mazzuri correct me if i'm wrong, but the engine bays of all the IS's is the same so the design of the headers will be the same. the differences will be in the size of the piping due to the different displacements. so based upon mathematical calculations pipe sizes can be found. so both sets of headers can be found. i beleive a set of headers will fit the AWD250 because to me the exhausts between all 3 models seem the same. can someone correct me if i'm wrong. any one has toyota part numbers for all exhausts from the headers back?

and as far as headers for the 250, i think the megans are crap and Jun is over priced. i'm willing to bet there is more 250's then 350's around even though the majority of people on here may own a 350.

 

I'm sure there are more IS250's then IS350's.. but it seems the ones who got the 350's are the ones looking for performance.

 

I agree that IS350 owners are more likely to mod their engines. I would bet that Mazzuri would sell twice the number of headers for an IS350, then headers for an IS250.

 

I never said I was going to make a header only for the 250. The reason I have a 250 is because it is easier to dyno since it's a 6 speed. The manifold is 100% the same for both engines, what will fit the 250 will fit the 350 and like you guys said, only the sizes will be a bit different.

 

I have it backwards??? with how many times i have screwed with exhaust on this car i am pretty sure i know where they are located. They are After your primary cats like i said before. not on them, or before them etc..

http://i125.photobucket.com/albums/p...t/IMG_4269.jpg

http://i125.photobucket.com/albums/p...t/IMG_4261.jpg

 

There are four O2 sensors. The wideband are in front of the primary cats. The narrowband are after the primary cats. You would be foolish to try and adjust AFR after a cat - the readings won't be very accurate.

 

So are you making headers for the 350?

 

That's good to hear.

FWIW, the 350 is easy to dyno if you disable TRAC / VSC, use ECT-Snow, select 4th gear in manual mode, and avoid WOT below 3K RPMs (or 2K RPMs in 3rd gear).

 

Have you started "fondling" the IS250 yet? Still think you'll have something by year end?

 

I think he is done with his business. read the honda forums or PM him. Not a big deal for me since I am going a different route, but sucks for you guys wanting headers from him. I could be wrong, but we'll see...

 

Dude ... you're going to have to spill more info than that! What do you mean he's done with his business?! It was just a few weeks ago that he said he would have something for us by the end of the year.

Also ... what's your "different route"?

 

That's a shame. His IS300 headers made wonderful gains.

 

Say WHAT??? Incredibly disappointing, if true.

 

we need more info, bc if this is true then thats a major let down, just when i thought there was some hope for some considerable power increase for the 250. his site is still up and running though......hopefully he'll come on and say something.

 

my different route is having some long tube built here locally with some cat work and other items. Trust me, I have learned that bolt on is not the way to go.

This was PM'd to me this weekend

http://www.honda-tech.com/zerothread/2151269

it wouldn't make a difference anyways, because there is no way 250 headers will work for a 350 due to the port size.