What nitro for tmax 3.3

vectra

I still think a TRX 3.3 engine will NOT run at its designed premium on 10%.. Now. I will say that my 3.3 ran good on 16% MT. Ran better on 25% until somebody apparently ran it too lean

OTOH.
My TRX 2.5 runs awesome on the 25% Tornado. Whilst it still runs fine on 16% there is no comparason between the performance with both fuels.

Plug

Flunked wrote:

See, you did it again;) It runs/would run good

10% fuel will run the engine too cool, too cool is not good, deminishes performance and will not allow the slieve to expand to optium size or whatever its called, this will cause the conrod to snap. Might be different with a carson motor or whatever one you have(think its a carson anyway) because the 3.3 is a high performance engine, decent running dosen't come with low fuel and low tempetures.

@Cmar-Ireland, just go for 16%;)

g5hn710m4xpdwy

lean it out:p

coolwings

Carson? Well my Carson Specter has a Force engine, for which read OFNA, and a few other "quality US-made (hah) renamed brands".
You forget that I have - to prove a point - used 5% in a T-Maxx - also where 16% is recommended. Something that is generally viewed as won't work.
It just takes a fine degree of tuning, but it is harder to do than using higher nitro...
Oh - by the way- the conrod didn't break.

Don't forget that with any nitro, if the engine is too cool, you TUNE IT, by leaning it out, and the engine temp goes up!

Plug

coolwings wrote:

Carson? Well my Specter has a Force engine, for whick read OFNA, and a few other "quality US-made (hah) renamed brands".
You forget that I have - to prove a point - used 5% in a T-Maxx - also where 16% is recommended. Something that is generally viewed as won't work.
It just takes a fine degree of tuning, but it is harder to do than using higher nitro...
Oh - by the way- the conrod didn't break.

Don't forget that with lower nitro, if the engine is too cool, you TUNE IT, by leaning it out, and the engine temp goes up!

Have you ever used 16% in a motor?

coolwings

This could go on for a long time.
It's really one of the reasons I prefer electric to liquid fuel. Fewer factors that affect the performance of my model with electric.

Anyway, there is a good reason for using higher nitro. Some engines are tight when new, and have a top-dead-centre piston position resistance that must be overcome if the engine is to roll over TDC and make another firing, and revolution.
Three things help your engine get over the top resistance:

the power carried forward from the last firing 1 revolution ago

the lubrication of the parts and ease in their movement

the weight of the flywheel on the crankshaft

higher temp, hotter glowplug, more nitro or higher compression increase the first factor

Leaning out increases number 1 but decreases number 2

raising nitro increases 1 but burns oils away therefore it decreases 2, so you have to richen up to compensate, decreasing 1.

Using higher nitro fuel, with higher oil content, raises 1, minimises losses power losses in 2. It is the way with the least expertise that gets a result.

nobody thinks about number 3

Nobody swops glowplugs and retunes for testing, they are actually happy as Larry if they can only start it!

coolwings

Plug wrote:

Have you ever used 16% in a motor?

I have personally used every mix from 0% nitro up to 65% nitro in engines.
That includes 16%, a lot of it.
While helping out modellers with starting problems I have started hundreds of model engines that were not my own, and were set or tuned wrongly..

vectra

Flunked wrote:

lean it out:p

I think I had a bad experience of that with my first 3.3 motor... BOOM..!!! :eek:

coolwings wrote:

You forget that I have - to prove a point - used 5% in a T-Maxx - also where 16% is recommended. Something that is generally viewed as won't work.

Did you compare performance levels between both types ( 5% & 16% ) during that episode ?

coolwings

Vectra
1st I suspect you were possibly using high nitro and low oil at the same time, and then leaned it out.

2nd It needed the fuel lines to be shortened and obviously preferred 10% or more. But it started and went which we were told it would not do. Our conclusion was that the setup the model came with was fine on both 10% and 16%. The 5% was for us.

There seems to be a competition about this discussion that I can't understand.
It is only a personal tradeoff we make with our gear.
20% get 1 to 6 months of ballistic competitive performance, new engine parts now
on 15 - 20% get 3 - 9 months of extemely hot performance, engine wear now
on 10%-16% get most of the benefits of nitro but little of the costs, engine 1 - 3 years
on 5% need a bit more ability, engine goes on and on.

The same size models that used to have a .21 engine now have higher compression, better tuned pipes, and 3.5 engines or more.

There is now ooodles of power to use or waste. This means there is no need to have it all running on the cliff edge of destruction to get the theoretical maximum performance. If that is what you want ok fine for you. On you go, enjoy yourself.

Some other people are happy with 10% lower performance ... still amazingly hot ..... and causing a fraction of the mechanical problems you have to deal with.

it's not a religion, no requirement to conform to any "nitro" rules, everyone can do it their own way, experiment, and see what they prefer.

Cmar-Ireland

Well, we picked up two gallons of 16% MT Go Glo and a 1/2 gallon of GX-16 expert mix to break in both 3.3 engines.
just waiting for the two trucks to arrive from Tower now....

coolwings

You will find breaking them in challenging. But be patient and give it time.

stephenmarr

we like a good challenge itching to get them

Plug

Ah coolwings when i got the T-maxx i was a newbie, how no problem at all because of the proper manual and DVD, very helpful and easy. Ah dought they wont have a problem, hopefully:D

vectra

Plug wrote:

Ah coolwings when i got the T-maxx i was a newbie, how no problem at all because of the proper manual and DVD, very helpful and easy. Ah dought they wont have a problem, hopefully:D

You forgot to mention the vital part of info..!!
Now you have a "special" revo..

Plug

vectra wrote:

You forgot to mention the vital part of info..!!
Now you have a "special" revo..

I miss it:(
Haven't driving it in a while, will drive it next week, got a week off school, lovely:)
Still no news off them other gomes?

vectra

Plug wrote:

I miss it:(
Still no news off them other gomes?

Huhh?

I had my Audi 1/5th out for a quick burst last week...
Mmmm..! Music to my ears.
Cant wait for the good weather to go to Rosegreen racaway with it..

Plug

I meant the germans:(
Yes I cant wait for the smeel of burnt nitron in morning!

vectra

Plug wrote:

I meant the germans:(
Yes I cant wait for the smeel of burnt nitron in morning!

No more news from Hanz.. :rolleyes:

Anyway.
The 8 weeks is up this week on the investigation period for DHL.
So. I reckon one more week and that should be it.

Plug

vectra wrote:

So. I reckon one more week and that should be it.

What happens then?
*Vectra buys guns and plane ticket*

Cmar-Ireland

If using 16% fuel in a 3.3 engine, does the heat range of a glowplug make much difference? I've seen cool, medium & hot glowplugs.

vectra

Cmar-Ireland wrote:

If using 16% fuel in a 3.3 engine, does the heat range of a glowplug make much difference? I've seen cool, medium & hot glowplugs.

The one that comes with it should be fine.
But there is a Heavy Duty one available as well.

Traxxas GLOW PLUGS:

Part #3232 Glow Plug, super-duty long (medium)
Suggested retail price $5.50

Part #3231 Glow Plug, heavy duty long (medium)
Suggested retail price $6.00

Plug

The 3232 one is out of stock everywhere, there more or less the same anyway.

coolwings

Cmar-Ireland wrote:

If using 16% fuel in a 3.3 engine, does the heat range of a glowplug make much difference? I've seen cool, medium & hot glowplugs.

Generally .... The hotter the engine .. .the cooler the glowplug required. :cool:

And the cooler the glowplug ... the more correct setting must be before the engine will start.

So glowplug choice is a balancing act.

Does this sound like "the nitro debate" all over?

Cmar-Ireland

Hehe... Don't want to start another "debate" ......
I bought a set of 5 plugs (#3231) from a seller in the US. Worked out a just under €20 for 5 delivered.

coolwings

Cmar-Ireland wrote:

.... I bought a set of 5 plugs (#3231) .....

Sfunny that....
And there was me thinking cars need 1 glowplug !

Plug

Was that on ebay?

Cmar-Ireland

Yep, bought through ebay, always handy to have a few spares though...

T-Maxx

coolwings wrote:

Sfunny that....
And there was me thinking cars need 1 glowplug !

Now that's Sfunny!:D

Plug

Yeah i saw that bolke selling them, there was a link for them on the traxxas website.
They'll be handy to have you will go threw quite a few;)

Cmar-Ireland

Just a quick update to this thread. The breaking in on the revo was so easy. It fired up straight out of the box on the factory settings. Got the 5 or 6 tanks of fuel through no problem. Just richened up the hsn to give a nice trail of smoke. Very happy with it so far.
Using 16% MT by the way.