i took my lid completely off just for kicks for 2 days.

just by feeling the filter after some hard driving (i.e. WOT runs), the filter feels warmer when the top is off than when the top is on. after hard driving with the top on, i'll take the top cover off, and the filter still feels cooler than with the top off...
i kept the snorkel ON at all times, and i even zip tied the snorkel onto the UICP since i've heard of issues where the snorkel gets lifted into the hood when the car's moving hence letting some hot air getting into the airbox (since the snorkel is lifted too high for the filter by wind, into the hood)

as noted before without the cover on there was no difference in anything other than sound. however just by feeling the filter with and without the intake box cover it seems the filter feels warmer without the cover, with the snorkel still resting firmly on the edge of the intake box (i used 4 big zip ties to secure it)

i put the cover back on because i was still afraid that there'll be more heat soak due to what i felt with my hand....

so basically based on the logs, more air temp. = less density in air, thus even with the help of IC the air is still not as beneficial since it's less dense since it's warmer?

i wonder what the big dawgs (ams, buschur etc) think of this thread, and why they havn't chimed in at all..

 

I think that, for any medium to long runs, like AutoX, leaving the cover off is a bad idea... you will drastically increase the air temp and lose power.

However, I can't see a downside to running without it for short runs, especially in cold weather. Summer time logs may provide a completely different result... but here's some more for your interest...

The following is a log comparing my IX w/ airbox cover and an VIII with HKS Suction and other mods (MBC, TBE w/ TP, Tune). Testing was done on the same day, same stretch of road, one right after the other.

I am Christian, my bro in the VIII is Karan:

 

If I'm reading this right then I think you did it wrong....
By snorkel I assume you mean that ram air scoop that sucks in air into the box, keep that on. I kept mine on and just cut a small hole on the side of the air box faceing away from the motor....the lid is still on. Does yours look like this?

 

This is an old Porsche trick.

Even the Mini Cooper S guys are doing this.

They drill holes in the intake cover and run tubing from the brake duct up to the intake.

 

It's not really an old Porsche trick rather it's a typical cold air induction mod/trick... what we are discussing is slightly different in that we aren't adding lines to send cold air directly into the box, we are trying to make the stock box more efficient by pulling more air in from a cold area under the hood.

A CAI like you described is nice but you have to worry about scooping in water which is something we are trying to avoid also by cutting just the side out.

 

FYI, anyone looking to experiment with a spare airbox cover, the Mitsubishi part number is MN153353. I just called up my local dealer, they said they can have it in 2 days, and quoted me $40. Again, this is just the cover, I don't believe it's the scoop or anything else.

 

Nope. I just tried it without the snorkel. I figured that taking off the snorkel would allow as much noise to escape as a hole in the other side of the airbox cover.

 

Just FYI - Walpole Mitsubishi sells them for $24 with the EvoM discount. I just ordered one yesterday. PM Spins4 and he'll set you up.

 

I get all of my OEM parts at RockVille Mistubishi online. I looked up the part number a few days ago and it was like $22.xx.

Here is the link to their site: http://www.mitsupartsdirect.com


Eric

 

You need the snorkel combined with the hole on the other side to bring in air.

 

Guys just FYI I went to the dealer to get an oil change to see if they would notice the hole and they gave me no problems. One of the techs test drove it and loved the sound lol He told me he was going to do the same for his evo....

 

I stated all this earlier...both places have excellent service and prices!

 

Depends on the dealer and tech so beware! They've voided warranties for more ridiculous reasons so do it at your own risk...that's why I advise you to buy another cover for $20.

 

Yes, I understand that. I removed the snorkel from an unmodified cover to get a feel for what increase in induction sound there might be.

 

Not that its going to do a lot, but I want more than logs. I'm going to the dyno March 17th and am going to test and tune stock lid and JCS-type side cutout lid. With the dyno, I can print boost out as a function of RPM. I also have a stock paper filter, Ralliart higher priced foam filter, and K&N to try out.

Granted the hood will be open and the fan will be on on the dyno, but I want some hard data.

Best news for all of you is that I use a Dyno Dynamics, and the results will be mirror smooth unlike a dynojet so we can have some great comparison.

I want to test both lids on my current tune, then see how much timing I can get away with and retain 0-1 counts of knock in Evoscan. I also wouldn't mind testing the cut lid for fatigue from heat and make sure the power doesn't reduce. With super low knock counts, these cars are straight needle repeatable on the dyno, almost like NA cars.