Power AdderGetting a Supercharger or Turbocharger? Thinking about using Nitrous? All forced induction and N2O topics discussed here.
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Blow thru TBI, figured someone here wants to see it
I decided that the BT carb thing isn't for me. I'm not saying it doesn't work, I'm just more familiar with EFI.
I'll be running the Holley C950 with WB02 correction. Not the best IMO but it was FREE so beat it! lol
I ran an Accel 4bbl TBI on my blower motor and loved it. But this time I wanted something more standard as the Accel TBI has a bunch of weird stuff on it. I couldn't find a 4bbl TBI that uses port injectors under $700 so I decided to make my own using my Demon carb throttle plate as a base.
here we go...
__________________ '96 Bronco: 302, 5-spd, 4wd, 32" tires '84 Impala: 350 with Dart heads 200cc IR 72cc CC, Ferrea valves, 9.3:1 compression zero clearanced, Comp 276HR cam, 1.52 Pro Mag roller rockers, ported Torker II + 1" spacer, DIY 4bbl TBI, 95#/hr injectors, single GT45 turbo, boxed control arms holding a GM 8.5" G80 with 4.10's
Re: Blow thru TBI, figured someone here wants to see it
Looks like all of us old V8 astro guys are going to turbo third gens lol.. Nice work on the machining and you can't beat free for the other hardware. I'm sure it's around here somewhere if I look, but what are the specs on your engine and turbo? That's a huge wastegate!
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1987 Iroc, 5.7 TPI with Megasquirt II 3.0, Precision Turbo PT6766, 14 psi, forged SRP Pistons, ZZ3 bottom end, L98 Aluminum heads, Comp Cams 224/224, Cold AC! 7.71 at 92.5 mph on radials!
Re: Blow thru TBI, figured someone here wants to see it
Steve! lolz...good to see you around.
The engine is a ZZ4 shortblock. I had it zero clearanced for proper quench. Sportsman II heads (ported), Ferrea valves. Comp 276HR cam, 1.7 ratio ProMagnum roller rockers. Torker II intake with a 1" spacer (probably a little too small).
The turbo is a T70. I forgot the nitty gritty specs but the exd is .82. Divided T3 flange. All this was sort of an experiment. I fab'd all this stuff in my car pad with a chop saw, MIG welder and grinders. The chinese BOV is a piece of sht. I really need to get one that doesn't leak vacuum. But it got me going.
I never really figured out the voodoo science of blow thru carb tuning. I knew I was fighting and uphill battle with a Demon carb and downleg boosters. It was idle, or full throttle. Anywhere in between would be 17-18:1 AFR no matter how much dorkin with carb.
Re: Blow thru TBI, figured someone here wants to see it
Nah, no more Astro's right now. I sold my last '91 Stro to the same guy who bought my '89 305 TPI van. The last van I converted to real 4x4 with an NP231 transfer case. I miss that '89 Safari with the 305 TPI. That thing ran GREAT. I think he still has them both...
Saabster, you pose a good question. The answer is "I dunno!". I didn't want to take it in the brown buying a MPFI manifold for $300...a $70 single plane carb intake with injector bungs in it. I'm not the best aluminum welder and didn't want to weld bungs in the intake I got for fear of turning the whole thing into a red hot pile of goo. If the blow thru TBI doesn't work then we'll spin up some plugs for the throttle body injector bungs and I'll just have to buy the MPFI intake and fuel rails.
Re: Blow thru TBI, figured someone here wants to see it
Quote:
Originally Posted by V8Astro Captain
Saabster, you pose a good question. The answer is "I dunno!". I didn't want to take it in the brown buying a MPFI manifold for $300...a $70 single plane carb intake with injector bungs in it. I'm not the best aluminum welder and didn't want to weld bungs in the intake I got for fear of turning the whole thing into a red hot pile of goo. If the blow thru TBI doesn't work then we'll spin up some plugs for the throttle body injector bungs and I'll just have to buy the MPFI intake and fuel rails.
I wish you luck. I've thought about doing something just like this for a roots supercharger. All the cheap roots setups are carb only and the biggest TBI can only support maybe 400 hp NA, definitely not that much running rich blown A/F ratios. I've also thought of taking a BBC TBI throttle and a square carb adapter plate and just drilling so holes in it for fuel injectors.
