ENR_Kyle

Do we need this, If not, would we gain anything from removing it?.. Thanks

mozzzy_2000

LOL why would you want to remove it in the first place? There's only one way in finding out; Do it!! LOL go on see what happens. I'd be interested in the effect. But having said that my guess is that yes it will have an effect because that part is what makes it into a "2 chamber" tuned pipe.

ENR_Kyle

do these engines need backpressure?.. Has anyone ever removed it before?.. I dont want the be the guinea pig..lol.. I am almost posative I read somone talkin about that b4?


It looks Really restrictive.

XTM Will

I'm not sure about nitro, But all 2 stroke PETROLEUM engines need back pressure.

{GBI}Harryball

Need back pressure for fuel flow

ENR_Kyle

ahhh.. true

ehroof

you can run it without that, it still give enough pressure for fuel, it will be louder and have more top end, but low end may be worse. gaulbaladder, lol. imagine

arlo1

Back presure is such a crude way of puting it! two strokes including these engings need tuning in the pipe it is not realy back presure that makes them work but the presure/sound wave that travels through the pipe to the end and back to the exhause port to try to help get the fresh air fuel to suck into the combustion chamber then stop it from flowing out the exhauste to put it simple. So there for the shape of the pipe and the size all controls that sound wave and thats why different pipes do different things in term of tuning a engine and how it makes its power. The one big problem that might happen with a nitro engine is, in order for the fuel to get from the gas tank to the carb they use presurized gas tanks and that presure comes from the exhauste there for if you remove the bladder it might not even run after.

arlo1

realy? cool! have you tried? I want to try. I am just working the bugs out of my rc car dyno and I hope to test the stock pipe and the aluminum one and I will try removing the gaulblader as well soon!

ehroof

i did it on my hpi, the stock plastic pipe, pretty much the same as the redcat, sounds better but low end not as good.

AllAboutFunHobbies

Basically turns into a single chamber RPM pipe.

arlo1

Did you find you had to adjust the fuel mixture much?

ehroof

a little richer actually, i went out a bought an associated rpm pipe after that

ENR_Kyle

i would like to know the results of that. I have heard you talk about this dyno before. explain more. what did you use?. how did you do it?

dclintonh

it will make it melt, at least it did mine

ENR_Kyle

make what melt?

arlo1

here is a link to a quick video I put together. http://www.youtube.com/watch?v=XdjQ445WoJw I used too pieces of 88.5 mm od tubing I calculated out the inertia of the roller and then you enter that into the program that comes with the electronics kit. I purchesed this kit in hopes of building a motorcycle/car dyno in the future (you just have to figure out the inertia of the roller and enter in the specs like trigger wheel teath ect then you conect the electronics assembly to your P.C. it is still in progress but that is why I built the rc dyno first so I could learn from it. It costed me $65 to build pluss a little over $400 for the electronics. and $42 was the pillow block bearings.

ENR_Kyle

wow.. im impressed

arlo1

Remember hp at the wheels is always lower then the engine it self and sometimes it can change alot going through the drivetrain. It realy dosent take much to hold these little engines back. The rpm is calculated It could be off a bit but if you listen to one of these engines and compare it to a hi end traxxas or something they dont compare. The traxxas sounds alot higher! I am hoping to change that I looked at the port timing in my .18 and the durations are stupid I realy think I could make this thing sing.

mozzzy_2000

If you really after great performance I'd just go out a buy a top quality tuned pipe instead of chopping one up. Great for an experiement but I doubt you'll get much out of it. Its all well and good to have great top end but its not much point if you loose the bottom end at the same time. You probably need more bottom end than top when bashing anyway I reckon.

FlyinGN

VERY nice.. Being an Engineer I can really appriciate the work you put into it.. Impressive..

arlo1

This is all for fun and for personal experiance not realy serious about racing rc's

ehroof

exactyly, fun, i just took it out to see what would happen.

rclynx

I think it needs a kidney transplant[&:]

ehroof

yeah, whats up with the gaulbladder? thats funny right, its up there with the clutch slice with spring