You've read our driving impressions of our 2008 BMW 135i now that it has been reflashed by DME Tune. And you've seen its test track numbers compared to stock.
As mentioned previously, my keenly-honed butt accelerometer had me curious about the acceleration results we measured. Said the cheeks, "you introduced too many uncontrolled variables for a proper apples-to-apples test, dummy."
I'm usually concerned about voices that come out of my posterior, so to quell them we spent a few hours at MD Automotive in Westminster, CA. The goal? To shed a brighter light on the degree to which DME Tune's reflash pumped up our 135i's urge.
There, proprietor Mark DiBella rented out his Dynojet chassis dyno to us for the afternoon. In fact, anyone can rent his dyno. Mark's swell like that.
What's that? You want less rump talk and more dyno charts? Jump, then:
Here's how it went down. We dynoed the DME Tune configuration first, conducting as many pulls as necessary to achieve a stabilized result
Then Scott from DME Tune reloaded our stock calibration back into our 135i while it sat on the dyno, and the process was repeated.
Same car, same dyno, same day, same fuel, even the same tension in the straps holding the car down. With so many variables removed, we've got a very solid comparison.
As per our standard procedure, these runs are uncorrected for weather as the 135i is turbocharged.
Click the thumbnails for a larger image.
Stock DME Tune Stock vs DME Tune
Initially there was a strange dip in the DME Tune torque curve between 5,000 and 6,000 rpm. More ignition timing was gradually fed in during subsequent pulls, however, as logged by our DrewTech DashDAQ OBD-II magic black box. A little timing goes a long way in a boosted car, and with every dyno pull the engine controller filled in the hole a bit at a time. The stabilized, repeatable result is what you see above.
Clearly, the gains provided by the DME Tune reflash are substantial everywhere in the rev range.
Peak power swelled 55 horsepower compared to stock and peak torque jumped up 67 lb-ft.
All of these gains came from remapping spark, fuel, cam timing and boost; all hardware on the car is still stock. Aren't turbo engines great?
The DME Tune reflash also increases the rev limiter from 6,500 to 7,300 rpm. There's such a thing as diminishing returns, though. The dyno chart reveals that reflash's power falls off hard after about 6,800 rpm. Winding it out much past this is good only for, say, saving a shift while at the track.
Finally, here's the DME Tune reflashed 135i compared to our long-term 2009 BMW M3
:
Of particular note is the difference up to 6,700 rpm. Discuss.
Jason Kavanagh, Engineering Editor
roadburner says:
07:37 PM, 06/21/09
The 135i will be easier to drive on the street, but the M3 will be more fun on the track- assuming you like a car that develops most of its power at the top end and that requires a bit of driving ability to keep it "on the boil", as the Brits say.
hondacura4 says:
07:41 PM, 06/21/09
I know its a turbocharged engine but its amazing what a simple reflash can do. Just imagine if more efficient intake and exhaust plumbing was implemented with the reflash. Is this the modern day version of the Toyota 2JZ-GTE?
Is that a white NSX I see in the background? Any info on that car?
bzzzbom says:
07:58 PM, 06/21/09
Please post the air fuel ratios vs. rpm. Thanks
bzzzbom says:
08:12 PM, 06/21/09
Please post the air fuel ratios vs. rpm. Thanks
huisj says:
08:58 PM, 06/21/09
I still am curious about long term fuel consumption with this setup.
cx7lover says:
09:12 PM, 06/21/09
But... it isn't that much faster. Did the person that did the first acceleration test do the second? Maybe whoever did the second didn't try hard enough.
church123 says:
11:11 PM, 06/21/09
Couple things to consider. If the ECU is adding timing on the dyno, that could mean that the engine management system has learned to pull out timing under normal street driving due to indicated knock. This could be due to higher temps, higher loads, and many other reasons. It also indicates, to me, that maybe a little less timing would net better performance on the road (if the ECU is aggressively pulling out timing).
Second, the hard dips at 2500, 3500 and 4500 rpm are a little unusual. Did you see the ECU pulling timing there? Of course, with a DI engine, it isn't just ignition timing that matters, but its a start.
I think it would be worth some time to datalog the engine parameters during acceleration testing. There is no way that the car shouldn't be significantly faster if it is making the additional power on the street. My guess is that our crappy California 91 octane is messing with what is otherwise a good tuneup.
church123 says:
11:33 PM, 06/21/09
BTW, just running the numbers, assuming the stock 103 mph trap is representative, then this new power curve (and additional rev range), should equate to a trap speed of around 109 mph +/- depending on test weight.
This also jives with my experiences. My vehicle, tested at El Toro with a Racelogic, ran a 111-112 mph trap speed with 305 whp on Mark's dyno and a full up weight of 3100 lbs. With about 340 whp on Mark's dyno it ran 115-116 mph.
Look to the fuel.... :)
sellaturcica says:
12:26 AM, 06/22/09
Give that little reflash a couple years and it'll probably blow this overly complicated, overly stressed BMW engine sky high.
chavis10 says:
07:24 AM, 06/22/09
What's an M3? Yet another reason to go for the cheaper 335i.
supergoji says:
07:45 AM, 06/22/09
you guys can get another 40whp with a Riss racing turbo back and intake...
go for it... you know you want to.
adrean8j says:
08:15 AM, 06/22/09
@supergoji: I am assuming you mean downpipes, catback and intake....I make 360whp (SAE corrected) 362lb/ft with a "piggy", catless DP's, intake, and axelback (135i)......These little monsters easily make M3's think twice 0-90mph in a straight line. After that the M3 is a beast. On the road tracks the M3 also definitely has the suspension edge.
blueguydotcom says:
08:55 AM, 06/22/09
adrean8j, do you think there's potential for changing the suspension enough for a 135 to behave as well as an M3 in the corners? The lighter weight should make some difference.
Another question - anyone here think BMW can fit the M3's V8 into the 1 series?
felonious says:
09:04 AM, 06/22/09
Nice jump in power, but those curves look seriously ragged...
jasper53 says:
09:37 AM, 06/22/09
As an owner of a BMW 335 I have been hearing about all sorts of interesting ways to improve the performance of the N54 engine. The one thing that you fail to comment on in your article is what happens when you take your new 135 into the dealer for warranty service and they see that you have "chipped" the ECU. I am not sure what they would do to Edmunds, but I know that there would be an entry into my service record and any warranty work would be refused for the term of the warranty (even if I run home and pull out the mod and replace it with the stock ECU code).
While I would like to take advantage of these performance enhancements I sure don't want to risk voiding the warranty on my "expensive to fix" BMW engine during the 48-month, 50K mile warranty period.
While interesting, this has the potential of being a $10,000 problem.
DCuerpoJr says:
11:48 AM, 06/22/09
Jasper53 makes a good point. I'm pretty sure that any modifications under the hood would void the standard warranty of a new car.
As for the stock vs DME Tune,
It seems that BMW knew there was more power & torque available on the 6 cylinder, turbo-charged engine, but intentionally kept the performance down to prevent the 135i & 335i from creeping up on the M3.
I guess another reason for doing so would be to potentially increase the engine's reliability.
DCuerpoJr says:
12:22 PM, 06/22/09
@blueguydotcom
I'm not sure if you would be able to fit the M3's small block V8 in the 135i.
The M3's V8 weighs 445 lbs. and while I'm not sure how much the V6 engine weighs with it's twin turbo, I'm pretty sure the V8 is still a few pounds heavier.
The 135i's weight distribution is approx 53% / 47% and adding a few more pounds from a V8 might change the car's handling. Then again this could be offset by upgrading or adjusting the suspension.
If BMW comes out with an M1 with a V8 I'd be first in line for a test drive.
kurtamaxxxguy says:
01:00 PM, 06/22/09
A possibly dumb question about reflashing:
Does all this reflashing help the current drivetrain run more efficiently?
...or....
Does it tell the engine to use more fuel in the ranges where it previously used less (burn more fuel = more power)?
In effect, does your reflashed BMW now burn more gas in return for more power?
blueguydotcom says:
01:09 PM, 06/22/09
Flashing the engine does not void the warranty - common myth in the VW world too. The dealer may try to void claims regarding the engine/drivetrain but they can't say "Your headliner frayed because you chipped the car." You'll still get brakes, oil changes, etc. And many shops around are mod friendly. They want you to bring you car in for service and develop relationship.
roadburner says:
01:17 PM, 06/22/09
"In effect, does your reflashed BMW now burn more gas in return for more power?"
It depends on the tune; some tuners only re-map the full throttle parameters while others tune part throttle as well. The Jim Conforti chip in my M42 added 12 peak bhp and improved midrange power as well. However, I also picked up 2 mpg at high rpm(4000+) cruising speeds.
adrean8j says:
04:20 PM, 06/22/09
@blueguydotcom:
I think there are "improvements" that can be made to the stock 135i Sport Suspension but to come up to the M3 level would take some extensive suspension tuning IMHO. The going trend right now is to get KW, HMS, or other coilovers and tune the rebound and dampening settings to whatever suits your driving style. In addition a stiffer front sway bar helps to reduce some of the body roll found on the stock suspension. Lastly get rid of the stock run-"craps" (runflats) and upgrade to better rubber on all four corners. Still not an M3 killer BUT much, much better.
@felonius:
Raggedness means nothing on those dyno scans...you can set "smoothing" and make the lines looks more OR less ragged
@Jasper53:
I seriously doubt that there will be THAT much of a problem at these power levels. Anything over 400whp will probably really effect the long, long term performance levels. BTW they specifically detuned these engines not only because they do not want to infringe on the M3's territory but because later they can offer a tuning "upgrade" to the N54 owners...more revenue for them.
smedin says:
09:08 PM, 06/23/09
Any word on when we'll be able to chip the 135i remotely? Not sure when I can stop by the state of California...
PDXLager says:
11:54 PM, 06/23/09
@smedin I'm seriously considering driving out there for this. Would like more info on MPG impact first.
wgtp says:
08:03 AM, 06/24/09
1. BMW does great engines and cars
2. Not that I can afford either, but we are fortunate to have these options to read about.
3. There are reasons BMW doesn't put this much power out from the factory.
4. It's great that IL does these types of mods and tests.
5. It's gone this far, might as well add more go fast goodies.
6. The V-10 needs to go to the M3, the V-8 to the M(1)???.
7 Soon, it will be turbo 4's instead of 6's, plus diesels...