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Discussion Starter #1
All,

I wanted to share with you the results of my two Dyno runs today at Motorsport Technologies in Houston.

Weather was overcast (cold front just passed through but clouds still lingered) and about 65 degrees, unfortunately with high humidity... around 90%!
Anyway, this was my first time ever to dyno any of my cars...

They use a DYNOJET. HP and Torque measurements were as follows:

2200 RPMs - 300 ft/lb. torque and about 140 HP

3000 RPMs - 320 ft/lb. torque and about 165 HP

as you can expect ... the HP numbers kept rising although, also as expected, the torque curve is pretty flat the rest of the way reaching a maximum of 326 ft/lb.! Max torque was reached around 4800-5000 RPMs.

Max HP of 331 was reached around 6750 RPMs.


I figure we could probably squeeze a few more horsepower by doing another few runs with the temperature around 40 degrees with much lower humidity, equaling much more cool dense air. The guy doing the test said he would expect another 10-15 HP with the right ambient conditions. I plan on doing this again in a month or two just after a nice cold front. I will post results after my next runs.

Bottom line....

my car has Dinan software, Dinan Cold Air Intake, and Supersprint mufflers... and the test was done completely in 4th gear.

Results again...

Max HP = 331 HP
Max torque = 325 lb/ft

This of course is measured at the rear wheels.

I would be interested to hear from others who have done Dyno runs and what results you had... also, what part of the country are you in and what was the ambient temperature during the tests?

-Andy-
 

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Discussion Starter #3
Not sure since I never dyno'd mine while it was stock... I don't expect the HP would be much different though.. but I would expect a little more torque with the mods?

This is why I would like to hear from others who have dyno'd? both before mods as well as after mods?

-Andy-
 

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Discussion Starter #5
farcknorf,

Base Horsepower for the M5 (at least the US version) is officially 394 HP. This is horsepower measured at the crank of the engine.

The horsepower measured on my car today was done at the rear wheels.

There is always horsepower lost due to friction, transmission, clutch, etc... i.e. you will lose approx 10-15% or more of the crank horsepower when the power finally makes it to the rear wheels and finally, the pavement! In the conditions in Houston today... my car lost approx. 16% of its total crank horsepower before finally reaching the pavement.

As you can see, HP ratings on any car are always published by the manufacturer at the crank... however, what we all want is more horsepower at the rear wheels.. this is what you feel every time you step on the gas!

Hope this helps?

-Andy-
 

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i didnt get to check my car......so the m5 accutally loosing power at different conditions.
acually any car...
no way the m5 will provide the whole pack(394-400) at the rear wheels?
 

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Really, your car seems to have lost power after your Dinan tweaks, even cosindering measured on your rear axle.

Anoynone of us euro guys suprised?

/Johan



[This message has been edited by johann (edited 25 November 2000).]
 

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HP, bhp etc is a yardstick, by which we initially judge and compare. Real comparisons can be had from in gear accel times and hands on testing. Don't think that 400 bhp means anything more than engine output of 400bhp. A better paper comparison is always bhp/tonne. For example a two tonne car with a 400 bhp engine is slower than a 1 tonne car with a 400 bhp engine.

even a bhp/tonne figure is not a good indicator of a good car, take the Aston Martin Volante as an example.

Also, Dynos are not calibrated to a common standard and therefore the only useful way to dyno a car and measure tuned over stock is to take a stock car, dyno it, then tune it and dyno it on same machine under exact conditions. No changes. i.e Dynao is the same, no mechanical changes, ambient environment is the same, and car is taken through exactly the same warm up etc etc.

hard to do!!

spend your moeny and enjoy your extras - don't try to justify them!!!!
Steve
 

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Discussion Starter #9
SteveG, et al,

I agree with you that Dyno results should be taken for what they are... a measurement in a specific slice of time. I also agree that they have more meaning if you can somehow perform the dyno runs before, during and after each modification...and somehow do this at the same exact conditions on the same exact machine! This is THE ONLY way you will achieve an accurate reading of what the engine is doing as you tweak it.

The only reason I placed my car on the dyno today was to satisfy myself that my car fits the profile of the majority of all other M5s. and it does... I did not expect to get tremendous gains over stock for my mods thus far... that is not why I did them. I realize that most of the HP gains that tuners post are done under extremely controlled circumstances, and are very difficult to achieve out in the real world.

I would recommend to all of you ... that if you are looking to spend money on performance mods (shy of actually doing a blower or other big time mods) for gaining tremendous horsepower.. save your money! Otherwise, for the rest of us that just want to do it for looks and/or a little more throttle response.. go for it!

Just one last item... I met Steve Dinan last year in Houston and he and I had a long conversation on BMW's and tuning. He said that ambient conditions alone can take away as much as 20 HP or more on an engine like the M5's. Therefore, what part of the country/world you live in definitely plays an integral part of what final rear horsepower your car will have. That being said however, I doubt it very seriously that anyone will notice the subtraction or addition of a few horsepower here and there on such a BEAST!

I love my car and that's that! No matter how much horsepower the dyno says it has or doesn't have! I know it can hang with the best and fastest cars out there and that is good enough for me!

later guys..

Andy
 

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Andy-
To pick up on something you said, does anyone yet offer a turbo or blower for the e39? I had a 540 for a few years and was surprised not to discover any such treatment for that. Anyhow, that's old news. What about the new M5? Anyone? Thanks.
 

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Andy,

Shouldn't the car be dynoed on the 6th gear?
All cars I have had has seemed to feel stronger when it has been cold wheather with high humidity.
I thought high humidity was good when trying to achieve a high hp measure, am I wrong?

If you add 20 hp to your measurement, you are still getting more or less the same power as a non modified car.

Does the car behave better in anyway?

Otherwise, since the Dinan sw mod and CAI does not add anything to looks nor to performance my conclusion would be that they are really a waste of money and that you should spend them on better brakes or suspension upgrades instead or get Kelleners sw mod or the engine kit which has been proven to really add power

/Johan
 

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Andy's dyno result is fairly consistent with other M5's, including mine. I and two other friends had our M5's dynoed back in July at the same place (MTI in Houston). My bone stock M5's best run was 335 hp and 323 lb-ft torque. My friend, Jim, got 334 hp and 327 lb-ft torque. He has a Dinan software upgrade and a SuperSprint exhaust. Jeff L got 328 hp and 327 lb-ft torque stock M5. His pull was done in 5th gear and the car was hitting the speed limiter before the max hp could be reached. Jim and my pull were done in 4th gear. The ideal gear to use on a dyno is the overdrive 1:1 (5th on ours) gear but since we have the speed limiter issue, we used 4th on ours.

As you can see, our M5's power are pretty close. It was a little disappointing to find out we weren't close to the manufacture's claim (394 hp) even after using a 15% correction factor for drivetrian loss. FYI,our #s were power from the wheels, not the crank. The M5's engine is very sensitive to heat. My third dyno run was 12 hp and 9 lb-ft less than my first run. I am confident the #s would have been higher if I had let the engine cool down longer. FYI, John Hennessey got 345 hp from his stock M5 awhile back.

As far as mods go, don't expect much from them. BMW has done an extraordinary job on optimizing the power output on the M5. There is really not much room for anymore improvement.

Later,
Kenneth
'00 silverstone M5
<a href="http://www.logicalsteps.com/m5">power by M</a>

<img src="http://www.logicalsteps.com/m5/dyno/m5dyno1.jpg" alt="M5 Dyno" border="0">


<img src="http://www.logicalsteps.com/m5/dyno/m5dyno2.jpg" alt="M5 Dyno" border="0">




[This message has been edited by kenneth (edited 25 November 2000).]
 

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Andy,

Thanks for posting all of the photos and dyno results. That is the neat thing about this board; you get very useful info on a wide range of topics including upgrades. Each individual can then draw their own conclusion about how they want to spend(or not spend) their money.

Kenneth's dyno data was an excellent baseline to compare upgrades against. In my mind it confirms that most of the tuners (including Dinan) are not getting any appreciable horsepower gain with their mods. Removing the speed limiter is not enough of a reason for me to get a "chip" upgrade; 165 MPH is fast enough.

Dinan supension or Brembo/Porsche brakes sound intriging to me, but only if I decide to track my car more often. I could push my stock M5 a hell of a lot harder on the street than would probably be advisable before I hit it's handling and braking limits. On a race course is another story. You can never get enough brakes or a stiff enough of a supension if you are racing and are willing to compromise a car's street characteristics. Do you want a race car or an awesome performing and comfortable street machine?

Conclusion: don't waste you money on tuners and get a real race car(an F1 would do).

John
 

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Official statement and measurement prerequisites form BMW M-Sport GmbH Germany.

You can't just do and let measure the power on the back wheels. They are only two possibilities to do that.

2 wheels measurement: You'll need a piece of software, because BMW has a emergency programme,
which automatically comes up if:
- The Speed difference between the front and back wheels are more 8 Km/h (~5miles/hour)
- Catalyst is not working well
- humidity is to high
This emergency programme is taking away exactly 15% (Europe version) of the hp and the max. rpm is 6350, even if it shows 6500 or more there is no additional hp or torque...

4 wheels measurement: You'll need again this piece of software because the max. performance of the M5 engine is available at 7000 rpm and it is impossible to get there without this piece of soft.
 

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Jlvink,

I agree that "I could push my stock M5 a hell of a lot harder on the street than would probably be advisable before I hit it's handling and braking limits".
However, you are not alone on the streets and upgraded brakes can save lifes. Keep in mind that upgraded brakes do not need to affect comfort.

/Johan
 

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Hello Andy:

Are you reporting the CORRECTED -or- RAW dyno results, in other words, has the atmospheric dyno correction factor already been applied to the data you report?

If YES, then your data has already been normalized for atmospheric conditions per SAE J1349.

If NO, then your raw data is biased upward by approximately 2.5 percent based on yesterday's local weather conditions. You will need to multiply the torque and HP measurements by a dyno correction factor. That factor should have been provided to you by Motorsports Technologies. Note Kenneth's print-out shows a "CF=1.02." This means his measured results had to be scaled upward whereas I expect yours had/have to be corrected downward.


Originally posted by AndyMenard:
...Weather was overcast (cold front just passed through but clouds still lingered) and about 65 degrees, unfortunately with high humidity... around 90%!...I figure we could probably squeeze a few more horsepower by doing another few runs with the temperature around 40 degrees with much lower humidity, equaling much more cool dense air. The guy doing the test said he would expect another 10-15 HP with the right ambient conditions....
 

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One thing the 3-way comparison proves once and for all: Chips and exhaust systems won't get you more power in an M5. Buy the chip to remove the rev and/or speed limiter. Buy an exhaust system to change the sound. Just don't expect a change in performance.
 

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Discussion Starter #18
ivory1:

the number I posted was corrected with a CF=.97

btw: I saw the same thing as Kenneth...i.e. I lost 10 HP and 8 ft/lb of torque on the second run.

-Andy-
 

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Discussion Starter #19
Some final thoughts to reiterate Greg's comments...

If you are looking for HP gains from your software, Cold Air Intake and exhaust... save your money.

I on the other hand would still do them for the same reasons Greg mentions...

1) the Supersprints look and sound FANTASTIC!


2) the Dinan Cold Air Intake = again looks great and sounds alot throatier!

and

3) the Dinan software removed the top speed limiter... not that I will EVER get to really go 185??.. but it is nice to know that I could!!


It does in fact seem that the mighty M5's engine will need some forced air induction to actually get some additional (measurable) ponies!

This should put to bed all of the banter on whether or not the performance mods = greater measurable horsepower... ANSWER = NO!

I still love it though! and I don't regret spending money on the mods... cause I did em for the right reasons!

later folks...

-Andy-
 
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