BMW e39 M5

Post by **Rossco** » Sat Jun 15, 2013 2:41 pm

Ahead of the supercharger arriving I took the car to a rolling road in Derbyshire to get a baseline reading.

The e39 M5 has both DSC and ABS which work together, there is a button for turning it "off" however from all the stories on the net about how it wont actually turn "off" you may as well try farting the national anthem while standing on one leg and see if that works.

It also has a "sport" mode which merely switches the fly-by wire throttle to a more aggressive map.

First run was with the DSC and ABS functional and without the sport button on. It went all the way to 7k and returned 354 at the flywheel. Not quite what I was expecting but it was the first run.

Second run we disconnected the DSC and ABS by pulling the fuses - 308 bhp

Ouch this is getting worse so we put the fuses back in and the third run went into limp home mode almost immediately

Fourth run we had the sport mode on and the DSC cut the power at 5700rpm, which is exactly what it should do. However when we looked at the plot this time it was showing a solid 50 bhp gain over the first run all the way up to the cut off at 5700rpm. My guess is that if it had reached 7k it was on target for a standard 390-400bhp.

This begs the question does the normal throttle map ever give the engine WOT or is it only sport mode which does that........oh yes and how the foooook do you dyno an e39 M5

kiwicar · Post by **kiwicar** » Mon Jun 17, 2013 9:23 am

Hi Rosco
I think you will find that there is a sensor that detects a camera crew/ motoring journalist and only offers wide open throttle when one is in the car or within 50 feet. . . I have heard of long tails of woe of people trying to get the BMW ECU to do what they want and the thing defeating them at every turn. Either it rejects the changes or reverts to limp home mode. Before you go too far into trying to modify/ reprogramme the standard ECU consider replacing it completely with an aftermarket one.
Best regards
Mike

Post by **Rossco** » Mon Jun 17, 2013 3:33 pm

kiwicar wrote:Hi Rosco
I think you will find that there is a sensor that detects a camera crew/ motoring journalist and only offers wide open throttle when one is in the car or within 50 feet. . . I have heard of long tails of woe of people trying to get the BMW ECU to do what they want and the thing defeating them at every turn. Either it rejects the changes or reverts to limp home mode. Before you go too far into trying to modify/ reprogramme the standard ECU consider replacing it completely with an aftermarket one.
Best regards
Mike

Mike......have you been stalking me?

Your explanation about motoring journalists could be spot on given that the car featured in Jeremy Clarkson's video 'Heaven & Hell'......maybe it's now a bit of a prima donna

DaveEFI · Post by **DaveEFI** » Mon Jun 17, 2013 3:41 pm

Just for info, there is an E39 forum on Yahoo Groups (mainly US based) where there are one or two quite knowledgeable M5 owners. Not that they talk to the likes of me with a 528, though.

Post by **Rossco** » Mon Jun 17, 2013 4:39 pm

Dave.....that makes you and me both.

Most M5 forums appear to be inhabited by knobs who only want to tell you what you're doing wrong instead of how to do it right.

DaveEFI · Post by **DaveEFI** » Mon Jun 17, 2013 10:38 pm

The E39 forum is ruled with a rod of iron by the owner - so generally a pretty friendly place. I was joking about my 528, as most of the US cars are V-8s.

Raffa · Post by **Raffa** » Fri Jun 21, 2013 8:21 pm

Hi Mate
Great car, just sold mine a year ago and still miss it, had mine RR at surrey RR and as you say that can be a little difficult to get the correct figure, but a good engine should be round 390-400bhp, in regards to forums i used the m5board just for info as they know there stuff, good luck with the supercharger, what sort off bhp you looking at 500bhp?
and if you ant changed the main bearing shells, do so, as with millage they can spin, first signs are a ticking noise in the bottom of the lump.

all the best

Raffa

Post by **Rossco** » Sat Jun 22, 2013 4:27 pm

Hi Raffa

The kit makes 6.5psi which if you do the maths means 550bhp allowing for some losses.

Raffa · Post by **Raffa** » Sat Jun 22, 2013 7:53 pm

Rossco wrote:Hi Raffa

The kit makes 6.5psi which if you do the maths means 550bhp allowing for some losses.

Hi Rossco
Well that should make a diffence mate

, i have seen one completed and it did sound pretty mental, good luck with the install, did you get it from Evolve or is it an ESS job and a rear ehaust box delite is a must, had mine done and it sounded sweet

Cheers

Ralph