Hello everyone,

Is there anyone who can tell mee the difference between an 523i and 525i, Both are 2.5 6 cil blocks, with different hp and torque. Is it just software or are there different mechanical parts?

If just software, is remapping possible?

 

Dear Sir,

The remapping is not possible.

The cylinderheads are of differant technique.

Please enhance your balance, a new 535i will be availble soon,
at your nearest BMW ripoff.

 

Hello Ricracing,

is a 525i enough hp, or should i better go for an 530i?

 

Go for the M5. Its much better.

 

Hi Eddy,

Well, a 523i has enough power to keep you happy.

What do you really need to power for?

If you are talking about a 523i you just cant be a Yankie.

A 3.0 litre six-in-line is about the best you can get, but new
engines a acoming...

 

Good idea, if i can find a spare ? 130.000,- (no extras)

 

Good idea, its a bargain for just 130.000 euros in Holland

 

Physically, I think there is a second inlet tract on the 525. Plus the re-mapping.
I was driving a 523i up until a few weeks ago and I was mightily impressed with the overall engine/drivetrain refinement, quietness and smoothness.

Although I haven't driven a 525i, I did drive an E90 325i just to see what the package was like a few weeks ago. It was certainly quicker that the 523i but what I could not get over was the lack of refinement over the 523i. I was expecting it to be a match for the 523i because it is basically using the same engine/transmission in a smaller package. The engine seemed rougher and the gerbox whined all the time. Thinking it was a one-off, I tested another 325i. Although it was better, it still lagged behind the 523i.

I reckon the additional bits in the engine and the re-mapping to squeeze out an additional 40bhp from the same cubic capacity has been at the cost of smoothness and refinement. I'm eager to try a 525i just to compare but haven't come across one to test drive.

 

finally a meaningful post on the topic.

i doubt there are any physical differences as NONE of the mod-shops have said anything about it. even the well known one e.g. DMS. As far as i know, someone here posted that the engine code is the same between the 523 and 525 (www.realoem.com or some site like that), but locally I've heard from 2 different mechs that a straight swop of the chips has been tried - and it doesn't work.

still no hard evidence.... a mystery. then again there's still hope that a software hack is all there is. or perhaps something less conspicuous in the drive train e.g. the torque convertor, if there is any on the BMW, a tranny chip - i modded my vw tranny chip for faster gear shifts !

 

I raised that point when trying to find out whether the 523i can be uncorked in some way. That thread died a quiet death some time ago. Yes, both the 523i & 525i have the same part number for the short engine. The cylinder heads & camshafts also shared the same part numbers if I remember correctly.
I think we can ask this question on many BMW cars, e.g. the E90 318i & 320i, or the E36 316i & 318i.