Independent dyno ESS tuned M3

[GIdriver]

So I recently took my car to the dyno (Dynojet). The guy working was not very knowledgable, but a very nice person though. No rpm’s or torque curve, but that’s what I have available where I live. At least I got the whp (STD), and AFR.

Car: 2011 e90 M3 DCT
Current Mods/fuel:
ESS Akra Evo tune V2 + 240 OE software upgrade
Akrapovic Evolution exhaust
Dinan underdrive pulley
BMC filter
93 AKI

Results were pretty consistent with 4th and 5th gear pulls (worst and best pulls within 2-3 hp at the most). Best it did was 382.90 STD. I wanted to convert that to SAE and found a conversion calculator (http://wahiduddin.net/calc/calc_cf.htm).

Conditions (reported on dyno chart)
Temp: 92.89F
Pressure: 29.84 in-Hg
Humidity: 52%
Vapor pressure (calculated with temperature): 1.55
(http://www.srh.noaa.gov/epz/?n=wxcalc_vaporpressure)

With this data I calculated a Dyno Correction factor of 1.057 X 382.90 (STD whp) = 404.72 whp SAE

Are my calculations correct, or am I way off?

No matter what the HP is, the car is running GREAT!! Thanks Roman and AJ!!!

Updated post with crappy iPad pic

[MilehighM3]

Doesn't the under drive pulley need to be swapped for the stock pulley? Otherwise you under drive the supercharger which causes a low boost condition. I'd swap that back to oem and go dyno again.
Which kit are you running? Did you measure boost?

[GIdriver]

Originally Posted by Bmw135er

Doesn't the under drive pulley need to be swapped for the stock pulley? Otherwise you under drive the supercharger which causes a low boost condition. I'd swap that back to oem and go dyno again.
Which kit are you running? Did you measure boost?

The car is NA. It has ESS' Akra Evo tune Version 2. And yes, if I were to get a sc kit, I would need to go back to stock pulley for the reasons you have explained.

[Black Gold]

You are confused, std always reads higher than sae

Sae is more accepted.

http://m.corvetteforum.com/c6-tech-p...ml?styleid=132

[GIdriver]

Originally Posted by KennyPowers

You are confused, std always reads higher than sae

Sae is more accepted.

http://m.corvetteforum.com/c6-tech-p...ml?styleid=132

So I am waaay off. lol!!! Thanks for clarifying. Those are two different forms of correction. So I corrected an already corrected value?

[chris3g]

Originally Posted by GIdriver

So I recently took my car to the dyno (Dynojet). The guy working was not very knowledgable, but a very nice person though. No rpm’s or torque curve, but that’s what I have available where I live. At least I got the whp (STD), and AFR.

Car: 2011 e90 M3 DCT
Current Mods/fuel:
ESS Akra Evo tune V2 + 240 OE software upgrade
Akrapovic Evolution exhaust
Dinan underdrive pulley
BMC filter
93 AKI

Results were pretty consistent with 4th and 5th gear pulls (worst and best pulls within 2-3 hp at the most). Best it did was 382.90 STD. I wanted to convert that to SAE and found a conversion calculator (http://wahiduddin.net/calc/calc_cf.htm).

Conditions (reported on dyno chart)
Temp: 92.89F
Pressure: 29.84 in-Hg
Humidity: 52%
Vapor pressure (calculated with temperature): 1.55
(http://www.srh.noaa.gov/epz/?n=wxcalc_vaporpressure)

With this data I calculated a Dyno Correction factor of 1.057 X 382.90 (STD whp) = 404.72 whp SAE

Are my calculations correct, or am I way off?

No matter what the HP is, the car is running GREAT!! Thanks Roman and AJ!!!

Your SAE calculation is not correct, the SAE correction factor would apply to the uncorrected results, not results that are already STD corrected.

Your SAE numbers will be about 5% lower than the STD corrected results.

[Black Gold]

Yea what it seems like you did was calculate sae from the std, but assuming that the std numbers were actually uncorrwcted.

Basically, sae would be about 4-5% lower than the std numbers you recorded

[GIdriver]

Originally Posted by chris3g

Your SAE calculation is not correct, the SAE correction factor would apply to the uncorrected results, not results that are already STD corrected.

Your SAE numbers will be about 5% lower than the STD corrected results.

Originally Posted by KennyPowers

Yea what it seems like you did was calculate sae from the std, but assuming that the std numbers were actually uncorrwcted.

Basically, sae would be about 4-5% lower than the std numbers you recorded

Thank you both. Now I understand.

[325rider]

Looks like a good dyno What kinda wheels u running?

[pbonsalb]

SAE will be about 2.5% less than STD. Your numbers are in the ball park for your mods, around 372 rwhp SAE.

[GIdriver]

Originally Posted by 325rider

Looks like a good dyno What kinda wheels u running?

Thanks! Stock 220m wheels, stock size PSS tires.

[GIdriver]

Originally Posted by pbonsalb

SAE will be about 2.5% less than STD. Your numbers are in the ball park for your mods, around 372 rwhp SAE.

Thank you, sir.

[regular guy]

Let me help you out with some real numbers. You gave 382.90 whp STD.
Temp: 92.89F
Pressure: 29.84
Humidity: 52%

Based on those numbers, STD correction was 1.0541.

First we need to get back to your uncorrected numbers by dividing 382.90 by 1.0541 = 363.248 whp uncorrected.

Next we need to apply SAE correction to this uncorrected value. Based on your weather above, SAE correction is: 1.0257.

So, your SAE corrected results are 363.248 * 1.0257 = 372.58.

I hope this helps.

[GIdriver]

Originally Posted by regular guy

Let me help you out with some real numbers. You gave 382.90 whp STD.
Temp: 92.89F
Pressure: 29.84
Humidity: 52%

Based on those numbers, STD correction was 1.0541.

First we need to get back to your uncorrected numbers by dividing 382.90 by 1.0541 = 363.248 whp uncorrected.

Next we need to apply SAE correction to this uncorrected value. Based on your weather above, SAE correction is: 1.0257.

So, your SAE corrected results are 363.248 * 1.0257 = 372.58.

I hope this helps.

Yes it did. Thank you very much!

[Someone?]

So what i can figure your crank HP is about 439HP which seems low to me for your mods, it mite be the High temps and humidity but you should be a little over 451 crank HP.

[GIdriver]

Originally Posted by ibmike

So what i can figure your crank HP is about 439HP which seems low to me for your mods, it mite be the High temps and humidity but you should be a little over 451 crank HP.

Yes. I believe temp and humidity are playing a role there.

FWIW, the guy said this was the highest number he's seen on a E9x m3. Said they usually do 340-350 whp on that dyno, so I think it did well.

[thorny]

My power mods are almost the same as yours. Evolve tune and MS filter/pulleys.

I did 398 std on EAS dyno, but temperatures were a lot cooler, around 70F if I recall

[Black Gold]

Originally Posted by thorny

My power mods are almost the same as yours. Evolve tune and MS filter/pulleys.

I did 398 std on EAS dyno, but temperatures were a lot cooler, around 70F if I recall

the temp difference doesn't matter since you are both using a correction factor (the point of which is to correct for different conditions and standardize the results).

what does matter is that it was a different dyno. as always mentioned, results from different dynos cannot be compared. they are never calibrated exactly the same, etc....

[pbonsalb]

Despite the correction factor, temperature can make a difference. For example, if it is hot enough that your ECU is pulling timing, the correction factor will not compensate. It will compensate only for the quality of the air -- not how your ECU is responding to that air. Assuming your ECU is not adversely reacting, the correction factor is pretty good.

[Black Gold]

Originally Posted by pbonsalb

Despite the correction factor, temperature can make a difference. For example, if it is hot enough that your ECU is pulling timing, the correction factor will not compensate. It will compensate only for the quality of the air -- not how your ECU is responding to that air. Assuming your ECU is not adversely reacting, the correction factor is pretty good.

fair point.

seems like the conditions were not extreme enough to result in this, specifically since the car is NA.

but something to consider, good post.

[pbonsalb]

93F is hot and these cars are actually pretty sensitive, timing could have been down -- especially if there was insufficient airflow during the dyno run (not enough fan). The ultimate dyno run would include data logging so you would know for sure.

[Black Gold]

Originally Posted by pbonsalb

93F is hot and these cars are actually pretty sensitive, timing could have been down -- especially if there was insufficient airflow during the dyno run (not enough fan). The ultimate dyno run would include data logging so you would know for sure.

I have seen many timing corrections via datalogs and associated dynos, mostly from the n54. every time there is a significant timing correction, you can see the correlating dip in the power curve.

I do not see any of those things in this dyno run, so I would venture to suggest that no significant timing corrections occurred during his run.

JMO