1MZ V6 MR2 exhaust - custom Magnaflow (startup/rev)

[@jmzw20]

@razer1000 Thanks! The porting was expensive - $550 per head or $1100 total. That's what happens when you have two heads to mess with. I had the heads ported before I put it in my MR2, so I don't have a baseline to compare it to. Fuel efficiency is about 25 MPG city and 32-33 MPG hwy; averages about 27-28.5 MPG regularly on 91 octane. The wideband air-fuel ratio sensors my ECU uses are responsible; they detect 12-19.0:1 AFRs in closed loop, so open loop is only WOT. Power is good ...

[@jmzw20]

@razer1000 ... but cam regrinds for more duration and lift are on the table as is the TRD supercharger.

[@razer1000]

DANG that sounds beast! How much did the porting cost and how much of a difference did you get in power (if you had the engine on the car before porting them) Also, did you get any fuel economy gain from it? Thanks

[@paulmarler3873]

jmzw20 what magnaflow muffler is this? im considering ditching by berk system for this option

[@jmzw20]

Not sure, actually. It came with my car way back in 2001 and was pretty old. I redid my entire exhaust system in 2018 because I had to move to the 3-cat system and also took the opportunity to get rid of that stupid 1MZ t-pipe merge. Replaced this muffler with transverse (Camaro/Firebird) Magnaflow 12265 (2.5” in/out). It’s quieter, but the same sound is still there. So, you might have to cut it up if you want it to sound like this. My pre-cats also aren’t helping here either.