whats the best nitro percentage ?

[HSPGuy2190]

whats the best nitro percentage ?

I'm running 16% atm in my on road car ? the manual says 10 -15 %

what do u guys reckon

 

[moe7404]

my guess it could take 30% up to 60%. i have ran 60% in my traxxas 3.3 but not sure it goes much faster. nitro needs a large chamber to really make power. 30% should make as much as you need.

 

[joshman1204]

Whats the best ice cream flavor?

Your probably going to get as many different answers to that question as you will the nitro question.

Whats best is what works for you in the kit you have. There are many other things at play instead of just nitro content. Your ambient temperature, glow plug choice, carb tuning and many other things can really change what nitro content is best for you.

 

[Racer 1966]

my guess it could take 30% up to 60%. i have ran 60% in my traxxas 3.3 but not sure it goes much faster. nitro needs a large chamber to really make power. 30% should make as much as you need.

Sorry moe ole'buddy, but that's bad advice. These engines are not made for that high of nitro content on a daily basis.

OP: Most manufactures recommend 20% but if your manual says 10-15% stick close to that. I ran some 16% Wildcat fuel and loved it and there was no noticeable power loss over 20%.

 

[HSPGuy2190]

iv been told my car is running to rich ? whats that mean has that got to do with nitro ?

 

[moe7404]

yep racer my brain was out to lunch. i DID give bad in info. sorry my brain was stuck in 1:1 race cars.

 

[hamz9561]

I tend run 20% in my nitros. It gives good performance for bashing.

 

[Punisher]

iv been told my car is running to rich ? whats that mean has that got to do with nitro ?

No - thats the short answer . . .

The long answer is:-

When you hear 'lean' or 'rich', it refers to the about the air to fuel ratio in your inlet charge.

The carburetor emulsifies liquid fuel into a gas and at the same time mixes the fuel with air. . .

If your car is running too rich, it means the carburetor is mixing too much fuel to the ratio of air.

If your car is running too lean, it means that the carburetor is mixing too much air to the ratio of fuel.


Your car will produce the most amount of power and run the best when the air/fuel ratio is correct for your engine.


Too rich, the engine will run sluggish and fowl itself with the excess fuel/oil that is not burnt.

Too lean, the engine will run hot and drop power.

Also, the reciprocating parts of an engine are typically lubricated by oil supplied from a remote reservoir (sump or tank) - RC nitro engines do not have a sump filled with liquid oil to cool and lube the reciprocating parts, lubrication is provided by the oil contained within the fuel that is pumped though the engine (as part of the induction cycle).

So if you run your engine too lean (too much air vs gas fuel), you will also starve it of the oil it needs for lubrication, and the engine may seize.



If you have been told your engine is running too rich - if it is blowing excessive smoke - and leaking oil; when the engine is warm, turn the high speed tuning needle 1/8 of a turn in (clockwise) do a full throttle run - keep doing this until performance does not improve - turning the high speed needle clockwise leans the fuel mix (less fuel to air mix) - make small changes and careful not to take too much fuel out (lean too much) or you will may ruin your engine - dont let that deter you though - we all started somewhere and you wont learn unless you try.

Tuning your engine is rewarding - 1/8 of a turn can be the difference between 'thats running ok' vs 'wow that's much more powerful and responsive'!!!

 

[HSPGuy2190]

running to rich ? or what

If you have been told your engine is running too rich - if it is blowing excessive smoke - and leaking oil

its not blowing excessive smoke but it seems to be leaking

View attachment 11566

but i always after evey run have to clean the bottem on the car ( as shown in the pic )

 

[Punisher]

Yep, a leaking engine is a sympton of running rich.

Lean down (turn clockwise / in) the high speed needle 1/8th of a turn - see if performance improves - keep on doing this until you have gone too far - you will know when you have gone too far as performance will get better, and better, and better - then at wot (wide open throttle) it will become 'fluffy' - dont persist at this point, go back 1/8 a turn . . .

Key is making small changes - 1/8 of a turn and listen to, and watch how the car performs.

Tuning can be frustrating when you are learning - but is most rewarding when you have the right tune. Once you have the right tune, normally only minor adjustments are required.

 

[HSPGuy2190]

is that the " high end mixture valve " ? sorry I'm new to all this ur talking about

---------- Post added at 1:42 AM ---------- Previous post was at 1:35 AM ----------

but clock wise is close ? in the manual on the high end miture valve

 

[Punisher]

is that the " high end mixture valve " ? sorry I'm new to all this ur talking about

Mate - no need to apologise - you are allowed to ask what you may consider to be a silly question - not gonna learn otherwise - the only condition is that you pass on what you learn to the next person . . . I would have been lost if someone didnt answer my simple questions.

There are most commonly two tuning screws on the carb of a nitro car - the slow speed needle (or LSN) - that is on the end of the throttle slide (smaller in size)

Ten there is the high speed needle (HSN) - that is the larger of the two needles and sits up near the throat of the carb.

There is a third adjustment - the idle stop/idle speed adjustment screw.

- The LSN controls throttle response from idle

- The HSN controls air/fuel mixture past idle to full throttle

- The idle speed sets the idle air gap - bigger gap = higher idle speed - smaller gap = lower idle speed


The needle I am referring to is the HSN - High Speed Needle - once the engine is warm, turn the HSN 1/8 turn in at a time - do a high speed run, when the engine does not drop cleanly back to idle (the engines RPM hangs on) then go back 1/8 of a turn.

Looks like it is leaking oil from the silicone header coupler - make sure it is tight.

 

[Punisher]

Have a read of this - lots of helpful info provided here . . .

https://www.rcnitrotalk.com/forum/showthread.php?t=60832

 

[Punisher]

[/COLOR]but clock wise is close ? in the manual on the high end miture valve

Yep - clockwise - winding the screw in.

The screw is actually a needle that feeds into a hole.

The more you screw the needle into the hole, the smaller the gap is for the fuel to get through.

* Screwing in = smaller hole = less fuel = leaner . . .

* Screwing out = larger hole = more fuel = richer