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Old 09-22-2009, 03:32 AM   #1
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Default How far should your carb open (slide carb)

Hi Guys,

Just little question as I've really thought about it.

When setting your end points & you have selcted what venturi you are using in the carb.
My questions is should you set the slide carb just to open as far as the venturi hole is ie 6mm/7mm etc etc.

You set it to where the slider is fully open?
If you do set it as the above does this just defite the object?

Love to hear some opions from you guys
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Old 09-22-2009, 04:11 AM   #2
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Great question! This has been an ongoing debate for a while now and I see it on about every forum I visit. I personally just always opened it full pull then backed off a mm or so. But I did see where drake said in his nova tuning school video that there was no need to open it up past the venturi opening. Others are probably gonna argue about flow and what have ya but I figure these guys(drake) do this for a living I'm sure they have tested and tuned alot more the average weekend warrior. Jmo
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Old 09-22-2009, 04:46 AM   #3
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You set it till the barrel just disappears behind the venturi. You should still be able to see it. But it should be flush with the venturi as long as you have plenty of slide travel left over for chassis flex.

Setting EPA more than that only creates a dead band at the top of your throttle. There is no point in opening the carb more than the venturi. The last bit of trigger movement will do nothing.
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Old 09-22-2009, 08:33 AM   #4
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I think opening more than the venturi defeats the purpose of the venturi in the first place.
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Old 09-22-2009, 08:42 AM   #5
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opening it anymore than to expose the venturi is pointless IMO. Actually if its open further than that, a pocket of air couuulld cause some air flow disturbance which may effect performance? Maybe an airflow engineer can chime in on that theory..
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Old 09-23-2009, 05:56 PM   #6
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I'm not an expert, but when you open the carb, it's letting in both air and fuel. So, if the air is being restricted at 6mm, for instance, and you open the carb beyond the restricter, then wouldn't you be adding more fuel and running a bit rich (at the top end)? Maybe that's something you want? Maybe not?
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Old 09-23-2009, 07:20 PM   #7
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Drake says it all.

http://www.youtube.com/watch?v=UsGCOTyNMAw


6 min mark.
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Old 09-23-2009, 08:14 PM   #8
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Quote:
Originally Posted by Integra View Post
Drake says it all.

http://www.youtube.com/watch?v=UsGCOTyNMAw


6 min mark.
That is quite a good video...Thanks Integra.
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Old 09-23-2009, 09:23 PM   #9
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Quote:
Originally Posted by Funking-Awesome View Post
That is quite a good video...Thanks Integra.
+1 that one gets bookmarked
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