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Old 01-21-2009, 09:03 PM   #1
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Default What is the average increase in run time by dropping from an 8 to 7mm carb insert?

What is the average increase in run time by dropping from an 8 to 7mm carb insert? I know there are lots of variables, but are we talking to expect 20 seconds or 1 minute?
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Old 01-21-2009, 09:10 PM   #2
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What is the average increase in run time by dropping from an 8 to 7mm carb insert? I know there are lots of variables, but are we talking to expect 20 seconds or 1 minute?

depends on a hell of a lot of things, your driving style, track, clutch, pipe, fuel ect ect...
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Old 01-21-2009, 09:15 PM   #3
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all depends on your finger.... i run a 8mm insert with a v-spec and i can get better run time than some guys with a 6mm insert in same motor, pipe, car combo. it's all in the finger.

i'm trying to hit 500..
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Old 01-21-2009, 09:19 PM   #4
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I know there are lots of variables, but are we talking to expect 20 seconds or 1 minute?

I know there are lots of variables. I was looking for stuff like "when I dropped down 1mm on my venturi I gained xx seconds"

Thanks for the respones.
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Old 01-21-2009, 09:25 PM   #5
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I'm afraid there is no way to say for sure. In onroad dropping from a 9 to an 8 usually gets me about 20 seconds. Off road is a bit different. Some motors can get real torquey when dropping the restrictor. This usually means you need to be even smoother with the trigger finger and then run time increases dramatically. Other motors can get a bit soft with a smaller restrictor so you start squeezing the trigger more and run time doesn't change at all.
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Old 01-21-2009, 09:30 PM   #6
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Thanks for the explanation. I guess my hopes for increased run time with this engine are fading.......
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Old 01-21-2009, 09:32 PM   #7
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Thanks for the explanation. I guess my hopes for increased run time with this engine are fading.......
not nessesarally, give it a shot and see what happins.
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Old 01-21-2009, 09:36 PM   #8
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Well, I am just pondering this for one last event out here on the east coast. There is no way for me to test it because the weather here sucks. I am just hitting the race in Feb with my currently 9 gallon old p7 evo 2
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Old 01-21-2009, 09:39 PM   #9
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not nessesarally, give it a shot and see what happins.

+1 try different things, its not all about the venturi, try other pipes as well. all the JP pipes are fuel hogs!

Different gearing, less on/off driving, there are lots of things you can do. Dont give up because you didn't get the answer you wanted, try rephrasing the question to how can I increase my runtimes??

You know the quickest easiest way to do it, is to just add more fuel tubing, and a filter
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Old 01-21-2009, 09:42 PM   #10
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Well, I am just pondering this for one last event out here on the east coast. There is no way for me to test it because the weather here sucks. I am just hitting the race in Feb with my currently 9 gallon old p7 evo 2
Dude! Big race+9 gallon old engine= good luck!
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Old 01-21-2009, 09:43 PM   #11
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Thanks. I am pretty well versed in the other areas, I just never experimented with inserts. If it wasnt for the weather, I would have tried it instead of posting, but thats the price I pay for living in this winter wonder land
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Old 01-21-2009, 09:44 PM   #12
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+1 try different things, its not all about the venturi, try other pipes as well. all the JP pipes are fuel hogs!
true, try the losi re11. it's a os2050 clone. 10 1/2 min is great for a $65.00 pipe.
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Old 01-21-2009, 09:46 PM   #13
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Dude! Big race+9 gallon old engine= good luck!
I'm pushin it I dont feel like breaking in my new motor in this cold. I am bringing my spare p7 with 4 gallons on it. I am sure my motor will be the least of my problems.... its my first big race
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Old 01-21-2009, 09:51 PM   #14
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You know the quickest easiest way to do it, is to just add more fuel tubing, and a filter
Since I am looking for more run time just for this event, I was concerned about tech inspection. I already have a filter.... I am not up on my ROAR rules
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Old 01-21-2009, 09:52 PM   #15
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Yes there are way to many variables but tuning with a restrictor and the correct pipe header combo will give you the best results. I will have to agree its all in the finger, I see a lot of drivers doing every trick in the book to be able and go 10 mins with out a pit stop but just cant do it and then someone with a very easy trigger finger can come along and get 11-12 mins a tank out of the same car.
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