side draft or down draft?
12-11-12, 02:03 PM
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the only real difference between a side draft and a down draft, especially Weber IDA vs DCOE, is the intake length.
the side draft has a longer manifold, so peak torque, and thus hp will occur at a lower rpm. the exact rpm depends on the ports and stuff.
the side draft has a longer manifold, so peak torque, and thus hp will occur at a lower rpm. the exact rpm depends on the ports and stuff.
12-11-12, 02:17 PM
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For a street driven 6port or 1/2 bridge, a 4 bbl makes a bit better choice. It isolates the large secondary ports at idle/low RPM for a better idle quality and off-idle throttle response, while allowing them to come into play above ~3000-3500 RPM, which is where they start to make more power.
Of course, getting the carb tuned right, no matter which type is used, makes all the difference in the world.
Racing application, and the 2 bbl weber carbs then become more desireable, since there's very little need for the lower RPM driveability concerns.
This is just my thoughts, and I do run a 4 bbl on a 6 port myself.
Of course, getting the carb tuned right, no matter which type is used, makes all the difference in the world.
Racing application, and the 2 bbl weber carbs then become more desireable, since there's very little need for the lower RPM driveability concerns.
This is just my thoughts, and I do run a 4 bbl on a 6 port myself.
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12-12-12, 11:49 AM
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The harder a carbed vehicle is driven, the more apparent the fuel slosh can become, due to the effects it has on the engine's performance. Sadly, there is no "perfect" carb for any/all use.
I use an edelbrock carb on one of my FB's (6p 13B), and to minimize the effects of fuel slosh, I lowered the floats ~1/16" and installed the "off-road" needle/seat kit. I saw no ill effects of fuel slosh at last year's rallycross nationals after performing these minor mods. Not only were there plenty of tight turns, but it was also on rather uneven ground, made even worse due to the blown front struts on the car......
12-12-12, 02:29 PM
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+1.
the IDA's do pretty well, but if you're in a turn @1g and hit a bump, it'll misfire... sometimes the sevensonly FD things run with us, and the exit of turn 15 is bumpy, and they all misfire at the same place...
the IDA's do pretty well, but if you're in a turn @1g and hit a bump, it'll misfire... sometimes the sevensonly FD things run with us, and the exit of turn 15 is bumpy, and they all misfire at the same place...
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