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thecrazyfish
02-01-2008, 11:01 AM
hi all

just wondering if you guys can give me a hand with my car. I have a na v6 legnum, 2.5ltr, str.

i have been running a k&n pod filter in the engine bay for about a year now, with a heatsheild, it runs reasonably cool.

today i moved it to the bottom of my front bumper with some induction pipe to get better air flow. i removed the battery terminals to reset the computer.

i let the car cool down and ran it. Now when i run it, while its cold and just starting, it feels like some bugger is putting there foot on the brake when im accelerating, but this tends to go after a say 1 to 1.5kms or running at 50km/hr. when its back in the engine bay its fine no hipcups or anything, again battery disconnected and reset. what could be causing this? why would better airflow be making it run like that?

i have also made the adjustment to the plug thingy on the bottom of the maf sensor.

thanks for any help

Nick Mann
02-01-2008, 02:53 PM
If the flow is too turbulent through the MAF then it can affect the MAF measurements. So if there is a bend in your tube just before the MAF or if the inside of the tube before the MAF is not smooth, you could be disturbing the air flow through the sensor.

Not sure I can say much more than that?

peter thomson
02-01-2008, 06:12 PM
I would adjust the MAF back to where it was first to see if this is the problem. It's best just to do one mod at a time .The MAF mod may only apply to the VR4's ?

bradc
02-01-2008, 07:55 PM
yeah the maf is very sensitive because it only measures a small amount of the airflow and it you've altered the amount of air that flows through that small amount compared to the rest of it, your car will be running rich or lean.

thecrazyfish
02-01-2008, 10:11 PM
ok thanks guys.

hopefully i've attached a pic of the pipe connected from the filter up to the maf, it doesnt have any bends in it before the maf.

looks like back to the engine bay, dang it

psbarham
02-01-2008, 10:21 PM
ok thanks guys.

hopefully i've attached a pic of the pipe connected from the filter up to the maf, it doesnt have any bends in it before the maf.

looks like back to the engine bay, dang it

your pictures answered it, the pipe your using isn't smooth bore so the amount of turbulance it creates screws with the MAF

bradc
03-01-2008, 01:24 AM
yeah thats going to screw everything up

thecrazyfish
06-01-2008, 10:25 AM
well i've been away travelling a few days and once it gets it sh*t sorted, the car seems to run really well like that.

more torque response and more passing power, and heaps better fuel economy.

the best i had before was 565kms on a full tank before the light came on, now its 590 till the light came on. same trip and roads, with 95% of both trips being long distance kms. its not a huge difference but it all helps with fuel prices the way they are.

so my next trick is to put the filter back up top with the heat sheild. then keep the other induction pipe in i will direct its flow to the side of the pod which should use it. wont be as efficient in terms of air flow/heat, but will be better for the maf.

cheers guys for the pointer, when i look at it being down low, its actually a pain in the butt for my job, coz some of the time i visit peoples houses and out in the country alot of them have long gravel roads or driveways which wouldn't be to good for the filter, and also water wouldn't be to good either.

Nick Mann
06-01-2008, 12:09 PM
Or just find a smooth pipe to channel the air up, rather than the crinkled effect one you have now?

hi flyer
06-01-2008, 01:12 PM
what size are the pipes? I brought a cold air intake system for a legnum. Turns out the pipes were to small for the vr4 so only got to use part of the kit. Think it might be for the non turbo legnum/galant.

thecrazyfish
07-01-2008, 11:53 AM
what size are the pipes? I brought a cold air intake system for a legnum. Turns out the pipes were to small for the vr4 so only got to use part of the kit. Think it might be for the non turbo legnum/galant.


not sure mate. it was just a cheap pipe kit from supercheap auto.

we had some rain today so i moved my filter. i had water on the heatsheild, and around the filter. may only be an str, but i still need it to run, cant afford a new engine at the moment.

solution, move filter back up, leave induction piping where it is, reset ecu. indcution piping is down in the left hand side, beside the spotlight. direct air flow onto side of filter. test drove it and it seems quite ok.

i was thinking maybe using intercooler piping, and leaving the pod down low, but we get some serious rain at times and it aint worth killing it, coz its an everyday work car as well.

cheers guys for all the help:happy: