I have a friend that did the conversion from sr20de to det, but after some months he saw a slow decrease in 1/4 mile times, he went from a 14.2-14.6-14.8-15.1. Someone told him that he was losing compression in his engine, they said " the engine was made for 9.5.1 compression but since he turbo it the compression is leaking from the rings due to the force intro" they advised him to install turbo pistons.

Could the turbo install be causing him to lose compression through the rings? Or is this BS?

Another question should he install stock 8.5.1 DET pistons or should he install 8.2.1 aftermarket pistons?

If he is building the engine from de to det what aftermarket parts should he buy NEW?

The motor could be loosing compression in one of the cylinders due to the fact he added a turbo and possible running too much boost with the wrong fuel management or low octane fuel. There are several factors they can lead up damaging the engine. Turbo is not for "dummies", I say that losely also. A turbo car MUST have the proper engine management. I know of several people with DE motors that have been turboed for several years without any problems. If the motor has lost compression in one or more cylinders, it is just a matter of time before it takes a ****.

If he has to do it all over again, it won't hurt to get a DET motor to be on the safe side.

If he builds a de motor, I would use lower compression pistons and metal headgasket.

Yeah, if the tuning was not done properly and he's running lean he could be losing compression. There's also the possibility that he's running a setup with enough boost to severely increase the wear on the piston rings (this limit is somewhere around 15lbs on a USDM DE, according to what I've seen).

His No.2 piston fried today, But the guys at the garge want to belive it was a poor o2 reading they were geting..

His plans now is to change the pistons to full turbo and get a 6BTM to retard the timeing... ill post more on the project soon.