Do you know what gear your X5 was dynoed in?

There's been too many beers and too many numbers gone through my head to where I can't remember what gear!

You won't see a large increase with any performance part unless you go with some type of Force Induction.

Should be zero difference between 04 stock and 06 stock 4.8is, same 4.8L N62 engine in 04-06 X5 4.8is models. But there is a variable which will make it hard to compare to Jeff's test: the dyno itself. You technically would need to test it on the same dyno to draw a sound conclusion. The airflow will be different on different setups, as well as the calibration of the dynoes.

FWIW, Dinan is very rigorous in their dyno testing of the individual mods, so you can get a pretty good idea of the performance gain on each mod just by looking at their website for your specific model. For example a CAI would bump you up roughly 15 hp on a 4.8is, a free-flow exhaust about 8 hp. A high-flow throttle body: another 8 hp. Although these numbers are specific to Dinan mods, I would think any high quality CAI (say AFE brand) and high quality exhaust (i.e Supersprint) will give you comparable gains. Assuming you do the software flash to take advantage of the improved airlfow. All are modest gains, but they add up to + 30 hp or so....you will definitiely feel a difference...primarily in throttle response.

You're right: Dinan is not cheap. The main reason I went with them is it was "one-stop" shopping and headache-free install and tech support. Any problems, you just bring the X back to them.

Wow wait, what force induction options do us 4.8is have? From what I understand there was a supercharger available but it ended with the 2003 4.6is and is not compatible with the 4.8is.
:dunno:

Yeah I agree, not to mention the difference in the type of dynos, altitude, weather, fuel, and overall health of the vehicles. But even with all of these variables, you would think the difference from the gains in mods would show through enough to make a rough gues-timate as to what those gains were.

Like when Dinan says a CAI is aprox 15hp gain are they talking about whp gains? Somehow I doubt it but if it was, 15 extra whp will make my X feel lighter on it's feet! With 30 extra whp that would probably be enough for the butt-dyno to feel the difference too!
I just don't want to pay any money for the ear-dyno. There are a lot of mods out there that make your X sound faster but in reality isn't. Maybe even slower!

The dyno doesn't lie as long as the mods to the car remain the only variable. I was just hoping that I would be able to see the difference in the numbers and take into consideration all the inconsistancies. If nothing else I'll have a base line to start with to measure my gains if I modd.

So far it would have to be custom made; I have talked to a couple places that have said they could do a bit-turbo or a supercharger.

The only "plug-n-play" for the 4.8is that I know of is the VF Supercharger, which is being made for the N62 engine. I spoke with VF Engineering the other week and they hope this winter to have an "official" release date.

They've been saying that for several years now... :confused:

Well, I can always wish.....:popcorn::popcorn:

Having a turbo or supercharger set up fabbed isn't the real hard part. Its the tuning. With the wrong tune you can easily blow your motor. I haven't heard of anyone tuning the X5's engine computer besides Dinan.