Does anyone successfully autocross their GS with LS calliper conversion? I recently installed the LS 4 piston brake system, but not even in to the second lap, a calliper sprang a leak. They were freshly rebuilt by what supposed to be a reputable company . I autocrossed on my stock GS callipers without ant issues. What gives? Are LS callipers not designed for high heat and constant load, and only good for 4 seconds in case of an extreme emergency?

 

I replied in your other thread as well.

Thinking how Toyota is, I'm sure that they tested the car and found the caliper reasonable for an extreme condition which a daily commuter might encounter, not just one or two hard stops.

In general, I would say they may not take the constant loading a tracked car will get. Have another go and if a seal blows out, a more appropriate caliper will be needed. Or the calipers you acquired have some problem, as in rebuilt improperly by the prior owner/ruined so it may no longer be OEM spec'd for the seals.

 

My guess is that something happened during the rebuilding process. Whether it is due to cheap seals or improper installation, I don't know, but the LS400 calipers should withstand autocrossing. OEM calipers are built with high safety factors. I've stomped on my brakes multiple times within a very short period of time and mine has not sprung a leak.