im wrapping up some work on my 92, and i went to install new strut mounts, and noticed a large difference is clearance from the strut tower to the brake masters reservoir. ( its interfering with my custom strut mounts)

so i took some measurements, red marks in this old pic. from the seam in the center of the ls1 reservoir, to the strut tower directly below.


on my 92, i have 3.5". on my 86 i have 4.25". Both cars have stock boosters, ls1 masters, and have never been hit. Is this just production tolerances? that seems a bit excessive, or something else? Did sheet metal change in 92?

anybody with a ls1 master in their car care to grab a measurement?

any ideas?

only thing i can think of is that i converted the 86 to a manual trans, is this caused by the extra pressure on the firewall?

 

EDIT: I saw the answer to my question after looking closer. Nevermind.

As for your question...Mine is stock, so my measurements wouldn't help you any.

 

4 3/8 on my 87

 

is that with the ls1 master or stock?

thanks!

 

ls1 master

 

GM may have changed something over the years. On a stock '92 Camaro (stock M/C & booster), the Spohn strut mount doesn't clear the M/C. I ended up sectioning the mount to clear.

This is with -0.3* camber and 5* caster.

I haven't seen anyone else mention this. Which points to something that has probably changed over the different model year cars.

RBob.

 

I was going to clearance my strut mount, but that wont really gain me a whole lot, so i may end up shimming the lower bolts of the booster a little to raise the master. I dont know how much that will affect the boosters pushrod stroke/angle, so i may have to tweek some other things as well.

 

i have measurements off another 91 car, and they are also about 3.5", so there is a difference in the booster/firewall that happened at some point over the years.

 

alright, I fixed this issue.

i know this may have possibly cause a geometry issue, i'll find that out when i get the car aligned and drive it, but i shimmed the lower 2 bolts of the booster off the firewall a little over 1/8", and that raised the master 3/4" and now my strut plates clear, and the measurement is the same as on my 86 now.

wonder if this was caused my worn tooling by the time the 91-92's were made or if the boosters are slightly different for some reason? I cant imagine GM would change the firewall over the production run of the 3rd gens.