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August 23, 2005
Car back at Comptech for injector tuning
Yesterday I brought my RSX back to Comptech in Eldorado Hills. I had been running a set of standard (read: inexpensive to buy) Honda injectors that Comptech had modified to flow about 530cc instead of the stock 240cc or so. Comptech is using those as a reliable, inexpensive alternative to expensive third party injectors for their Stage II supercharger upgrade kit. Another advantage of using Honda injectors is that they fit without having to splice wires. Anyway, Comptech had some customers experience Check Engine lights with these injectors and so we wanted to see why. Turns out that the modified injectors had a different fuel delivery curve than stock injectors. Under light load they delivered too little and under full load too much. That's no big deal as in closed loop, the ECU will compensate via short term fuel trim. However, it may be enough to trigger a Check Engine light for a "lean condition" that customers without programmable ECUs or scan tools cannot diagnose or eliminate.
So Comptech is now doing a new baseline for my car on their Dyno Dynamics chassis dynamometer, and will then re-tune the car so that the fuel curves are okay. I will then road-test the new configuration and check it via K-Pro datalogs.
I also plan on replacing my current 3.6-inch pulley with a 3.3-inch pulley later this week. That should increase boost from 6 psi to maybe 8 psi. Comptech also has a 3.1-inch pulley for the new MP62 snout assembly, but I'll switch to that once the aftercooler is installed, to make up for the cooling-induced lowered boost. As for the aftercooler, it is still not finished. The two test cooling cores are still sitting on a bench, without all the other parts required to install them in my car for testing.
After experiencing a total lack of traction at the drag strip last week with my Kumho Excta 712s I am switching to Falken RT-615s which have a much stickier rubber compound. Should be interesting to see how much of a difference it makes. The Kumhos are not bad tires, especially for the money, but they simply do not provide good traction in powerful frontwheel drive vehicles.
Posted by conradb212 at August 23, 2005 2:01 PM