1/8 buggy on FAI fuel (0% nitro)
06-06-2009, 12:25 AM
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1/8 buggy on FAI fuel (0% nitro)
Hi there.
Normally a rc car engine runs on 25-30% nitro in the fuel. Why shouldn't they be able to run on FAI (0% nitro) fuel? I've been writing a lot with Brian, Australia aka Downunderhere on RCU and many other RC forums, and his son races a .28 engine on 80% methanol and 20% castor oil. After a modification that increased the compression ratio, his engine runs as fast as all the other engines - AND runs 2 minutes longer on one tank of fuel, compared with drivers that uses 25% nitro (same engine and car).
That's why I wanted to test it. My friend Dennis Munch from Denmark was so kind of letting me borrow his Kyosho Inferno Kanai 3 1/8 buggy powered with a sweeeeet RB WS2 .21 engine.
The only modification I made, was removing the 2 head shims to increase the compression ratio from approx. 8,5:1 to 11:1. The perfect compression ratio with FAI fuel is 13,5:1 (one more thing Downunder has found out :-) ). Both a Rossi 4 plug and a OS No. 6 (formerly A3) was too cold (the one I'm using in the video). 4 Days later I tried a OS F (4 stroke plug) and that was the right plug. Perfect idle, transition and top. That day the track was pretty bumpy and I didn't fly over the jumps (to save the car):
12 minutes and 28 seconds on one tank of fuel!
At the race I'm going to drive the 14th of June 2009, it should be able to run at least 10 minutes pr. tank of fuel (only 2 pitstops in a 30 minutes main).
For me it has got more than enough power with this lovely FAI fuel (I'm using 16% AeroSynth3 oil) and it costs approx. 1/4 of the the "normal" 25% car fuel.
http://www.youtube.com/watch?v=ykiffCV4xgk
Normally a rc car engine runs on 25-30% nitro in the fuel. Why shouldn't they be able to run on FAI (0% nitro) fuel? I've been writing a lot with Brian, Australia aka Downunderhere on RCU and many other RC forums, and his son races a .28 engine on 80% methanol and 20% castor oil. After a modification that increased the compression ratio, his engine runs as fast as all the other engines - AND runs 2 minutes longer on one tank of fuel, compared with drivers that uses 25% nitro (same engine and car).
That's why I wanted to test it. My friend Dennis Munch from Denmark was so kind of letting me borrow his Kyosho Inferno Kanai 3 1/8 buggy powered with a sweeeeet RB WS2 .21 engine.
The only modification I made, was removing the 2 head shims to increase the compression ratio from approx. 8,5:1 to 11:1. The perfect compression ratio with FAI fuel is 13,5:1 (one more thing Downunder has found out :-) ). Both a Rossi 4 plug and a OS No. 6 (formerly A3) was too cold (the one I'm using in the video). 4 Days later I tried a OS F (4 stroke plug) and that was the right plug. Perfect idle, transition and top. That day the track was pretty bumpy and I didn't fly over the jumps (to save the car):
12 minutes and 28 seconds on one tank of fuel!
At the race I'm going to drive the 14th of June 2009, it should be able to run at least 10 minutes pr. tank of fuel (only 2 pitstops in a 30 minutes main).
For me it has got more than enough power with this lovely FAI fuel (I'm using 16% AeroSynth3 oil) and it costs approx. 1/4 of the the "normal" 25% car fuel.
http://www.youtube.com/watch?v=ykiffCV4xgk
06-06-2009, 02:07 AM
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RE: 1/8 buggy on FAI fuel (0% nitro)
looks good, dosent have quite as much 'snap' as a nitro motor. but it still looks good......also, is running that much compression putting more wear on the con-rod?
06-06-2009, 04:19 AM
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RE: 1/8 buggy on FAI fuel (0% nitro)
Hey.
It should take some more RPM if the engine was modified in the head, just like Downunder has done with his sons engine.
The engine sounds a lot healthier with the 4-stroke plug - and 16 % oil. In the video I used 12% oil, but that is not enoughdueto the low fuel flow (ones again Downunder’s knowledge).
The load on the conrod is a little higher now, onits way up, but that is not even close to the load, when the conrod is being pressed down by the explosion (with or without high compression ratio).
jpilkinton:
Thanks Champ
I drove the car with the original well used tyres from 2004. It should be able to go faster in the corners with some new ones.
xjqkz
It should take some more RPM if the engine was modified in the head, just like Downunder has done with his sons engine.
The engine sounds a lot healthier with the 4-stroke plug - and 16 % oil. In the video I used 12% oil, but that is not enoughdueto the low fuel flow (ones again Downunder’s knowledge).
The load on the conrod is a little higher now, onits way up, but that is not even close to the load, when the conrod is being pressed down by the explosion (with or without high compression ratio).
jpilkinton:
Thanks Champ
I drove the car with the original well used tyres from 2004. It should be able to go faster in the corners with some new ones.xjqkz
Hey. I don't use temp guns etc. If you like, I can make a measurement at the race
Cheers
06-06-2009, 08:54 AM
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RE: 1/8 buggy on FAI fuel (0% nitro)
defintaly looking good, and the sound of the price being alot cheaper than nitro fuel sounds good to me. Some places price a gallon of fuel for $45 around here.
06-06-2009, 11:01 AM
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RE: 1/8 buggy on FAI fuel (0% nitro)
and the sound of the price being alot cheaper than nitro fuel sounds good to me
06-06-2009, 02:01 PM
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RE: 1/8 buggy on FAI fuel (0% nitro)
ORIGINAL: JB COMP
I know a few months ago I could a get a gallon of 5% nitro for $10.00 and 0% was $8.50 a gallon
and the sound of the price being alot cheaper than nitro fuel sounds good to me
few months as in 65-70 months ago?
06-06-2009, 02:18 PM
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RE: 1/8 buggy on FAI fuel (0% nitro)
ORIGINAL: ProRCRacer88
defintaly looking good, and the sound of the price being alot cheaper than nitro fuel sounds good to me. Some placesprice a gallon of fuel for $45 around here.
defintaly looking good, and the sound of the price being alot cheaper than nitro fuel sounds good to me. Some placesprice a gallon of fuel for $45 around here.
For me, the most importedissue is that it can run so much longer (approx. 25%) on one tank of fuel, compared with 25 or 30% nitro.
One downside is that the needle setting is a little more sensitive without the nitro. What the hell, turn the needles 1/10 of a turn instead of 1/8 turn
06-06-2009, 02:48 PM
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RE: 1/8 buggy on FAI fuel (0% nitro)
ORIGINAL: xjqkz
few months as in 65-70 months ago?
ORIGINAL: JB COMP
I know a few months ago I could a get a gallon of 5% nitro for $10.00 and 0% was $8.50 a gallon
and the sound of the price being alot cheaper than nitro fuel sounds good to me
few months as in 65-70 months ago?
06-17-2009, 03:30 PM
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RE: 1/8 buggy on FAI fuel (0% nitro)
If there is someone who will have little information about my first race in Skanderborg/DK without nitro:
The engine ran very well for the free practise. Halfway into thetimed practisethe engine suddenly ran lean. 3 / 4 turn at HSN did not help a bit . The error was the 5 years old pressure tube, which was broken just afterthe pressure nipple on the exhaust. There was a risk that the glow plug has been damaged, but I chose to use it for classification + semi. I hadonly 1extra glow plug (4 stroke), which I would prefer to saveforthe mainfinal.
Just after the start of my semi-final, the engine flamed out at the end of the main straight. Into the pit and it started up just fine, and ran without problems 10 minutes on a tank full. About 2 minutes before the end of the semifinal, the engine died again - the glow plug was destroyed (due tothe lean run in the timed practise). I am convinced that it was due to the bad glow plug, the engine died in the start of the semi.
In themain final the engine flamed out after the first pitstop (at 10 minutes) because ofa little too richLSN - entirely my fault. (Ifan engine is running with little or no nitro, it will be moresensitive on the needles than if you run with onfor example. 25% nitro). After a little hassle in the pit, itwas ready again (lost approx. 4 laps), and ran perfectly the rest of the final. After lastpitstop (at 20 minutes), it should of course run the last 10 minutes pluscomplete the last lap, when time had passed. So I had to drive 10 minutes and approx. 35 seconds on the last tank full. There were approx. 2 ml of fuel left in the tank when I drove into the pit! . Could not be more perfect .
Overall I am very well satisfied with the fuel, and will NEVER run with nitro again.
Links to 2 videos from the main final. "My" car is the green one with white wheels - first seen at 0.45 in the first video.
http://www.youtube.com/watch?v=w578MdY3GM8
http://www.youtube.com/watch?v=709rFIgd ... re=channel
No one could tell by the performance and top speed, that I drove without nitro. I hope, that there will be shared some videos from the main straight to prove it.
Addition: It must be said that I controlled how much fuel that could be in the tank + filter + fuel tube completely over to the carburator before the race: Exactly 125 ml.The reason why I could run +10minutes on one tank of fuel was not because of atoo bigfuel capacity.
The engine ran very well for the free practise. Halfway into thetimed practisethe engine suddenly ran lean. 3 / 4 turn at HSN did not help a bit . The error was the 5 years old pressure tube, which was broken just afterthe pressure nipple on the exhaust. There was a risk that the glow plug has been damaged, but I chose to use it for classification + semi. I hadonly 1extra glow plug (4 stroke), which I would prefer to saveforthe mainfinal.
Just after the start of my semi-final, the engine flamed out at the end of the main straight. Into the pit and it started up just fine, and ran without problems 10 minutes on a tank full. About 2 minutes before the end of the semifinal, the engine died again - the glow plug was destroyed (due tothe lean run in the timed practise). I am convinced that it was due to the bad glow plug, the engine died in the start of the semi.
In themain final the engine flamed out after the first pitstop (at 10 minutes) because ofa little too richLSN - entirely my fault. (Ifan engine is running with little or no nitro, it will be moresensitive on the needles than if you run with onfor example. 25% nitro). After a little hassle in the pit, itwas ready again (lost approx. 4 laps), and ran perfectly the rest of the final. After lastpitstop (at 20 minutes), it should of course run the last 10 minutes pluscomplete the last lap, when time had passed. So I had to drive 10 minutes and approx. 35 seconds on the last tank full. There were approx. 2 ml of fuel left in the tank when I drove into the pit! . Could not be more perfect .
Overall I am very well satisfied with the fuel, and will NEVER run with nitro again.
Links to 2 videos from the main final. "My" car is the green one with white wheels - first seen at 0.45 in the first video.
http://www.youtube.com/watch?v=w578MdY3GM8
http://www.youtube.com/watch?v=709rFIgd ... re=channel
No one could tell by the performance and top speed, that I drove without nitro. I hope, that there will be shared some videos from the main straight to prove it.
Addition: It must be said that I controlled how much fuel that could be in the tank + filter + fuel tube completely over to the carburator before the race: Exactly 125 ml.The reason why I could run +10minutes on one tank of fuel was not because of atoo bigfuel capacity.
