lexus250

I have this intake, i showed the same dyno number, but yet everyone says no gain from intake except only joe-z with 5rwhp gain..
(PS: the dyno came of injens web site)

kingofire

Wow thats a weak dynoooo

maxnix

Less than 10% gains are virtually unnoticeable by the butt dynamometer.

nsxiboi

iTrader: (2)

Those are pretty good gains from an intake. Which intake is this?

lexus250

Thats an Injen SR intake the same one I have, but the issue is most people on the forms swear up and down there is no hp gains from SR intakes and for the most part you lose hp. I have shown similar results when I put my car on a dyno, (for the money dollar to dollar intake and exhaust is the best performance part you can buy (1rwhp for every $20 in this case)) so if you add in the 30 to 40% loss to the rear wheels thats about (1hp for every $15).

Also notice that the second run was at a higher temp. so you can probably pull another 1 to 2 rwhp out of it.

al503

You should always take manufacturer's dyno claims with a grain of salt. Dyno results can be manipulated/skewed very easily.

In addition, dyno's don't test the cars under real world conditions (unless you drive with the hood up and have a fan(s) blowing into the engine bay.)

Because the IS only comes in auto, we can't get any info on what the intake might do in the lower RPM's. Many aftermarket mods will actually add power but they usually do it in the upper RPM's where the less restrictive parts have an advantage. However, this may cost you power in the lower RPM's where most of us do our day to day driving. For instance, you might gain a few HP from a less restrictive exhaust in the upper RPM's but the reduction of backpressure in the lower RPM's might cost you even more down low. You usually have to give a little to get a little.

You also have to ask yourself that if Lexus could have gotten +~13 rwhp (according to the dyno info above) with a simple intake change, why wouldn't they have done this in the first place? Why spend all the $ they did on R&D on direct injection, ultra high compression ratio, etc?

lexus250

Your right, if you look at the dyno it shows a decrease in hp at lower rpms and an increase at higher. but the reson for lexus not doing it in the first place is because the safer they can make the engin run the cheaper it is for them in the long run becuase of repairs and such.

4TehNguyen

iTrader: (1)

I dont see any spot on that graph where you lost low end power, since the car is an automatic anything below the 4000 rpm is unknown/unreliable because of the transmission

because the car isnt as quiet anymore with an aftermarket intake, sure they they coudlve gained power but increased noise isnt worth it and not acceptable to Lexus to sell as new

al503

You can't really look at the area below ~4500 rpms as you can't go full throttle without the tranny downshifting.

As for the safety/reliability/warranty issue, what makes the stock intake safer than an aftermarket one? If you're referring to the oiled filter element fouling the MAF, then I'm sure that they could figure out a way to shield the MAF from that possibility. Creating a shield for 13 rwhp? No brainer.

al503

A good a reason as any. However, more sound insulation is cheap and would have helped with the direct injection ticking also. A few more lbs of sound deadening material v. being able to advertise the car with ~15 more crank hp? No brainer, IMHO.