High flow cat hp increase?

[Reaper1354]

Just curious. I'm redoing my entire exhaust system, and wanted to know how much more hp I'm getting. I'm not expecting a whole lot but I'm curious as to how much. I'm getting pacesetter shorty style headers, replacing my 2 stock cars for 1 highflow cat, and having a single inlet, dual outlet super 10 series muffler. All for my ol' reliable 97 ranger with the 4.0. Any guesses as to what to expect? My current system is stock from the factory. Appreciate any help guys.

 

[miller time]

Dyno it

 

[bobbywalter]

if the oem tune dials itself in tight...up to 20 peak.


otherwise you can lose efficiency and mpg and actually lose power.


i would guess the midrange will be noticable if it goes good.

 

[Will]

I would replace the stock stuff for the sound. You aren't going to see any power.

The next real upgrade for your motor is the SOHC 4.0 which has no pushrods in the way and enormous airflow passages through the heads. That's good for 210hp stock and up to 250hp with parts from other vehicles--like Mustangs. The next real upgrade is the 3.7 4-valve V6 Ford with 300hp and all of the modern goodies.

You have to understand what you have and don't spend money trying to make it what it can't be. The old pushrod 4.0 is a great tractor motor, and I love it because I have a tractor Ranger. It has all of its sting right down there below 2,500rpm where you need it. It does better than all of these modern V6 engines down there.

But you can't spend a little money and compete with anything newer if you are going for power. You have a 150hp motor and even if the tweek added a few, which it won't, any 1.8 liter 4 will beat it. Ford didn't build those pushrod Cologne motors for speed. They are maybe the last true truck motors. I like them to sound good and pull good, but they don't race.

 

[bigmark303]

You really wont pull anything out of it it doesnt already put out in stock form. High flow cats without a tune usually allow the engine to lose power because of the O2 sensors looking for certain readings the computer runs by in closed loop mode from the factory.

The old pushrod 4.0 is a great tractor motor, and I love it because I have a tractor Ranger.

That is just what one of my Pushrod 4.0s is used for. Stripped down body, Locked front and rear, 4.56 gears, and 34" agricultural tires. The good old yard tractor. I use it to pull whole trees out of the back of my property and other fun stuff around the property.

 

[JohnnyO]

Maybe 10 hp. It's only worth replacing the OE cats with a high-flow unit if they're shot and need replaced anyway.