[1bade92]

So the famous "near 400 ft lb tq" people get are corrected? Seems 360-370 after ECU tuning is the norm. What do I have to tell my dyno shop to get the correct #'s, just to give me "uncorrected" numbers?

[RiXst3r]

Originally Posted by 1bade92

So the famous "near 400 ft lb tq" people get are corrected? Seems 360-370 after ECU tuning is the norm. What do I have to tell my dyno shop to get the correct #'s, just to give me "uncorrected" numbers?

near 400ftlb is possible with ECU and Exhaust

this graph showing near 400ftlb is from a STOCK car, tuned cars can actually acheive that, since my car was stock, obviously it was wrong

Yes, get uncorrected numbers. or if they give you SAE or STD corrected numbers, ask for them to show the run conditions and correction factor, so that you can see how much correction is in place. All they have to do is right click the map in winpep, and tell it to show conditions.

This was my BONE STOCK, no mods, no tuning, SAE corrected run: obviously the uncorrected run was the CORRECT one

Same Runs, UNCORRECTED

[1bade92]

Understood. You had pretty high stock HP readings on your car, nice dyno! Yeah so many things vary between dynos that it is hard to compare sometimes. At least now I know to make sure and ask for uncorrected #'s. I'll obviously wait until the car is broken in though. So what do you think is the proper way to break in a car?

LOL j/k

[Juggs]

excellent post

[RiXst3r]

Originally Posted by 1bade92

Understood. You had pretty high stock HP readings on your car, nice dyno! Yeah so many things vary between dynos that it is hard to compare sometimes. At least now I know to make sure and ask for uncorrected #'s. I'll obviously wait until the car is broken in though. So what do you think is the proper way to break in a car?

LOL j/k

i romped on her hard since day one

[LOLrance]

Great post. +1 on the idea that this should be stickyed

[1bade92]

+1 here for making this a sticky. I would do the "romp on her since day 1" but i'm too much of a coward to do that to brand new car hahaha.

[RiXst3r]

Originally Posted by 1bade92

+1 here for making this a sticky. I would do the "romp on her since day 1" but i'm too much of a coward to do that to brand new car hahaha.

[Stage 2 Drew]

I dont know why yours are SO off....Im thinking the dyno temp, altitude settings were wrong from the get go.

here are my dyno numbers. Dyno is at approx. 1000 ft. Only thing I changed was the correction factors.

Car is SRT-4.

conditions: 72*F , 28.6 in-Hg , 5 % humidity

UNCOR 1.00
SAE 1.02
STD 1.04





so.....Is yours right or mine right.

dont always believe everything you read. unless its from shiv

[RiXst3r]

We are talking about 335 dynos... Yours is right... Mine was wrong, that was the point... read the whole first post again, you seem to have misunderstood.

1. Your car is not a 335
2. Your CF is very close to 1.0
3. Your car is not a 335 :-)

[Stage 2 Drew]

Originally Posted by RiXst3r

We are talking about 335 dynos... Yours is right... Mine was wrong, that was the point... read the whole first post again, you seem to have misunderstood.

1. Your car is not a 335
2. Your CF is very close to 1.0
3. Your car is not a 335 :-)

just post the correction factors of your runs w the winpep software. That will show the real story. IMO-its not just cause u have a 335

[RiXst3r]

Originally Posted by Stage 2 Drew

just post the correction factors of your runs w the winpep software. That will show the real story. IMO-its not just cause u have a 335

I really dont think you are understanding... my post was about how easy it is to fool a dyno when the run conditions are bad, because the 335 doesnt lose as much power as other cars. This is proven many times over... YOUR RUN CONDITIONS WERE NOT BAD... AND, YOU DONT HAVE A 335... I know the REAL story, the real story is that the SAE correction was way high because the conditions were so bad, I was there, it was bad... but yet the car still put down normal stock numbers, WITHOUT correcting for the bad conditions

You can see the run conditions at the bottom of my original post.

SAE and STD are algorithms that process air temp/pressure/and humidity and based on how far off these are from 60 degrees at zero altitude and low humidiy, then it calculates the correction factor... you dont need me to post it, I already did... just do some math! (1.0 = 100%, no correction = 1.0... take my corrected graph, and compare it to my uncorrected graph, and you get my CORRECTION FACTOR)... its all just basic math, and a computer that thinks its dealing with a car that neeeded tons of correction because of crappy conditions, when obviously it needed no correction

[Stage 2 Drew]

Originally Posted by RiXst3r

my post was about how easy it is to fool a dyno when the run conditions are bad

exactly it has nothing to do with your 335 and yes, I know its basic math...your SAE corrected it 1.41

so my 244whp would have been like 344whp

[RiXst3r]

Originally Posted by Stage 2 Drew

exactly it has nothing to do with your 335 and yes, I know its basic math...your SAE corrected it 1.41

so my 244whp would have been like 344whp

no, you still missed the point!

your car would not have made 244whp in my conditions

[Stage 2 Drew]

Originally Posted by RiXst3r

no, you still missed the point!

your car would not have made 244whp in my conditions

ok bye, thanks for playing

[RiXst3r]

Originally Posted by Stage 2 Drew

ok bye, thanks for playing

if your car doesnt have a closed loop MAP based boost control system with closed looped fuel control.... then it does not adapt as much as the 335 to the varying conditions... if it does, then this will apply to you also, IF YOUR RUNS WERE DONE IN MY CONDITIONS... ITS ALL ABOUT THE CONDITIONS DURING THE RUN!

You seem to have missed my main point... your run is only inflated if the conditions are bad. Sure, its nothing super special about the 335, it works on a few other cars too... but this is a BMW forum, and people getting their 335 dyno'ed need to know to request printouts of the uncorrected numbers as well as whatever the shop uses by default.

Your so hung up on the dyno numbers and the car... its not about that, its about the conditions, and the correction, and the correction not being at the correct levels for this type of vehicle.

[hotrod2448]

Ok, so with your standard correction dyno's being that far off, what can we make with Shiv's being what would appear accurate?

http://www.e90post.com/forums/showthread.php?t=65548

I'm guessing the weather was very close SAE standard conditions which gave a low correction factor for these pulls. I don't know for sure because I don't believe the weather was posted.

I guess I'm not understanding what Standard is. I understand SAE correction but, is Standard different from dyno to dyno?

[RiXst3r]

Originally Posted by hotrod2448

Ok, so with your standard correction dyno's being that far off, what can we make with Shiv's being what would appear accurate?

http://www.e90post.com/forums/showthread.php?t=65548

I'm guessing the weather was very close SAE standard conditions which gave a low correction factor for these pulls. I don't know for sure because I don't believe the weather was posted.

I guess I'm not understanding what Standard is. I understand SAE correction but, is Standard different from dyno to dyno?

STD works exactly like SAE... it just has different ratios, and ussually comes up with a little less correction.

Your correct... in shivs case, the weather was very close to zero correction (1.0), so STD does not make much of an impact. If shiv did his dyno testing on the same location as me, on the same day as me, his numbers would be just as far off as mine were!

The correction factor is not a setting, its simply the result of the SAE or STD calculations which are based on weather conditions

What i am trying to prevent is people trusting STD or SAE correction without seeing the CF or Run Conditions. Its best to just use uncorrected numbers, and provide all the enviromental data, so that people can do their own math... IMHO

[e36jakeo]

Excellent post - you truly taught many (most?) of us something. The fact the 335i has so much power in "reserve" that allows it to keep its engine performance almost the same in most conditions proves to me how much BMW left on the table with this motor.

If they come out with a new version of their 4.8 Liter V8 (which is about due for an upgrade), say to about 390 - 400 HP, I predict they will retune the N54 to make 330 HP -- which might be more like 360 BHP.

Anyone second that?

[Coldintake]

Great post + Nice car = Double whammie.

[boosted]

Dyno numbers can be easily inflated regardless of SAE or STD when playing with CF and 1.0 should always be a standard. It's up to a dyno operator to keep it standard and consistent REGARDLESS OF the CAR used. And yes one needs to run on the same dyno, SAME CF and actual correction (SAE or STD) to determine the gains between STOCK and MODDED vehicle.

Generally speaking SAE correction ALWAYS reads lower than STD, hence it's considered industry standard and prefered by many from imports to domestic muscle LS1/LS2 crowd. Again as long as CF = 1.0

[RiXst3r]

Originally Posted by boosted

Dyno numbers can be easily inflated regardless of SAE or STD when playing with CF and 1.0 should always be a standard. It's up to a dyno operator to keep it standard and consistent REGARDLESS OF the CAR used. And yes one needs to run on the same dyno, SAME CF and actual correction (SAE or STD) to determine the gains between STOCK and MODDED vehicle.

Generally speaking SAE correction ALWAYS reads lower than STD, hence it's considered industry standard and prefered by many from imports to domestic muscle LS1/LS2 crowd. Again as long as CF = 1.0

sorry to burst your bubble, but this makes zero sense... a dyno op cannot change, or "play with" the CF... they can just switch between uncorrected, sae, or std. The ONLY way to get a CF of 1.0 is to show UNCORRECTED numbers... or do the run in precisely ideal conditions. STD and SAE are algorithms that create the CF.

CF is not entered by the operator, it is calculated based on enviroment variables... STD and SAE are different ways of calculating the CF.

Its amazing how many people are confused on this... you are not alone.

Here is how CF is calculated with the SAE calculation...


Pd = the pressure of the dry air, mb
Tc = ambient temperature, deg C

cf = the dyno correction factor end result (THIS IS A RESULT, NOT AN INPUT)


The horsepower and torque available from a normally aspirated internal combustion engine are dependent upon the density of the air... higher density means more oxygen molecules and more power... lower density means less oxygen and less power. Our turbo car already compensates by running the turbos harder, to create the same ABSOLUTE pressure... meaning that we dont lose all this power like a normally aspirated engine does.

The relative horsepower, and the dyno correction factor, allow mathematical calculation of the affects of air density on the wide-open-throttle horsepower and torque. The dyno correction factor is simply the mathematical reciprocal of the relative horsepower value.