sometimes backfire through the wastegate at 15psi 8.2krpms

fox30 · Post by **fox30** » Mon Mar 15, 2004 12:45 pm

I have a B18C1 built from the bottom up. 9.5:1 compression / 720 cc inject / high flow fuel (walbro 255) spark plugs gapped at .028 / stock ig/ Hondata S200 / P28 Ecu / T3 T4 Turbo/ boost cut at 16 and rev limit set to 84 with cams and springs that can take me to 9k rpm anyways.
I have an Apexi AVC. I have the Gear Specific Boost Control option set, instead of RPM. 1st is set to 4lbs boost, 2nd set to 8, 3rd set to 12 and fourth set to 15. When I get on the Highway slammin gears at 8200rpm everything is great. When I hit Fourth I get backfiring through my wastegate a little. I'm thinking it might be because of the heat generated from the previous shifting or its 15lbs of boost.
BUT if I stay in fifth at 75MPh and cruise for a few minutes I can downshift to fourth and it will be fine for a few seconds and then start to backfire a little through the wastegate again. I think its heat related. My lambda meter registered 12 but that was 4 months ago before it got run over ; )
I orderd another today. but before I get it I was wondering if any of you think its timing needing a bit more retarding or fuel enriching. I'm leaning toward timing.

CivicVTi · Post by **CivicVTi** » Mon Mar 15, 2004 4:41 pm

I don't know if this is the reason but I would upgrade my ignition for 15psi of boost.

fox30 · Post by **fox30** » Fri Apr 02, 2004 7:33 am