The Best Damn Bike Pt. 1 (planning phase)

[TheViking]

greetings all,

I'm new to the whole motorized bike world,

but my buddy, who is a licensed welder and mechanic looked at me a few weeks ago and said: "hey man, how fast do you think we can make your old bike go?" so i did a few weeks of research and came up with this list of mods to a grubee skyhawk slant fire 80 cc 2 stroke.

1. expansion chamber.
2. twin boost bottles and nitrous.
3. larger carb.
4 better timing.
5. high octane fuel.
6. faster sprocket
7. lower weight
8. variable transmission.
9. ram air intake.
10. micro supercharger.
11. capacitance discharge ignition

can this be done? I doubt #10 is even possible, but ill let the experts be the judge of that!

-Viking

 

[Dirty tiki]

take the boost bottles and nitrous and throw them in the garbage.

 

[Vistaman73]

high octane fuel won't make it run better, it might even make it run worse, all it does is reduce some chemical to prevent pinging or misfiring. i hope im right, im having a little brain fart right now but trying to get an opinion in.

 

[TheViking]

take the boost bottles and nitrous and throw them in the garbage.

explain your reasoning?

 

[TheViking]

high octane fuel won't make it run better, it might even make it run worse, all it does is reduce some chemical to prevent pinging or misfiring. i hope im right, im having a little brain fart right now but trying to get an opinion in.

ah, i thought higher octane fuels also are cleaner, i could be wrong

 

[Vistaman73]

No not really cleaner... At least not that I know of.

Nitrous is the worst addition to a bike. It's way expensive, doesn't last long, and can blow your engine because it makes your engine run extremely lean, it does more damage than good. But I have a boost bottle and I feel OK about it, I needed to tune my bike afterwards and I was able to lower my idle but I don't know if it really did anything in the speed range, but double bottles? NO WAY, if you new how a boost bottle works and the equation, then you wouldn't want two, the cc of the bottle and tube should match that of the engine. With two, you have double the cc, now since they are two separate bottle, it might be different, but only one is good enough. Cheers!

 

[TheViking]

No not really cleaner... At least not that I know of.

Nitrous is the worst addition to a bike. It's way expensive, doesn't last long, and can blow your engine because it makes your engine run extremely lean, it does more damage than good. But I have a boost bottle and I feel OK about it, I needed to tune my bike afterwards and I was able to lower my idle but I don't know if it really did anything in the speed range, but double bottles? NO WAY, if you new how a boost bottle works and the equation, then you wouldn't want two, the cc of the bottle and tube should match that of the engine. With two, you have double the cc, now since they are two separate bottle, it might be different, but only one is good enough. Cheers!

thanks! very helpful!
any other tips?

 

[Vistaman73]

How do you want to go about doing 7, 8, and 9. I read in some threads about ram air intakes (just search it) that it doesn't do much. Have you heard about the SBP Shift Kit? And the last one, what do you mean, these engines have a CDI, do you mean and upgrade?

 

[TheViking]

How do you want to go about doing 7, 8, and 9. I read in some threads about ram air intakes (just search it) that it doesn't do much. Have you heard about the SBP Shift Kit? And the last one, what do you mean, these engines have a CDI, do you mean and upgrade?

i have heard of the kit, but it makes the bike illegal in my state (Illinois: if its possibly dangerous in the hands of idiots, NO ONE MAY HAVE IT)

by upgrading the CDI I mean increasing the energy output, from two picofarads or so to like half a microfarad. (google Faraday's law if you dont understand capacitance, Wikipedia will help) but the more energy you blast into that cylinder the more and faster you ignite gas yes?
and lower weight = titanium frame. problem solved, wallet destroyed.

 

[BarelyAWake]

10. micro supercharger.

Jus' as a FYI - it's... extremely difficult to effectively supercharge a two stroke engine, due to the lack of valves the charge "blows through" with little pressure remaining in the combustion chamber.

Not saying it's impossible ofc, but given the difficulties folks have trying to supercharge even the small four strokes (diminishing returns, as much or more power may be required to drive the charger as is gained), compounded by the problems encountered with these relatively low quality kits and capped off by cost - if ultimate power to weight is the goal, you may wish to consider the Morini engines.

Even without modification they're at least 3-5 times the HP (depending on model) than the Chinese two-stroke and yet cost about the same as just a supercharger in approximately the right scale...

Don't get me wrong, I love these lil HTs - but sadly there's a limit to how far you can bring such a primitive design... depending on your goals, there may be better tools for the job than the HT *shrug* I too love to tinker an' try to get the most outa them tho heh, ya might wanna check this thread out for examples & inspiration: http://motorbicycling.com/f13/hybrid-chinese-motors-performance-tuning-14204.html

 

[kipharley]

high octane fuel won't make it run better, it might even make it run worse, all it does is reduce some chemical to prevent pinging or misfiring. i hope im right, im having a little brain fart right now but trying to get an opinion in.

Which end are you talking from?Right now!Kip.
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