Larger air filter.

[militarymaxx]

If you have a well tuned engine and increase the size of the air filter only, will you need to re-tune ?

 

[Error401]

Yeah, but not much. If I'm not mistaken, if you don't touch the needles, it should run a tad leaner since there will be more air coming thru the carb.

 

[militarymaxx]

The reason I ask is I replaced my stock filter (GS .21 engine) with a much larger one. But when I put the body on, the clearance that was once there is gone and the new larger filter is slightly squished covering approx. 30-40 percent of the surface area.
Subsequently, it ran like crap and now I'm back to tuning again.
Maybe I should just go back to the original filter. The factory thought it sufficient enough, so why change ? LHS guy talked me into it.

 

[SkyMaxx]

The size of the air filter will only impact the tuning of the engine if, and I say again IF, there is a change in airflow through it. The amount of air the engine can take in is more constrained by the neck of the carb than it is by the size of the air filter. I qualify that by saying a clean airfilter designed for the purpose of letting air through.

Why do I qualify it? Well, if the air filter is filthy and constrains the air flow (ie it has a throat that is smaller than the throat of the carb), then the air filter will impact the performance of the carb.

So back to your original question...as long as the throat of the filter (the part that attaches to the carb) is the same size or larger than the throat of the carb, and the filter elements are cleaned and not over oiled...you should only have to make very minor adjustments to the tuning. Going to an air filter that is oversized for your engine gives you very little gain in performance and is more of a nuisance than anything else.

If you want to see better performance, get a basket style airfilter or something that is not simply a sponge. Motorsaver makes some really nice ones.

 

[Error401]

Hmmm, I'm not familiar with your setup and installation, and I can only assume that it's in a buggy from your last post. I can tell you that I had the stock filter on my savage, and it did run ok, then I canged to the motor saver and it ran alot better, though I did have to retune a bit. Is there anywhere under the shell that the filter would not be restricted? I have a traxxas 1/10th scale rubber exhaust manifold between the filter and the carb. This puts the filter under the rollbar (about 4 inches from the carb) and there is no apparent power loss from this setup. I have also seen flexable clear PVC tubing used to relocate the filter. But I definately would not have the filter squished like you said.

Whitt...

 

[militarymaxx]

The newer larger filter is more complex than the stock one. It has two foam pieces, an inner an outer core. I oiled both of them and in retrospect, may have ended up with too much foam and way to much oil. I guess oiling the filter is a case of too much of a good thing can be bad. I made this mistake before with my T-Maxx. I saturated the filter to the point that it restricted air flow dramatically. While we're on the subject of oiling filters, what's a good number of drops to use on a standard size filter ?

 

[SkyMaxx]

What you want to do is get the filter saturated, and then kind of wring it out. You basically want to squeeze the oil out of the foam to the point where it just feels oily. If it is so oily that it leaves more oil on a napkin than a fresh batch of fries from McDonalds, then it has too much oil in it.

If you do not want to completely saturate the filter element and then wring it out, you can just add drops and massage the oil into the foam element until it reaches the point described above. The purpose of the oil is to help the foam element catch the dirt. Too much oil and it will not only catch the dirt, but constrict airflow.

 

[militarymaxx]

SkyMaxx - you a Navy pilot (sorry, aviator?) Guessing based on your icon photo. CPO in the Navy here, stationed in NORVA.

 

[SkyMaxx]

We're playing tag...I just hit you on another one of your posts with a similar question.

PMing you at this time.

 

[HumboldtBlazer]

If you just bought the Kyosho three stage filter it works great. I run that filter on my Storm pro. When I switched to it I was using the stock filter from GS on my sport engine. I didnt have to retune and didnt notice any higher/lower temps from the engine. I think I did notice a little better performace, but that could have been in my head. Is it the filter with the sweet cosmetic pad type filter with the outter yellow layer with the optional rain guard?

 

[militarymaxx]

Close on the filter description. It's all black, an aluminum center shaft enclosed in a foam core, wrapped again with another thinner layer of foam, all black. It also came with a water/rain guard similiar to the storms blue guard. And to top it all off, I need to get the engine tuned again, or at least close to what it was. Man, I struggle with it sometimes. I still can't find factory or ball park settings, something to fall back on when I screw it all up.