• Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.

Took out the K&N, put in a stock air filter. Measured with G-tech.

Joined
2 July 2002
Messages
364
Location
Oslo, Norway
I've always taken the NSX Prime suggestions seriously, and I decided to buy a stock air filter to replace the K&N that was in my car when I bought it. I assume the prevoius owner has used it for about 15000 miles or so. The K&N was actually a lot smaller then the stock filter.

Just for fun I did some measurements with the G-tech pro gadget, to see if there was a noticable difference. I know the G-tech is not the most acurate tool out there, but my experience with it is that it is faily consistent, even though not acurate. I've used it on my ITR before and always got around 140 hp.

With K&N, 220-222-223-225 --- Avrg. 222.5 hp
With stock filter 222-225-223-226-228 --- Avrg. 224.8 hp

The runs were done within 10 minutes apart and the swap was done 4 times (i.e. in and out with stock 2 times and k&n 2 times)
so the weather and other conditions sould be the same.

What does this prove? Well, actually close to nothing. But at least it's nice to see that the stock filter is not losing any power to the K&N (maybe the other way around), and I now drive with the nice feeling of not damaging the car any more than necessary.

My stock ITR's numbers on the same G-tech was 140, showing about 20 hp less that what people typically het at the wheels on "normal" dynos (typically 160-165) The NSX average should be 224.8 + 20 (friction loss and drag loss) = 244.8 at the wheels.

Ok, enough talk. Any comments?
 
Thanx :)

To me, the K&N is one of those mods you might or might not gain power. Even a shift nob cost more than that.
 
Very interesting results. However, friction loss on a MR car should be close to 11-13%.
 
I love friends of mine that stick in there 4x4 pickups and claim 50 hp. The k&N will be less restrictive than a stock but after a few hundred miles becomes more restrictive. After I saw the president of K&N in his tux on television, I would never buy another
 
Brian2by2 said:
Informercial for K&N????? WoW.........:rolleyes: pathetic
Carefull 2by! Infomercials are just another legit way to market something, just like vertical or network marketing is legit. :D J/K
Heck, I'm going to go out and clean my K&N and experience a big a$@ HP gain.:cool:
 
Did you disconnect the battery when you changed filters? To reset the ECU so it can 'relearn' the new filter?

Think I read that somewhere, don't know if it makes a difference or not.

These 'mod' filters can produce a gain in hp at one particular rpm range , but not always throughout the rev range. Which is OK if your racing and keeping the revs at a certain rpm.

Same goes for 'hot' chips.
 
SNDSOUL said:
You are referring to the cone type K&N filter, right? Replacing the stock airbox?

No, it's the drop-in replacement that goes in the stock airbox.
(A thin flat thing, with only 80% of the potential area covered with a filter.)

And no, I didn't reset the ecu. I still don't know wheather ther NSX ecu will adapt to better air filter or better fuel. (I.e. advance timing or give more fuel) It did seem to give more hp on the latter tests, but that may have been a coinsidence.
Does anyone really know how the NSX ecu works in these areas?
 
Ponyboy said:
Very interesting results. However, friction loss on a MR car should be close to 11-13%.

True, but on the G-tech it's a little different. It measures actual acceleration on a moving car. That means there will be additional losses due to the air it has to pass through and the friction the wheels has to cope with on the road.

Problem with the G-techs are the variation of the testers and the actual G-tech device. I've seen to meny different results on these things, but if you stick to the same one and same tester, it should at least be consistent. HP and 1/4 mile tests are ok with it, 0-62 is usually not (i.e. a wheel hop can produce some peak G's, messing up the result.)

I estimated a 20 hp additional loss, based on actual dyno runs on stock cars, and then comparing them to the G-tech results. The G-tech always show less hp. The real hp loss due to a moving car can probably be anywhere between 10 and 30 hp. I just picked 20.
 
Interesting, but I suspect that if you did a statistical analysis you would find that the difference does not reach statistical significance. i.e. p-value is well above .05. You would need a larger number of readings and subject your data to a chi-squared
test. With a difference of less than 5%, you would need an n of
>50.
-Jim, victim of SISE syndrome (syndrome of inappropriate statistical evaluation)
 
JimK said:

I totally agree, but for all practical purposes, I didn't want to spend all day doing this just to be able to call it a scientific result. I think the results are good enough for observation and discussion purposes at NSX Prime. People reading can draw their own conclusions from it. Hey, a K&N is re-usable that might count a whole deal more for some people, than hp or durability of the engine.

When all the readings were within 6 hp or so (+/- 2.7%) , I assume the measurement to be fairly consistent. I never concluded anything in my first post, just assumed. An assumption does not need statistical proof. There you go:))
 
Ya, it makes that sound like a small version of the BOV everytime you turn on/off the car: BBBVVV. Very nice in my opinion.
 
Actually my post was tongue-in-cheek. I happen to have a K&N
in the NSX and had one in the old Accord. I thought the Seat-of--the-pantsometer showed an improvement in performance in both.
Chalk it up to more intake noise and placebo effect?.:D
 
Hi BITeR,

FYI, I tried the GTECH Pro too ! My results were consistently between 260-265HP. At this time my only engine mod was the Remus exhaust.

Last year, I dynoed my NSX on a REAL dyno (Bosch FLA-203), the results were 213kW (290HP) at the crank, 294,2Nm of torque and a top speed of 286 km/h.

The gains in comparison with the official numbers from Honda were 12kW (16HP), 10.2Nm and 16km/h for the top speed with the following mods : Remus exhaust, RM cold air intake, Comptech Cat Bypass pipes.

The day I dynoed the NSX was one of the hottest day here in Switzerland (34º celsius)and the guy who proceeded to the test said to me that according to his experience the results would have been better of something like 7kW(10HP) if the temperature had been in the usual range of 15º-20º celsius.

Not so bad for a 12 years old, 126000km NSX with an heavy exhaust, an intake which is only louder and cat bypass pipes that serve nothing but pollute the atmosphere ! ;)

I am wondering if a Dali Racing chip would allow me to break the 219kW(300HP) barrier ! Should be my next mod ! ;)

Hera are my dyno charts :

http://www.macs.ch/homepages/david/New_Pages/dyno.html

Regards,
 
Re: Re: Took out the K&N, put in a stock air filter. Measured with G-tech.

Enzo said:

Not so bad for a 12 years old, 126000km NSX with an heavy exhaust, an intake which is only louder and cat bypass pipes that serve nothing but pollute the atmosphere ! ;)


Like I said before the G-techs vary a lot between each other. 265 on yours may be 225 on mine. You may also have a strong engine of course. Once you dyno a car and then test it with the g-tech, you should see a constant difference and may actually use the G-tech for numbers.

About your cat bypass, I believe that will actually yield some power, if not all the power gain you are experiencing.
If you go chip, make sure you buy the highest octane available.

Let us know if you dyno your car again with the chip.
cheers :)) R
 
Back
Top