OPEN CHALLENGE

[GTR]

Hi Guy's,

Now I know you're all going fast and having fun but in places other than the Staets the price of fuel (Nitro) means that most countries get by on much lower Nitro than you do.

My challenge is do you think you guy's could achieve 50 MPH on 0% Nitro? 10%Nitro?

I ask this because there has been much comment about the boats getting bigger because of all the extra power available - take away the Nitro and is this true. I know it sounds a bit strange but if for heat racing everyone used low or no nitro the boats would still be fast and everyone would still have close racing.

Call me the devil's advocate.

cheers

GT 8)

 

[Jerry Dunlap]

GT,

Just my opinion, but based on 38 years of racing model boats, no/low nitro racing in the USofA will occur about the same time "Hell freezes over."

Nitro provides the ability to "GO FAST" and that's a big part of the fun factor in this hobby.

Jerry Dunlap

 

[duc]

Doing 46 mph now and planning to go over 50 in a short period of time with 25%.

 

[GTR]

Hi Jerry & Oscar,

Yes I agree that I don't think the US will abandon pouring in bucket loads of Nitro but hey I thought boat set-up combined with the right prop and carefully tuned was what made the boats go fast.

I brought this up because pretty much throughout the entire RC hobby boating is the only area that uses Nitro in such high percentages. Car racing on the world scene is no more than 25%, Helicopters 30%, FAI Pylon racing 0% - Boat racing in the US 60%? Why?

I ask from a cost benefit analysis point - does 60% fuel cost twice that of 30%? Do the boats go twice as well?

Love stirring up people thinking about this stuff.

cheers

GT 8)

 

[TimD]

GT,

I went very close to 50MPH - 80Kph (78.9kph with gps) on 25% with the old boat. The old boat (TT powered) had a gear reduction system in it so the motor revved higher than the prop which multiplies the torque.

When I finished the new boat with the direct drive (novarossi / lawless) I initially ran it on 25% and then stepped up to 50%. The increase in torque was very noticable. Admittedly the head button on the nova was made for 50% nitro so it was undercompressed for 25%.

What I'm getting at I guess is that if you set the motor up specifically for low nitro i.e made the head to suit, then you could go close but it is much easier to make more power with the nitro.

Oh yeah - with cars the nitro % is in the rules - as with pylon / combat. and I think heli's it is more for heat reasons but not too sure - cost is not such an issue for those guys - seen how much the radio's cost????? just my opinions ;D

 

[Hammerhead]

We have riggers in Japan that go well over a hundred in rough water. This is called the Choukyouri Race. It is a 12km race where the use of nitro is prohibited.

OS makes an engine called the .46VZ-ST. It is designed to run on straight fuel. It's practical RPM range is up to 28000.

Not bad in my book when you consider that the Nitro .46 has the same Practical RPM range.

Hammer

 

[GTR]

Hi Everyone,

My point that may be lost on the US guy's is the fact that most motors in the world were originally designed to operate on low or no nitro. Motors have been altered/adjusted to run on the extremely high nitro % used in the US. I guess my other point is good perforemance is available at much lower nitro percentages (read cost) and if everyone played the game racing would be just as good. On the point of price I don't know how much you US guy's pay for nitro but in Oz it is $25ltr so 50% costs around $60 per US gallon (around $35USD). As you can see droping the % cuts the cost quickly.

Extra thought - high nitro doesn't make the motors rev any harder but may help with the torque to pull more pitch or more diameter.

nuff stirring for now

GT 8)

 

[Hammerhead]

For the 45% that I use in my 90 boats, it costs about 60dollars for 4 liters ( a bit more than a gallon)

Straight costs about 10 bucks a gallon. In heat racing over here, there is no limit on the Nitro, so if you want to win, it is best to use the appropriate amount for your engine.

I think that with the work that you have to do to really get the Straight fuel engines spinning is a little too advanced for the younger boaters, so they would get turned off from racing. Altitudes play a big part as well. It is really hard to get a needle that will perform over 500m above sea level. You will most likely fry your engine if you don't use some nitro. Most people here run at sea level or close to it though.

Hammer

 

[Kris Flynn]

hey GT, sounds like they are too scared to try and takeup your challenge joking, hopefully Grim checks in soon to have his 2cents on the topic, he may be the one to do it

Kris

 

[Grimracer]

Hi guys

Well this is a good topic... HUM.....

I can tell you this.. Its tough to jump in to this when you are sponserd by the best fuel maker in the country.. Byron fuel.. Little shameless plug for my freinds there...All kiding aside i realy like this fuel...bearings seem to last forever..

Lets see. In 1998 I went 72mph using 25% byron fuel in a 40 hydro. The boat was a Dumas Hawk powerd by a OPS 45.

It was enough to teach me that head space and pipe length are everthing. Can i get involved in a FAI fuel chalange of some type? I dont know maybe.. All this talk lately about nitro, quite pipes and the like... I do not care if we have to tape 20 lb dumbells to our boats and race them.. If we all have to do the same thing then i will do every thing in my power to try to beat you.

You know that if I (we) began to limit the amount of nitro i (we) were using (and i have done this in the past) chances are that i (we) will become faster..Why you ask.. Because it makes us take a closer look at boat setup..

Hum...5 Internats titles... it just might work...

got to go

Grimracer ;D

 

[GTR]

Hi Grim,

Welcome to the discussion - I think you have understood my point. Tipping in lots of nitro is not the answer to going faster - although it does have it's place. Boat set-up & engine tune/pipes is the answer. What made me think of this originally was comments from several people that the boats were to small/light for the amount of power available. In any other field to go faster you try to get smaller or lighter why is this so different. I started to wonder if people are forgetting how to set-up, develop better boat handling. People seem unaware that although it can be a problem initially to set-up once adjusted to FAI fuel the motors are super reliable and last almost forever, nitro fuels (even the best LOL) are very hard on the metals in motors. Although I acknowledge that people like yourself and JD are absolute legends & I guess if you want to win (like everyone does) you have to follow everyone else with amount of nitro. I would suggest that OB's only really face 2 problems in the future - price to buy in and race & how noisy they are. I think these issues will eventually put pressure on OB classes.

Nuff stirring

GT 8)

 

[Hap Mulvany]

If you want to run 50 to 80 mph with no nitro by a gas boat Zenoah,QD, or J&G will get you there depending on the hull

 

[Hap Mulvany]

If you want to run 50 to 80 mph with no nitro by a gas boat Zenoah,QD, or J&G will get you there depending on the hull

 

[TimD]

I forgot all about this but the AMPBA (australia) has just introduced a new class called pro-am 45. Basically it is a controlled 45 mono class - everyone runs the same hull and hardware but the motor and pipe type is up to the competitor. The main difference for this to 45 mono is that only FAI 4:1 fuel is allowed - no nitro allowed at all. It should be very interesting to see how this class takes off and to see what speeds they will achieve compared to the nitro 45 mono's.

If you want to read more about it look at www.ampba.asn.au

 

[TimD]

Update!!!!!!!

I attended the Hunter Valley Championships on the weekend and saw a pro - am 45 mono win the 45mono class running 4:1 fuel against the guys running high nitro.

Just goes to show it can be done with low / no nitro fuel.....