I just bought my '89 4Runner, and the tailpipe is mangled pretty bad. Fortunately, I have the opportunity to get a custom cat back exhaust. My question to the forums is "how big is too big?" I was thinking of getting a 2 inch exhaust. I was wondering if anybody knew if 2 inch should be ok, or if another diameter would be better. I think stock is 1 3/4 inch. Since I have to replace it anyways, I thought I would go with something less restrictive, but I know that back pressure is important, too.

 

The best size seems to be 2.25 " Although going bigger does not hurt there is no real gain.

A 22REC is still what it is.

 

For a stock 22RE I'd go mandrel bent 2.25" from the manifold to the cat and the cat to the muffler. Then a mandrel bent 2" tailpipe. This will preserve good exhaust velocity and give you the best overall powerband. There might be a couple HP to gain up top if you went bigger but you might lose it on the low end.

If the shop can't do mandrel bends I'd go 2.25" press bent all the way.

If its a modded 22RE with all the bolt-on's I'd increase the sizes above by a quarter inch.

 

I went with a Walker direct fit 2" tailpipe from Summit racing. Worked great on my 88 and I have one on my 94. Cheap too.

 

2.25...

 

welcome to YT!
2.25".
please use the search function before asking common questions that may or may not have popped up in the past 33yrs since the 22r-series engine was introduced.

 

They do have a mandrel bender. Thank you for the advice, all!