sleepyca31

Well went to dyno my 530 on a dynojet today to compare it to the dynodynamics I did last week-and at first I was very happy pulling 222hp v. 203 at dynodynamics-confirming what I believed to be a 20whp increase from some mods.

Well that is fine and well until I got in my car to leave and FOUR codes were thrown
1.Power steerin gone (servtronic )or something
2. Dynamic stability limited (gone)
3. ABS light on and code saying not working
4. Passenger safety restraint/airbag not functioning

Like WTF happened! Anyway to clear this or remedy-really stinks driving with no power steering! I shut the car down and hopefully it will work itself out-It threw some codes last time I dynoed but cleared itself and the power steering never went out.

Oh well-not really thinking I am going to tell the dealer I dynoed it-didnt really do anything I havent done before on long highway stretches-basically floored it in 4th gear to 7k RPMs-not sure what happened.

sleepyca31

Nevermind-codes clear-as usual the BMW computer is smart! Man no powersteering was a trip-really made me appreciate power steering and even more-active steering. Try parking in a tiny garage space in my condo with no power steering-awful!

6spd

I threw some codes after a smog check(here in cali, you have to do that if you buy a car from a private party and transfer ownership). dynamic drive went out when I left the shop. once I got home, and started it up again, everything was fine.

Bad Bimr

The dyno dynamics dyno (also known as the heartbreaker) will always show lower numbers then a dynojet duno. The dyno dynamics numbers are assumed truer indication of HP then other dynos. People forget that dynos are meant for tuning and NOT to show HP. Unless you did a baseline run, you do not know how much HP was added by the mods. Assuming your car is a manual you will have approximately 17% drivetrain loss (1.21 correction factor), thus 203 X 1.21 = 245.63 HP. The 2007 530i engine is rated at 255 HP, so your mods did not give much performance. Again a baseline run would be very helpful.

sleepyca31

Ya I gave up on the dyno world since the variation was just too much. I made the mistake of not pre-dynoing my car to get a baseline so everything now is a guessing game.

Mine is an auto

and 17 percent seems low even for a dynojet?

The dynodynamics dude here at dynocomp in phoenix-a pretty nationally known mod place for bmw and merc told me dyno jet uses 20-25 percent drivetrain loss and their dynodynamics use a 30-35 percent drivetrain loss on all cars. So 17 is low I believe, atleast for this dudes dyno.

Anyway my dynojet-as posted below was just screwed up-the guy operating the dyno didnt know what he was doing as you can see and I was driving which I admit I dont know what I am doing.

Anyway I was trying to get a stock 530 auto to go to the same dynodynamics to get a baseline for the 530-until I can get that nothing was really found with the mods.

ivan545

Well as far as the DSC goes, when it's dyno it should be turned off, hold the button down till the lights comes on. When the rear wheels are spinning for a period of time the ABS light will come on it's normal and then after that you will see both light the ABS and DSC on the same time. But after you shut off your engine and turn on again and drive for a few miles the ABS and DSC lights should go off, its normal for it to come on, and the ABS light comes on because two of your wheels are spinning and the other two is not so the computer sees this fault and thinks that something is wrong thats why the light comes on and after driving it again normally the computer sees the all four wheels are spinning again so it shuts off because it's back to normal. As for as the light coming on or staying permanent on i think it's possible that the person forgot to turn off DSC before dyno and that can cause it to stay on because you might have damaged it.

sleepyca31

no it definetly was off-actually impossible/very hard to do any dyno with it on-a few weeks ago at the very first the dude turned off dsc but left on dtc by just hitting it quickly and the car did not want to get moving since the wheels were spinning

anyway it was off-it took probably 15-20 minutes of normal driving. First the passenger restraint oked, then the DSC and ABS oked themselves and last to come back was "servotronic" which must be power steering since I could barely turn the wheel without that and that is what the message said-something along the lines of loss of power to the steering or something along those lines.

Anyway all was fine and well after 15 minutes.

The only reason this concerned me was the other week at the dyno-the loss of dynamic control came on but after shut down and restart immediatly went away. Nor did any of those other lights come on last time.

Anyway-dynoing is too much of a hassle-I dont race my car and am done modding-plus its 100 plus degrees here in arizona and I can tell by my butt dyno when it is 100 plus degrees by car is dragging itself so those outdoor dynoes do nothing for giving me a useable result.

Bad Bimr

Drivetrain loss on an automatic is higher then a manual, however it is not 35%. I would estimate no more then 25% and the is on the high side. The dyno has nothing to do with drivetrain loss. Drivetrain loss is the amount of power it takes to spin the rotating parts, fly wheel, tranny, drive shaft, diff, axles, wheels and tires.

Bill

sleepyca31

Ya well obviously you are not familiar with a dynodynamic dyno (not being rude) just saying it actually does not use how fast you can spin the barrel-rather it applies a set load and directly calculates hp rather than torque and calculating hp

You can search around-it does matter on the dyno dynamic v. dyno jet. You can call it whatever you like. some say it is 10 percent lower than a dyno jet, some say 30 percent instead of 20, some say 35 instead of 25. Bottom line is it definetly dynos lower.

The way he explained it to me is this "load" they put on is useful for tuning since it simulates TRUE whp on the road which a dynojet inertia dyno does not. That weight when they are truly "tuning" a car, they can play around with rpms and shift points and all sorts of things in real road conditions. Since a load is put against the wheels it slows the wheels down since a force is going against them v. an inertia dyno drum freely rotates with no force applies agaisnt the wheels.

Anyway not justifying a number or arguing but a big misconception and makes for poor comparison is how the dynodynamic and dynojet differ.

sleepyca31

I meant it directly MEASURES, not calculates hp v. a dynojet which calculates hp based on torque=inaccuracy