[Slke46]

I've heard a number of times that the 2007 323 is a detuned 2006 325? Is this true? Are there any vendors that carry performance parts and/or ECU upgrades to up the performance? I heard one way of restricting the HP is by limiting the exhaust flow. The headers and downpipes are smaller... can anyone confirm?

[MINNOW]

Can't say about the size of the headers and downpipes, don't know.
But I can say that the current 323 is not a detuned 2006 325, at least not a North American 325, which uses the 3.0 liter N52.
Where it gets confusing is the European 325 uses the 2.5 liter N52 six, and so the 323 can be construed as a detuned Euro 325.
For 2006 the Euro 325 produced 218 hp, and the Canadian 323 174 hp, so the extent of detuning was substantial.
2007 models fare better as the 323 now produces 200 hp - I am not sure, but think the Euro model may have also been bumped up.
Turner Motorsports has some new tuning products for the E90 that should fit up to the 323.
I was at the dealer today and noticed for the first time some Dinan parts on display, parts department was closed, but it looks like they are offering Dinan product now.
I think one of the best "tuning" products for a 323 is a set of lightweight wheels, maybe OZ Ultraleggera, and some sticky non-runflats. Changing the runflats alone saves as much as 7 lbs. per corner if using conventional performance tires like Toyo T1R or ContiSport 2's or 3's.

[epiphone3]

Originally Posted by Slke46

I've heard a number of times that the 2007 323 is a detuned 2006 325? Is this true? Are there any vendors that carry performance parts and/or ECU upgrades to up the performance? I heard one way of restricting the HP is by limiting the exhaust flow. The headers and downpipes are smaller... can anyone confirm?

Here is the deal...

I have the 174hp 2006 323i. It is a detuned version of the Eurospec 325i. These were two versions of the N52 2.5 liter engine.

The 2007 323i with 200hp is the newer N52KP engine. As far as I know, there was no European counterpart of this engine built in the 2.5 liter size. A look on RealOEM.com supports this theory.

With regards to the 2006 323i, it has the same three stage intake manifold and engine as the Euro 325i. The only differences there are the exhaust manifold and the software. All that should be needed to move a 323i up to Euro 325i power are the euro software and the higher flow exhaust manifolds. THE place to source this stuff from would be through www.factorypartsonline.ca . THIS IS A CANADIAN SITE! Your contact there is Martin and if you are interested in this, tell him that Marc sent you. He has a relationship with some tuners, including Turner Motorsports, and should be able to source Euro 325i software and high-flow exhaust manifolds. The only reason I haven't attempted this yet is because all of my money is going to my wedding in September right now.

As for the 2007 323i, I haven't been able to have a look at the exhaust manifold but I can only assume that it is different than the N52 ones. I do not believe there is software available to tune this engine, but I could be wrong.

[Slke46]

Interesting... thanks for the info. I'm driving a 2007 323i, well the wife is as I drive my X5. But I guess its still a little early to determine what is worth getting for this car until R&D is done by tuners here in Canada.

Going to check the Dinan website to see if there is anything worth putting on this car. I find it very sluggish in first gear when driving in manual mode but then really opens up in second. I'll keep you guy informed with what I find...

I'll contact my local sponsors to find out what the deal is...

[montreal_bimmer]

im not sure if there is an ECU update available for the 323, but if there it, it would be pricey.... but there is more than just a software different between the 323 and 325...

[epiphone3]

Originally Posted by montreal_bimmer

im not sure if there is an ECU update available for the 323, but if there it, it would be pricey.... but there is more than just a software different between the 323 and 325...

correct. The difference between the 2006 323i and 2006 Euro 325i is both the software programming and the Euro has the high-flow version of the exhaust manifolds.

EDIT: I am not totally sure that the high-flow exhaust manifolds are required. I have recently heard otherwise...

The 2007 is not related in this way to the Euro 325i. 2007 323i is N52KP and the Euro 325i is N52.