Hey all, I posted this as a new thread so as not to bury it in the 122 posts to the 'big brakes GD post -although I posted in there as well.

As expected (after all, it's kit #1)I ran into some problems yesterday: the aluminum hat supplied with the kit is not the right depth. Thank God I had not disconnected the brake fluid lines, otherwise it would have been a long evening, this was all during what I call 'dry-fititng'.

The hat I received has a .810 offset, with that offset and the 1.25" thick rotors, there is interference between the rotor and the lower A arm -also called the transverse link- right at its very end, where the ball joint is. If you ordered that combination as well, and has already been shipped with the .810 hat, you will have problems as well.

All this was troubleshot with the Precision Brakes chief engineer on the phone with me, I called them as soon as I saw the problem. As it turns out, they fit the kit on a bare spindle...of course, a bare spindle does not have the lower A-arm attached to it so....they had no way of finding that interference until the first real 'customer car' install -which was me.

The solution is new hat with 3mm less offset. Along with new aluminum spacers (to keep the caliper centered over the rotor) this will still require about 2mm to be ground off the tip of the lower A-arm as any less 'hat offset' would put the caliper at risk of hitting the wheel. As it is, with the new hat I expect I will have only about 3mm clearance between the caliper and the wheel so...it's a tight fit -again, caused by the 1.25" rotor and the large Superlite calipers.

If you have not yet taken delivery of the kit and want the large Superlite calipers , you might want to consider dropping the rotor width to the next smallest size (22mm, or .81 inches) instead of my huge 1.25" width rotor....this might eliminate the problem of interference, allow the use of the .810 hat and thereby expand the clearance between the wheel and the caliper -something to consider if you want to change wheels in the future as this will give u some more wheel options before u run into interference problems

The Precision Brakes guys were great....very apologetic and like I said, spent nearly 45 minutes with me on the phone as I dry fitted, measured, etc. They'll be cutting the new hats Monday & will ship all the bits and pieces Tuesday so the installation will be next week, I hope.

Any questions, just post here of the Gen5 forum where I'm posting this as well, I'll get to them tonight

 

yup.. this problem seems very common on 4th and 5th gens.. fortunately the 3rd gens don't have the same clearance issues. When I installed the Skyline rotors on mine (11.8 x 1.25"), I talked extensively to Loren about it, who pioneered the conversion on his 96SE... He ran into the same clearance issues as you have, and for him it was as simple as trimming a small amount off. mine bolted right up without problem. there's still not much clearance, but it does clear nonetheless.

from what it sounds like on yours, there's even less room than what he had, as he said he only had to trim a small amount off of his to get it to fit, so if you're having to change rotor hats and STILL trim it, there's some pretty big clearance issues there.

Anyway, it's good to see the resolved it so quickly. That's what I'd expect to see, but often it doesn't happen like that (ahem, $tealin).

 

and if I would have ordered the smaller Dynalite calipers would have been easily solved with the next smallest Wilwood hat which measures .625 instead of .810

But, with my Superlite calipers, I only had 6mm clearance between the caliper and the spokes on the wheels so if we went the way of 'hat only' it would have left us only 1mm clearance between the caliper and the spokes on the wheels (SSR Integrals) and I did not want to chance it that close.

The 3mm lower hat will still give me about 3mm clearance to the wheel and will create at most 1mm of actual interference with the A-arm; shave 2mms there and I'm home free all around.

The Precision Brakes guys are great -and this is a helluva lot cheaper & better than the Stealin AP kit...

 

yup.. sounds good.. I went with the Dynalites on my first kit (see pics in my profile for an up close shot of one)..
I had less than 1mm clearance on some parts, and the only problem I had was in winter when I'd pick up sand and gunk.. there's scratch marks on the top of the calipers where they got smashed in there...