I just hacked my air box recently by opening up the whole (triangular shaped) wall facing the chassis on the lower air box. I've driven my car around for a week now and I don't know if it just me, but it feels like the performance actually went down from the stock air box. Does anyone have any dyno test results of the hacked air box versus the stock air box? The sound on the other hand is dramatically different than the stock set up. It was actually louder than I expected and is fun to hear but not at the expense of performance. My guess is that there is too much turbulant air flow as a result of the change and somehow this is causing a loss in performance. Oh yea... I have a K&N panel filter on there as well. Does anyone have any thoughts? I'm thinking about glueing the damn thing back on unless someone can convince me that I am wrong. Please help... I appreciate it!

Yeah I remove the bottom half of mine and used double sided stick tape to hold the air filter in place....it sucked, I hated it. I could no longer burn my tires from a dead stop.

I think we get a ram air effect with the stock setup above 60 mph,

Has anyone tested for this ram air effect? If not I am going to.

Stock is better...0-60 in 6.6 secs..If ain't broke, why fix it?

All I have is the K&N panel air filter with the stock air box and a Budget stainless steel y-pipe. I'm not into noise and have none presently other than some at WOT.

Glue those hacked air boxes back together while you still have the pieces. If not buy one from an auto wrecker. Hacking an air box, in my view, is a dumb thing to do.

or u could have jusr drilled some speed holes in the bottom portion and rmoved the snorkel on the bottom toooo.,,but IMO STOCK AIRBOX 4L

Us aftermarket intake folks have been had!!!!

It's called placebo effect. Your body is not sensitive enough to detect anything less than probably 10hp, let alone the 1-2hp this might or might not give you. You probably couldn't even notice it at the track even if you are super consistent.

I'd be curious about this myself. I hacked my airbox in similar fashion and like the wot sound but am dubious about any increase in performance. Maybe the Nissan engineers know better than us? lol

here is a recent thread in the dyno forum shows some great info for back to back dyno runs. this is of course on a 3.5 and your hacking would/should produce a similar effect to the gab. the numbers start on post #17.

I hatched mine...and I know I lost power and dramatic decrease in low end for sure...then went back to stock and it seemed like night and day I regained my low end, and the responsiveness seemed to come back right away...but I do like the growl, not worth it IMO.

i just went from the K&N cone back to stock....im almost certain i lost alot of low end. never going back to the cone

I have heard these kind of things in the past but never really thought they were true and now its talked about again. That hurts... i wish I still had my stock air intake setup to compare. I really dont want to believe I paid to loose power.

I bet none of those dyno's account for ram air effect either.

maybe we gain more on the highend, where we need it. I did notice i squealed the tires less from a stop.

i love how tires making noise is how we are measuring our intake upgrade performace results

i custom fabbed a cone filter bracket out of the little bronze piece in the stock box, and used heat tape and cardboard for a gasket.

a cone filter, or any basic CAI will decrease your low end power (torque) but conversely it will widen the hp range throughout the high end of the power band. so basically the hacked air box mod is only good for the sweet induction growl and better high end throttle response which means that unless your droppin' gears at high speed or doin' freeway racing...hacked box=cool noise.

just what i've noticed and researched...peace
phil

I feel increase in the upper rpm range, but low end not very good. Love the sound too much though.

the gains or loses form an intake are not going to be really noticable....unless u have dratically modded ur motor.......its all in ur heads.....the basic idea is that our stock airbox>* aftermarket intake setups...yes NISSAN engineers knew what they were doing....

So the verdict is the addition of the weapon - R intake in my car more than likely caused a loss of power?

must not forget its a grocery getter we are talking about here, intake/exhaust is engineered for quiet preformance over HP.

yea i had one on my old maxima and it jsut made lots of noise and made it feel like more power until i put the stock box back on....the only thing u really notice is the throttle response is much better on the stocker.....and interms of designing for quietness for the grocery getter....the silencer resonator that used actually increases power (helmholtz resonator) exhaust definately ment for quietness hence the ****ty stock y-pipe.....its all about balance......they made the car so it would accelerate nice but still be semi-luxerious

I'm going to glue the air box back together and modify the resonator section of the inlet piping. I am a mechanical design engineer by profession and I have the benefit of a rapid prototyping machine, which for those who do not know, is basically a 3D printer that builds functional parts out of ABS plastic. I'm going to see if I can design some new piping to route that section of piping (going to the resonator) to the front grill or in that general area. I'll post some pictures of the part to see what you guys think. Hope this isn't a waste of my free time... =)

Doesn't look like anything decreased on this Altima with a cai. It might as well be the same thing as a maxima
http://www.nissanperformancemag.com/...projectaltima/

its a gereralization. all cars are different. my bmw (1983 528e) only gained about 4-5 hp on a cai, but a buddy's 240sx gained 13hp in the upper end with no losses. i definately dont dispute the fact that a cai can and in some cases will increase hp, but as a generalization you have to give up hp to get it somewhere else.

phil

Can you explain in technical terms exactly:
1) One would have to give up anything?
2) If 1) is true, then why didn't that apply to this Altima, maxima that decreased his 1/4 time with a cai, and the 2 cars you just mentioned.

Thanks

ghetto style biatch!!



j/k

generally with a cai if you gain hp in one area of the power band you lose it in another part of the power band, for example: with the stock box my car would chirp 2nd gear and had good high end throttle response, but with my cai i can no longer chirp 2nd gear, but on the other hand my high end acceleration has improved marginally over the stock box.

and as for the second part, it is a generalization. cai improvements all depend on your mods and how your engine is tuned as well as many other factors. and again, i dont claim to be an expert just stating what i've seen on my various cars, read and hear about.
phil

hehe gotta love the tire noise dyno

Hacking the airbox alone introduces hot air into the intake, bad for performance. You're better off leaving the box alone and leaving the snorkel in (if you took it out).

Check out what I did in this thread. Start reading from post 11. One thing I will do next to increase flow thru the snorkel is by disconnecting the elbow to the resonator under the battery and plugging that up to prevent hot air from entering it.

I see you have a hybrid intake haha....

not a measurment BUD...

Actually, lengthening the intake tract in GENERAL should have the opposite effect. Try thinking of long/short tube header theory

I thought colder air would benefit any engine in most any reasonable tune? Explain what mods and tuning pos and neg affect hp with a cai type intake.

Thanks.

im just trying to get 15 posts so i can start my darn thread, sorry guys!

i hacked my airbox, the performance increase/decrease is negligible....if you're not squealing your tires, check your TIRES first. Then check the knock sensor. I fail to see how INCREASING air flow would hinder performance. I did the mod because of the sound, and because it was free.

You're a dumbass and a clown. You're a dumbass clown. The guy you quoted was pointing out to some moron that measuring power by listening to your tires squeal was pathetic and not right. Until next time

I have been working on a system that involves disconnecting the pipe going from the snorkel to the resonator, and hooking it up to a PCV pipe leading to a series of intakes that are placed right below and in front of the radiator and behind the openings in the bumper.

I have been waiting to receive a manometer so that I could check pressure readings at various locations within the system and at different driving speeds versus the stock setup. I also plan on testing the hacked-box theory as well.

I learned from the y-pipe incident that none on this board will give you the time of day without some kind of "objective proof" that your mod makes a difference.

Stay tuned, as I plan on finishing it and posting the results this weekend.

trust me custom intakes like that has been done... several times matter of fact, dont waste your time. its just an intake

as far as i understand the amount of hp gained with a cai is conversely proportional to air temp. so your correct, colder is better, but unless it is designed properly the cai doesnt grab the coldest air so the gain is nominal and in some cases the cai grabs hotter air from the engine block resulting in the loss of hp.

oh and the first part of your post: i concede defeat. the stock box and a few good intakes illustrate your point they both create a type of ram air effect which increases pressure of induction air over exiting air which increases low end power, like how BMW crimps the end of there y-pipe to increase low end torque. i just read/researched this last night let me know if i have something backwards.

our intakes are designed real well, just look at it, it draws cool air from the outside and is plastic so it doesn't heat up as much as metal so just keep the stock intake!

Dave, couldn't have said it better myself

mike