Good points to bring up. These aren't cheap but either has the $18k we put into the wife's X5 in the last 2 years just to keep it going. It's all perspective I guess. I've seen $5k stereos and $5k in wheels, either make the car more fun to drive unlike this.

As this car is my mid-life crisis car and lifelong project, I might as well go for the good stuff now while I'm earning money.


I am running a 4.6 in my wagon and plan on installing these with before and after dynos. All questions should be answered there.

I will say this about the headers being worth what they cost:

If I went VF supercharger, for $5-6k I get a kit and for another few grand in testing/tuning/parts I finally get it up and running, I'd worry about things breaking. With headers, these headers, after the install and tune, I'm not only not worried about things breaking, I am not wondering of I could have passed up on better headers.
People who've gone evolve or SuperSprint sometines question if they should have gone with another setup. I won't be doing that.

Now if the gains are above 40hp, I'm totally happy and if I can hit that mark in torque, also thrilled.

It will make the power loss from running a supercharger (50hp to run the damn thing) seem not so noticed. But, even if I decide to keep things naturally aspirated, what fun it'll be.

Truth be told, if you just want power for the buck, an LS is the only answer but there's a fun challenge in getting more power from a stock engine that retains all the features of the stock vehicle. (I know mjne isn't stock but it is a bmw engine and almost exactly like the 4.4 I had originally)

I don't love bmw's for their economical prowess. Smiles per gallon is all I'm in it for.

Wait till they get installed and I get some real numbers off the dyno and then we'll know. I have high hopes.

-side note-
My goal in the entire engine swap on my wagon was to beat M5's. As is, I am neck and neck in the only 3 races (safe areas to do so) I've been in. But the look on the face of the M5 owner as I pull away is what I'm really in this for. If I can do that naturally aspirated, I'm happy as can be and might not even get a blower down the line. Who am I kidding, of course I'll force air but just for funzeez.

__________________
'03 4.6is (the wife' s ride)