TTAC Commentator pleiter writes:
Convince me one way or another, about OBD-II. I want to know if I should invest in it for personal use. I need to know things like what are the major options, is it just pigtails and a PC laptop interface, now, does it work very well with one publication or not (Chilton’s, Haynes), will I still have the risk of purchasing wrong electronic parts that are not returnable.
Also, is there any emerging market for economy chips or economy (mpg) reflash? I know cold camshaft profiles are starting to show up, but I’m looking for something easier to implement and reversible, because I’m lazy.
I have a Scion tC and two 325i’s.
Sajeev answers:
I come across questions like these on car forums all too frequently. Whenever it happens, forum veterans usually reply with, “what are you trying to do?” That isn’t a dickish comment, because people want other people to be an informed consumer of high performance automobile parts. So let’s do this thing.
Know that any OBD tuning goes far beyond the scope of Chilton or Haynes manual. But even the factory books won’t help you in the computer-tuning department.
Next? OBD-II. Aside from two extra oxygen sensors and some Big Brother monitoring abilities, it is a great system. OBD-II is very tunable, provided there’s a good software hack for your car. Most Detroit Iron uses plug-and-download OBD modules and many German/Italian rides require a little down time to remove the computer, mail it off and wait for “reflashed” processor: the result is more power and torque, with little to no penalty in fuel economy. I am having a tough time finding an easy tuning solution for Toyota products, which is quite odd considering their popularity relative to Detroit brands.
But here’s the dirty little secret: your results may vary. And I am less than optimistic about the improvement you will see (more importantly feel) on either of your cars. It may not be worth the hundreds you’ll spend to make it happen.
And, finally, custom tunes are available for 87 octane, which does save money at the pump. Low restriction exhaust and a (functional) cold-air intake can get the car moving with less throttle input. But this is still less bang for the buck: the odds these modifications paying for themselves in fuel savings sometime in the next decade are not likely.
So forget your notions and take my advice: modify to your taste, but only with performance in mind.
[Send your technical queries to mehta@ttac.com]
As competitive as today’s auto market is, do you really think that automakers are holding back lots of HP or MPG that can magically be unlocked with a simple computer program? Please – Automakers spend millions of dollars scratching and clawing for an extra .25 MPG.
Besides, most of the performance improvements from software changes come from things that can be detrimental to the long term health of your car – increasing the redline, increasing turbo boost, or increasing the octane requirements.
For Toyotas you can try checking out some of the Apexi products found at http://www.apexi-usa.com/categories/?id=3083. The Power FC is popular with people who have the 2ZZ-GE engine found in the Celica GTS and old XRS because it allows you to adjust what RPM lift engages.
Right now, the difficulty is more in meeting emissions requirements. The tradeoffs seem to be:
HP vs MPG vs emissions vs octane requirements
Optimizing for one limits the others. The trick for OEMs is staying legal for emissions, optimizing for MPG/octane while not killing off HP too much. If you’re in a situation where you can say “bugger off” to emissions, you have a whole lot more latitude in tuning, which is where the aftermarket tuning comes in.
thalter: Steve C’s comments are a good answer to your question. I’ll go a step further and say that OEM tuning is “safer” (i.e. overly rich at high throttle inputs) to ensure decades of consistent performance as the motor wears out.
Also factor in EPA noise requirements, something that the aftermarket doesn’t worry about. Headers, full exhaust, cold air (not the eBay hot air kits) induction and a tune that fully optimizes the A/F ratio will probably open up 20+hp on any car, not to mention a more responsive throttle, faster shifting automatic transmission, and a more efficient package…provided you can keep your foot out of the throttle.
I’d look at reducing the drag coefficient, rolling resistance and vehicle mass. So rip out your interior… rent a wind tunnel and do some airflow analysis… maybe get some vortex generators, place them strategically on the body. Fabricate complete underbody aero panels… select tires with lower rolling resistance etc.
The ECM is likely pretty well tuned from the factory, they’ve got folks that do that for a living. Where ECM tuning really pays dividends is with forced induction, more specifically turbocharged engines.
qfrog : Where ECM tuning really pays dividends is with forced induction, more specifically turbocharged engines.
That’s so true. True enough that it needs to be reiterated.
Exactly.
WRXs, Evos, etc. all benefit the most from this.
I have read that the BMW 330 does not benefit much from an ECU tune. The 325 may or may not be the same story. Further to some of the comments, though:
The ECU tune I got leaned out my fuel map and improved my MPG on the highway from 31 to 33. City is the same at 22. (MB C320, 2002). The comments about the manufacturers’ restrictions are valid, as is the comment on the manufacturer’s tuning, but some cars have a lot of room for tuning while others do not. My car was designed for old people to cruise comfortably, so I get a nice 22hp/26lbf gain whereas my buddy with a 330i got no measurable gain at all.
The question, “what are you trying to do?” is the important part. If you are looking for fuel economy, then the canned ECU tunes from the mail order guys aren’t going to be the ones you want. You need someone with a custom tune for your car and your stated goal, or a shop that can put your car on a dyno and do what you need with the chip. The mail order companies generally go for as big a spike they can get in the HP and torque curves so they can advertise the highest gains rather than looking for the best overall performance. The stated performance gains from one of said companies was much larger for my car, but the hp and torque curves were not smooth and the area under the curve was minimal (but the spike was big, so they could say it had a 30 hp gain).
Good luck
thalter: Steve C’s comments are a good answer to your question. I’ll go a step further and say that OEM tuning is “safer” (i.e. overly rich at high throttle inputs) to ensure decades of consistent performance as the motor wears out.
I think that emissions regs are getting so tricky to meet that even the idea that the factory calibration is “safer” is worth challenging. For example I have read the stock program in my ’09 WRX runs stoichiometric under many significant turbo boost situations simply to meet emission regs, something unheard of in OEM programming just a few years ago. That is way on the other side of “safely rich.”
Now I am sure that Subaru has done the work to make sure the reliability is there, but I don’t feel I am taking as much of a risk loading up an AccessPort map that eliminates the emissions compromises in favor of driveability and safety in addition to more power.
do you really think that automakers are holding back lots of HP or MPG that can magically be unlocked with a simple computer program?
This is just a tired old argument meant to thwart critical thinking and useful debate. There is no 200MPG carburetor the automakers are holding back, but on the other hand the powertrain calibrator working at the OEM has many other tradeoffs to consider as mentioned above, and at the end of the day, the corporation is not perfect, the people are human there as well. There is no place for “you can’t improve on what xxx corporation does, they have millions of dollars”. There is plenty of room for discussion though on whether it is worth it.
I find it interesting that I am hearing fleet manangers are starting to reprogram for better fuel economy for Crown Vic taxi cabs.
There is no 200MPG carburetor the automakers are holding back, but on the other hand the powertrain calibrator working at the OEM has many other tradeoffs to consider as mentioned above, and at the end of the day, the corporation is not perfect, the people are human there as well.
As an example, there is a lot of excitement being generated at newcelica.org over a 2ZZ intake manifold created by one of the members (search for DD Performance Intake on the site, or on Youtube for some clips of it in action). Dyno-measured improvement in HP is in the teens even if the rest of the car is bone stock (plus a CAI). With a huge 3″ CAI, a bigger throttle body (Toyota Tundra!), and an ECU tune he expects up to 50HP can be gained. No one thought the stock manifold was bad, in fact no one thought there was room for improvement to be had. Why didn’t Toyota and their millions of dollars discover this and do something about it? Well, they probably did. You see, this new manifold is…big. You have to move some stuff around under the hood to install it and still allow the hood to close. And the 2ZZ motor had to fit inside the Matrix, Corolla, Vibe, and even the Elise. The reason for a compromise solution becomes clear when viewed at a higher level…
Another example of turbo tuning that works is on VeeDubs. My brother “chipped” his Passat 1.8T and the difference was night and day. I’m pretty sure most of the tuning comes from an increase in boost pressure. The same engine made 200 HP in the Audi TT, but it was detuned to only 150 HP in the Passat (and other VWs) from what I’ve gathered.
MidLifeCelica : Why didn’t Toyota and their millions of dollars discover this and do something about it?
That intake package sounds big enough to destroy a torque curve, that’s why. Got a before/after dyno curve handy for us?
What does any of this have to do with OBD-I or II? Those are a US government required set of standards for data collection and reporting for emmissions related parameters, and nothing more. Just because some automakers use the same port to interface with the cars computer(s) for other things does not mean it has much to do with it.
I chip-tuned my ’86 535i. It required physically replacing the eprom inside the ECU with another eprom. Worked great, 15hp on the dyno plus better drivability, but at the expense (literally and figuratively) of REQUIRING 93 octane go-juice. This car was built a decade before OBD-II existed.
krhodes1 : What does any of this have to do with OBD-I or II?
It may be beyond the scope of this discussion, but anyone can run aftermarket fuel injection if they really wanted to. Big Stuff, MegaSquirt, FAST, Electromotive, etc.
Oh, just tear the heads off and gasket-match port & polish them with your favorite air grinder! :P
If you can avoid fart-cannons, exhaust is a nice place to start.
Remember, a lot of cars are built to a price; even if it saves $1 per car (hi GM!).
Reasonable money to you can improve it a little.
Big improvements on NA, short of ITBs? -probably not. When I did exhaust, I think it was under 10hp. Intake was certainly less. P&P was ~7-10?
I think there may be port-size restrictions on things like headers, exhaust, TBs, etc.
Like the total area of an intake can’t exceed the exhaust by x-factor, which is why massively-oversized TBs are not always great, but plus-sized or ported can work, etc.
I’d ignore the hand-work, though. It’s expensive, boutiquey and time-consuming.
Use as many things as possible that roll off an assembly-line;
Then do the knifed/balanced crank, oil scraper girdle, windage tray, lightened flywheel, light h-beam rods, arrow pistons, cnc or extrudehone street perf. P&P, titanium retainers, beryllium valves, custom Schrick hollow camshafts, ITBs, tri-y headers, Ram-air CAI, dahlback racing intake, peloquin LSD, BSI trans rebuild, light cam+crank sprockets, underdrive pulleys, flux capacitor, etc. etc. etc.
(before just buying a GTR, btw)
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+I forget again; what is it w/ intakes short-runner vs. long? short is torque, long is hp? -or something?
Sorry to burst your bubbles but thalter is right…
With some exceptions (notably, Turbo charged cars, Supercharged cars and some diesels..)
A stock normally aspirated car/truck will run best on (sit down for this) a stock tune!
You only need a “chip” if you have modified the engine in some “serious” kind of way… (more compression, different heads, cam, etc.)
Turbos, S/C and diesels aside… I have never seen a “chipped” car beat a stock car within the error tolerance of the dynojet.
In some rare situations some of these cars can pickup a 10th 0-60.. but this is done not by making more power but by defeating all of the “self preservation” built into the transmission shift algorithm. Ya, your car might be going 0-60 in 6.5 seconds instead of 6.6 seconds but it only a matter of time before you get meet your local transmission rebuild guy.
Considering the costs of these chips there are several easier and cheaper ways to make more power. A Cat back system is a good place to start… a set of coated headers is the second .
Guys that brag about the half second faster they went in the quarter always leave out the “other” changes that were made to the car… “My 328 is almost a full second quicker on the chip”… wow is the car stock? “Heck no, its got an CAI, bored out throttle body, ported intake and heads, half a point more compression, headers, cat delete, Borla exhaust and a 4.10 rear end…”
Sorry, there is no magic bullet, there is no quick fix.
Ah… a subject near and dear to my heart!
“Stock” tunes are, as many others have indicated, a huge compromise. They compromise performance and fuel economy to meet emissions, longevity and servicing requirements. While, yes, this means that a stock tune should be, technically, more reliable… in the real world, your mileage may vary.
Simply put… with the manufacturer shoving thousands of Corollas, tCs, whatever… out the door, they don’t have the time to optimize tunes for every single car. To eliminate guesswork, they leave a wide “safe” zone in their tuning.
OBDII tuning from the manufacturer is a weird mix of running too lean at some points, too rich at others and with too little timing to take advantage of any of these changes.
By retuning your air-fuel and spark maps, you can successfully extract up to 15-25 horsepower in the midrange (where stock tuning is at its most compromised) and around 5-15 hp at the top-end, without making your car a maintenance basketcase or an emissions-flunking hotrod.
A good alternative to a reflash, which limits you to the factory sensors and whatever the ECU can do, is a good custom-tune with a piggyback. But you need the ability to reference a wideband O2 sensor and to clamp the factory O2s in certain situations where you don’t want the factory ECU relearning around your changes (actually, with adaptable fuel trim maps, the factory ECU can relearn around anything done to it or done around it unless you modify the stock sensors).
And it’s always best to tune it yourself or have it tuned for your car. We’ve seen big gains from out-of-the-box chips… but they definitely ignore the safety factors an on-the-spot tuner can program for. One turbodiesel we tested made a bit more than our programmable Unichip Q system, but at the expense of creating clouds of black smoke at full throttle… Not good for the environment… or the engine. Our current record is about 20-25 hp more for the Ford-PSA 2.0 turbodiesel, and 50 hp total (at redline… this isn’t counting the monstrous midrange) with bolt-ons and no change to the factory turbo or boost pressure… and with alcohol injection, it’s cleaner, to boot. Reliability? The piggyback-equipped engines are run in a one-make series, and they haven’t blown up, yet.
Strange… the guys on the Euro-boards were saying this engine was a brick to tune… of course, armchair theory is never a substitute for real-world testing.
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Granted, some cars are closer to optimum performance than the rest… the aforementioned 330i, basically having the same motor as the 325i (both 3 liter sixes) is probably tuned close to optimum, while the 325i is greatly detuned to give much less power and better economy. I’ve heard that the 325i can benefit greatly from a re-flash.
That said, I don’t believe that a piggyback that does both fuel and timing won’t do anything for the 330i. Some fuel-only controllers do very little for many factory-tunes, but the extra flexibility of modern chips on electronic ignition engines makes a huge difference.
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A drag-strip isn’t the best place to test a retune. Many naturally aspirated stock cars don’t see more than 5-10 hp near redline, which isn’t going to make a big difference in your quarter-mile… but the gains in midrange performance make driveability and real-world overtaking performance much, much better.
Another thing that you can program away is the annoying “hang time” for RPM decay after you pull your foot off the throttle. Rapid decay can cause an NOx spike; most cars have artificially delayed RPM decay for this reason. Most people are pretty much used to this, but drive an old car with a carb and you realize how annoying this “hang” is…
niky has a great post
and he sums it up nicely
naturally aspirated stock cars don’t see more than 5-10 hp near redline, which isn’t going to make a big difference in your quarter-mile…
So you just spent 400-600 for this new tune… but don’t take it to the track to test it… cause you aren’t going to be making more power at redline…
5-10 HP can be found on a dynojet in just how the car is strapped down and is well within the error range of most dynos..
As I said if you have a stock car and are looking for more power, there are lots of things to try first… They WILL make more power and WILL cost less money.
Sadly most people who rave about their “tuner” chips is all based on “butt dynos testimonials” Every now and then someone actually takes a stock car to the track, does a back to back run… and discovers this is all snake oil.
(of course if you have a turbo, S/C, or diesel then different rules apply)
@sajeev
Actually, the new 2ZZ manifold seems to increase torque and HP almost evenly along the entire RPM range – this link contains some before/after dynos, pics of the manifold itself, plus the whole story behind it.
DD Manifold
@CamaroKid: Oh… many chips actually do work… unless we’re talking about the one whose name starts with “J” and ends with “et”… or anything else that consists of nothing more than a resistor chip and a black plastic casing or a repackaged stock ECU in stock tune.
It’s just that the legitimate ones that are prepackaged with “tuned maps” are never as effective as those tuned specifically on the car… and, as I said in my long meandering post… sometimes dangerous or compromised. Dyno-tuning is everything for new EFI cars… refer to Sajeev’s new article…
https://www.thetruthaboutcars.com/product-review-sct-dyno-tuner/
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Ran against a mate once… same car, same modifications, same exhaust size (and really, the difference between a good exhaust and a bad one on this car is just 3-5 hp…) only I had the Unichip Q and he had bumpkis. Through the rev-range, between corners, the difference was immense (say, several car-lengths) thanks to the fat torque curve. He was skeptical at first, but right afterwards, he went straight to the shop and put the thing on his credit card.
Damn the guy. Had to buy cams just to stay ahead. Unfortunately, the wild grind only kicks in at high rpms, so I still have to figure out some other way to trump him.
It really really depends on the car.
Honda has Hondata which enables the user to modify the ECU in real time. A good tuner knows how to lean it out to a safe level and increase fuel economy. Cobb’s ACCESSPort is similar, and plugs in through the OBD-II port.
A lot of the “reflashes” or “plug & play” systems are one size fits all, which is ok, but every car is different so the best options are ones which allow you to fine tune the car.
Many reflashes, particularly on turbocharged cars, definitely give a gain in fuel economy, as most turbo cars run rich from the factory.
MidLifeCelica : Nice! Looks like the stock intake is fairly restrictive, and the switch over is worth it. (if you don’t mind buying a new intake, and that one looks expensive!)