NOVAROSSI Engine thread....
#7355
I have yet to run my Virtus engine in my Truggy...that said, I have raced with others who have raced the engine in a truggy during the 2014 season. The baseline pipe combo most team drivers use is the 9901ss/41021. This is where I plan to start when the spring racing season begins here in the NE.
#7356
Tech Rookie
Joined: Aug 2013
Posts: 17
I've been looking for a video or article that can help me understand my new Nova 3 needle carb. Most say leave it alone and that's it, but I need to understand when and how I should use it. I've been running nitro for a long time .... I am a competent tuner. Just new to the three needle. Anyone have some good material/ media they can share?
#7357
I've been looking for a video or article that can help me understand my new Nova 3 needle carb. Most say leave it alone and that's it, but I need to understand when and how I should use it. I've been running nitro for a long time .... I am a competent tuner. Just new to the three needle. Anyone have some good material/ media they can share?
It adjusts the where low end of the tuning ends and the high end takes over. You can use this adjustment to move where that point is, either earlier or later in the RPM.
95% of people will adjust it because something else is off, whether its the high or low end, and it will move the tune of the engine higher or lower and usually further out of tune. Then they end up chasing it until they readjust it and start over.
There are a couple videos on YouTube about it if you are still interested...
My suggestion.... put some sealant over it and forget about it.
#7358
First off, do you know what it does. If not here you go.
It adjusts the where low end of the tuning ends and the high end takes over. You can use this adjustment to move where that point is, either earlier or later in the RPM.
95% of people will adjust it because something else is off, whether its the high or low end, and it will move the tune of the engine higher or lower and usually further out of tune. Then they end up chasing it until they readjust it and start over.
There are a couple videos on YouTube about it if you are still interested...
My suggestion.... put some sealant over it and forget about it.
It adjusts the where low end of the tuning ends and the high end takes over. You can use this adjustment to move where that point is, either earlier or later in the RPM.
95% of people will adjust it because something else is off, whether its the high or low end, and it will move the tune of the engine higher or lower and usually further out of tune. Then they end up chasing it until they readjust it and start over.
There are a couple videos on YouTube about it if you are still interested...
My suggestion.... put some sealant over it and forget about it.
#7359
I've been looking for a video or article that can help me understand my new Nova 3 needle carb. Most say leave it alone and that's it, but I need to understand when and how I should use it. I've been running nitro for a long time .... I am a competent tuner. Just new to the three needle. Anyone have some good material/ media they can share?
#7361
Steve Pond wrote a few articles about carbs I could not find the exact one I was looking for but here is the best I could find. This is from a magazine Steve Pond wrote for.
THE THIRD NEEDLE
The third “needle” isn’t actually a needle at all; it’s an adjustable
seat. These third adjustments are found exclusively on slide carbs
because their design allows them (I’ll get to the variety of carb
designs later). In most slide carbs, the low-speed needle is in the
center of the slide valve. The seat for the low-speed needle is fixed
in the body of the carb, opposite the slide valve. As a slide carb
opens, the vacuum helps to draw fuel into the engine. Once the
airflow has a direct path over the fuel inlet, fuel draw is increased
slightly. By adjusting the low-speed needle and the third “needle” at
the same time, you can adjust the throttle position at which the fuel
inlet is fully exposed to the air flowing through the carb. For
example, if the inlet is fully exposed at 1/4 throttle, an extra dose of
fuel can be expected at that point. If, however, the low-speed
needle and the seat are adjusted in the same direction—farther into
the carb’s venturi—the inlet may not be fully exposed until 1/3
throttle is reached. This is why the third needle is often referred to
as the mid-range needle. Its use will marginally alter the rate of fuel
flow in the mid-throttle range—an extra tuning option for the
accomplished tuner.
It’s often recommended that the third needle be left alone by all except very experienced engine tuners. More harm than good can potentially result from trying to use this adjustment without knowing the consequences. You’ll never get the experience without trying, however, so use your best judgment. Even if you opt not to use the third needle as a tuning tool, a three-needle design offers a secondary benefit: another way to adjust the low-speed mixture. The conventional way to adjust it is to adjust the needle, but simply by adjusting the seat or the third needle without adjusting the low-speed needle an equivalent amount, you accomplish the same thing. This is helpful in applications in which the low-speed needle isn’t very accessible because it’s blocked by some hardware on the chassis.
this is from rc nitro mag written by Steve Pond. the file size was too big.
THE THIRD NEEDLE
The third “needle” isn’t actually a needle at all; it’s an adjustable
seat. These third adjustments are found exclusively on slide carbs
because their design allows them (I’ll get to the variety of carb
designs later). In most slide carbs, the low-speed needle is in the
center of the slide valve. The seat for the low-speed needle is fixed
in the body of the carb, opposite the slide valve. As a slide carb
opens, the vacuum helps to draw fuel into the engine. Once the
airflow has a direct path over the fuel inlet, fuel draw is increased
slightly. By adjusting the low-speed needle and the third “needle” at
the same time, you can adjust the throttle position at which the fuel
inlet is fully exposed to the air flowing through the carb. For
example, if the inlet is fully exposed at 1/4 throttle, an extra dose of
fuel can be expected at that point. If, however, the low-speed
needle and the seat are adjusted in the same direction—farther into
the carb’s venturi—the inlet may not be fully exposed until 1/3
throttle is reached. This is why the third needle is often referred to
as the mid-range needle. Its use will marginally alter the rate of fuel
flow in the mid-throttle range—an extra tuning option for the
accomplished tuner.
It’s often recommended that the third needle be left alone by all except very experienced engine tuners. More harm than good can potentially result from trying to use this adjustment without knowing the consequences. You’ll never get the experience without trying, however, so use your best judgment. Even if you opt not to use the third needle as a tuning tool, a three-needle design offers a secondary benefit: another way to adjust the low-speed mixture. The conventional way to adjust it is to adjust the needle, but simply by adjusting the seat or the third needle without adjusting the low-speed needle an equivalent amount, you accomplish the same thing. This is helpful in applications in which the low-speed needle isn’t very accessible because it’s blocked by some hardware on the chassis.
this is from rc nitro mag written by Steve Pond. the file size was too big.
#7362
Tech Master
Joined: Jul 2004
Posts: 1,842
From: Norway
As written in the article, the third needle can be good thing. the moast important thing when you have a three needle carb, is to move the LSN and the "third" needle exact same amount.
If you screw the LSN in half a turn, screw its seat out half a turn.
If you screw the LSN in half a turn, screw its seat out half a turn.
#7363
Ok so I am getting ready to build an 8ight 3.0 nitro buggy to go with my ebuggy for this upcoming outdoor season. I have never raced nitro buggy. I have raced gas truck in the past, but that was many years ago. I used to run Novarossi motors in my gas trucks and loved them, so I want to stick with one for my nitro buggy.
I am leaning towards the KEEP OFF 21-4. Not sure what pipe/manifold would be best to go with it but would like to keep that Nova as well.
Any advise would be appreciated, I have been reading through this thread but I am still not quite sure what would work best for me as I am new to nitro buggy. I just want a reliable setup that is easy to drive and will run well throughout the season.
I am leaning towards the KEEP OFF 21-4. Not sure what pipe/manifold would be best to go with it but would like to keep that Nova as well.
Any advise would be appreciated, I have been reading through this thread but I am still not quite sure what would work best for me as I am new to nitro buggy. I just want a reliable setup that is easy to drive and will run well throughout the season.
#7364
Ok so I am getting ready to build an 8ight 3.0 nitro buggy to go with my ebuggy for this upcoming outdoor season. I have never raced nitro buggy. I have raced gas truck in the past, but that was many years ago. I used to run Novarossi motors in my gas trucks and loved them, so I want to stick with one for my nitro buggy.
I am leaning towards the KEEP OFF 21-4. Not sure what pipe/manifold would be best to go with it but would like to keep that Nova as well.
Any advise would be appreciated, I have been reading through this thread but I am still not quite sure what would work best for me as I am new to nitro buggy. I just want a reliable setup that is easy to drive and will run well throughout the season.
I am leaning towards the KEEP OFF 21-4. Not sure what pipe/manifold would be best to go with it but would like to keep that Nova as well.
Any advise would be appreciated, I have been reading through this thread but I am still not quite sure what would work best for me as I am new to nitro buggy. I just want a reliable setup that is easy to drive and will run well throughout the season.



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