6-1 header leaning out my stock EFI
Switched out to an MSA coated 6-1 header last year or so from the MSA 3-2 as I liked the sound and the look of it. Then buyers remorse started kicking in. By my butt dyno I am making less torque and have to rev higher than the 3-2 did for my normal driving. I put new plugs in and its definitely leaner that the 3-2 by the readings. The one that gets me is plug 2 looks a lot like 6 as it is common for 6 to be lean on a 280 with oem EFI. 6 looked like it was brand new so it is a little lean for my taste. The coated header no longer shines its definitely burned off some of the coating.
1. Put the other header back on and drive it. Cheap and relatively easy fix.
2. 280ZXT injectors, Cheap and relatively easy fix have to retune what I can.
3. Gut fuel system and install carbs.Or Megasquirt with bigger injectors. I have round tops ready to rebuild with 260z intake manifold. Cheapest and easiest on this choice but more expensive than the header. Megasquirt has a higher entry price plus some dyno time.
I decided to go to an older set of plugs NGK BPR5EY, I took a chance on these BPR5EIX-11 IX Iridium Plugs. Drove 15 miles and there is a difference in copper and iridium, much more torque. Now to read them after a few tanks of 93.
1975 280Z F54/N47 MSA 6-1 Header 2.5 Exhaust
Last edited by bificus; 11-02-2019 at 05:42 PM.
Reason: Went to a older copper plug.