Turbo Poll - Fuel used and boost

[Jon Mutiger]

I was hoping to get a feel for what people are using out there for fuel for their turbo powered bikes, and how much boost they typically run on said fuel.. And what bike and related mods (related to the compression of the motor)..

Last year I was on a KTM500 with a Boondocker kit, my normal psi was 9psi, and I was using Gulf racing fuel, 106 octane, non-leaded, non oxygenated. The motor is stock, and hasn't been a problem at all durability wise.

My average riding zone is between 4000-6500'.

I had no problems, but will be running different fuel this year, VP C12.

My plan was to cut the C12 with 94 at about 50/50 so I should end up with around 103 octane.

My first couple rides out I had the boost set way too high, and the bike was crazy fast.. But I knew it wouldn't last long like that. I'm hoping to keep it reliable, yet have more power than I do now.

 

[swedenturbo]

Running Sunoco 102 TC.
10:1 compression ratio and 10.2 psi of boost.

Race fuel is pricy but pleasingly, fuel consumption is low on snow bikes, about half as sleds.
With a 200 liter barrel you ride almost an entire season.
Put that in comparison to sleds that have both higher consumption and expensive clutch belts that evenually blows time another....
Look at it soberly, the fuel cost on turbo snow bikes is negligible in this context.

Haven't much knowledge in different race fuels and how octane is affected if you blend high octane race fuel with pump gas.
Many do, but at the same time quite uncertain what final octane rating will be with different blending ratios. Trial and error will maybe be the way to go in this home chemisist experiments....?
I'm skeptical about this path. The cost saving is small, while risking costly engine failures. You can buy a lot of good race fuel for the cost of a blown engine...

There are fuels with even higher octane but they get pretty extreme to use. Sensitive to sunlight which means that you can not have them in a opaque gas tank, short shelf life. In addition, toxic and sometimes harmful to the hoses and seals.

Aviation fuel such as avgas 100LL is cheaper than race fuel and may work. Have read different articles in this topic. Some state that avgas is for low reving big displacement eninges like Lycomings and Continentals, old school engines on airplanes. Led residues on valves are problems that might occur.

For everyday use, I think Sunoco 102 or similar is recommended.
At least this is my opinion but I could be wrong ...

 

[Jon Mutiger]

Haaken,

On your low compression setup, I think you'd be safe to run more boost. I know some guys on stock MX'ers running 106 octane fuel at 12psi (desired) boost.. Spikes would be higher..

I know there are lots of other turbo users out there, why not share with us your experiences?

If you've melted down a bike, let us know what boost and fuel you had so we don't do the same thing.

 

[swedenturbo]

I honestly do not know what I can boost. I may be cautious and higher boost might be posislble with the same degree of reliability.
I would like to be safe , both combustionly and mecanically.
So far, clutch, head and tranny seems to cope with the power.

In retrospect I would run standard compresion with race fuel. Hardly no difference between 0,5 bar or 0,7 bars of boost. No custom made piston is reqired in this setup.

Agree with you that there are not many people share their experiences.
It looks to be few turbo-charged snow bike riders here.
Wish we had more turbo snowbike riders who can honestly share their experiences. Whether regarding engine or track kit issues.
I try to tell you honestly about faults in design so that other riders can avoid same issues.
So far it works very well despite head gasket and cooling issues...
Go turbo, takes snowbiking to an other new level

 

[Jon Mutiger]

Well, I haven't had a single issue with mine at 9psi.. I do see 12psi on occasion while asking for 9psi.

I have a stock clutch, and the motor hasn't ever been opened from stock. It's on it's 3rd snowbike season, and really only been used as a snowbike.

I went through about 200L of race fuel last season on boost, and 2 seasons before stock.

I've been running Maxima 530MX oil ONLY in this bike, and I think that oil is what has allowed me to keep the motor together. That oil is simply amazing stuff, I highly recommend it to anyone wondering about oils. It has more anti-wear additives than any other oil out there, bar none. It's worth the extra costs IMHO.

I expect I'll bump up my desired boost to 10psi this year, as I think my new fuel will allow for it. It'll be next to impossible to detect knock via the human ear, so I'll have to scope the piston mid season to look for any signs of pre-detonation. The last thing I want to do is have something that leaves me stranded.

I think you and I are both ultra conservative in our setups.. I think others with perhaps a bit more lust for power will push the limits and let us know where those limits are for them. Obviously each situation is different, but nobody really seems to be sharing info, while I know there are at least 30 guys reading this who have boost on their bikes.

Jon

 

[powdermuncher]

I am very much against mixing fuels if you mix 92 with 110 in a 50/50 mix the result is much lower than the expected 101 octane.
While probably fine for running at regular settings boost spikes will get you.

Just my 2 cents worth.

 

[cr500afx]

Avgas for years. Boosted sleds and bikes 10 - 15 psi.

 

[Mike@KMS]

Im surprised more of you havent played around with Ethanol and tried the E85 or E100 route... Unfortunately the cold starts can be tricky with cooler temps, but cost wise at usually $2.50 a gallon or less for 105+ octane depending on the pump, it sure makes boost fun and safe! Ive run it in a lot of higher horsepower setups and between the octane and cooling ability, it REALLY shines with boost! Ive also seen people cut their own Ethanol blends and mix in more gasoline of a higher octane (most E70-E85 is mixed with 87 or lower and it can be cut with 91/93/XXX) to help with the cold starts.

 

[wwillf01]

I am very much against mixing fuels if you mix 92 with 110 in a 50/50 mix the result is much lower than the expected 101 octane.
While probably fine for running at regular settings boost spikes will get you.

Just my 2 cents worth.

Why does it end up being lower? Is it a chemical reaction? I mix race fuel with the highest none ethanol I can find in my town which is 88.... I was pretty sure that is what the pumps do here at maverick it mixes high octane and low to get get the repective level?

 

[Jon Mutiger]

Mike, before recommending Ethanol I'd highly recommend everyone do their own research on what is called, phase separation. To me, Ethanol is not a suitable ingredient for fuel.

 

[Mike@KMS]

Mike, before recommending Ethanol I'd highly recommend everyone do their own research on what is called, phase separation. To me, Ethanol is not a suitable ingredient for fuel.

Out of curiosity, how many times have you tried ethanol? Phase separation is not an issue if you are properly using the fuel, not storing your bike with fuel in it for extended periods of time, and either have a properly sealed container, or get fresh fuel often from a station. I ran it for 3 years in my vehicle as a daily driver (which it was NOT an E85 factory vehicle) with no issues, as well as many other vehicles I have converted and get daily driven for clients. While I respect you not using it, there really isnt a comparable fuel offering the octane, cooling ability and stability for a boosted application, especially at under $3 a gallon.
I will say to anyone converting though, do your research before the conversion as there are draw backs such as harder starts when its below 30 degrees out, it requires 40% more fuel to run so make sure your pump/injectors or carbs are up to the task and if stored for extended periods of time it can erode away rubber hoses and seals or as Jon stated, separate and absorb water.

 

[wwillf01]

Out of curiosity, how many times have you tried ethanol? Phase separation is not an issue if you are properly using the fuel, not storing your bike with fuel in it for extended periods of time, and either have a properly sealed container, or get fresh fuel often from a station. I ran it for 3 years in my vehicle as a daily driver (which it was NOT an E85 factory vehicle) with no issues, as well as many other vehicles I have converted and get daily driven for clients. While I respect you not using it, there really isnt a comparable fuel offering the octane, cooling ability and stability for a boosted application, especially at under $3 a gallon.
I will say to anyone converting though, do your research before the conversion as there are draw backs such as harder starts when its below 30 degrees out, it requires 40% more fuel to run so make sure your pump/injectors or carbs are up to the task and if stored for extended periods of time it can erode away rubber hoses and seals or as Jon stated, separate and absorb water.

I know as far as 2 strokes go it does shorten the life and you are more likely to have bad gas.... At least that is my experience if it is over 10 percent ethanol... I know Utah did a study on this.... Then with the more extreme temp changes it really likes to produce water...


Sent from my iPad using Tapatalk HD

 

[C-man]

Hey guys, Im a noob to turbo's myself. My bro's have been running turbo's for year but on there cars(figure this is my chance)
I just got the BD turbo. Do I need to run race fuel? I can get it but was hoping to run pumpgas this year. Or is that a bad idea? I was always under the assumption that I can run premium at low boost...say 6-7psi. Forgive my noobness.

 

[KMS]

My suggestion on this is to run a race fuel or av gas for your first outing. There will be some rich and LEAN spots that you will need to work out on their tuner. So until you have sorted out the fuel side, protect your interests and run a race gas or av gas.

 

[C-man]

My brother has a barrel of C16 race fuel. Can I run this fuel....is the octane to high? Is that ever a issue??!! I will order a barrel of whatever will work. Im hoping c16! These rich and lean spots.....Will my tuner be telling me when its running rich or lean? Should I get a AFR gauge? Boost gauge? Damn I have a lot of crap to do before my first ride!