Estimated power output

[CherBear]

Just wondering if any of you engine gurus could estimate the power output of a 2000 4.0 with a K&N cone filter and a 2.5 inch cat back exhaust with free flowing muffler.

 

[old_man]

Probably about 5hp more than stock.

 

[urban yan]

I'm not sure about the other brands, but
AFE claims 9hp and 14ft/lbs torque @ 3400rpms on it's intake
Magnaflow claims 6hp and 7ft/lbs torque on it's catback.

 

[wolfpackjeeper]

those are flywheel numbers though are they not?

I'm with the old guy

 

[DanMan2k06]

Yea, look at the dyno sheet that I think GoJeep has posted on his site. After a full exhaust, bored tb, and late model intake, it's pushing near 150 at the wheels...

Edit: here ya go. Mother of God 119 before?! What a joke...

 

[urban yan]

those are flywheel numbers though are they not?

Here's magnaflows dyno

AFEs dyno

 

[wolfpackjeeper]

Dino has a 1992 doesn't he?

 

[CherBear]

Well I definitely can feel a seat of the pants increase. Especially at the top end of the power band.

Thanks for your thought guys. I greatly appreciate it.

 

[Talyn]

Here is my 2000 4.0L dyno with Rusty's K&N, Gibson 2.5" exhaust, Thorley header, 0630 head, and stock cat. No before dyno though.

 

[tizzdizz]

Interesting charts. From the few that I've seen online (I'm not too familiar with this stuff), it seems typical that real results from everyday people's cars never match the stock claimed power numbers. Why is that? I mean, I realize that with age, output might decline but really that much? Or are stock numbers done without any accessories?

 

[wolfpackjeeper]

claimed is a best case with locked drivetrain, ideal conditions and usually adjusted for atmospheric conditions. That is if it was actually measured. It is the best estimate most of the time

Real world is still adjusted sometimes, but usually not a much. And may be moving through larger tires and an auto. It certaintly has more loss involved

 

[Talyn]

What the factory gives as a HP rating is taken at the fly wheel, not at the rear wheels.

 

[CherBear]

What the factory gives as a HP rating is taken at the fly wheel, not at the rear wheels.

Which is generally 120% (ish) of the hp at the wheels?

 

[wolfpackjeeper]

I would say it is a bit higher than that, certainly so if you have an auto and 4wd. The AW4/NP231 have a rather large percentage of drivetrain loss.

 

[Talyn]

Generally 20%-25% is an accepted number for drive train loss. But our combos seem to generate a bit more.

 

[Dr. Dyno]

Dino has a 1992 doesn't he?

I do indeed and it has a 4.6 stroker with an AX15 behind it. Goes like a raped ape.

Just wondering if any of you engine gurus could estimate the power output of a 2000 4.0 with a K&N cone filter and a 2.5 inch cat back exhaust with free flowing muffler.

About 10rwhp more than stock.