Mad Scientist Lab test - Boost Bottle

[Mogyver69]

HI Mogyver69,

Concerning the optimal size for the boost bottle I was basically going by a lot of what I had read in other forums.....Scooter forums, moped forums, Motorcycle forums, etc....While, the bottle may not necessarily have to match engine displacement to the exact CC, it would seem that there should be an optimal size somewhere and most people seemed to indicate exact CC including the tube was needed (the bottle need not be an perfect in much the same manner as a tuned pipe need not be perfect (given mounting constraints) BUT the more perfect it is the better off performance will be)...Of course true optimal may also have to consider the original intake runner length and diameter...

Additionally, there was a bit I was reading somewhere (I'll have to try to find it but I think it was an old Hot rod magazine article ( I think by David Vizard (sp?) talking about how to make the optimal intake....they went into how to determine optimal runner lengths, diameters etc.....the bottom line seemed to indicate that a certain runner volume was necessary to achieve optimal performance (in the case of a boost bottle plumbed into the intake tract, the bottle/tube alters the factory intake and resonances for better performance in certain RPM ranges because it alters the overall intake system volume)...

With the article in hand I attempted to make a tuned intake (minus the bottle at first because I wanted to optimize high speed power first then use the bottle to catch the reversion wave at low to mid range)....first test was done here (I can't remember what I titled it but something like 2 foot intake yields performance increase)....so basically, by messing with intake runner lengths, diameters, and volumes, performance can be tailored and increased.....in the case of the 2 foot intake tract....bottom end was great BUT mid and top end suffered (either length too long or diameter too small or combination of both)....I was doing the test with available tubing that proved to be too small in diameter but was the only piping I had available at the time....I have since ordered and gotten larger tubing to help flow (again have to adjust the length of the runner because of the volume change of the larger tubing BUT one can only adjust so much because of wave reflection distance and tuning....like making a tuned exhaust only on the intake side)...

While most people don't go through the trouble of making a new intake tract, benefits can be had....I admit tho' it is easier to simply add a bottle to change the volumes to alter performance characteristics...Given some stock systems this is the easiest way.

Basically in a nutshell, I have been tinkering with intake volume, length, and diameters to see which combo yields the best ramming effect for maximum power production at the top end and then possibly adding the bottle later to reclaim power at low to mid RPMs (theory being smoothing out the reversion pulse at low revs).

Hope this helps clarify.

Andrew

Hi Andrew, It would seam that you are very educated with engines and intake systems. Ive decided I want to be your friend. Anyways I did want to point out with the boost bottle kit I originally sent you at the 84cc as you indicated. By simply shorting the hose 2.5" you can reduce the cc to approx 80cc which in turn would give you the 80cc you requested for your engine. What I have found though which may pose a problem is the engines being advertised as 80cc motorized bicycle engines are actually 70cc engines. Ive decided based on this information Ive been given that I should be selling a 70cc kit rather then a 80cc kit. For those people that ensist they have a 80cc engine they should buy our 80cc kits. For the 70cc kits I will list our auctions as 70/80cc for the 70cc kits used on motorized engines.For the most part our kits were designed taking into account the length of the hose. The idea was by shortning the length of the hose you could fine tune the boost bottle. Most kits are set up a couple CC larger when including the hose length. But the hose is generally longer then needed and most people cut the hose to length so we end up with a very close match. As you indicated matching the volumn of the boost bottle to the cc of the engine is the idea but there are many people that believe you can get some increase in power buy slightly going smaller or larger in cc to get optimal performance. I try taking that into account when making our kits.
Thanks again, Keith

 

[Mogyver69]

Can I race with you guys? I've only got 46cc so you'll need to give me a big head start.

Well then you better be running one of our nitrous kits. http://www.boostbottleindustries.com/nos_kit_with_5_refills.html
I know I will be. Im in Northern Idaho. I was wondering how far Augie was from us since he's always talking about getting a ride together. Maybe we can all get together and meet. Wouldnt that be a blast to have a 3 or 4 day event. With racing and a long tour ride. Man that sounds like fun. But first I gotta hook up with Norman he's not running one of my boost bottle kits so he's got head up.

 

[Mogyver69]

What do you want to race with?
By the way I'm not a sping chicken anymore so no foot racing or off road stuff.
Norman

Well I dont have any race cars laying around these days so we will have to stick with our mountain bikes to make it fare. Ill run my 70cc 2 stroke you run yours. Anything goes!!!

 

[Mogyver69]

Thats cheating!!!

 

[runslikeapenguin]

i just wanted to add here with this ghetto drawing of an idea i had. if one could install a reed valve in the intake manifold you could possible still get the boost bottle gains by making sure that it was down wind from the valve. which means that when the piston pushes the gas out of the crank case and causes revulsion the pressure would shut the valve and the remainder of the pressure from the piston down stroke would be diverted into the boost bottle instead of taking horsepower form the piston as it fights against the pressure on its down stroke.

http://i114.photobucket.com/albums/n265/runslikeapenguin/untitled-13.jpg

 

[Toysaresuss]

Can someone tell me why my bike would be losing speed with a 36t sprocket when i originally had 44t sprocket and it was faster with that. same road and weather condition but just heaps slower. i have a two stroke engine kit 66cc

 

[Mogyver69]

Im guessing you dont have enough power for that sprocket to push your weight... The motor is reaching its power band easier with the larger sprocket allowing you to go faster...

 

[5-7HEAVEN]

Can I race with you guys? I've only got 46cc so you'll need to give me a big head start.

Kerf, you're teasing the Happy Time guys.

 

[kerf]

You have to take a lesson from the boat guys. Boat props are much like gearing on your bike, except they're measures in pitch rather than ratio but the same difference. The greater the pitch, the faster you go, to a point. You can increase the prop pitch but only as long at the engine will reach peak RPM, as specified my the manufacture. If the engine won't reach that RPM, you're overloading the engine and top speed will suffer.

 

[Handyguy2have]

I love my Boost Bottle.

I have a boost bottle and can tell you that it has smoothed out my ride. I only wish it came with a NOS sticker! lol. Glad I got one. After several engine mount failures . I have machined my own mounts that smoothed the ride also. Keep up the good work. as far as people questioning their worthyness, oh well.