Decided to keep my 4.6is, mod update
 

Thanks in part to helpful opinions from some of you ( http://www.xoutpost.com/x5-e53-forum/...eep-4-6is.html ), I decided to keep my 2003 X5 4.6is, rather than sell it and buy a new 2007 E70 4.8i. I really love my 4.6is, and with only 36K miles on her, I figure she's got some good years left.

I estimated that getting a new E70 fully loaded (and with 8+% sales tax) would cost 35K-40K more than I'd get for my 4.6is. Therefore, I figured I could spend a considerable chunk of money "upgrading" my 4.6is and still be $15K-$20K ahead. Here are the mods in my plan:

Done so far:
- XM Commander installed ($170 at Crutchfield), wired into AUX, controller in ash tray, antenna inside rear spoiler with foil tape to enhance signal -- works great!
- New Yokohama ADVAN ST tires ($1,254 at Tire Rack) - love the look, handling seems same as OEM Diamari's, no noticeable difference in noise
- Smartire tire pressure monitoring system ($210 at Tire Rack) installed with new tires - monitor installed under driver dash -- nice, inconspicuos addition.
- Installation charges for all of the above: approx. $600

Still to come:
- Smartire remote display for setting parameters and seeing specific air psi and temps ($50)
- Backup camera system: the bumblebee camera $149) and VSM kit ($425) from EAS.
...and the big one:
- Dinan S3 package with supercharger ($17,200 installed) - parts ordered...should be installed around Thanksgiving.

When it's all said and done, I should have a screaming 450hp X5 that will leave any E70 in the dust! :D :nanana: And over the next 2-3 years, I don't figure I'll suffer any more depreciation than I would with a new E70 4.8i, so when BMW decides to produce that souped up E70 in '08 or '09, I'll be in no worse position to buy it than if I hadn't gone this route...

...PLUS I'll have an extra $15K or so to spend on dive trips to faraway places! ;)

Since you're adding signficant HP, a big brake kit would be in order. It's not absolutely necessary, but it's a good safety measure since your X5 will now perform beyond its original design specs.

Dont forget cosmetics as well- AEs, fenders, hood, etc. Also dont forget things like Bluetooth, etc... .the fun stuff!

Although brakes are certainly another thing that COULD be upgraded, it's something I feel I can live without. I don't push my X5 the way some of you do; after 36K miles, I just replaced the tires for the first time, and I STILL haven't had my first brake job yet! :wow:

Besides, even if I did drive it hard, I think the brakes on the 4.6is are already more than necessary. Quoting from the April, 2004 Bimmer article on the Dinan S3 4.6is, which seems to agree:
The 4.6is comes with BMW's biggest brakes ever: 14-inch discs up front and 12.8-inch rotors at the rear. The stopping power is massive, and the fade-free performance lets me take this massive car deeper into each corner than seems possible - and with total confidence. The brakes alone are worth the $16,850 premium that BMW charges for its X5 4.6is vs. a standard 4.4i. :woot:

Not sure how much I'll do cosmetically on the exterior; I really like the look of the Estoril blue 4.6is as is (although I reserve the right to change my mind! ;) ). Already have the Bluetooth kit (and had the AUX kit installed, too, which I considered essential to be able to use MP3 player, XM, etc.).

Stage 3!!! Very cool! Is Bellevue doing the install? I'd be curious to see if Strickly BMW across the street can do it for less. If so I'd consider this upgrade too!

Actually, Bellevue BMW isn't a Dinan dealer, but Strictly BMW is. And while I'm sure it would be cheaper there, I'm having it done at Seattle BMW -- I like the people there, and they'll also be doing a few last minute things for me before my original warranty expires.

P.S. Are you going to come all the way from Oklahoma City to have a Dinan conversion? ;)

Good to know. I always see performance upgrades going into BMW's at their shop but didn't know that they were a Dinan dealer!

Can't wait to see if this S3 upgrade meets your expectations! So far I haven't done any performance upgrades to my 4.8 since in the end the S3 is what i want. Do we know if the S3 upgrade changes the towing capacity of our X?

make sure you talk to the SA and the tech doing the intall on the blower. you WILL bring the car several times after the install i guarantee it, i had a problem particularly with a part that dinan sent the dealer that WAS NOT fitting, and so my SA MADE dinan do a custom part to FIT PROPERLY. i had A/C leaks mostly, because that part was not fitting...you might have to look into that, but again, make sure you have a solid relatiosnhip with the people you are doing the install with, as you will need them when you bring your car back; so theres no finger pointing after the install.

congrats and enjoy the s3, its like having a brand new car!

That's partly why I chose one place over another. I feel like I have a better relationship there. And from what you say, I'll need that to "fine tune" the S3 installation.

As for the S3 being "like having a brand new car," that's exactly why I decided to do it (in lieu of actually BUYING a brand new car), so I'm really looking forward to it! :thumbup: