Burst32

Ok, before you give me the whole "hot-air intake" is there any other reason why it could feel slower. Now, don't get me wrong, I LOVE the sound it makes, it is awesome because it offsets the Tanabe very well. I get good sound front and back now. But does anyone have reason why it would be sluggish? Now, mind you, it felt this way on the first run after i just installed it, so the engine wasn't warm yet therefore eliminating the "hot air" deal.

Any help would be great! thanks.

joonsta

You expected a significant improvement in speed with your intake and exhausts, huh?

The thing is, these "bolt-on" mods seem to only add around 15HP MAX together.

And sometimes, these mods take away from your low-end power.

I think that's why your car might feel slower.

But it could simply be an ECU issue. Try resetting it.

You can ask a technician at the dealership to do this for you.

LexusIS-TL

When did you start feeling this sluggishness? After the exhaust upgrade, intake upgrade, or did you have them done all at the same time?

Ramon

A V6 at only 2.5 liters will lack low end torque in a stock setup, add to it your intake and exhaust and you just lowered it even more. I'm willing to bet if you run your car against a stock IS250, you'll lose every time. You MAY have gained SOME top end HP with the exhaust, but not enough to offset what you lost. As far as the intake, you repalced an efficient CAI stock setup with a less efficient SRI aftermarket one, it's as simple as that. The sooner everyone realizes that aftermarket does not always equal better, the better off you'll be. Toyota invests millions of dollars in R&D in just about every aspect of the cars they build, aftermarket does not. Heck, most aftermaket intakes have no R&D in them at all, they simply take an existing design and simply tweak it to fit inside a different application. That's why you see the aftermarket for intake systems ready as soon as the first car leaves the assembly line. They cost virtually nothing to make and many people are foolish enough to buy into them.

Oh, and then you've got an AWD which has a lot more parasitic loss than RWD and is even more dependant on torque to get it going.

LexusIS-TL

But the Lexus OEM performance HKS isn't that different to a Tanabe exhaust and they promote it pretty well to stock vehicles as an option. Both are technically axle-back systems. Maybe the muffler technology might be slightly different but I don't feel it's enough to offset performance significantly. Maybe when the CAI is put in, the ECU got all out of whack.

Burst32

My exhaust was put on 4 months ago, and it IMPROVED my car.

The K&N intake was put on last night, and I think it was just my imagination that made me think that the car was slower. I took it on some back roads today when I woke up, and everything feels fine.

I also reset the ECU.

I know that my intake may hinder my performance slightly, but the sound it makes is freaking awesome. And besides its an IS250, I really didn't have that much speed in the beginning : ) haha

Burst32

wouldn't a better (higher-flow, less-restrictive) exhaust and intake throw down the compression of the outgoing and incoming gasses/air. therefore hindering performance?

llamaboiz

No, has to do with volumetric effecincy, scavaging in the piston, lotta complicated stuff.

lobuxracer

iTrader: (2)

It's not that complicated. If you just learn to think like an air molecule, it's all pretty simple.

Burst32

HAHA I think this thread just needs to stop here.