Air box eliminator

[gojk]

Hey Carlos, I am wanting to get an air box eliminator kit but it I hear that the ESR kit isn't the best option for power. What is the best option to eliminate the air box?

I am also needing an inline water gauge, what is the best option and where do they install(I assume inline with the line coming out of the head, but I want to double check).

[Craig B.]

I would like to know the answer to this also. I just bought a ESR air box eliminator. Just can't see the stock air box flowing more air with that tight 90 degree turn into the box.

[mennis1971]

It prob doesn't on an atc, but the ESR kit isn't tapered(that is important as it increases velocity of the air entering the intake) like the BDT kit is, but Idk much about the bdt kit except that it looks like I would buy that one instead of the esr kit.

[atv fan 28]

Until i see actual dyno sheets of tapered vs straight, im still unsure which one works best? I talked with a few guys that run high dollar motors and they perfer running the filter straight off the carb.

[mennis1971]

Common sense would tell me that the tapered intake will make more of a difference on smaller bore motors then compared to BB's. As far hanging the filter straight off the carb, why not? It was quite common on to do on quads,sportbikes and other stuff before fuel injection or even all these "eliminator kits" were available. Used to be you found an air filter that fit your carb and whatever your space limitations were and that was your "kit".

[atv fan 28]

All im saying is the guys i have spoke with have tried both setups, on BB of course, and they perfer straight off the carb.

[mennis1971]

I don't doubt you a bit Wayne. What kind of riding were they doing? Drags? You gonna make it to LS on this next trip?

[nico]

Is the BDT kit actually tapered? I have studied alot of these setups, and after looking at pics, I assumed the BDT kit was just a polished ESR kit. I have the stock box and the ESR kit, and am still undecided on which to use on my 330 when it gets done with porting. I really like the aluminum plate setups that use the stock 86 boot, but am still undecided.

[derby]

For a dune bike I think the best setup is the aluminum plate with the 86 boot. I have used the esr kit and that thing flops all over the place unless you zip tie it to the frame. I think carlos made a kit to mount the esr style kit to the subframe which is what I would have used if I would have known about it. It has been debated before that the oem filter boot serves as a velocity stack and speeds up the flow.

[acecarlos]

A tapered intake tube is theoretically hands down better than a straight tube, however; documenting the difference even on an engine Dyno is very difficult. We make both and have played considerably with intake system for many years; most of the information being thrown around is false. The difference between a "tuned" straight tube and the OEM intake with aluminum plate is ZERO.

The key here is "tuned" tube length (straight or tapered does not matter as much as "tuned length"), the correct "tuned" intake length is a lot more important than any other factor...the LAST thing you want to do is run a a filter "straight of the carb"...you want to allow at least 9" in length from the Bell end of the carb to the rear wall of the airfilter for an engine running around 9K RPM's. Any shorter length such as you get when you mount a K&N airfilter "straight of the carb" will cause the intake wave to bounce of the back wall of the filter (tail end) with enough energy to turbulate the intake velocity in a negative way.

The BDT Eliminator kit is NO better than the OEM boot with aluminum bracket, it is also no worse...it does provide a good intake system, with a larger bell shape (better flow) coming of the carb, uses two internal o-rings to seal the intake tube to carb bell (no ugly hose clamps), is a "tuned intake system", and provides a mounting bracket to the frame that maintains the intake tube off the frame rails while fully supporting the intake system...it works great and looks great.

Carlos.