dual TBI
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Joined: Jan 2001
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From: Annandale,NJ
dual TBI
I just saw someguy trying do this and i thought that is is pretty cool. I was just wonder what kind of power could you obtain with the dual TB and are there any real major problems with this set up.
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Joined: Jul 1999
Posts: 686
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From: Brevard Florida
Power potential... 2-2" bore units can support as much power as can be made on a N/A small block.
The complication is that you are running 4-injectors on a computer designed for 2. This cuts the current to the injectors in half (injectors wired in series doubles the resistance in the circuit). Its been said that this can make the injectors a bit lazy and that injector firing can become unreliable with low bat voltages. My observations with the Holley 4bbl on my setup contradicts this. I've started the car with low bat voltage on many occasions. If it will turn over it starts and runs normally.
My car has a cookie cutter chip so the calibration is not perfect but I'd say this EFI setup runs at least as good as a carb as far as driveability goes. I haven't done extensive performance testing but things appear to be in line there as well.
Perhaps I'll eventually do some comparison testing against a 2bbl and perhaps an Edelbrock 600 cfm carb I have laying around to see if there is a performance increase.
------------------
1988 T/A,
9" Ford, 3.50 gears, Auburn posi, 700r4 -w- 2100 converter
350 .060 over with forged 1 pc rms crank, and forged TRW pistons, 9.5:1 cr
Factory GM heads Pocket ported, 2.02/1.60 valves, back cut
Lunati roller 219/227, .479/.480, 112 LSA
Holley 700cfm 4bbl on TBI truck 7747 computer and chip by Howell-EFI
Edelbrock Performer EGR intake, Edelbrock TES and 3" cat
The complication is that you are running 4-injectors on a computer designed for 2. This cuts the current to the injectors in half (injectors wired in series doubles the resistance in the circuit). Its been said that this can make the injectors a bit lazy and that injector firing can become unreliable with low bat voltages. My observations with the Holley 4bbl on my setup contradicts this. I've started the car with low bat voltage on many occasions. If it will turn over it starts and runs normally.
My car has a cookie cutter chip so the calibration is not perfect but I'd say this EFI setup runs at least as good as a carb as far as driveability goes. I haven't done extensive performance testing but things appear to be in line there as well.
Perhaps I'll eventually do some comparison testing against a 2bbl and perhaps an Edelbrock 600 cfm carb I have laying around to see if there is a performance increase.
------------------
1988 T/A,
9" Ford, 3.50 gears, Auburn posi, 700r4 -w- 2100 converter
350 .060 over with forged 1 pc rms crank, and forged TRW pistons, 9.5:1 cr
Factory GM heads Pocket ported, 2.02/1.60 valves, back cut
Lunati roller 219/227, .479/.480, 112 LSA
Holley 700cfm 4bbl on TBI truck 7747 computer and chip by Howell-EFI
Edelbrock Performer EGR intake, Edelbrock TES and 3" cat
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