Air Filter Probs?

[JoshIsSciFi]

Ok, as said before, I put in a Ractive cone filter not too long ago, you know, when the friggin passenger side hood bracket snapped.. yeah... anyways, ever since then I've been feeling the car seem to be hesitant at lower rpm's, we're talking 2k-3k here, it just seems to every now and then sputter, but the moment I hit the gas in a little further, she just takes off like its nothing. Wondering if its just the manifold isn't getting enough air at those rpm's, or if maybe something is wrong? I should mention that I got the Ractive w/ Heat Shield already on, and completely removed the stock box.

[AZhitman]

Then you're sucking hot air. AND you may have damaged or partially disconnected the MAF connector.

Put the OEM system back together. Run a duct from the bottom of it to the space between the foglights and add a fat scoop. Take off your MAF and spray it with some brake parts cleaner.

Voila. Cold(er) air intake without the hassles.

[Q45tech]

Why? Other than sound would you change efficient oem cold air intake. The MAF flow calibration curve is set up with at least the horn shape and distance to filter/upper box shape.

Cone filters even with heat shield tend to cause idle and low speed problems especially in Summer heat.

Use a remote accurate electronic thermometer and measure the ingessed air temp to the MAF.

[squeefoo]

Mine was 150 F. intake temp at/ between 75-80 amb. youcouldn't imagine what a dog it was , I'll never do it again!

[Q45tech]

Why I love to race Q where the owner has installed some cone filter and never checked the efficiency of his jury rigged cool air/external air pick up point.

I KNOW I'm only loseing 4" WC pressure by using the oem system, and gladly accept the 1% power loss.

Try to talk to them for a while so they get good and hot from heat soak............thinking of rigging a fine spray from wiper fluid into oem air horn input not enough to wet air filter just enough to cool things.

[Q45tech]

Actually low intakes get hotter air from road air, the usual highest pressure point is just above the top of bumper where ever the radiator midline is.......headlights.

Look at the location of oem air inlet horn.........you can actually get some postive pressure 3-6/100ths of a psi at 80 mph.What happens at 100-135 mph is the losses thru the oem system almost disappear as measured after the filter at 3400-4500 rpm.

[maxnix]

There was a link in a previous thread on this topic concerning an LS400 where the highest air pressure was just above the bumper at the headlight. Considering the aerodynamic similarity of the front fascia designs, I would believe the G50 is about the same.

[Jeff Williams]

I still think the best solution, is to buy a Subaru WRX scoop, and cut a hole in the hood, right above the MAF, then cut a hole in the factory box, and balnk-off the front inlet. Then, you are getting 100% fresh air!

[Jeff Williams]

Unload a full can of brake parts cleaner on the MAF & the plastic tubing, then empty a full can of Fuel Injector Cleaner on the Throttle body, Butterfly, and inside the plenum. USe an old toothbrush, to get all the surfaces as clean as possible. It will take a full roll of paper towels, as well.

This should improve the idle, and the throttle respones by 500 to 1000%.

Not a bad trade-off, for 1 hour of work, and about $15 in material.

It wil lbe real hard to start, after al lthis cleaning. Just keep the pedal to the floor, and it will fire. You might want to let the car stand for 30 minutes, after all the cleaning.

Don't forget to put all the vaccum lines back, and re-connect the MAF, before trying to start.

If you use any activating oil on that cone filter, it will gunk up the MAF, and you will have to clean it about a week after you spray the oil on the filter.

The biggest problem, is when you dont't let the filter dry, before running the car. Give it a day, or so, before you try ot run it. I keep 2 separate filters, one on the car, and one drying.

The good part about all that hot air getting into your engine, is that it helps with the gas mileage.

[Q45tech]

"good part about all that hot air getting into your engine, is that it helps with the gas mileage" Say what?

The O2/ecu block learn adaptive learn immediately does lean the mixture to fit the air density BUT if also reduces ignition advance to limit further heating of charge and to compensate for the octane sensitivity of fuel temperature.........it usuall washes with the lowered thermal efficiency of engine. As 3-4 degrees advance decline is significant...........not to mebtion the chance of KS activation.

The throttle body, plenum and runners heat the air more than enough [too much actually] from radiational effects as the cruise/idle air flow is so slow to need further heating from underhood heat via a cone filter.............50F rise is at least 5% power loss and probably more than 10% with the affects of timing retard added.

Measure the power with 50F air flowing just above injectors vs 200F air [150/11=13.6% alone].........a 150F peak combustion temp variation is significant.

[Falkdesigns]

My best thinking and looking around led me to believe that the stock air intake system is VERY well enigneered and therefore my only plan with that is a K&N drop in air filter. With the intake at the leading edge of the hood, it's got that constant source of clean, fresh, ambient temp. air. The only thing in the intake/exhaust side of things I'll be changing is the massive, restrictive stock muffler. Of course if I could afford these beautiful headers I saw in Japan...$1600!.....

[Q45tech]

At the maximum air flows for a 4.5 liter engine [400 CFM] you won't find a measureable difference in air flow: with no filter, a K&N drop in filter, or an oem paper filter.

If you are willing to waste a little money......destroy the K&N and stretch it out and compare the square footage with the oem paper filter........measure pleat depth and number of pleats.

Twice as big in area compensates for paper having a tiny bit more restriction.

http://www.shotimes.com/SHO3airfilter.h ... m/...1.htm

Constant battles to dispell bad science of manufacturers who sell speed mods.

[PalmerWMD]

Too bad I have to run a cone filter with my SR in my S13 cuz the intercooler tubing is in the way of the stock intake system (like it sadly is on all the better set-ups that run an FMIC)

I always feel that when I am waiting in line at the track I lose power, because I know whats happening.

At least the S13 underhood temps dont appraoch the Q ones and also its a bit more open design with my Silvia front end.

I had a high buck cone filter system on my other car (also a Q45) from previous owner when I got my car.

Threw it out the very first day I could get my hands on a stock intake box from a junkyard ( $100 grrr)

Fred..

[Jeff Williams]

I think some people buy K&N filters, just for the little sticker.

I have the little sticker, on my I30t's filter box.

Infiniti said it would not affect the warranty, and I had $45 to blow, so I bought one. It sure beat spending the money on a pair of shoes, or something I really don't need.

A true cold air box, is the "snorkel" system. You might see some on Hummers, or off-road trucks. It picks up air about 8' off the ground. Really good, if you intend to drive through huge swamps, or extra muddy areas.

[AZhitman]

Wonder what happened to the thread that generated this discussion? I notice it went bye-bye...

[Jeff Williams]

Too bad I have to run a cone filter with my SR in my S13 cuz the intercooler tubing is in the way of the stock intake system.

I always feel that when I am waiting in line at the track I lose power, because I know whats happening.

At least the S13 underhood temps dont appraoch the Q ones and also its a bit more open design with my Silvia front end.

I had a high buck cone filter system on my other car (also a Q45) from previous owner when I got my car.

Threw it out the very first day I could get my hands on a stock intake box from a junkyard ( $100 grrr)

Fred..

You should have sold it on eBay. I bet you could have got $100 for it, from some new Q45 owner.

[Falkdesigns]

You put a K&N drop in and go for a drive, you notice a difference right away, you put in a new stock air filter, you notice no difference. I have to disagree with the statement about the K&N drop in's. They are better than stock at both air flow and filtering capability. Fram is now making their own version the "Air Hog" which is basically a K&N copy.

[PalmerWMD]

You should have sold it on eBay. I bet you could have got $100 for it, from some new Q45 owner.

Yes,But I would have felt bad for selling a product I dont believe in.

Its been stored in my house for a year now.And I finally found a use for it!

My S13's Cone filter had been damaged from a bolt that was tightening a fitting to the intercooler and had been jutting into the side of the filter at times.

It didnt actually puncutre a whole but it seemed to me slightly ripped some fabric.

I just put in the Q45 KN in a few minutes ago it fit just fine and is a better unit with an addtional center inlet too.And its clean!

So I am quite pleased.

Fred..:fruit

[AZhitman]

I'd run a K&N if I didn't have the oiling issue...

Hate disconnecting the MAF connector to clean the sensor.

[Rex]

FWIW, I had a K&N drop in used it from new out of the box (pre-oiled) and before time to re-oil started to get CEL's. After going back to the OEM drop in, I have NOT had a CEL since and it's time for another OEM drop in filter.

IMHO, K&N's are not for daily drivers.

[JoshIsSciFi]

Well, I think tonight I'll be trashing that Ractive, unless someone on here wants it, I don't need it, has a 3" inlet, heat shield, blah blah. A quick question for you all that have ordered from Joe, how quickly is he able to get parts out? I'm in WV right now, so anyone close could give a good estimate. I have to order the hood brackets and spark plugs, as my local Advance and Auto Zone are out or only have 4, and for some reason are unable to get more from NGK right now. I have some pics of the Q ready to go at home, just have to upload them after work.

[JoshIsSciFi]

OH, and btw, have any of you experience a CEL flash when in the On position, before startup, and then turned the car off, waited a few seconds, turned it on, and not had it? It flickers extremely quickly when in the On position until I restart.

[JoshIsSciFi]

And another btw, I'm pretty sure that you all are right about losing power with the cone, considering I ran a 9.9 1/8th with stock intake, and 10.2 with cone...

[maxnix]

Call Joe and ask for overnight. Do it!

[JoshIsSciFi]

aye!

[maxnix]

... therefore my only plan with that is a K&N drop in air filter......

Might want to read the previous posts on this topic. There is no performance benefit with K&N (unless noise is a benefit for you) and several deficiencies with it.

It's your bucks. Ignore Q45tech at your car's peril.__________________Brian1995 Q45 & Q45t & 2000 Q45

Discover the power of the button!

[Falkdesigns]

A K&N drop in will not make any more noise, it's inside the airbox. It flows better and filters better. I will get either a K&N or an Air Hog.

[Q45tech]

Filters worse than the NISSAN Q45 oem paper filter and surely can't flow better than no filter at all [other than straightening the air flow into horn].

We've done dozens of test and the K&N drop in flows 2/10ths of a percent [actually 0.24285%......they vary we tested 6 new different ones] better at 6900 rpm at 72F ambient at 1003 AMSL and uncorrected 29.22" HG [looking at my notes].

http://www.bobistheoilguy.com/...3.htmh ... /p...c.htm

My god even the NAPA drop in filters better than the K&N

[squeefoo]

Josh try Elwesso for the plugs- (good price & IN to WV should be quick) win/win !

[JoshIsSciFi]

Actually I need to find out where in IN wes is, I'll be taking the car to Louisville this weekend, maybe I'll drop in and pick up the plugs then... hmm.... Oh where oh where is Elwesso at...