[Saboteur]

I ran Dynamite Blue Thunder in my nitro sedan tuesday and it seems that my MT12 and Mach .15 both run faster with it. Previously, I have been running Sidewinder fuel (race blend..not backyard basher) and have had good performance. I've tried to tune the MT12 with the SW fuel but it didnt seem to get upto the speeds I've seen them run at. The BL fuel has answered my wish. The MT12 really opened up and it was just outstanding. In the past though, I heard from others that blue thunder does leave those crystals or some residue in the engine. The guy at the lhs told me its true for other fuels but he hasn't heard that much from BL. I believe mine has 14% oil content compared to the 12% or 10% in sidewinder race blend. If it's really true about those crystals, is that because the people haven't run their rides for some time and forgot to use after-run oil? Or does it really happen even when you properly lube your engine? I payed $24.95 for it and I'm happy with it..as well as the color . Think I should sell it and get Odonnels instead, or just use up the whole gallon and then later on use something else? The LHS had Odonnels and byrons in qts at the moment. Thats why I got the BL if you were wondering.

[MaxxGT23]

I really don't think there is nothing wrong with it. Like you said, as long as you don't store your r/c with fuel in it, and you put some after run oil the head, it should be fine. I have heard that BL will stain your engine blue though, but who really cares the color of the inside of your motor, ya know. I really like Byron 20% though. Before hand I always ran Traxxas Top Fuel 20%, which is great fuel. We then switched to Byron and we are getting better performance with lower temps. Just thought I would tell ya about me and my buddies expereience.

[Saboteur]

Sounds good. Just with those nasty reviews of Blue thunder I was beginning to worry. Didn't want to ruin my MT12. Guess I'll stay with the fuel and run it for a while. With the warm weather I normally run my rides 3-4 times a week. So far this fuel rocks. Good stuff and its my favorite color...BLUE!

[Fidelio]

O'Donnel fuel is clear like water, which can make it hard to tell by sight if there's fuel in the fuel line. It's also hard to tell how much fuel is left in the tank with clear fuel.

So far my favorite is Byrons, although I have yet to try Sidewinder, Wildcat, or Maxy's. Tried most others that I'm going to though (not gonna bother with HPI or Traxxas).

Some people claim lower temps with O'Donnel but I went from O'Donnel to Byrons and my temps went down so who knows. I think you have to find which fuel your particular engine likes.

[StormPilot]

I have a couple of guys at my track that use Odonnell 30% and they swear that they can run faster and cooler than with the Blue thunder 20 %. What I have been told is since you can run more fuel at 30% you run cooler. I have not tried it yet( dont want to richen it up and wait a tank) I really like the thunder and I like being able to see the fuel "at a glance" and know how much I have left.



Darin Gray
RCSX Eugene

[rocknbil]

Welcome aboard neighbor! Southern OR here!

I hear this time and time and again and would like to know the logic of it. Higher nitro percentage makes for less oil percentage, which is the lubricating and cooling element in the fuel. Additionally nitro burns hot compared to methanol alone, how would higher percentage make it run cooler?

Anyway I also don't mention my fuel often because everyone seems to think BT is crap, but have never had a single problem with it and have used it since my aircraft days. I've never even seen crystals inside an engine, and I've picked apart some pretty neglected dust-collectors from eBay. The blue dye does STAIN internal parts, and this is perceived as "gunk." It's just a stain, IMO. it works fine.

[MaxxGT23]

Originally Posted by rocknbil

Welcome aboard neighbor! Southern OR here!

I hear this time and time and again and would like to know the logic of it. Higher nitro percentage makes for less oil percentage, which is the lubricating and cooling element in the fuel. Additionally nitro burns hot compared to methanol alone, how would higher percentage make it run cooler?

Anyway I also don't mention my fuel often because everyone seems to think BT is crap, but have never had a single problem with it and have used it since my aircraft days. I've never even seen crystals inside an engine, and I've picked apart some pretty neglected dust-collectors from eBay. The blue dye does STAIN internal parts, and this is perceived as "gunk." It's just a stain, IMO. it works fine.

I don't understand bill. You said that a higher nitro percentage makes for less oil percentage. Trinity Monster H.P. 30% still has 12% oil content, which is the same for the 20%. That is the exact same oil percentage and like what other people said, you can run richer needle settings with 30% and still get the same or better performance. Beyond 30% you don't see power increase though.

[rocknbil]

By logic of percentage is what I meant, I erred (oh my GAWT! ) I should have said "everything else."

20% nitro + 80% everything else = 100%.
30% nitro + 70% everything else = 100%.

If you're keeping the oil content the same, then guess what? 10% less alcohol. Alcohol is the fuel, what actually begins the burn. Now you have a lower alcohol to oxygen/nitro ratio. Hmm.

[Mastec]

Originally Posted by StormPilot

I have a couple of guys at my track that use Odonnell 30% and they swear that they can run faster and cooler than with the Blue thunder 20 %. What I have been told is since you can run more fuel at 30% you run cooler. I have not tried it yet( dont want to richen it up and wait a tank) I really like the thunder and I like being able to see the fuel "at a glance" and know how much I have left.



Darin Gray
RCSX Eugene

I use Odonnel too and my motor does not go above 240 degrees with the HSN at 1 1/2 turns out, at idle it runs around 206. I started out with Blue Thunder and my motor was reaching nearly 300 degrees at 2 1/4 turns. Odonnel being a clear fuel is no big deal to me, something I can overcome as long as my motor is running cool.

[Fidelio]

when tuned properly, higher nitro percentage can actually reduce engine temperature because the higher nitro percentage allows you to get the same level of performance out of a richer needle setting, which in turn brings more fuel and lubricant into and through the engine which helps reduce the temperature since the fuel/oil is one of the main sources of cooling.

how's that for a run-on sentence?

however, if you don't retune your engine after bumping up the nitro percentage then yes, your engine will run hotter.

there was also an article several months ago in RCCA with a nitro vs temp comparison with and without retuning. if you want to end the debate in your own mind (and your buddies), i would find this article.

[rocknbil]

Originally Posted by Fidelio

... which in turn brings more fuel and lubricant into and through the engine which helps reduce the temperature ... would find this article.

Not according to this article, which contains the following:

1:

RC car engines are designed to run with a certain percentage of nitromethane. An engine designed to run on fuel with 20 percent nitro is configured for a certain compression ratio and a fuel/air ratio that provides ideal performance. Introducing a considerably higher concentration of nitro allows a greater overall amount of fuel volume. It can result in higher compression (air is the only compressible component in the fuel mix), detonation (when fuel explodes rather than burns) and higher operating temperatures. These outcomes show the fuel exceeds the design limitations of the engine. . . . .

The added fuel volume that you think COOLS the engine is counteracted by the additional compression and combustion. Remember the purpose of nitro is to get more fuel molecules in the engine, allowing for a higher alcohol/air mixture, resulting in a bigger and hotter combustion.

2:

There is a “window” of about 5 percent both above and below the recommended percentage of nitro you can have in your fuel before engine performance will be noticeably affected. If a manufacturer recommends 20 percent nitro, you can get away with 25 percent. Go beyond that, and you are likely to wind up with an engine that runs hotter, gets poor fuel economy and is more difficult to tune. . . .

Relying on what one's "buddies" say is a very hazardous way to make decisions. They should be made based on actual scientific studies by fuel induistry experts which result in reliable facts, not impressions. Mr. Pond's article is based on such an expert.

[TC3Racer]

I've tried a few different fuels and Byrons has also produced the best results. I use the RACE blend and i run all my engines with it, 20%. AE .12 to a Picco G1 and a couple in between. All have run well and cool. Its the popular choice at my track and mostly all the guys use it. I haven't tried too many others but i do want to try Trinity monster horsepower and see how they run on that. I have heard some good things about it. Also this is the first bad remark i've heard about Sidewinder, its seemed to be a pretty solid fuel.

[MikeWz]

Last season I ran my truck everyday. I ran blue thunder. I found that it got my engine up to temp fairly quickely but also had my engine runnning a good 10degrees more than my traxxas fuel. As I was tuning my engine to try to compensate for this....sure enough there were little blue sandpaper like crystals in the throat of my carb. I don't know what the would do if anything at all to my engine, but I wasn't going to take the chance. I mentioned this in the xxx-nt forum and CAVE checked his carb and sure enough they were in his too.

We have both since switched to Trinity Platnum (he recently went O'Donell because he can't find trinity) and I find it's the best fuel I've ever run. The Klotz oils never gum up the engine and keep it running at 220 at optimum settings despite it's 10% oil content. Works for me. I put 7 gallons of it through my first MT12. As long as my LHS continues to stock it I'll continue to buy it

[rccardude04]

I told you Sidewinder isn't so great didn't I?
-Eric

[Saboteur]

Originally Posted by rccardude04

I told you Sidewinder isn't so great didn't I?
-Eric

Yap yap yap..... it's still good fuel though. Well the BT works fine for me so I'll finish using it.

[Fidelio]

This article appeared in the premier issue of RC Nitro.

as we both know, that was some time ago. i'll look through my mags and see if i can find the newer article when they actually did side by side comparisons instead of just hypothesizing.

[QDiddy]

I run sidewinder race blend 20% fuel that I get at the shop for only $21 a gallon. It states on the jug that you do not need to use ARO, but I drop a couple drops on the piston anyway.

[Fidelio]

i'm sorry it wasn't rcca, it was Xrc Cars (Xtreme RC Cars) in issue 96 which is the Nov '03 issue.

http://www.rc411.com/cgi-bin/SoftCar...508+1082693978

see if you can find someone with that issue so you can check it out. their results might suprise you.