bad acceleration but good high speed???

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nitro_desert

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hey guys i gots a hyper 8 with a mach.28 engine and a tuned pipe ummm I've been getting really good high speed runs but my acceleration is kinda bad... my friends buggies all have reaal good acceleration! they could do donuts in the street! but i always pass them when going in a straight line.... so my car has a higher top speed..... my conclusion is my gear/timing is big so i can reach higher top speeds is that true?? plus i never used diff oil.. :mex:
 
Sounds to me like you've got it geared way too high, try a clutch bell with a smaller gear on and/or a larger pinion gear. I don't run Nitro so as far as tuning goes I dunno from that angle, but generally speaking if your acceleration sucks but your speed is great it's a gearing issue.
 
First thing to look at would be your Low Speed Needle setting. Do this... after a high speed full throttle pass bring the car back and pinch the fuel line just off of the carb inlet. As soon as you pinch starting counting one one thousand, two one thousand... If it takes more than 5 seconds or so to stall the engine then your LSN is too rich. make small 1/16 turn adjustments (clockwise to lean it out) until the car stalls 3-5 seconds after you pinch. Just make sure you always do it after a high speed pass so you are gauging against constant conditions.
 
btw i tryed that and burnt me fingers lol

You burned your fingers pinching the fuel tubing?

Do what Lessen suggested. As long as you pinch the tubing hard, it doesn't matter where you do it. You only have the break the 'siphon' effect. Once you get fuel to the engine, it will act as a siphon and continue to pull it, by pinching the tubing you are cutting off the siphon effect. The motor can't pull additional fuel, it will only burn what it already has in it. Thus, the 3-5 second rule will tell you how rich/lean your LSN is.
 
my lsn is tuned well..the car wont pull off when i squeeze it and will not just die off..it takes about 6 seconds to turn off..do all hyper 8's have this problem? and is there a way to adjust gearing? or do i have to get a new gear? plus i can't spend that much on this car cause I'm buying a revo 3.3 so I'm kinda saving up
 
Well that one second difference can have a dramatic effect on your low end power. I would try to get that time down to 4 or 5 seconds. You should see a major improvement on low speed power. Also, you can switch out your clutch bell to one with less teeth. A CB with less teeth will give you more overall torque and acceleration but it will also drop your top speed.
 
You're WAY too rich on the LSN. Start to lean it a little at a time, and soon you'll see a major change in its' take off. Keep an eye on your temps. A LSN that's too lean will cause an overheat.
 
You're WAY too rich on the LSN. Start to lean it a little at a time, and soon you'll see a major change in its' take off. Keep an eye on your temps. A LSN that's too lean will cause an overheat.

Agreed, Now does the engine sound boggy when taking off then seem to really come to life, if so you are to rich on LSN as previously stated. Now if it seems the engine is snappy off the line then its your gearing count the teeth on the clutch bell and Spur gear and let us know what you got. If its boggy try this Make small adjustments leaning the LSN and make a few passes then check your acceleration of the line. If it still seems boggy lean it a bit more keep doing this til its snappy off the line. And keep a eye on your temps.
 
i went to the hobby store yesterday...i had some extra cash on me so i got a BIG filter, new tires and smaller gears..i also put on new throttle servo for better acceleration...the parts are being fitted on right now..i tell u guys what changed when its finished!

and hey do bigger filters give more power? its a cotton filter btw
 
Ah, of course. You should really run a Motor Saver air filter. It's got a dry outer filter and an oiled inner filter. It's the best there is to protect the engine from road and track dust.
 
Have you checked your center diff. Maybe thicker fluid if it seems to be slipping a lot off the line.
 
I'm putting thick diff fluid too... and hey smokedogg do bigger airfilters give you more power? will the engine run lean?
 
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