[PencilGeek]

Here's the dyno results for 2008 BMW M3 and ESS Tuning ECU Upgrade on 91 octane gas. The baseline is the same motor with the Gruppe-M Cold Air Intake + Evo Sport pulley.

Company: ESS Tuning
Price: $995
Contact Information:
Roman (Private Message: X350 on m3forum.net)

Instructions for removing your ECU:
See this posting.

Background:
An ECU upgrade affects a broad range of motor performance. Therefore comparing before and after results cannot be summed up by a single number. Max HP and max toque will not be enough; we need to look at the entire graph of performance over the broad RPM range.

The ESS Tuning ECU upgrade gains its performance by opening the throttle valves earlier and changing some of the fuel/air mapping tables, spark timing, and camshaft timing. On a stock BMW M3, the ESS ECU upgrade has shown a net +10hp gain; on mine, we gained 6-8 horsepower in some areas, but lost 1-3 horsepower in others.

Dyno results:
The ESS ECU upgrade produces reasonable torque gains over a broad RPM range. Even though max torque is approximately identical to our baseline, there are significant torque gains from 3300-7400 RPMs. Since horsepower is a function of torque and RPM, we also see similar horsepower gains in this same RPM band. At the very top, we lost about 3.5 horsepower over our baseline configuration, but this only occurred at the very top of the RPM range. In my opinion, a slight loss is more of a psychological defeat, than the actual loss will be in real life. Regardless, even the slightest loss on my car sent the guys at ESS looking for answers. Within 24 hours, they managed to send my exact car ECU configuration files to their home office, download into a US-Spec car and test the results on a Dynojet -- showing a net 10hp gain on a stock vehicle (see graphs below).

The Dyno: Dynapack 4000 Chassis Dyno (wheel hub attachment).
RPM Range: 2000-8400

Baseline Performance:
Baseline TQ: 267.5 ft/lbs @ 3983 RPM (Run-3)
Baseline HP: 362.1 hp @ 8055 RPM (Run-3)

ESS Performance:
ESS TQ: 269.7 ft/lbs @ 3970 RPM (Run-4)
ESS HP: 357.6 @ 7956 RPM (Run-4)



To help decipher where the ESS ECU adds and subtracts power, The following graphs demonstrate where the gains and losses occurred. Since measuring below 3000 RPMs is difficult and produces wildly erratic results, the deltas in the lower RPM ranges can safely be ignored.

Torque Delta:


Horsepower Delta:


Dynojet Results:
After the problems I had running low on fuel on the dyno, ESS sent my exact ECU configuration files to their home office in Europe where they could download and test on a stock E90 M3. Below are the Dynojet results reflecting this testing of a stock car with my exact configuration files.


Driving Results:
I've noticed considerably more torque in the bottom end and midrange up to about 5000 RPMs. The extra torque makes the car much more drivable around town, and much easier to punch the gas in any gear to get the acceleration you desire. Before the ECU upgrade, my car seemed like it would bog down quite a bit at lower RPMs. It seemed like my car had it's good days, and it's bad days. Some days it would bog down, and other days it wouldn't. Most likely, this situation is caused by the ECU itself...because the ECU dynamically adapts over time to your driving style -- delivering performance based on how you've driven in the past. The ESS upgrade doesn't disable the adaptive behavior of the ECU -- but instead changes how it adapts. Instead of bogging down in low RPMs on 'bad days' -- the ESS ECU is always-on, ready to deliver maximum torque. In my opinion, the extra torque is very nice -- something I wished the stock motor had.

Gas mileage:
There's an old addage that goes something like this: Speed costs money...how fast can you afford to go. Clearly, nothing is free -- and the extra torque comes at a price: gas mileage seems to have suffered a bit. This was no surprise -- as I expected this to happen. Around town, I would get 14-16 mpg; with the ESS ECU, I'm now getting 12-14 mpg. Driving to work, I would get 15.5-17.0 mpg, now I get 14-16 mpg. On the open highway, I would get 21.5-22.1 mpg, now it would seem that I'll be getting about 19.5 mpg. Again, this decrease on gas mileage didn't surprise me because that extra power has to come at a price.

Gas Mileage:
City: 12-14 MPG
Hwy: TBD

Problems during testing:
I had some problems during testing. My car was low on gas -- VERY LOW on gas. After seeing the initial results were -8hp from the baseline, we began to wonder if the ECU was trying to conserve fuel. I believe it's possible that running low on fuel might have caused the ECU to go into 'safe mode' to conserve what little fuel I had. So I ran to the gas station, bought 6 gallons of fuel and ran the dyno tests again. Mostly, the results were the same, but we did have one run that was stronger than all the others (but for some reason cut off before 8100 RPMs). So maybe the ECU really was cutting back on fuel; we'll never know until we have another chance to dyno in mid-November.

Understanding the results:
I still don't know why the max hp results were lower than my baseline. These differences are possibly due to the upgrades I've already made to the car, and also possibly due to the other problems we had during testing. The modifications I've already made might be forcing the ESS ECU into situations that did not exist on the stock motor they used for development. Running low on fuel might have caused the ECU to go into 'safe mode.' Then the gas itself might be at fault. I've always used Union '76 91 octane fuel during all of our testing. After the dyno results were done, my wife informed me that the Union '76 station on the corner by my house, is no longer Union '76 and now sells no-name brand gasoline! I doubt this will make a difference, but I might as well list it as a variable in the equation.

Disclosure:
ESS offered me a deal on the ECU upgrade in exchange for dyno testing and this review. The results presented here were the best results we observed (same thing I've done in all past postings). I tried not to let their generocity influence my review. My goal was to give an honest and accurate review that contains both the pros and cons of the ECU upgrade.

Update: 2008-09-16
ESS is still in the process of developing this software. My tests were a first step in the fine-tuning process. As more tests are done on different cars, those results will feed back to ESS, and more changes will be made. The tests I made were not on final software; but were a 'first look' of what will be coming soon.

According to ESS, the fuel economy decreases I experienced were most likely caused by my driving style (while training the ECU). ESS believes the software should yield a small increase in fuel economy -- approximately 1-3%.

[M3 Sedan JPS]

Holy crap! I have to do a review too? EXCELLENT REVIEW!! There is no way in the world i can top this Robert haha!

[leletyM3]

Great review....

[b16r1ch]

Great review. Though you're right about the psychological factor of the whp loss, and that 'feel' would outweight that, but I it would be interesting to see the gains associated with a header-back exhaust (i.e. catless, straight pipe).

Again, great review!

-Rich

[JIO]

So basically you are saying that for $995, it's really not worth it. I'm a bit suspicious where on your car you actually lost hp, but when ESS ran it, they gained 13 hp....hmmm. In Europe are they using race gas to get their results?

[sciaenops]

Thanks for the honest review. I'm wondering if my M3 came with the ESS upgrade already installed since I only get 12.x mpg city.

[AMPowerJ]

Thanks for the very detailed and honest review. I think I would have been a bit disappointed with these results especially since the introductory post about this software advertised up to 20hp gains and significant torque increases. What I am most interested in is how the car actually drives and feels and it seems like things are positive there so that is cool. Please keep us posted and I look forward to your future dyno results.

[Porshapwr]

You're the man. Thank you for putting together so much detail on this as I'm sure it will be used for a long time to come.

BIG

[MaleChimp]

What a shock it didn't push +50hp with an ECU tune

[Porshapwr]

Originally Posted by Lil. Lucas

What a shock it didn't push +50hp with an ECU tune