Gin319:
thinmint:
I want to use an arduino, either a mega or an UNO R3, to make both signals at the same time. I know a mechanical relay would not be capable of running the necessary frequencies (0 - 100khz-ish), so how would I do this? Transistors?Better use MOSFETs, they're more efficient in switching, faster, too. Provides more power if you need it, aswell.
Good luck on the project! Quite ambitious, but FUN! Post some pictures!
Would a mosfet like this work ? RadioShack.com Official Site - America's Technology Store
What would I do with each of the pins? I need a fritzing diagram!
As for the project, take a look here 
Wait that isn't an F20c - S2KI Honda S2000 Forums