Okay, it's a small start, but we installed some Deatschwerks 750cc fuel injectors on the STI. These are a new type that use an OEM-style Denso core. I expected that they'd act a lot like stock injectors, but larger, and I wasn't disappointed. I plugged the laptop computer in and drove around the neighborhood with the computer data logging for me. A few adjustments to the "injector scale" constant, and the car was behaving just like it did before, just with lower injector duty cycles. The car is now ready for a bigger turbo.
Sharp-eyed blog readers will notice that previously I said I'd use 850cc injectors. Well...my relatively mild power plans don't really merit that large of a fuel injector, and I'm always preaching to MY customers how they should use only as much fuel injector as their power goals require, and not larger. So I thought I'd practice what I preach.
In general, the larger the fuel injector, the tougher it is to tune low-load and idle fueling. Cars equipped with very large injectors sometimes can't trim the injector flow low enough at idle, so they'll idle very rich, smelling of extra fuel out the tailpipe.
While I'm going back on previous blog promises, you know when I said the exterior of the car was done? Well...maybe not. Besides a front lip, which I wrote about before, I think I'm going to up-size the rear wing. Stay tuned.
The photo above doesn't really have anything to do with today's topic, but I liked it. I took it at sunset back on January 28, 2009.