b35 intake - Tii booster alternative

One of the issues resulting from the use of the b35 intake manifold is clearance from the stock CS brake booster. This is generally resolved by shortening the booster mounting neck by 3 - 3 1/2" and substituting a Tii booster. This is a lot of work and Tii boosters are becoming hard to find and more expensive with time.

Lee Vuong of Massive Brakes offers a booster delete kit for the e30 (e9 has the same bolt pattern as the e30 and e10) that looks like it will provide the clearance with much less effort with a few modifications to the parts he supplies. I have to confirm this with some of the issues of getting this to work (since I've already done the Tii conversion) but it's winter and I'm up for the challenge and will report back. Lee's comments on my inquiry are below the link.

http://www.massivebrakes.com/brake-systems.php?p=brake-booster-delete

The bolt pattern of a Tii booster is the same as an e30 or a 2002. Therefore the adapting plate will work. The unknown is the distance between the pedal and the surface where the booster bolts. In the worst case scenario, you'll need a longer 8mm rod. The current e30 distance is 130mm (5")

Looking at the e9 pedal box diagram, it should work. You will only need to drill an 8mm hole higher on the pedal stem to increase the pedal ratio from 4:1 to 6:1

I shall have a batch of 50 kits in 10 days. I am currently out of those kits.

Lee

Doug,

So this sounds like you would no longer have "vacuum power" assisted brakes? and this is compensated for by the increased pedal ratio? Do you know how the final braking effort compares between stock and modified?

Brake Booster delete

I asked Lee and will relay the comments when I get them. Mechanical advantage replaces vacuum assist.

Based on the link below of the brake system cross section are two questions:

In order to increase the ratio the pivot point has to be raised above the existing - is there enough room here to get 6:1 (or more if desired)?

As that pivot point is raised, the piston rod to the MC starts to angle away from the centreline axis - is this a problem?

http://i54.photobucket.com/albums/g120/decoupe/M30B35 EFI/P1000167.jpg

I have heard

And I don't know, but I have heard that if it's the intake manifold that's causing the clearance problem you can shave off the corner of the intake and re-weld a flat piece with no performance degradation. It actually seems like the easier (and less expensive) solution. I was toying with putting the 3.2 engine from a 633 CSI in my CS, but all the wiring etc probably would have meant another 6 months of work :-(

Oh well

Comments from Lee at Massive Brakes.

Hi Doug

A physical assist cannot be substracted from a system, and the same effort/pedal travel expected. There's a reason why hydraulic and pneumatic brake assist were created. ;-)

Even with the higher pedal ratio, a smaller MC is required. pedal will still be stiff. This is a system from the 1960s (pre-assist) or for a racecar.

I suggest you visit www.e30tech.com <http://www.e30tech.com> where all the effort questions have been answered.

Lee


Damn, I was really pumped about all that extra space which is why I went with the Tii and not cutting the intake manifold.

Doug

2800cs booster vs tii booster vs 3.0cs booster ... is the 2800cs booster the same as the tii booster? it seems quite a bit smaller than the 3.0cs booster. or is it just that mine has been replaced with the tii booster?

They all show different part numbers and the Tii used only on Tii. CS includes e12, e24 and e3.

An alternate is to use the hydraulic system from the E24 and E28, as that system should fit with the Motronic manifold without issues.

x_atlas0 said:

An alternate is to use the hydraulic system from the E24 and E28, as that system should fit with the Motronic manifold without issues.

Click to expand...

This was Lee's recommendation plus it improves the access to everything below which is what brought this all to light.

This is why I went hydraulic in the end.

A bit of work to do it but it was a "simple" work around and works well.

johanaxelson said:

This is why I went hydraulic in the end.

A bit of work to do it but it was a "simple" work around and works well.

Click to expand...

Can you post a photo of the installation?

I was reading the other thread and saw I did not reply I will try and dig out some pics, need to get an external drive to work first. Transformer is broken...

guys, is there a reason why you cannot have the original master resleeved / and the piston machined to the appropriate diameter bore, surely there are guys who could do this?

I just read this thread for he first time and may have not read it thoroughly, but the support does not have to be shortened to use the Tii booster. I've also used the e23 and e24 hydraulic systems which work well once you've gone to the considerable trouble of adapting them, except that they are prone to periodic leaks because of the difficult routing of all the high pressure hoses. Also, I haven't had much success using the stock power steering reservoir (modified) as it will overflow under certain conditions and create a mess that way as well.. Using the correct e23 reservoir is slightly challenging fitment-wise....

Tom,

The discussion was for the b35 intake manifold and shortening the mount is definitely necessary or some other accommodation must be made as the stock vacuum booster interferes (contacts) the b35 housing at the lower corner.

I've done a number of these, starting 25 years ago and with the (at that time b34 manifold), I don't think any amount of shortening the mounting post would have allowed me to keep the stock 3.0 booster, nor would I like to have done such a modification where I have to damage original components vs. simply bolting in a Tii booster without cutting more than just the internal push rod. Just my input as the other methods also will work... On my own Coupe I went back to the old D-jet manifold, even if it means losing a few HP....

Has anyone used a e12 chassis 6 series/motronic pedal box for this? Solves the throttle cable issue and the booster issue as well "I think" that is what I did with my Bavaria race car with m30B35...

Thanks

Al Taylor

Isn't one way around figment issues to use an Ljet intake with adapt ore for the investors? This is what I have been contemplating as I have a complete '87 735 I plus the Ljet intake bits from an '81 E12. Just need to find time and energy to go forward...

Charlie- no adapters, just use vanagon injectors. # 206
if you use the stub manifolds from the e12 or csi it's nice to use the e32 head.
A bunch of us on Maui in ten days- care to join us?

Is the flow of the 206 injectors (168cc/min.) sufficient for our engines ?