New Custom Atom Exhaust System

**Kim** · June 17, 2011, 07:52 AM

Originally Posted by silver

hopefully those aren't your times................otherwise I'd have to make fun of your slow time

Didn't I mention that all of those times were with the parking brake on?

No, actually you are correct; those are not our times - or our tests. I should have noted that these times were for a non-Atom sports car used in a series of tests to gauge performance by way of exhaust modifications.

**Karl** · June 17, 2011, 09:56 AM

Graphs without their axes set at 0? Exaggerate much?

**DarthChicken** · June 17, 2011, 10:23 AM

I love graphs like that.. OMG, its 50% better! Oh.. wait...

**McFred** · July 1, 2011, 08:24 PM

Originally Posted by Kim

Interestingly, Mark Swain with TMI explained to me that the Honda K20R engine has been tuned by Ariel such that it needs virtually no back pressure from the exhaust system to run perfectly - so there are only benefits to enhancing the exhaust flow.

IME with various Honda drivetrains "backpressure" is a negative in every aspect. There are lots of people in K-Series drag racing circles that swear by a 3" exhaust system. Any backpressure or restriction is a limitation every time.

I like the fact you're trying differnet things but a before/after dyno comparison with optimised ECU tunes for each header/exhaust combo would prove the efficacy of each system and would be a better comparison than a similar system on a NASCAR engine with supporting graphs on a mile-long scale. Same day, same dyno numbers are harder to dispute with a proper tuner on hand.

I have no experience with the X-pipe design myself but it's similar to Calscot's Hytec design for his Honda/Rotrex Atom 475 as observed from the last two AtomFests. He seems to make power in spades.