Had a race with a highly modded Sklyline GTS with a TD06, uprated cams, bigger headgasket, etc... and as many mods you can do without going to bigger pistons etc... running approx 500 bhp @ 1.4 bar proved on dyno... I havent had my car dynoed after the new map and was running just over 1 bar ... we started from standstill... first gear he got a good launch and was infront about half a car, as for me my backend was all over the place shifted into second, again tires were spinning and started to slide outwards so let go of throttle, the car straightened up and I nailed the throttle.... this time the car just jumped forward and I was level with him, shifted into third and we were still level... as I started getting higher into third I was creeping ahead, into fourth and I really pulled on him and was just about a car ahead, I kept slowly creeping ahead but had to let off before 5th as the road was coming to an end... lol...

 

a bigger head gasket?

 

A thicker head gasket is a band-aid that is used to lower the compression of piston motors. This was a common addition to a turbo car 5~10 years ago when fully tuneable ECU's were not readily available or were not cost effective to purchase. Lower compression is another band-aid that is used by poor tuners!!

Nowadays, there is not a need to use this band-aid because aftermarket ECU's and internals are affordable.

 

good answer.