ISjunky300

So i have 03 IS300. Im slowly working on a 2jz turbo swap. im having a custom 3" catback exhaust built for it. I understand that due to exhaust gas velocity which in turn effects backpressure you lose low end power. this does not bother me as im just trying to get certain aspects ready for my turboed engine. however i did hear that you can actually harm your non turboed engine if you push the engine for an extended period of time. is this true? can someone explain the reasoning behind this if it is?

mzs14

Back pressure is such an old school redneck v8 myth in that it will destroy your engine if there is too much diameter. That used to be true in the pushrods designed from the 60's with equally old and crappy muffler designs, but doesn't nearly impact a modern engine. I ran a 3" exhaust on my ka24de 240 prior to my sr20 swap and nothing blew up and power gains are still well documented. On a 3.0l you'll be fine, it's not like taking of the header and running open ports where you burn up your valves.

Do it and enjoy!

mitsuguy

iTrader: (2)

nice first post, accurate, as well mzs14

welcome to ClubLexus!

jdmSW20

iTrader: (12)

Yeah like mzs14 stated you wont harm anything by running a 3" exhaust on a non turbo motor. you will probably lose some lowend but if you are just prepping for a swap anyway, i wouldnt think twice about it.

ISjunky300

Thanks for the information. i ask because i tend to have a fairly heavy gas foot and i dont want to mess up my current engine (as i plan on selling it) due to my driving habits. can i expect a power gain at the top of band (i know itll be minimal if there is one). Thanks for the welcome guys. this is my first time working on any 2jz engine so ill be back for all the info i can get.