Lvangundy

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Lvangundy

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JBrady

Ah-ha... notice the MAF adapter necks DOWN to fit the K&N filter. This means that the filter to adapter transition area is less than the MAF openning. This causes the air to bend around this restriction and probably disrupts the MAF to some degree. The back of the stock housing is definitely a better transition.

I would still recommend modifying the housing itself

1993lexusls400

i have a k&n replacement filter on the way for my 93 ls400. what you are saying is that this will decrease hp overall. is this just for replacing the whole airbox and not just the filter? what about installing a air mass sensor to help. is it still going to hurt hp? in conclusion, it is best to get the oem filter straight from lexus to get the most hp from a 1993 ls400? any other upgrades to help increase hp and acceleration? thanks in advance.

Jeff

Lvangundy

You might have some trouble with installing a K&N on your 1993 unless you do some modifications.

Anotehr user BHC had some problems with this and it was discussed here. Please read through that forum and think tiwce about the K&N. It may not work on your car.

https://www.clublexus.com/forums/sho...threadid=41334

As far as the power goes, at least in my case yes I lost horsepower and toruqe by using the K&N filter.

Jbrady if you read this, check that link - do you remember that?

JBrady

There are 2 choices for K&N (or other replacement filters).

One is a replacement for the factory filter ONLY. This is the same size and shape as the OEM element and simply installs in the stock housing. Using this type will probably offer a VERY slight increase in power provided the red filter oil on the filter is completely absorbed by the gauze filter material. If excess oil is present either on a new filter or after cleaning and re-oiling... this oil can contaminate the MAF and create problems.

The other type uses a MAF adapter and a cone style filter. This is what Lee and BHC tried and found problems with. The adapters actually flow WORSE than the stock filter housing and create a net LOSS in power.

The best bet is just properly modifying the stock housing cover

Lvangundy

I still wanna see dyno results for your mod jbrady

1993lexusls400

installed the kn replacement filter dont notice that much increase in power. how do you properly modify the stock housing cover? thats odd that it would not help give the engine a little more breathing. does the mass air sensor have anything to do with it. also the check engine light has come on after changing filters...any relation??? thanks

meZoom!

you might have a leak somewhere in your air system. check that you have properly clamped everything together and that your hoses are not cut anywhere along the lines.

1993lexusls400

yea everything is in place, the check engine light may be another problem, probably gonna take it to a mechanic and get the computer code checked out. any suggestions on modifying the airbox for more power!!!

LexusWhoSmokedU

I have a friend who works at a performance shop so we got to really find out what air filter set up worked out the best. I first began by taping and cardboarding to make the area around the filter only take in air from below the headlight and the lower part of the bumper. I then began the test with the stock Toyota filter, housing in place, and the ducting to above the radiator there. On that run I had about 170 RWHP max. Then, I removed just the plastic air ducting above the radiator and made sure to seal the area so that no radiator air was getting into the intake. I had a 178 RWHP max. I then removed the front piece to the filter housing, wrapped the edge of the filter in tape making it seal and then just secured the clamp so that you could see the entire filter cylinder. I made 185 max RWHP. Then I removed everything and descreened the MAF and made sure there was no air leakage in from the hot radiator. This produced an astonishing 195 RWHP BUT the car did not run all that well and the service engine light came on alot. I put the MAF screen back and attached the Rod Millen Intake I bought with a K&N filter. It made 186 RWHP. I was happy with that but then decided to run without the K&N, open intake, no filter, with just the Rod Millen intake on. 197 RWHP is what I managed AND it ran really well. The Rod Millen intake is what I suggest to anyone wanting better flow. The cast MAF adapter is the same dimensions as the MAF housing so it doesn't restrict, my car ran smoother, and it sounds great. I thought this all might be some help but whatever you do, get rid of your stock intake from the filter housing forward. By the way, I used to get only about 13 MPG in my car no matter where I went. Once I replaced my intake, I easily manage 24-25 MPG on the highway. The only problem is that if I floor it all the time, it uses more gas. A more freely flowing intake will always improve gas mileage. It is the manner in which this more free flow is used that causes problems in gas mileage. Oh and one last thought. The intake was the first of my performance work. My last dyno showed 273 RWHP at 5,823 and then 291 torque at 5,236. The exhausts on these cars rob more power than you know...
Sean Gillette

SWEETSOUND2001

Are you using forced induction or happy juice to get those numbers :eek:

LexusWhoSmokedU

The car, until this Christmas is naturally aspirated. Rod Millen intake, I polished the MAF, MAF adapter, put PVC from the MAF to the throttle, polished throttle body, polished the intake, ported the exhaust, took off rear catalytic converter, and have dual straight pipes to the rear (no mufflers). The car passes emissions with flying colors. I also defeated the EGR circuitry and just capped it all off. I spent alot of time though polishing and wound up with a mild porting on some parts. I also made myself a homemade transmission kit. I made a controller that feeds impulses to the computer from the odo pickup to make it think the car is rolling and then I also use a switchable adjustable resistor for the ECT for first gear to cause the valve for first gear to engage more slowly and allow the tranny to slip so that I can put the car in neutral, rev to 6100 and then pull the car into drive without destroying anymore flex disks and driveshafts. The car launches through first gear and runs 5.3 to 60. My only problem is that this will ruin my tranny in no time. I ran it in the quarter and managed a 13.3 at 104 MPH. Not bad for a standardly 8 second 0-60 beheamoth!

Lvangundy

I am at a loss....

To see a first gen LS pulling that much power?

OMG!

All the little tricks you've done - I'm so impressed! I'm reading it over and over again trying to get all the details..I've never seen the rod millen intake- do you have a picture of it??


I'd love to leanr a few things from this..the airbox mods you described seemed a littrle confusing though. Are you saying leave the front cover (part that connects to plastic intake piece that goes to grill?)

I don't see how your intake mod experience gave you power..mine certainly wasn't fun having the K&N in there.