V23 vs V25 - power issues - The Unofficial BMW M5 Messageboard (m5board.com)

PitziM5 · 26th August 2007, 17:23

As most of you probably know, I bought my M5 4 months ago. It was a 2005 model with 11000kms on the clock
Everything was stock standard including the V23 software.

I ran a V-box on the car in this state and it ran a 12.90 @ 185km/h 400m up here at altitude (1600m above sea level) on a level road.

I subsequently fitted an Eisennmann Race exhaust, and took the car to an internationally recognized raceway for a proper timed 400m run, the best on the night was a 12.90 @182km/h.

In June, the car went in for a service. Both the SMG pump and software was changed under a recall, the latter being updated to V25. I then complained of notable decrease in power, which sorted itself out after a week or so and the car then felt as strong as ever.

I then returned to do another timed 400m at the track. I did a 12.990 @ 176km/h, this was the best I could get that day.

Just to prove the above, we ran another V-box test just the other day, 12.90 @ 176km/h.

So where has 5-6km/h trap speeds gone after the V25 upgrade? Do we finally have proof that V25 software actually reduces engine power somehow?

Whats even more puzzling is the fact that the 400m time has remained unchaged, but the exit speeds have gone down, which in my honest opinion is proof that engine power is indeed down.

Nothing else has been changed or altered on the car since.

avry8542 · 26th August 2007, 18:15

I just had the v27 upgrade put in my car. At least thats he version the service adviser told me they were up to. I started a thread which you may find interesting. In your case it would be weather related. Temperature and humidity make a huge difference on how these cars run; it also take some time for the new ECU to adapt. I am not really sure. But you are right there have been complaints about this issue. It is hard to get a straight answer. if you want more power get the AA software upgrade you will love it.

PitziM5 · 26th August 2007, 18:39

Quote:

Originally Posted by avry8542

In your case it would be weather related. Temperature and humidity make a huge difference on how these cars run; .

Thanks for the reply. It's not temperature related. All my runs were done in winter, not one of these runs were done more with than 5-7C difference between them.
I agree regarding the ECU needing time to adapt, but I've done 4000kms since the upgrade, and I drive the car hard everytime. I don't think it has anything to do with the ECU as such, but the software has caused a power loss.

avry8542 · 26th August 2007, 18:43

I agree. check out my thread on the v27 software the dealer just installed. I have had the same power loss problem.

T Bone · 26th August 2007, 19:27

Quote:

Originally Posted by PitziM5

Thanks for the reply. It's not temperature related. All my runs were done in winter, not one of these runs were done more with than 5-7C difference between them.
I agree regarding the ECU needing time to adapt, but I've done 4000kms since the upgrade, and I drive the car hard everytime. I don't think it has anything to do with the ECU as such, but the software has caused a power loss.

Pitzi, thanks for the data, I think you are one of the ones who proved powerloss by trapspeeds....

That is a huge drop in trapspeed.... As Avry suggested, run it hard for a little while and see if the programming changes.

PitziM5 · 26th August 2007, 19:47

Quote:

Originally Posted by T Bone

Pitzi, thanks for the data, I think you are one of the ones who proved powerloss by trapspeeds....

That is a huge drop in trapspeed.... As Avry suggested, run it hard for a little while and see if the programming changes.

Pleasure.

I honestly doubt anything will improve. I've driven it very hard for the past 4000kms (2500 miles) after the software uploadThis car is not my daily drive, which means that when I drive it, it's P500 S6 and pedal to metal as soon as the oil temp reaches operating range.It had improved after the first 1000kms or so, after that no improvement.

I'm actually tempted to take it back to have the V25 uploaded again, as the service manager offered that to me. But I don't know if I want to have to deal with the old I-drive menus which I found slow and pretty pathetic to use.

avry8542 · 26th August 2007, 19:54

Get the AA sofware you will love it. It gives alot more power and the smg stops that jerking stuff. Trust me look into it.

PitziM5 · 26th August 2007, 20:15

Quote:

Originally Posted by avry8542

Get the AA sofware you will love it. It gives alot more power and the smg stops that jerking stuff. Trust me look into it.

My problem is I'm in Africa. AA is in the US, not an easy logistical matter should there be any problems.

avry8542 · 26th August 2007, 20:32

If you have a BMW performance shop near you all they have to do is ship your ECU out over night and AA will reprogram and overnight it back. I'm sure it may take alittle longer cause you are in africa Its well worth it trust me. Do you have a shop that you can trust to do the job?

RussRamz · 26th August 2007, 20:38

My friends...

From what I understand, there might be a problem to put an older version of the software on your car once it has been programmed with a newer version. I know of one person who needed to ship his ECU back to someone in Munchen after his ver 24 was overwritten with ver 25 and reported a power loss...