To cut the long story short, for the last run the HPR guys had recommended shutting off the waste gate (or something) on the turbo to increase boost as they thought it was not running more than 4psi originally. This was done for the last 4th gear run, which sounded pretty scary to me
Anyways, many thanks to to Ali aka Charged and Mechanic Farooq we were able to measure the pressure on the turbo using a meter Ali had in his car. After restoring the waste gate to standard settings, we hooked the meter near the boost compensator via a t-joint. Ali read off a max reading of 1.4 kg/cm2 in a small run. Later I hooked another PKR 160/- desi meter to the pipe and got a max reading of around 18psi. Hence on normal settings, the 2LT turbo appears to be currently running around 18-20 psi of max boost. With the waste gate mod, we were probably running 20+psi of boost whereas I understand OEM pressure is around 10-12 psi max.
So in simple english we were over boosting the engine with the turbo, while the pump was overfueling it at least upto 2400rpms where the boost compensator moved to he off-boost setting thankfully cutting back on the extra fuel. We were lucky, not to have fried the engine....