1996 Camry 5S-FE Turbo Install

Conclusion...

OK, here's some final notes on the turbo project:

#1 rule: Never do more than necessary to support the turbo!

When we realized compression pressure was being lost in one of the cylinders, it was decided that the engine needed to be pulled and rebuilt to correct the problem. At that same time, we figured forged pistons would be a great addition for the turbo...then we also figured let's drop the compression ratio to allow a higher boost level.

Let me first say that pulling the engine was needed to correct the problem. But changing more than necessary was a bad idea and here's why. Changing the pistons to forged caused the pistons to grow a lot more than cast as they heat up in the bore. If the machinist does not fully understand what that means, you will have serious problems later on. Changing the air flow characteristics brought about the need for a better fuel management system. A higher boost level demanded a better boost controller, an intercooler and ignition timing modifiers be installed as this raises the intake air temperature, which leads to detonation.

The turbo has been on the vehicle now for about 1 year (11,000 miles). Ever since installing the forged pistons, it has always had somewhat of a knock. We kind of assumed it was the piston knocking around in the bore. Before starting the installation of a newly built performance cylinder head, I did a compression test and found cylinders 1, 3 & 4 at 190 - 200 psi. Cylinder 2 was 120 psi. I pulled the piston and found the skirt had been ruined. This was the problem I eluded to ealier. The previous machinist didn't understand how much more the piston would expand and the skirts landed up hitting the cylinder wall pretty badly. After pulling the rest of the pistons, they all had signs of skirt damage...some worse than others.

I was planning to install the following when I installed the cylinder head: