Most of my performance info comes from the groups
that run the 4x4 Toyotas. They run the same engines
we do. (very few auto trans' here.)
They run headers, 2 1/4" pipe, a low loss cat
and a good muffler. They are getting a noticeable
performance gain and better MPG.
Many also run the K+N air input filters and
boxes, but there is a lot of pro and con
(mostly con) on whether these help the 22re.
These engines must breath pretty well stock.
IMO a header add on would be the way to go if you
were going to replace all, or part of your
exhaust system anyway. To take off a good
system and replace it with a high performance
system, I don't think would be worth the cost.
I have not anywhere seen the HP increase numbers,
but from my experience with other well designed
engines, big power boosts do not come from bolt
on changes. (Superchargers excepted.) A 22re with
internal changes, and a cam, headers etc, can be
made to put out 150 HP. For fun take a look below.
http:/www.doaracingengines.com
All the above only applies to the 22re. The 20 and
22r Can always use some bolt on help.
Jack A2
