Looking for fuel percentage suggestions

[EB4S2PRO]

Hi all

I have a thunder tiger eb4 s2 pro and was wondering if you could suggest a fuel percentage to use that would be easy to tune and bash around with also glow starter I currently use R2/5

 

[Certified Mike]

You want to keep your percentage at between 20 and 30%. This is actually a kind of heated subject. Everyone has opinions. Personally, I run 20%. I just haven't had a need to kick it up yet. The general consensus as I have read is that the 30% will run stronger and faster but will shorten engine life. I have no evidence to support or negate this tho. I have also read that they run hotter with the higher % fuels... This has its obvious consequences of accurate. Again, not sure but it tends to make sense. For just bashing around, no races to win etc, I would stick with 20%. Mine are easy to tune, run well in all weather and have yet to blow anything up. Now I'm gonna go hide in a corner with a bowl of popcorn and watch the fireworks!

 

[EB4S2PRO]

You want to keep your percentage at between 20 and 30%. This is actually a kind of heated subject. Everyone has opinions. Personally, I run 20%. I just haven't had a need to kick it up yet. The general consensus as I have read is that the 30% will run stronger and faster but will shorten engine life. I have no evidence to support or negate this tho. I have also read that they run hotter with the higher % fuels... This has its obvious consequences of accurate. Again, not sure but it tends to make sense. For just bashing around, no races to win etc, I would stick with 20%. Mine are easy to tune, run well in all weather and have yet to blow anything up. Now I'm gonna go hide in a corner with a bowl of popcorn and watch the fireworks!

Hey thanks for the reply so would you suggest going from 15% to 20% or would you say that 15% is ok I got a full bottle wondering if I must go swap it for 20%

 

[Certified Mike]

I don't know anyone who runs under 20% on a surface rig. 15% works for planes. I haven't seen it run in a car so I won't say to toss it but I wouldn't run it personally. It just seems like a tuning headache and lower performance to boot. Just my personal thoughts on what I have read tho. I have seen up to 30 and maybe someone running higher (like on a track, although they wouldn't admit to it as it's illegal). 30% really gets them going, no doubt. One thing you should be aware of... You do need to retune for a change in %. It is also recommended by manufacturers that you do not change. Stick with it if/when you step it up.

You should verify the oil content in the fuel you have as well. If it is too low, toss it for sure!
I have read that you can add castor oil to your fuel but I would stay clear of that personally.
I should mention, 7.5 is the lowest I have heard of in fuel and have heard above 20% but again, not sure if that. Some fuels don't even tell you which can be risky I suppose. However, I can't see traxxas or blue thunder not putting enough oil in their fuel and blowing thousands of engines either.
However, where the fuel mixtures and ratios change with altitude, I am not sure how the %'s change to accomodate. 15% nitro is an aircraft fuel to the best of my knowledge.

 

[Certified Mike]

I guess to sum all this up, is your $20 bottle of fuel worth your $200 engine?

 

[EB4S2PRO]

I don't know anyone who runs under 20% on a surface rig. 15% works for planes. I haven't seen it run in a car so I won't say to toss it but I wouldn't run it personally. It just seems like a tuning headache and lower performance to boot. Just my personal thoughts on what I have read tho. I have seen up to 30 and maybe someone running higher (like on a track, although they wouldn't admit to it as it's illegal). 30% really gets them going, no doubt. One thing you should be aware of... You do need to retune for a change in %. It is also recommended by manufacturers that you do not change. Stick with it if/when you step it up.

You should verify the oil content in the fuel you have as well. If it is too low, toss it for sure!
I have read that you can add castor oil to your fuel but I would stay clear of that personally.
I should mention, 7.5 is the lowest I have heard of in fuel and have heard above 20% but again, not sure if that. Some fuels don't even tell you which can be risky I suppose. However, I can't see traxxas or blue thunder not putting enough oil in their fuel and blowing thousands of engines either.
However, where the fuel mixtures and ratios change with altitude, I am not sure how the %'s change to accomodate. 15% nitro is an aircraft fuel to the best of my knowledge.

Thanks mate you've been a great help I ended up swapping the 15% for 20% and will wait for the rain to stop and send the car out for a run. I also got the R5 glow plug.

 

[Certified Mike]

Glad to hear that. Let us know how it goes!

 

[EB4S2PRO]

Hi Mate did some running around this weekend and the 20% worked like a dream easy to tune, smoother running And the car was a blessing to drive, although I was a bit scared with the accelorator cause it is my first Nitro car and I didn't realise that they were so brutal, I mean my electric car is quick with a 13.5t motor but my thunder tiger EB4 S2 is a machine. I did a dice with the 2 cars and the electric got off the line faster but once the nitro car catapulted is zoomed past the electric.

 

[Certified Mike]

I'm glad you got it running right! Spend some time dialing it in etc... You'll get even more performance out of it once you get to know it better.
Don't forget to spend time doing it's break in process again!

 

[DXtreme1]

Also don't afraid to play around with gearing as well to suit your driving style and running conditions.

 

[EB4S2PRO]

Lol that is way beyond me I don't know how to do gearing and break it in again explain please

 

[DXtreme1]

If the engine is broken in already you don't need to do it again if you're just changing the gearing. Changes in gearing can be accomplished through changing the teeth count on the spur(tranny side)or the clutchbell(motor side). You can do one side or both to gear it for high speed or more low end torque.

Lol that is way beyond me I don't know how to do gearing and break it in again explain please

 

[Certified Mike]

No, the break in is for a higher percentage of fuel. Ok... Let me give you a couple links to get you educated in your kit... Before you run again LEARN THIS STUFF!!!

https://www.rcnitrotalk.com/forum/threads/nitro-rc-beginners-guide.68224/

https://www.rcnitrotalk.com/forum/threads/nitro-tuning-tips-and-tuning-flow-chart.60832/

https://www.rcnitrotalk.com/forum/threads/glow-plugs-dos-donts-tech-and-tips.113922/#post-1111694

 

[olds97_lss]

Usually when you change fuel percentage, you just keep a close watch on the engine temps to avoid it getting out of hand. Higher nitro fuel doesn't run at the same mix as a lower nitro fuel, you usually run a bit richer to keep the temps in a proper range.

I ran 20% for 10 years, then got an engine that suggested in the manual to run 25%. So I did. Then I tried 25% in my other engines to see how it did. Instead of keeping 2 fuels around, I just ran 25% in everything. That extra 5% did add a little more power, but things ran better in general for me. Idled easier, started easier... So now I've been running almost 10 years on 25%. lol

Once you get up to 30%, then you have to possibly concern yourself with changing plug temp and head shims to keep compression in check. So, odds are, I'll never deviate from 25%.

 

[Certified Mike]

I don't remember if traxxas mentioned it but I recall reading in OS manuals that they recommend a break in when increasing percentages. I can't imagine running 15% and figure that this engine was run on 20% anyways. Figured a break in period can't hurt anything.
It should help to learn the tuning process and learn what the needles really do before WOT is the norm.
I am also a believer in checking and maintaining temps. Not tuning to the 100% necessarily, but at least 75%

 

[EB4S2PRO]

Yup I ran the 20% and it was alot easier to tune and way more stable problem is I have a half full bottle of 15% laying around now lol but hay as long as the car is running nicely I don't mind, I did keep an eye on the temp and highest I got to was 160 degrees which wasn't to bad I thought and a bit of smoke from the exhaust not to much, I heard it's good to run a little rich cause it keeps the engine cool and well lubed. Just waiting now on a few parts to arrive, I've bought new cougar radio gear with 2 new servo's, rear wing assembly and front bumper as I bought the car second hand for a good deal, so just getting all the bits and pieces to make it complete. I've done so much to the car as is putting silicone oil in the 3 diffs, reoiling the shocks and just general maintenance and cleaning, I replaced the battery carriage and on/off switch, I bought a new filter and sorted out servo adjustments cause the brakes weren't working and the guy who had the car before me didn't know to much telling from the state of the vehicle when I got it. Since then it honestly feels and looks like a new car a little work and money goes along way with these nitro cars. I don't think I'll be adjusting the gearing cause honestly the car is so fast in my opinion, when driving it on the weekend I was constantly tapping off the accelerator cause with full throttle the arse just dips and the car rockets off the line and feels like if just keeps going, as I'm riding I just think to myself holy crap if this car rolls at that speed on road it'll cause alot of damage and i value my cars so was being a little cautions ha ha ha, I know if sounds stupid but spending all the money and time on it making if look and run nicely has me wanting to keep it in one piece and in summer I'll start bashing around off road. Thanks for the help though everyone I like the feed back and enjoy chatting RC. I put a picture of my 2 cars the radio gear for the thunder tiger will be changing and rear will assembly should be arriving before the weekend who knows how long the bumper will take but will keep posting pictures.

 

[Certified Mike]

Looking good! Happy that it's getting sorted to your liking too! Let me make a suggestion to protect your investment... Throttle return spring! Pick one up and install it. Its extra insurance on the fail safe (which you also need) these 2 items will keep your investment from riding off into the sunset, or traffic, or a brick wall.... Etc... If you loose power to the radio the throttle return spring will bring the engine back to idle which a failsafe can not do. Its not really an option imo.

 

[EB4S2PRO]

Good suggestion Mike, are the throttle return springs universal or is it brand dependent.

 

[Certified Mike]

Throttle return isn't brand related at all. You just need to pick up a spring strong enough to pull your throttle and attached linkage etc... back to idle yet not so strong that it is overworking your servo. A local hardware store should have just what you need.

 

[DXtreme1]

I would use the 15% nitro fuel to clean your air filters and your carb when you do maintenance on them. At least it won't go to waste. As usual Certified Mike provided you with a great suggestion. I install TRS on all my rigs including my 1/10 scale touring cars when I had them. Just need to have enough tension where the spring returns your throttle to the idle position. You don't want to put unnecessary stress on your servo and carb. You can even tweak your linkages if you put too much tension. If you don't have a radio with a built in failsafe I suggest you get one. If you have a 2.4 radio need to make sure the failsafe is compatible.