly before I start to really beat on the car) I will likely just gently bend some of the lines out of the way and flip the bracket to make more room for the reservoir. The other option is to just use the small reservoirs that mount directly to the cylinders, which would fit fine (probably need a separate one for the clutch somewhere in that case though).

I ended up getting 3/16 stainless tubing (25ft)s from summit racing for like 38 bucks. Everything in the bay, including the brakes, is using AN-3 at the moment (also from summit), with AN adapters where they join the factory lines at the wheels and where the rear brakes connect. No proportioning valve, all my brake biasing should be doable by just adjusting the bracket (note - I have not done this yet, i.e. goosed it in a big parking lot, so I cannot confirm. Worst case I will have to change a cylinder out to a different size).

[Massive Lee]

Hi guys.

May I suggest NOT to keep the OEM bias valve s it will work against you. It can cut up to 40% of the hydraulic pressure.

Also, when removing the brake booster, it is preferable to compensate fo the lack of assist with brake pads having a higher coefficient of friction.

I am currently doing some customer support and am shipping for free a set of free stainless steel shims to be placed on each side of the balance bar. It is not 100% necessary, but it helps keep dust away from the spherical bearing, while helping the alu clevis to slide on the sides of the balance bar lever.

https://www.facebook.com/Massive-Brakes-178417442267056/photos/pcb.3234172290024874/3234166386692131/

Please take note that the two MCs are spaced 2.5" apart, which is basically a standard for race pedal boxes. Therefore, as per online instructions, the clevises on the balance bar shall also be spaced 2.5" apart. One basic rule that also applies to all twin MC pedal boxes is that once fully pressed in, the balance bar shall be approximately perpendicular with the car. But once released, it is most likely that the balance bar will be at an angle. That angle depends on factors such as MC diameters and caliper piston sizes.

To get your free set of stainless shims, simply email me at massivebrakes@gmail.com and add "Dual MC shims" as the subject of the email. Shims are free. Shipping is free.

Thanks

Lee

[JehTehsus]

Hi guys.

May I suggest NOT to keep the OEM bias valve s it will work against you. It can cut up to 40% of the hydraulic pressure.

Also, when removing the brake booster, it is preferable to compensate fo the lack of assist with brake pads having a higher coefficient of friction.

I am currently doing some customer support and am shipping for free a set of free stainless steel shims to be placed on each side of the balance bar. It is not 100% necessary, but it helps keep dust away from the spherical bearing, while helping the alu clevis to slide on the sides of the balance bar lever.

https://www.facebook.com/Massive-Brakes-178417442267056/photos/pcb.3234172290024874/3234166386692131/

Please take note that the two MCs are spaced 2.5" apart, which is basically a standard for race pedal boxes. Therefore, as per online instructions, the clevises on the balance bar shall also be spaced 2.5" apart. One basic rule that also applies to all twin MC pedal boxes is that once fully pressed in, the balance bar shall be approximately perpendicular with the car. But once released, it is most likely that the balance bar will be at an angle. That angle depends on factors such as MC diameters and caliper piston sizes.

To get your free set of stainless shims, simply email me at massivebrakes@gmail.com and add "Dual MC shims" as the subject of the email. Shims are free. Shipping is free.

Thanks

Lee

Hi Lee,

Thanks for the info! I will shoot you an email shortly here.

I did ensure the bar was perpendicular (under pressure), as I believe the Tilton directions also stress is of great importance.

[digger]

Any updates on your experience with this setup?

[JehTehsus]

No issues, brakes still work! I can also say I am definitely happy with them. I should probably spend a little more time really fine tuning the balance bar but I have fairly sticky tires on the old girl at the moment and I don't think I actually want to push them to lockup in the dry. The car certainly stops fast enough right now. In the wet the lockup point seems pretty well balanced, relatively low speed testing it is comfortable and controllable, extremely repeatable compared to the old boosted brakes.

Actually supposed to be out on the semi-local track on the 4th of June, so we will see how it really handles then. I just put brand new pads and rotors on for the track, car is being stripped right now and lots of other little bits are being handled so I have not even bedded the new pads and rotors in yet.

[digger]

No issues, brakes still work! I can also say I am definitely happy with them. I should probably spend a little more time really fine tuning the balance bar but I have fairly sticky tires on the old girl at the moment and I don't think I actually want to push them to lockup in the dry. The car certainly stops fast enough right now. In the wet the lockup point seems pretty well balanced, relatively low speed testing it is comfortable and controllable, extremely repeatable compared to the old boosted brakes.

Actually supposed to be out on the semi-local track on the 4th of June, so we will see how it really handles then. I just put brand new pads and rotors on for the track, car is being stripped right now and lots of other little bits are being handled so I have not even bedded the new pads and rotors in yet.

Ok good I’m going to be proactive in installing mine. Ordered the bits to do lines. I’m also going to remove the rear reduction valve but not sure the best way to fill the gap.

What sizes m/c are you currently running?still 2x 5/8”?

[JehTehsus]

Ok good I’m going to be proactive in installing mine. Ordered the bits to do lines. I’m also going to remove the rear reduction valve but not sure the best way to fill the gap.

What sizes m/c are you currently running?still 2x 5/8”?

Yup, still running the same cylinders, I see no reason to change them until I really tear into new wheels and larger brakes, and balance seems fine (good enough based on sliding around in the rain) at the moment running the factory calipers. We will definitely see how it holds up on the track - not going for any records but I still think I am going to get a decent workout, I bet 20 minutes hard braking will wear my fat ass out.
City driving zero issues at all, I don't even notice the manual brakes at all anymore unless I am stuck holding the car on a hill for a bit. I put a few thousand km's on the car so far with the setup and all I can really say is I am extremely happy with how consistent the brakes always feel - something I didn't even realise was missing with the old vacuum assisted setup.

[digger]

Yup, still running the same cylinders, I see no reason to change them until I really tear into new wheels and larger brakes, and balance seems fine (good enough based on sliding around in the rain) at the moment running the factory calipers. We will definitely see how it holds up on the track - not going for any records but I still think I am going to get a decent workout, I bet 20 minutes hard braking will wear my fat ass out.
City driving zero issues at all, I don't even notice the manual brakes at all anymore unless I am stuck holding the car on a hill for a bit. I put a few thousand km's on the car so far with the setup and all I can really say is I am extremely happy with how consistent the brakes always feel - something I didn't even realise was missing with the old vacuum assisted setup.

ok thanks, i will run a similar setup but compensate the front MC given i am using the Dynapro which are bigger piston area