Intake questions for 12a bp...
01-01-13, 10:43 AM
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Intake questions for 12a bp...
I have a side draft manifold i was going to have drilled for injector bungs and have a plenum fabbed up to bolt to it. My question is will 2 injectors work for a bridge.. when making the plenum what size/ how much volume should it hold? and what would be a good throttle body to use? i was thinking of a single mustang throttle body or a LSx truck throttle body? Will it allow enough flow for a NA engine? Any insight would be greatly appreciated.
01-01-13, 12:31 PM
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two injectors can work just fine, in fact it makes ECU tuning a little simpler.
2x720cc injectors should work, 2x1000cc injectors would also be good. the smaller injectors obviously will support slightly less power, so duty cycle will be higher, and if you max them out you might need more fuel pressure
for the throttle, since a 48IDA Weber works, you should be looking for a throttle body that is 2x48-55mm. since there is a lot of overlap between the intake and exhaust a plenum usually isn't a great idea, you want to separate the two rotors from each other. although if you're drag racing or something a plenum will work.
2x720cc injectors should work, 2x1000cc injectors would also be good. the smaller injectors obviously will support slightly less power, so duty cycle will be higher, and if you max them out you might need more fuel pressure
for the throttle, since a 48IDA Weber works, you should be looking for a throttle body that is 2x48-55mm. since there is a lot of overlap between the intake and exhaust a plenum usually isn't a great idea, you want to separate the two rotors from each other. although if you're drag racing or something a plenum will work.
01-01-13, 01:22 PM
#3
I have a custom BBK throttle body made by 61620b can't remember the size worked very well on my bris former rx2 running T2 13-b streetport semi pp.
if you go with carb, Ida or Holley are the choices. be sure to get a strong fuel pump with a bypass regulator. a Holley 1_4 regulator will work by converting to by-pass type as dead head suck. return line must haves restrictor
if you go with carb, Ida or Holley are the choices. be sure to get a strong fuel pump with a bypass regulator. a Holley 1_4 regulator will work by converting to by-pass type as dead head suck. return line must haves restrictor
01-01-13, 02:14 PM
#4
Old [Sch|F]ool
two injectors can work just fine, in fact it makes ECU tuning a little simpler.
2x720cc injectors should work, 2x1000cc injectors would also be good. the smaller injectors obviously will support slightly less power, so duty cycle will be higher, and if you max them out you might need more fuel pressure
for the throttle, since a 48IDA Weber works, you should be looking for a throttle body that is 2x48-55mm. since there is a lot of overlap between the intake and exhaust a plenum usually isn't a great idea, you want to separate the two rotors from each other. although if you're drag racing or something a plenum will work.
2x720cc injectors should work, 2x1000cc injectors would also be good. the smaller injectors obviously will support slightly less power, so duty cycle will be higher, and if you max them out you might need more fuel pressure
for the throttle, since a 48IDA Weber works, you should be looking for a throttle body that is 2x48-55mm. since there is a lot of overlap between the intake and exhaust a plenum usually isn't a great idea, you want to separate the two rotors from each other. although if you're drag racing or something a plenum will work.
I can't find sufficient words to describe how much better the drivability is with the independent throttles (with all four bridged) vs. a plenum manifold (with primaries not bridged). It's like the throttle plates are acting as plugs in the intake column to prevent reversion, whereas with a plenum, the overlap period happens right when the other rotor is seeing its highest vacuum so the manifold is acting like a pro-reversion device.
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