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Old 07-26-2013, 08:23 AM   #31
Mike Taylor 3601
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Default Re: Which is faster carb or Fuel injection?

I don't have the best comparision,but I'll throw it out there.
Dynoed 350 chevrolet w holley fuel injection can't recall name,had 950 throttle body w/injectors above throttle body,that is why I don't like this comparision,because injectors mounted in intake runners are advantage,I feel make EFI worthwhile, because of indvidual cyl. tunability, intake not effecting fuel flow,etc
Also this injection was limited on tuning,if I recall correctly had idle,mid and wot adjustments.
So with this being said I feel like you could call this system a electronic carb.

They dynoed almost identical, w/ the efi or carb,but he never could get efi to run on the track.
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Old 07-26-2013, 09:38 AM   #32
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Default Re: Which is faster carb or Fuel injection?

Every engine is nothing more than an air pump. Some better than others. It does not know or care how fuel is delivered. (In a perfect world)

When AFR and spark timing within the combustion chamber are optimal the engine will make max power. The burn is more important than the method of delivery.
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Old 07-26-2013, 12:56 PM   #33
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Default Re: Which is faster carb or Fuel injection?

Ok Joe next question. Which is faster a real good metric 200 or a real good Pro Trans 350. Who's done that test before?
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Old 07-26-2013, 02:06 PM   #34
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Default Re: Which is faster carb or Fuel injection?

Does anyone know what cfm a 48mmGM throttlebody flows? I would guess maybe 580cfm but this is a wild guess. I cant see how it would be close to a Q-jet's cfm. Just thinking out of the box but I would think the performance advantage of the efi would be a imediate throttle response with improved low rpm torque, with the carb making more total top end power while giving up some on the bottom end. The larger LS-1 or the drag pack efi I think would be superior to a carb in all rpm ranges. Just my $0.02. Don Jackson.
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Old 07-26-2013, 02:46 PM   #35
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Default Re: Which is faster carb or Fuel injection?

well, seeing how a throttle body (port fuel setup) flows ONLY air and not a fuel/air mix, I can see a less cfm TB flow as much air as a Q-jet....just my opinion...


is a carb flowed "wet"?
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Old 07-26-2013, 04:32 PM   #36
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Default Re: Which is faster carb or Fuel injection?

Quote:
Originally Posted by Bench Racer View Post
Does anyone know what cfm a 48mmGM throttlebody flows? I would guess maybe 580cfm but this is a wild guess. I cant see how it would be close to a Q-jet's cfm. Just thinking out of the box but I would think the performance advantage of the efi would be a imediate throttle response with improved low rpm torque, with the carb making more total top end power while giving up some on the bottom end. The larger LS-1 or the drag pack efi I think would be superior to a carb in all rpm ranges. Just my $0.02. Don Jackson.
Don. The smaller throttlebody only flows air not a mixture.
I had a real hard time grasping throttlebody do's and dont's. I might not be right now. But the way I under stand it (simplified) the throttlebody is basicly feeding one cylinder (at max) at a time.
I had a 65mm throttlebody (probably over sized) on my 4 cylinder Neon and a box manifold feeding all 4 cylinders. I switched to 4 Individual Throttlebodies each one directly feeding a cylinder. Each throttlebody is 52mm. It took a long time to sink into my brain that this setup wasn't way to big. But it finally sunk in that the motor was only feeding one cylinder at a time (100%) and one throttlebody over each hole needed to be big enough to feed that cylinder.
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Old 07-26-2013, 07:31 PM   #37
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Default Re: Which is faster carb or Fuel injection?

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Originally Posted by B Parker View Post
Ok Joe next question. Which is faster a real good metric 200 or a real good Pro Trans 350. Who's done that test before?
I'll Bite:
Would think the ET may be about the same but the Pro Trans will live behind engines where an M200 will not.
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Old 07-26-2013, 07:41 PM   #38
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Default Re: Which is faster carb or Fuel injection?

Quote:
Originally Posted by Bench Racer View Post
Does anyone know what cfm a 48mmGM throttlebody flows? I would guess maybe 580cfm but this is a wild guess. I cant see how it would be close to a Q-jet's cfm. Just thinking out of the box but I would think the performance advantage of the efi would be a imediate throttle response with improved low rpm torque, with the carb making more total top end power while giving up some on the bottom end. The larger LS-1 or the drag pack efi I think would be superior to a carb in all rpm ranges. Just my $0.02. Don Jackson.

If the 48mm throttle body was too small an LT-1 engine would likely run weak when built as a SuperStock engine....The throttle body would limit performance.....and thats what I thought when I raced one in Stock...

From the numbers I have seen those engines run in SS/IA or SS/JA or in a GT car......they run very well.....so I think the 48 mm throttle body's ability to move air can not be directly compared to a carb like a Q-jet that flows air and fuel....
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Old 07-26-2013, 08:29 PM   #39
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Default Re: Which is faster carb or Fuel injection?

LT1 throttle body 783cfm at 28"
If I remember right it was 660 cfm at 20"
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Old 07-27-2013, 02:55 AM   #40
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Default Re: Which is faster carb or Fuel injection?

If memory is right Holley is flowed dry @ 17''
Q-jet can't remember but some reason dry @ 12'' is coming to mind?
Have info on Q jet but have to dig out,but not tonight, well this morning.
I always heard Carter's ratings were wet flow #'s ?

Going back there was huge difference in tunnel ram w/660's vs Crower injection.
My Dad has Crower he bought new around 1970 back then cost $ 375.00 is what he always told me,he sent to Kinsler and had redone in late 80's cost about $3000.00

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