Tuning my nitro

[mzanzirc]

I came across this thread:

https://www.rctalk.com/forum/threads/nitro-tuning-tips-and-tuning-flow-chart.60832/#post-537066

WOW! What a treasure trove of information.

But I have one question regarding the visio chart in the second post.

After the "accelerate at full throttle" block, it asks "Does the engine suddenly die or lose power".

Yes, adjust the high speed needle CLOCKWISE 1/8 turn, and then in brackets (rich).
No, then asks again "does the engine bog or die" then adjust the high speed needle CLOCKWISE 1/8 turn, and then in brackets (lean).

Can someone maybe explain this a bit further?

Or am I being stupid?

 

[johnnydmd]

I can make no sense of that chart, and it seems contradictory.

There are two different types of "bogging" you might experience - one by being too lean, one by being too rich. It's pretty easy to tell which is which. If it's too rich, there'll be a ton of smoke.

 

[offroadrcguy]

That chart is so confusing. Usually after breaking in the truck from factory setting i start to lean the HSN 1/12 a turn till i don't feel a change i performance Or until it starts to bog down because of being too lean. If it starts to bog down then it richen it 1/8 a turn. And then tune the LSN so it starts easily and idles.
If its bogging down out or cutting out even at factory settings. Something is blocking your fuel. For me once i was so confused because It was cutting out when applied gas no matter how much I richend the LSN. Turns out that there was something caught up in the HSN which was blocking gas. If your engine was sitting for a long time make sure to disassemble The HSN to make sure its clean or else you wold be wasting so much time on tuning.

 

[mzanzirc]

I will be doing the pinch test first and checking if my LSN is set correctly, and then from there tune the HSN.

I don't need a race ready tune. Just something generic to get the most top end and response from the car. I will be running in parking lots and open grass fields only anyway.

 

[offroadrcguy]

If you do the LSN first you will be chasing yourself in circles. First do the HSN because after tuning your engine will make more power so adjusting the LSN will not help. Make sure to have the idle set screw gap corrected

 

[mzanzirc]

If you do the LSN first you will be chasing yourself in circles. First do the HSN because after tuning your engine will make more power so adjusting the LSN will not help. Make sure to have the idle set screw gap corrected

Thanks.

So is there a quick and dirty tuning guide for dummies like me?

Lemme know if this sounds ok.

Set idle gap.
Run it around and tune HSN. But what am i looking for? For it to not bog down and stutter when hitting WOT? Meaning to lean and richen it a bit?


After that i tune the LSN?

 

[offroadrcguy]

if you know the factory setting for the nitro car bring it back to factory settings. If the needles are already messed around with you will find a hard time tuning. Then from the factory settings lean the HSN 1/12 turn. do a high speed pass. You will notice a difference in power. Do it until the Car start showing symptoms of to lean (overheating, bogging down, stalling, etc) when this happens then richen the mixture 1/8 turn. And then the bogging down and over heating will go away. Then you set the LSN.
when tuning the LSN i tune it so the engine will be easier to start and will idle.
after tuning the HSN your engine will make alot of power. the engine will probably stall at idle and wouldn’t want to start unless the throttle is open half way. So if you dont want this to happen. Rich the LSN enough so that the engine will start and idle.
Edit
Always tune when engine is up to running temp. If you don‘t your engine will show symptoms of being too rich/lean when in reality it is just not warm enough to tune.
if you tune your engine right it can last easily for 10 gallons through it before rebuilding engine so if something doesn’t work dont come to the conclusion that the engine is bad/ loosing compression.

 

[gandalfnz]

Pinch test is not a good way of tuning LSN.
Its never consistent, and imho should not be recommended.
Just tune the LSN for a snappy take off, after you have done HSN.

 

[cbaker65]

A pinch test is only a rough reference on how close you are to a good LSN tune ,which is
about 4 or 5 seconds!
Your engine does not have to be perfectly tuned ,just as long as it idles good ,take offs
are descent an on throttle remains consistent with out studders!..

If the engine is running rough an wont tune ,then something else isnt right as you
can't tune an engine if it has massive air leaks an or other issues!..

 

[mzanzirc]

A pinch test is only a rough reference on how close you are to a good LSN tune ,which is
about 4 or 5 seconds!
Your engine does not have to be perfectly tuned ,just as long as it idles good ,take offs
are descent an on throttle remains consistent with out studders!..

If the engine is running rough an wont tune ,then something else isnt right as you
can't tune an engine if it has massive air leaks an or other issues!..

Thanks. Yeah I mentioned I don't need a race tune. I just want decent take off and decent top end.

Last night I tuned the HSN, and actually had good takeoff. Space was limited to check the top end.

So I'm guessing my LSN is kinda ok.

Pinch test is not a good way of tuning LSN.
Its never consistent, and imho should not be recommended.
Just tune the LSN for a snappy take off, after you have done HSN.

Thanks.