S4 4.2 vs. RS4 4.2?

[Penman]

I've tried to do a little reading around on here and on the Audi website to find the distinct differences in the two 4.2L engines. The S4 max output is 340hp @ 7,000 and the RS4 max output is 420hp @ 7,800. I haven't been able to find very much so far specifically comparing the two engines. Does someone know another website where I could read about the two, or perhaps someone in here can break down the differences? Is it possible to tune the S4's engine to 420hp with chip, exhaust, and other supporting mods? I'm actually in the market for an S5 next year depending on my finances. However, if the S5 is still out of reach, I'm definitely looking into a B7 S4, hence the questions on the engine. Thanks in advance for the input and direction.

[dreamcar=rs4]

check out the thread called "Project RS4"...its a few threads down

[Penman]

You know, I actually glanced at that post last night and stopped reading after the first 10 posts were bashing the poor guy. Who knew? Thanks for the suggestion. I read down a bit further and found the breakdown by Liam. Too bad I'm a noob and understood about 1% of it, ha! In any case, it gives me somewhere to start. Thanks again.