Carb to EFI hp gain?

[Revved]

WOT total HP on an identical engine with a perfectly tuned carb will be essentially the same as it would be on EFI. You have to remember that tuning for WOT or your "BIG NUMBER" is the easiest thing to tune for. How many cars have you seen that run great at WOT but are horrible to drive around town? Greg mentioned half the story- that EFI is going to give you better all around drivability but taking that point further is that EFI is going to give you better fuel control throughout the range most likely broadening your USABLE horsepower and torque. By properly controlling fuel flow throughout the entire range you are also gaining fuel economy, managing proper engine temperature,cutting down on unnecessary engine wear due to over or under fueling, and saving you money.

Stating it simply carburation has three main modes. Idle, part throttle, wide open. Everything in between is a fudge of those three. When we tune carbureted vehicles we use a FAST dual wide band 02 meter and can dial them in pretty damn well and get huge drivability gains over a vehicle "tuned by ear." Typically it takes us about 8 hours on a blown big block carb application of driving, tear down, drilling, jetting, driving, tear down, adjusting timing curves, etc.. again and again until what we are seeing coming out of the engine is "dialed in." When done.. the drivability is huge, torque curve is huge... I'm convinced that if you have to run a carb using a dual 02 meter is the best way to accurately tune it. (yes- EGTs as well but how many street cars are driving around with a bung in each of their primaries!)

I can do the same thing with a sequential EFI blown big block in about 2-4 hours tapping away on a laptop. Is there more time getting to that point...yes. I'm OCD... I tailor my wiring harnesses to fit the vehicle... even if they come prefab..I cut them apart and tailor them. Typically I put about 25 hours into wiring an EFI system...I build electronics panels to mount all of the fuses and relays, I put connectors anywhere the harness touches another harness. But when I'm done it looks like it was born there.

I would disagree on carb atomizing fuel better... With a port injection setup you have 8 high pressure pin point applications of fuel instead of 4 big holes sucking low pressure fuel through four straws. EFI gives accuracy and efficiency again and is less succeptable to ambient temp changes (ie. fuel dribbling down the intake walls from your carb)

my .02

[Ron Sutton]

Originally Posted by Revved

WOT total HP on an identical engine with a perfectly tuned carb will be essentially the same as it would be on EFI. You have to remember that tuning for WOT or your "BIG NUMBER" is the easiest thing to tune for. How many cars have you seen that run great at WOT but are horrible to drive around town? Greg mentioned half the story- that EFI is going to give you better all around drivability but taking that point further is that EFI is going to give you better fuel control throughout the range most likely broadening your USABLE horsepower and torque. By properly controlling fuel flow throughout the entire range you are also gaining fuel economy, managing proper engine temperature,cutting down on unnecessary engine wear due to over or under fueling, and saving you money.

Stating it simply carburation has three main modes. Idle, part throttle, wide open. Everything in between is a fudge of those three. When we tune carbureted vehicles we use a FAST dual wide band 02 meter and can dial them in pretty damn well and get huge drivability gains over a vehicle "tuned by ear." Typically it takes us about 8 hours on a blown big block carb application of driving, tear down, drilling, jetting, driving, tear down, adjusting timing curves, etc.. again and again until what we are seeing coming out of the engine is "dialed in." When done.. the drivability is huge, torque curve is huge... I'm convinced that if you have to run a carb using a dual 02 meter is the best way to accurately tune it. (yes- EGTs as well but how many street cars are driving around with a bung in each of their primaries!)

I can do the same thing with a sequential EFI blown big block in about 2-4 hours tapping away on a laptop. Is there more time getting to that point...yes. I'm OCD... I tailor my wiring harnesses to fit the vehicle... even if they come prefab..I cut them apart and tailor them. Typically I put about 25 hours into wiring an EFI system...I build electronics panels to mount all of the fuses and relays, I put connectors anywhere the harness touches another harness. But when I'm done it looks like it was born there.

I would disagree on carb atomizing fuel better... With a port injection setup you have 8 high pressure pin point applications of fuel instead of 4 big holes sucking low pressure fuel through four straws. EFI gives accuracy and efficiency again and is less succeptable to ambient temp changes (ie. fuel dribbling down the intake walls from your carb)

my .02

Agreed x2