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Old 06-12-2009, 11:19 AM   #1
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Default EPA and Carb Venturi?

This may be a stupid question but can I not achieve the same results as say a 5.5MM Venturi by just setting my Throttle EPA to like 75% open, or will this kill my bottom end? Seems like a much easier way than to try all different inserts
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Old 06-12-2009, 11:25 AM   #2
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It might achieve the same thing, but I don't know how it would mess with your tune, if it would at all.

I might try this next race day, seeing as the LRP .28 has a 9mm opening, and you can't use a venturi.
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Old 06-12-2009, 12:10 PM   #3
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pull off your airfilter and look down the carb....now open the throttle all the way see how the venturi is nice and smooth all the way into the carb. now open carb 75% and look down the carb see the throttle slide? the air would not flow as smoothly into the engine by having the slide their. maybe someone else can explaine this "better"
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Old 06-12-2009, 01:06 PM   #4
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pull off your airfilter and look down the carb....now open the throttle all the way see how the venturi is nice and smooth all the way into the carb. now open carb 75% and look down the carb see the throttle slide? the air would not flow as smoothly into the engine by having the slide their. maybe someone else can explaine this "better"
I understand what you say..better explaination is not needed..but will that make much difference?
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Old 06-12-2009, 01:16 PM   #5
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I tried running my epa low hoping to increase runtime. But all i managed to do is take all the snap out of the motor.It turned a OS speed into a fat, lazy, pig. it did however increase my runtime. went to the 6.5mm venturi and let her eat.

try it, for a tank. See if there any noticable changes.
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Old 06-12-2009, 01:24 PM   #6
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My WS7 is too much power for my skill, too much top speed. I changed out the 8mm venturi for a 7mm, and it was still pretty insane, so I adjusted my EPA to stop at about 80% and it's still wicked fast, but I can control it now.(To a point)
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Old 06-12-2009, 01:39 PM   #7
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Jaz dont do it, just get a restrictior and retune.

i already tried this and my motor kept over heating, i kept tunin it,noting,

i went to fisher asked him. he opened my carb retuned it and problem went away, he said the motors gettin pushed to hard and the carb wasnt opening to allow it, he was explaining it and made my brain hurt so i nodded and said ok lol
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Old 06-12-2009, 02:28 PM   #8
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What you say makes sense Doug (the stuff I can understand anyway)

I just got my +4, so restrictors there are fine, and I have a 7MM for my V-spec but my practice engine (hyper .21 8 port) does not take restrictors, so I was wondering If I could just take out throttle and get the same result
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Old 06-12-2009, 05:07 PM   #9
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the way i see it...these motor's load up enough as is Even with the Perfect tune and its Crispy as toast on bottom if you drive it like a dog (carb 1/3 open trying to make RPM) they load up and do not perform as they should...our little motor's need the blipping to keep them cleared out for those section's were you can open it up on.....I would also say get a selection of venturi's and test and tune from there....but since your inquiring about the hyper...just run it all out and try to cut back on throttle input on the radio....also you could try running a real aggressive negative throttle expo to try and stretch out the power.
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Old 06-12-2009, 05:24 PM   #10
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Thanks Bud
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Old 06-12-2009, 05:31 PM   #11
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What you say makes sense Doug (the stuff I can understand anyway)

I just got my +4, so restrictors there are fine, and I have a 7MM for my V-spec but my practice engine (hyper .21 8 port) does not take restrictors, so I was wondering If I could just take out throttle and get the same result

Must be nice!!!!!!!!!!!!!!! Ponied up some cash I see. No more V-Spec?
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Old 06-12-2009, 05:43 PM   #12
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Jaz240, if you want to cut it back in the radio, fine, but tune it when its opening all the way........then cut it back.

If you are running a restricter then let the slide open all the way.

I think you will find you will have a smoother power band with the restricter vs just limiting the slide opening.

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Old 06-12-2009, 05:44 PM   #13
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Must be nice!!!!!!!!!!!!!!! Ponied up some cash I see. No more V-Spec?
V-spec only has 2 gallons on it..I found a +4 for $264 shipped, no tax..couldn't pass it up
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Old 06-12-2009, 05:46 PM   #14
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DAMN any more at that price ?
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Old 06-12-2009, 05:50 PM   #15
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DAMN any more at that price ?
No they went up again..It was A-main $299 plus $25 off and I had $10 in credits

it kind of sucks how the price of these engines keeps going up and down..I jumped on it while it was there
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