by Remps » Fri Oct 09, 2015 12:49 pm
I think most IC fuel screws bottom out before getting runaway. I don't think re-indexing is required unless you have a longer unclipped 4200 gov spring. Some re-index to get more throttle travel, I just chop the high idle stop off the linkage. It is possible to have too much throttle travel though, and actually lose power. As for your fuel screw, turn it in already!
Always beware of runaway, and if you start to feel resistance turning in the screw, stop, and turn it back out a hair. If it were mine, I'd keep both turbos under 35 psi. If full fuel brought it over 70 psi total, I'd add a little more timing to try and bring it back to 70ish. Remember, max volume from the hx35 is around 30 psi, at 52-54ish lbs/min, down to 40-42 lbs/min at 43-44 psi, and nearly off the map on the compressor, with high drive pressures. 35-38 psi is just fine for a single hx35 though, and it'd produce more power than at 30 psi. With twins? MAYBE your secondary would be better off at 30 psi, I really couldn't say. Only one way to find out and that's to tune it and run it. Never seen a map for a 3b, but it's gotta be good for at least 35 psi of good air, maybe 40.
'90 D250 R/C,727,IC,6x.009's,1/8" bump,fuel psi,straight pipe w/5" stack.
'90 W250 R/C,47rh,K@N,HX35,1/8" bump,2nd gen IC,boost,egt,trans temp.3.07's.
'96 2500 S/C L/B,2wd,NV5600,3.54 L/S,cai,egt,pacbrake,mbrp exhaust,10 plate.
Bring back the Bank of Canada, PRE- 1974.