998 turbo mod

[Turboflash]

Recently, I completed a turbo modification that consisted of changing out both compressor and turbine wheels with the goal of improving air flow/efficiency in a stock system.
My attitude going in to this project was this is an experiment on an occasional use toy. If it works, then great and I'll be pleased. If it doesn't, then I'll change it back to stock.
My qualification on whether or not it was successful was to evaluate pre and post track dyno HP. If dyno HP was higher after change (with no other changes) then turbo must be performing better. If not, then change was not beneficial.
Summary:
1. There is a gain. Stock wheels are not optimal.
2. Without divulging the exact details, the engine performs better with mod turbo.
3. Without divulging the exact HP numbers; let me just say I had to increase fuel pressure about 5-6 lbs to keep same AFR as before change (in cooler 53 degF air). Keep in mind, the air temp and humidity was much cooler and dryer on test before change. So, having to increase fuel pressure that much with much warmer and humid air in dyno after change only means there was more air going through engine which equals more HP. The engine is an air pump. More air volume = more HP (everything else being equal). (P.S. I know the track HP change).
The cost of change, to me, was conservative. Less than $1000.
Was it worth it? Depends on your perspective and expectations.
I

 

[guardrail]

Are you keeping the details secret because you plan on selling it as a kit at a later date?

 

[Turboflash]

Absolutely not.