Ram air vs rejetting carb

[Karl Snarl]

You are not well enough informed on this subject and therefore just don't get what is being said here, Neither the carb nor the engine suck in air/fuel, atmospheric pressure rushes in through the carb body when the port or reeds open due to the case pressure being lower than that of the atmospheric pressure outside of it, the outside air is not drawn away from the carb in a vortex or vacuum or ever air speed around it because it's NOT moving fast enough nor does it have the pressure to over come the atmospheric pressure so the only fight here is you beating a dead horse not understanding the facts! Your gains though small are very easily explained since you've unshrouded the carb of it stock cover the volume was slightly increased which is normal and to be expected, put a more restricted air filter on and you'll lose that volume gain it's really quite simple!

I didn't even think about the housing volume gain. Makes sense why it is doing what it's doing.

@DAMIEN1307 I have a similar filter.

 

[Jayraye39]

well to make it more interesting I also have changed carbs the carb I had in the picture was an NTspeed carb with a 69 jet at 500 ft when having the ram air system on that carb with all four air tubes open I got plus two miles per hour faster than without changed the carb to the new bowfang had to run a hair higher on jet at number 70 and with the air system on that carb with two open air tubes I got plus 2 mph faster so something is definitely going on here with air flow because I'm getting same results with the system on two different carbs and jetting is not the problem at all not sure what else can be said about this but that there is definitely a mystery happening

 

[DAMIEN1307]

so something is definitely going on here with air flow because I'm getting same results with the system on two different carbs and jetting is not the problem at all not sure what else can be said about this but that there is definitely a mystery happening

You can be sure that the something going on is simply no more than better airflow with 2 different carbs that just happen to be tuned to the motor in question.

It is not your "ram air" because it simply will not work on 2 strokes.

Proper air flow, good tuning...no mystery here...DAMIEN

EDIT...May the dead horse R.I.P....lol...lol.

 

[Street Ryderz]

More specifically, atmospheric pressure is constant at whatever specific altitude you reside in...The higher the altitude, the lesser the pressure, but always, definitely, a constant...lol...DAMIEN

Yes the difference between 0 (sea level) and 5000 ft is only around 2.5 p.s.i. and not that big of a deal but from 5k to 10k ft it gets a little sketchy and after that well oxygen it's self becomes an issue LOL

 

[Karl Snarl]

Yes the difference between 0 (sea level) and 5000 ft is only around 2.5 p.s.i. and not that big of a deal but from 5k to 10k ft it gets a little sketchy and after that well oxygen it's self becomes an issue LOL

I don't think the lack will be a problem for some people, if ya feel me. lol

 

[Wevil Knievel]

Damn Jayray you make me not want to post pictures of my set up... That bike of yours is next level...

But this is what works for me and it only cost me $1.25 at ace hardware.

A p.v.c. p-trap from under the sink and a conduit bracket and two screws. Its adjustable so I can use it when Im trying to haul ass. I get 45mph stock 80cc motor with a flex pipe.

 

[DAMIEN1307]

Yep...cheap to do and directs air to the carbie...thats why we really cant call these devices "Ram Air" systems, but rather more like "hood scoops", not unlike the hood scoop that was on my 1967 Mustang many years ago...it merely "scoops the available air and directs it a little more fully to the carb resulting in greater air flow is all...Good air flow is why i also chose my low profile, 360 degree K & N knock off air filter for my bike...DAMIEN

Ps...you hopefully have some oil impregnated foam type material in there somewhere to prevent "scoring" from sand/dust particulates from damaging the cylinder/piston?

 

[Wevil Knievel]

This makes no sense, and we've been through this again and again with folks not understanding how a 2 strokes intake works first and foremost then understanding at what speed and volume of air will over power atmospheric pressure. Ram air simply put does not work on a 2 stroke, if this were a viable way of making improvements of air flow through the body of the carb and actually effected the volume with a gain all 2 strokes would have been manufactured that way!
How do you explain a very turbulent and oxygen deprived spot and has a negative air supply, when atmospheric pressure is constant and most reed valved 2t's use an air box? Oxygen deprived? How?
A better understanding of how a 2 stroke works is needed here along with air flow characteristics.

But it does make a difference having air diverted into the carb hole. I gained 6 mph just doing this. Some of that may be due to the larger jet than it needs (70 when a 68 would make it run normally.).. Idk but I cant argue with facts. Its 6 mph faster with than without.

 

[Wevil Knievel]

Yep...cheap to do and directs air to the carbie...thats why we really cant call these devices "Ram Air" systems, but rather more like "hood scoops", not unlike the hood scoop that was on my 1967 Mustang many years ago...it merely "scoops the available air and directs it a little more fully to the carb resulting in greater air flow is all...Good air flow is why i also chose my low profile, 360 degree K & N knock off air filter for my bike...DAMIEN

Yes an air scoop would be more proper in terms. Thanks D.

 

[DAMIEN1307]

your hopefully have some oil impregnated foam type material in there somewhere to prevent "scoring" from sand/dust particulates from damaging the cylinder/piston?

You did do this, Right???...lol...DAMIEN