Last time out, it leaned out. The BG400 pump couldn't supply enough fuel pressure. I had bumped the 2 step to 4000, upped the rev limiter to 6800, and upped the wastegates to 16 psi, which should have made about 20 psi manifold pressure, and the BG pump, ( I found out
after the fact), is only good for about 25 psi. When I tested it, it
deadheads at 32 psi. So, 6.5 psi base fuel pressure + 20 psi manifold pressure +
the 6~8 psi differential between hat pressure and manifold pressure means 32.5 to 34.5 psi was demanded by the regulator.
When boost rises above fuel pressure, it will actually push the fuel back toward the fuel cell/tank. I'm pretty sure the rings butted, (I never planned on boost or nitrous when I originally built this motor, so never opened up the ring gaps accordingly), it broke a piston on #3 and cracked that cylinder wall. So right now I'm doing up a .040 over, 2 bolt, cast crank, hyper flat top piston motor I bought months ago, just because it was a really good deal, and I'm porting a set of W/P 2.02/1.60 S/R heads I've had laying around forever, for it. They started out at 165cc intake ports, I raised the roof of the intake ports about .150"~.200", (to match the Bowtie Victor Jr. intake, 1205 gasket), and opened up the pushrod pinch points, d-ported and opened up the exhaust ports to match my turbo headers, and I'm just about ready to check port volumes again, then match the combustion chambers to the cylinder walls. I'll be dialing back the boost a bit to begin with, but with the new Holley Billet Dominator fuel pump, the better matched heads, and lower compression ratio, this motor may wind up being nearly as fast as the other one. Not sure if I'm going stock block with splayed caps, or aftermarket when the good motor goes back together, but it will be planned out to go DEEP into the 8s. Got any info on where to source those dual inlet bowls? I don't need them yet, but may later, when the good motor goes back together.....
Rickracer
ASE Master Auto Technician, 36+ years
'76 Vega Notchback, Twin Turbo 355/TH350 (soon to be a Powerglide w/Brake), 4 link, Koni Coilovers, 3.50 geared 9" w/Spool & Moser Axles, drag only, best all motor 1/8 mile pass to date, 6.90@99mph, 6.57@107.0 on a 60 shot, Best 1/4, 9.66@139.78, still tuning...
Project Album:
http://s68.photobucket.com/albums/i4/Ri ... 20Begins/'93 S10 RCSB, Hyd. Roller Vortec head 363 ci SBC, 2800stall lockup 700R4, LS Front Brakes, Narrowed F*rd Exploder 8.8 disc brake 3.73 posi rear,
8.0s@89 mph, (all motor, haven't sprayed it
yet...)
and tows the Vega to the track too