Have anyone tested the new airbox? whats the feedback with it.
last year at Macau I ask around and some said it run cooler, some said no difference at all, some even dare said its 2th per lap.

From what I gather power delivery at the low and mid are more consistent, that's the feedback from my son. All P7 comes with the new intake, I think. Mikko is using 1.

I haven't done back-to-back testing with the new airbox vs. the old airbox so I can't say for sure if there is any difference.

The new one looks nicer, is easier and faster to assemble and put on the kart, and it has a hole on the bottom of the airbox as standard so no need to drill one. Running cooler would make sense because it does look like it should make the airflow to the radiator cleaner resulting in better cooling - again I haven't done any back-to-back testing but I think it might be in the region of 1 to 4 degrees C cooler.

So if its just 1 to 4 degrees C cooler, is it worth the money to get it ?

FWIW I don't have a Rotax, but I read a tuning software program (the widely used one from the UK, don't remember the name) has the new and old box as input and recommends different jetting depending. You might want to look into that. The jetting difference might be a clue to any power difference.

Jet-Tech doesn't have that option, that's the only popular UK-software I'm aware of. Someone on ekartingnews claimed to have put in on a dyno and recorded a 0.5hp gain.. I'd think that the way you mount it and how clean you keep the airbox has a similar advantage.

A related question about the airbox - are two types of filters still available? I remember there being a coarse and a fine filter available but now I've only seen the fine ones available. One would think that the coarse ones could offer an advantage on clean tracks where a fine filter isn't needed?

In answer to Mikko's question on the two type of filters. First of all, Rotax only supply one type of filter - the fine type. The coarse type was used way back in 2002/2003 and maybe 2004 when the regulations does not specify the type of filters to be used. The coarse type were available locally. However, Rotax put a stop to all this when they came out with the new regulations that stipulated that the fine filter MUST be used at all time.

I remember when we used the coarse type, we had to replace the piston, bearings a lot earlier than usual. Also the power advantage was minimal. Hope that answer your question.

James Leong
Kartmore Racing Services

If thats correct. Its in my shopping list..

That explains the filter situation. I did some testing with the filters and wasn't able to really notice an advantage so it's good that only the fine one is allowed so that engine wear is kept down.

new airbox no stock at SHAP.
2nd hand anybody