Doug Thorley Headers apparently now making headers for 3.5 V6 2gr-fks

Yes. Fixed it.

 

Well if they are the same part number and casting as the Lexus variants they can already support over 300 HP. I can't see that being a very cost effective mod. The downpipes and cats would probably be much cheaper & better place to start sniffing around for power.

Quite the opposite, if I remember right. Anymore they want the cats right up against the engine so they fire off ASAP. A cold cat is an inefficient one. Also they want these motors to get up to temp as soon as humanly possible because of all the crazy emissions regs. So it's probably actually to warm the coolant.

 

After the truck warms up, the cats can overheat. I'm just going by what Mike Sweers said in several interviews.

 

Do the collectors come off? I thought they were cast into the heads.

 

Extrudehone still around? They could do it. They did abrasive airflow machining a long time ago. No hand porting.

 

so confused by this thread. there arent manifolds or headers... just one pipe out with a catalytic converter like a foot down the pipe. maybe a high flow cat? sounds like lotta money, little gain territory to me

 

Yep, only gain would be to ditch the cats, retune, and run bigger exhaust pipe. More power can be made by tuning the VVT and D4S system.

 

That ^^^^^ .. they do make high flow cats as well.

 

Underrated post, IMO.

 

I just called Thorley about 3rd gen 3.5 and was told that they DON'T make any for a 17

 

and only purchased with parents money.

 

Truck identifies as "Hawaiian. "

 

6 years who has a update about this