[grashuir]

As I mentioned earlier this week I went to MK in Germany. Before I had the chiptuning done I asked them to measure the original power first. The results were very disappointing: 343 PK (HP)!!
So I asked MK to cancel everything and I went to BMW The Netherlands first complaining about this and telling them to fix the problem. No way I am going to pay for a boost up to 400 PS when BMW should deliver this in the fisrt place.
Can anybody comment on this or have similar experience or advise?

 

[tfung]

Is that 343hp at the wheel or engine power? That figure sounds like wheel horsepower, which is signicantly less than engine horsepower due to driveline loss.
Terence

 

[RaMsEs]

BMW along with every other auto maker sites HP at the crank. When you get dyno tested, you are measuring power at the drive wheels. There is anywhere from a 15% to 25% loss when comparing the two figures. 343HP is about right compared to what I've seen, a tiny bit low...most are in the upper 340's, but that difference in negligable when you consider all variable such as ambient temperature, engine temperature, engine mileage, etc...Check this out and you'll see that you had normal results, I forgot what page it originally came from, but it compares a 540i and and M5: http://www.gourmetshit.com/Shawn/M5/m5dyno.jpg

------------------
-Shawn

 

[grashuir]

Thanks RaMSes, I feel a little bit better now. Nevertheless, I made an appointment with BMW The Netherlands on June 21st, I will go along with that, see what they come up with. You never know, maybe they'll find a way to improve the power a bit anyway. I have the results from the power measurements on paper, will scan them in later and post the to you. Thanks again..

 

[grashuir]

By the way, MK told me they could 'chip it up' to 400 HP. Is that good or could it be better?

 

[tfung]

I think you should ask MK to let you know if it's engine hp or hp at the wheel. If they can increase your hp at the wheel from your 343hp to 400hp... that's nearly a 100hp increase in engine hp, which is impossible for just chipping a car. If they're talking about engine hp, then it doesn't make sense that they can chip a 400hp car to 400hp... or maybe their chip doesn't do anything at all.. =)

 

[raymondw]

343hp at the rear wheel equals about 15% in drive train loss, which is good, but the E39 ///M5 engine does not allways has 400hp at the cranck. We have had long discussions of that in the past, but the general concensus was that 400hp is what you can expect at best. Most have 380-385hp at the cranck, so it is indeed the best thing to go to BMW. If you need more details about this, contact Peter Gutniak or Chris. You can find their Email addresses somewhere else on this board. Peter is a Swedish E39 ///M5 owner who has dealt with allmost all troubles with the E39 ///M5 before and Chris is one of the moderators of this board.

Personally, I doubt that BMW Netherlands have had complaints about the power before, since most customers in the Netherlands don't feel the difference between 380hp or 400hp.

I agree with Terrence that simple chip chuning does not bring 400hp at the rear wheels because the M5 engine of the athmosferical type. With turbocharged engines, this is more easy, allthough most tuners don't respect the mechanical reserves in the bottom end and temperature reserves in the high end of the rev range, giving their owners problems with longevity.

If MK thinks they can give you a power gain of 15%-20% with simple chip tuning, I would be very sceptical.

with best regards,

Raymond

 

[daniel]

1. If someone believes (Gustav and others), that they are getting less power, please post your results. A dyno measuring rear-wheel HP would be fine. I would just like to see the evidence, as I am very interested.

2. If a company says they can take you from 343 RWHP to 400 RWHP (going from around 400 to 460 engine HP), don't buy anything from them. This increase won't happen with just a chip on a non-turbo engine.

3. 343 RWHP is something close to 400 HP (using 15% which works well on Porsche and Viper)... so maybe nothing to complain about.

Dan

 

[Jeff L]

I do not know about Euro cars, but in the US with OBDII cars, a true dyno run is not possible. The dynos I have seen look pretty good, but since OBDII has a learning capability, the results can vary based on driving patterns. Jim Conforti, the GOD of BMW chip tuning has given long dissertations on this on the web. Essentially, you can easily lose or gain 20 HP based on the software adaption. Here is the link that explains the pitfalls of true dyno measurments:
http://www.gis.nsw.gov.au/staff/rnott/bmw/BMWText/technical/WhyYouCantDynoOBD2.html

This site has an unbeleivable wealth of info and is well worth browsing. A lot more info than this messageboard with its Trolls and pot shots at the M5.

So, I do not know what is up with the Euro cars, but this may explain some dyno variations. Me, I am very happy with my M5's power and I plan on hanging onto the car and enjoy driving the **** out of it. I have experienced what it can do by itself and with other cars.

 

[Jeff L]

Here is the index for the BMW tech site. This guy has done alot of quality work putting this together.
http://www.gis.nsw.gov.au/staff/rnott/bmw/

As far as a chip adding power, I agree that probably is not going to happen. The only way to add any real power is through cams, headwork etc.

 

[daniel]

Blah, blah, about the OBDII (used for all cars). Let's see the dyno charts showing the 20hp loss against baseline on a few cars. No doubt it CAN happen... the 1999 Mustang Cobras have been recalled due to overstating the power (on all cars, not just some of them). And Grashuir, MK didn't tell you that they were quoting rear-wheel horsepower??? Dan.

p.s. not starting an argument, just want to see the facts.