I've been on this board a long time, and I've heard a lot of opinions on mufflers/exhaust systems when guys have installed them and their opinion of the performance increase they gained. This is mostly relating to the 3.0 3vze V6 for the most part as that is the engine/mods I pay most attention to for obvious reasons.

What I want to know is why one guy might say he got a noticeable improvement from his exhaust system and one guy said it was a waste of money?

Could it be the pipes were pressure bent versus someone who had them mandrel bent? Could it be related to what brand of muffler was used? Do cheaper mufflers give as much flow or performance as more expensive ones?

I'd personally be interested in first off what you did i.e. what type of muffler or exhaust system (EG factory mandrel bent catback), if it was mandrel bent or pressure bent, and if you made any change in exhaust size and what you noticed? Also note if you had any previous mods before you did your exhaust.
Overall I'd be interested in hearing why.

For example UKMeyers posted his opinion of his Borla catback on his 2nd gen 4runner, and he described it as a "noticeable increase," and said he felt his powerband now really opened up around 2000 RPM's where before it was more around 3000. But the Borla catback is a premium unit with mandrel bent 304 S/S and a high quality Borla 304 S/S muffler.

 

Because everybody has different senses. Anybody's opinions which are based on seat of the pants feel I take with a grain of salt. Give me hard numbers with statistical relevance and you've got my attention. Numbers are hard to come by on these off road boards.

 

I agree with you. You give some numbers, and you may get more responses then if you just say "Well, I didn't notice anything different." Some people would rather get the kind of improvement where they can feel it low end, but that doesn't mean anything (a percentage of the time that is).

 

my 91 4runner is bone stock and the exhaust system is shoot in a few weeks im getting a new cat 2.25 pipe all the way back to a flowmaster delta 40