Supermileage Vehicle

MountainousDew · Tue Jun 09, 2009 1:34 pm

rcman50166 wrote:VERY GOOD! However we run 100 octane "Iso-Octane" as our fuel. It requires quite a high compression no? What is your take on belt drives vs chain drives?

I'm definitely no expert, since I'm only 13... But I have been around dirtbikes and four-wheelers all my life, and I would go with a chain drive between those two options... But shaft drive would be best overall, I don't know how it would affect MPGs though.

jeepkahn · Tue Jun 09, 2009 1:47 pm

chains are more effecient when your dealing with small sizes, belts only win out when your dealing with ability to transmit lots of power, now if you could say make a belt out of a silk scarf it may benefit, but I doubt it... high octane doen't require hicompression, it allows hi compression, with a long stroke motor you need more burn time and the 100octane will not burn as quickly allowing more power per stroke, similar to a diesel(diesels only need high compression for ignition, once ignited it burns very slowly, hence the undersquare design of diesel engines)...

MD...Shaft drives eat horsepower like a coppers eats donuts.....

spudtyrrant · Tue Jun 09, 2009 2:02 pm

if you want highly efficient bearings use the bearing found in street luges they will give you a nearly frictionless roll i'm not an expert though but i would use a chain drive since you dealing with low power you want to get the most efficiency of it and using a chain drive will accomplish this

rcman50166 · Tue Jun 09, 2009 2:15 pm

Ok, so I think we shall continue to use chains. Hi performance road cycle wheels should have an extremely smooth roll right? The ones we have are $300 per wheel. Can you find better or do you believe what we have is sufficient? We have also thought about lean steering, similar to how a skateboard works. What are your thoughts on that?

jeepkahn · Tue Jun 09, 2009 3:13 pm

the wheels should be fine, but upgrade the bearings, as good as the stockers are, there are better ones available... I would stick with normal steering... I'm guessing the wheels are 700c.... I wouldn't go any smaller than a 19 on the tire size...prolly around 100-110psi with 19's, 95-100 on 21's, and about 95 on 23's... And balance them... also if you can plumb it like this, run the exhaust out directly in front of the rear wheel to disturb the air to reduce drag....

rcman50166 · Tue Jun 09, 2009 3:22 pm

You are a genius, how do you know all these efficiency tips by only racing? Anyways, what direction would you want to point the exaust to create turbulence to reduce friction?

jeepkahn · Tue Jun 09, 2009 3:39 pm

years of racing road and mtn bikes, then roadracing motorcycles, racing atvs, building/tuning motors, learning tips and tricks from the many HIGH DOLLAR factory race teams I've been around..... I've done R&d work with severalrace teams, and performance manufacturing companies.... And I've even had a few of my ideas/designs stolen and turned into small fortunes by companies, And I'm a gearhead aspie with ocd....

pizlo · Tue Jun 09, 2009 3:58 pm

LOL Rcman your team would do far better paying for transport to get jeepy here in to win you this competition... I don't know shit about cars or bikes or engines, but I know that whatever it is better have a real nice paintjob, and a SUPER skinny guy driving, seriously dude starve him for about 20 days first and you should win.

jeepkahn · Tue Jun 09, 2009 4:02 pm

pizlo wrote:LOL Rcman your team would do far better paying for transport to get jeepy here in to win you this competition... I don't know crap about cars or bikes or engines, but I know that whatever it is better have a real nice paintjob, and a SUPER skinny guy driving, seriously dude starve him for about 20 days first and you should win.

getting me there would be cheap, feeding me would be EXPENSIVE...

rcman50166 · Tue Jun 09, 2009 4:05 pm

Well do you live anywhere near Connecticut or Michigan? My team would love to hear your advice. And there is a minimum weight limit of 130 lbs. Oh and you didn't answer my question about how to orient the exhaust

pizlo · Tue Jun 09, 2009 4:17 pm

Hahaha, we'll what I've found in my short 14 years on this earth is that people either like a LOT of foood, or GOOD food. People who shovel it down normally aint picky, and people who care about garnish (wtf??) will only have a normal serving. so I'd clock this guy in at about... 50 a day cause you can grab a solid breakfast for 12, a solid lunch for 20 and dinner/dessert for the rest easy. Now that's assuming he is a nice food kind of guy that likes large quantities. If your lucky you can do it for >30 but hell you said you had almost no budget:P while you're at it bring me along and I'll do a full assessment of your pantry situation.

jeepkahn · Tue Jun 09, 2009 4:36 pm

The exhaust should point down and back in front of the rear tire.... by disturbing the air in front of wherethe tire meets the ground/airstream it helps to eliminate the compression of the air in front of the tire, watch the dust in front of cars at bonneville, the tires even at less than 50 mph kick up dust before the tire actually gets there....when you are pushing air you are creating drag, the exhaust turbulunce "breaks" the air up so that you go through it instead of pushing it....

And I actually eat pretty cheap, A monster energy for breakfast, a monster for lunch and an All-U-Can Buffett for dinner.....Golden Corral, Seafood, Bojangles on Wednesdays...I'm not picky...

I do have family in the SouthBend Indiana area, just across the state line outta michigan...

pizlo · Tue Jun 09, 2009 4:39 pm

Heh my friend said he would drink a whole case of monsters in an hour, he got to 7 before he had cardiac arrest and we called the ambulance, was pretty scary.

jeepkahn · Tue Jun 09, 2009 4:51 pm

I don't exceed the amount per day listed on the can, I wish they made it with less caffeine so I could drink more... the green monster is the best tastiing ED on the market IMHO....

Sorry, back on topic...

rcman50166 · Tue Jun 09, 2009 5:03 pm

Well I don't know, If you can get up to Michigan maybe we can get you into the competition. But I'd rather you come to Connecticut so you could help us with the build or design. I guess I'll bring it up at the next meeting, which is probably in September. What typical gear ratios do you see on vehicle similar to this or what would you recommend. The 6:1 ratio gave the vehicle a top speed of 41 mph. So I want to cut in half to get right in the butter zone of 20 mph. But there has also been talk about just making it very fast so the car has a longer coasting time. What would you recommend?