Jonesy000

Whassup, I have an 86 SR5 22RE with EFI. It's got the stock header and a 1 3/4" exsaust pipe, cat and muffler. Also I have 31" tires. My question is: what diameter pipe cat and muffler would be best from the front flange back? 1 3/4", 2" or 2 1/2". I am buying magnaflow cat and muffler

HighLux

Id say 2 1/2 if you have mods to support it..ie header cam etc...
Rolling stock Id go 2"

Toyota~Boy

iTrader: (2)

2" is fine. I run a 2" from my header through my cat to my muffler. Then I go from muffler to 2 1/4.

I'm running TriY header, Magnaflow Cat, and single In, Dual out flow master exhaust

Edit:::: I use to have a magnaflow exhaust and it sounded like S*** in my opinion. Sounds like a pissed off bumble bee.

timothy47129

Heres a good start .Too big and the exhaust will cool as it leaves the header and will hurt the scavanging effect.Too small and it would be restricted .So take your pick of a good middle ground for pipe size.

timothy47129

Oh and a good long resonator at least 16" will get rid of that pissed off bumble bee sound.

Jonesy000

U guys rock thanx for the responses.. I do not have any mods. Just a K&N air filter in the stock air box.. Sounds like 2 1/2 is too big for me for sure. @ Timothy, the graph is awesome thanx dude ill check my book for HP and stuff but I am a layman at best with auto mechanics.. Always room to learn more tho. Well guys, with the fact of my stock rig what would ur recommendations be??

Jonesy000

Ok I see it now. Thanx HighLux. 2" on stock then.. Once again thank you everyone. Any additional thoughts u may have are greatly appreciated as well

timothy47129

I agree with 2" also

BamaYota1

2 inch is right, but do 2 1/4 exiting muffler. Tried and true formula.

Gamefreakgc

All the muffler shops I spoke said the same, up 1/4". I only did cat-back and when from the 2" stock to 2 1/4". Magnaflows are great for these trucks because it's a straight-through design, allowing more airflow. I put one on mine last summer and notice and increase of power and gas mileage. Not huge, but definitely noticeable. The $250 I spent will pay itself off in gas mileage.