[Taxvictim]

I bought a used '07 328Xi with an automatic transmission. It was my first auto transmission in two decades. I bought the car because it seemed like a really good deal.

My main complaints about the 328Xi were acceleration lag, particularly when trying to accelerate out of corners, or when I had just braked hard, changed lanes, and was trying to get back up to speed with traffic coming down on me fast. I thought this was due more to the auto transmission and the all-wheel drive (giving the computers too much to think about). The BMS (Burger Motor Sports) Powerbox has fixed this issue. I bought it through Alan at www.**********s.com after the Thanksgiving sale.

I've only driven the car about 10 miles today after doing the install, but I noticed a huge difference, even though I was driving in D mode. Tomorrow I'll check out S mode. Today, the car was very responsive right from the start. It's a great mod. I've left it in the default mode 3, which is 100% throttle re-mapping with performance tuning.

Installation is not for the faint hearted, if you're a first timer. This was my first time doing any mods under the hood of this car. My last three cars were a Maxima and Infiniti I-30t's (fancy Maximas). I knew my way around under those hoods. For the E90, now all you have to say to me is "remove the AC air filter, the cowl, and the side covers", and I could have that done in less than ten minutes. Today for my first time, however, it probably took me more than a half hour just to get through those steps. (It didn't help that the Powerbox comes with no printed instructions. You have to go online to read the installation instructions. I don't have a printer, so I was going back and forth from the garage to the PC.)

Removing the top from the ECU box was also difficult. I was trying so hard not to break anything. Once I got the connectors out, however, connecting the wiring was pretty easy. Just make sure you do one wire at a time. The ECU box is packed with wires and stuff, and it's very frustrating trying to work in that limited space, but I took my time and got it all done correctly.

Here's a tip, when working with the small ECU connector: don't push the slider all the way in! It locks down, and you have to push a pin on each side of the connector to get the slider back out. You have to repeat that process to get the slider off. It was a real pain. There was nothing to unlock when you take the small connector off of the box, so it made no sense that it does lock when it's off the box. Also, you need a small flat blade screwdriver, but for some tasks (unlocking sliders and wires) it's better to have a small pointed tool, like an ice pick or the awl on a SAK.

Anyway, total installation time (including a search all over the garage for my socket wrench) took two times through a White Stripes CD and partway through a Clap Your Hands Say Yeah CD.

I was very relieved to start my car and see no CEL and hear no sputtering. You couldn't tell there was any difference until you mashed the accelerator and took off. The car is all back together and runs great.

I had bought into the notion that there is no point spending money on mods for a 328xi, because you should just save your money and trade up to a 335. But, I'm very satisfied with this low cost mod that addressed the very complaint that has bugged me from the second day I owned this car.

After a few weeks, I'll post any new impressions that may form.

One other tip: if it's been a long time since you changed the air filter for the cabin HVAC system, go ahead and get yourself a new filter before you start the install. At a minimum you can do what I did, which was to beat the existing filter against a brick wall to shake out a ton of dust.


ETA: drove it again tonight. Backing out of my parking space later, I forgot about the extra pep. Being used to the laggy acceleration, I was pretty close to the car next to me. After backing, I started to turn the wheel expecting a slow crawl forward to clear my bumper from the next car, and the car leapt forward passing my front corner a lot closer to the next car than I wanted. Next time, I'll remember the new throttle mapping.

[Neutrino45]

Good review! Thanks!!

[Mr&Mrs323i]

Driving in DS mode makes your car go crazy mad!
One thing I noticed when I had it in map 7 was how weird it drove, like it was in limp mode. The car would barely move. I had to park it, restart the car and put it back to map 3.

[inabis]

Awesome! I have a couple questions if you dont mind. So basically does this mod feel like you're driving in DS mode most of the time? I understand it remaps the throttle but I'm still having a hard time grasping of it does exactly. Does it just shift at higher RPMs?

Should we be worried about the fuel pump? It's usually the first mechanical part to go due to an increase in pressure... I'm very interested in this mod!

[Taxvictim]

Good question, Inabis. Hmmmm.... my impression of sport mode (before this mod) was that it affected only the auto transmission by keeping the car one gear lower than regular mode, at least until you got to cruising speed. That way the engine RPM was generally higher in the powerband, and you had some extra pep under your foot at most times without waiting for a gear change.

The Powerbox gives you added pep even in first gear, right off the line. I know it's just a throttle re-map, for the most part (they claim performance tuning, and have the dynographs to back that claim), but either way it's still a lot better than stock.

[E90jerz]

i have the same year & same model as you w/Auto trans.
my PBX was installed on Saturday.
great write up...i felt the same as you in what the car was lacking...what a great purchase.
ITS ONLY $270!!! WHY WAIT! JUMP ON IT!!!! YOU WILL NOT BE DISAPPOINTED!!
Ohh & my performance exhaust sounds so much better now!
MAP3 FTW!!

[Taxvictim]

E90jerz, how long did it take you to do the installation?

As someone else pointed out, this is the way the car should have come from the factory.

[mike-y]

Originally Posted by inabis

Should we be worried about the fuel pump? It's usually the first mechanical part to go due to an increase in pressure... I'm very interested in this mod!

The BMX does not increase fuel pressure.

[E90jerz]

I paid Alex - nj323ci - to do it...took him about 1/2 hour.
he had a friend of his put on a OEM performance intake for me - that was done within 1/2 hour as well.
i had a blast driving home!!!
i turned it off - MAP0 - on Sunday & i made it 1 mile before i pulled over & turned it back on!
i purchased the car a month ago. never drove it in D...always sport shifting.
the car launches off the line. pulls very nicely. going up hills & through turns like a champion.
& with the performance exhaust it sounds beautiful!

U mentioned you had a maxima...i had 1 too. 07 supercharged w/r34 head&tail lights, 19"lowenhart BR5. - damn i miss that car!

Originally Posted by Taxvictim

E90jerz, how long did it take you to do the installation?

As someone else pointed out, this is the way the car should have come from the factory.

[Mike@N54Tuning.com]

Originally Posted by Taxvictim

The Powerbox gives you added pep even in first gear, right off the line. I know it's just a throttle re-map, for the most part (they claim performance tuning, and have the dynographs to back that claim), but either way it's still a lot better than stock.

You're right its basically two tunes in one.

1) Throttle remap

2) Performance chip (8-10 hp/tq) which should be noticeable but most likely masked by the throttle remap as thats something you feel instantly!

Mike

[ModBargains.com]

W. Randall, I'm glad that the you are happy with the product and you received the product as discussed through the phone.

The BMS PowerBox is:

• 100% Plug and play
• Gains of 8-10 horsepower & 8-10 Ft./Lbs of torque at the rear wheels
• 7 available maps
• Easy switching of maps can be changed from the drivers seat
• Improved throttle response

Please feel free to contact me with any questions!

[Saint330i]

Does anybody know who can install this in the DFW Metroplex?

[Mike@N54Tuning.com]

Originally Posted by Saint330i

Does anybody know who can install this in the DFW Metroplex?

Its relatively simple so you should be able to do it yourself. I can PM you my phone number if you run into trouble

Mike

[DC_Oldboy]

Originally Posted by **********s.com

W. Randall, I'm glad that the you are happy with the product and you received the product as discussed through the phone.

The BMS PowerBox is:

• 100% Plug and play
• Gains of 8-10 horsepower & 8-10 Ft./Lbs of torque at the rear wheels
• 7 available maps
• Easy switching of maps can be changed from the drivers seat
• Improved throttle response

Please feel free to contact me with any questions!

So for $270 I can improve my e90 330i performance a bit?

[Andrew@ET]

correct

[c_jeong89]

Originally Posted by BringsMoreWomen

So for $270 I can improve my e90 330i performance a bit?

For $270, this is probably the best mod you can get for NA vehicles

[ModBargains.com]

Originally Posted by BringsMoreWomen

So for $270 I can improve my e90 330i performance a bit?

It will definitely improve the performance of your N52 engine

[Mike@N54Tuning.com]

Originally Posted by c_jeong89

For $270, this is probably the best mod you can get for NA vehicles

+10000

Its the best bang for the buck mod as it gives you 8-10 hp/tq and it remaps the throttle to make the car much more responsive and fun to drive

Mike

[beemerdan]

Ah so sick!! Good Review. Deff Making a purchase soon for this product.


Just to double check, its this : http://www.**********s.com/BMS_PowerBox.htm

And will work fine with a 2008 328i sedan?

Thanks!

[Taxvictim]

Yes, beemerdan, that is the link. In fact, I copied my review above and posted it as a review on that website.