ToothDoc

Well yesterday, I ran with the K&N intake with a fully stock motor and exhaust. The temp was 71 degrees and pressure and dew point were about exactly identical as today. Today the temp was 75. Today I ran with the stock intake.

After reading much about the K&N intake and I know that Juanca said he LOST power while others including K&N say that power is guaranteed on the dyno. I remember reading a thread where an independent shop even verified the 20 hp gain. I was a little optimistic but at the same time incredulous that Lexus would leave so much HP to be had so easily.

So what were the results? Weight was exactly the same, same fuel load (1/3 tank), same tires, same everything except 4 degree difference in temp. Yesterday was all 12.8@111 with 2.0x 60' and today was 12.8@111 with 2.0x 60'. Not just one run, but 8 runs yesterday and 6 runs today. I threw out the ones where I mis-shifted or had 2.2 60' due to spin.

So, at least in my own little experiment, there is nothing to gain with an intake except sound. 60' was identical (no loss or gain) and trap was identical (no loss or gain). With the VBOX, the car was registering 4.5 seconds 0-60 both days also. My VBOX is setup with no rollout BTW.

Yes, on a sidenote, VBOX is highly accurate. My 60' times on my VBOX was 2.1 where the slips say 2.0. Once again, it's because I short stage and VBOX doesn't have rollout. Also, I ran 12.8 and VBOX says 13.0 due to no rollout (.1 60' is approx .2-.3 seconds et). MPH said 111 on the slips and VBOX says 112-113 because it's actual speed at the quarter vs. a trap setup at the end of the quarter. I suppose I don't even need to bother going to the dragstrip anymore. If I can run a 4.2-4.3 0-60, I know the DA is good and I'll go racing.

So, for you guys that are pondering an intake or not, I wouldn't bother. Also, for those of you guys that don't have a dragstrip nearby, get a VBOX and find a safe street. It's the next best thing.

lexsane

just for the sound it is worth it my friend.

ToothDoc

I used it for a week, tested it, now it's sitting in the garbage. LOL BTW, if anybody wants it, I'll fish it out of the garbage - Monday is my garbage day. I personally like the "sleeper" type of cars. It's already a sleeper as it is but I plan on doing mods that give me gain but don't give me away. So far the only mods I have are 18" rims for drag racing, drag radials, and lightweight battery. Those two mods alone save me 70+ pounds. Next up are FIG's rotors which is another 20+ rotating weight loss. That's 100 pounds. I also have the black PPE headers coming in next week which is good for 40 hp and probably a few more pounds. I haven't decided if I am going to do a catback yet or not - want to hear how loud the headers are first. Coilovers I hear are also lighter than stock. After that, I'm out of mods.

But in the end, I should be near 380-400 rwhp and about 125-150 pounds lighter than stock w/o stripping the car and WITH a spare tire and jack and engine covers. How about that for sleeper IS-F?

DCoolBeans

I'd love for you to try out the afe wet filter and a silicone intake tube.

Awesome info and thanks for sharing!

lexsane

thats why i'm torn between more mods or just saving up to buy the next generation F when it drops hopefully in 2014

ToothDoc

DCoolBeans, after this experiment, I'm really skeptical if any intake hose or tube or filter really improves performance on our IS-F. Perhaps the bottleneck simply isn't in the intake. The headers removes the cats and don't the O2 sims make the engine run a little leaner? Those are obvious performance increasers. Also, the cat back exhausts w/o cats are also obvious performance increasers. Less weight is always a bonus. In my experience, every 40 pounds is roughly a MPH and .1 second. If I ran fully stock today, I'd probably be at 13.0 at 109.

lexsane

how much is the vbox?

ToothDoc

They're about 500 bucks. I've had two other G-meters and they are both kind of accurate but nowhere near the same accuracy as the VBOX so don't get the 200 dollar G-meters. I've already tried those.

lexsane

let us know the vbox info after your header install

MRxSLAYx

Nice comparison. Have you done any 60-130 logging?

ToothDoc

It takes me practically forever to get to 130 so I haven't actually done any 60-130 logs. Too many cops and speed traps where I live.

ISF001

TD,
You are running 4.2-4.3 0-60s with an all stock engine?

ToothDoc

ONLY in the BEST BEST of conditions (40-50 degrees), drag radials, almost empty fuel load, nothing in the trunk, no spare and tools, and 40 pounds of lighter rims (18" RE 30s), and a 3.5 pound battery. Otherwise NO power mods at the moment. I'm hoping that the new rotors, headers, and possibly exhaust might get me down to 4.1 or optimistically 4.0 (in the best of conditions).

Juanca

iTrader: (5)

71F - 75F is not bad. Give them a try again the next time you hit 90+F and you'll see how the K&N starts suffering from heatsoak. I can't wait for this summer to be over, we are over 90F even at night down in Miami!

BTW, I had problems with an oiled K&N filter, I never tried the K&N intake. Also the 2nd stage flap gave me lower times at the track.

ToothDoc

My bad. Sorry didn't mean to screw it up Juanca. My memory is foggy after 4 years of beers LOL. But there was a rather convincing writeup and test of the K&N intake by that one dude who did all sorts of dyno testing and I really was hoping it was going to give me some easy HP.