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Latest Updates: automotive RSS

  • erik 10:31 pm on June 20, 2007 | 2 Permalink | Reply
    Tags: automotive, , , , , , ,

    Ubuntu + Hildon UI = in-Car PC UI

    Awhile back, Ubuntu announced a mobile and embedded edition of it’s popular Linux distribution. The buzz was around the possibility of Ubuntu Mobile showing up on future UMPCs. The news caught my eye, but didn’t really get my attention until the plans for Ubuntu 7.10 (Gutsy Gibbon) were announced:

    “Ubuntu 7.10 will be the first Ubuntu release to offer a complete mobile and embedded edition built with the Hildon user interface components” (developed by Nokia for the Maemo platform.)

    Now that’s interesting. Could it be that we’ll see Ubuntu Mobile booting on Nokia N800’s? It’s certainly a possibility — and one that could bring a larger breadth of software to Nokia’s mobile Linux tablets.

    However, as interesting as it may be if Nokia adopts Ubuntu, the possibilities for wider Hildon support didn’t hit me until my drive home today. It was one of those obvious moments. I had been using my Nokia N800 while walking to my car, so the touch- and small-screen friendly UI was fresh in my mind. Then I started thinking about my Car PC. It uses a 7″ touch screen and runs Ubuntu (a full distribution, with a UI designed for full-size monitors.) Running Gnome on my cheap, in-car 7″ monitor makes for a pretty lousy experience. Text is hard to read, and everything is too small to click on. However, if this news is right, Ubuntu 7.10 will change all of that. I’ll be able to run Hildon on my Car PC! That’s killer. Imagine having Canola running in-car, sitting on 100GB of multimedia…

     

  • erik 3:58 pm on September 11, 2006 | 0 Permalink | Reply
    Tags: automotive,

    In-car hillclimb footage

    A little something for your @Friday folder — here’s some fantastic in-car footage from an Audi RS4 and an Audi R8. The soundtrack alone is worth it:

    Audi RS4 Hillclimb (A record-breaking run, from what I gather): http://video.google.com/videoplay?docid=1806221753710392507

    Audi R8 Hillclimb: http://video.google.com/videoplay?docid=6184680728064832823

    (Via Autoblog)

     

  • erik 4:04 pm on July 19, 2006 | 4 Permalink | Reply
    Tags: , automotive,

    Texas heat and a coolant leak

    Somehow I always end up working on the car during my holidays, and this past week was no exception. It’s been hovering somewhere around a million degrees in Texas for much of July, and with heat-soaked concrete and traffic jams, the temperatures can be a little harsh on our combustion-powered friends. Upon returning home on Sunday, my Subaru promptly expelled it’s coolant into a stinky mist of boiling fluid dumped onto the exhaust manifold. (Fortunately, the car had returned home unharmed before launching this little performance, since the carburetor gods have been less friendly to a few other folks I know. Over the past week, two have had their radiators blow, and one killed an engine [overheating so far as to melt some plastic bits in the engine bay and ruin the heads.])

    Expecting the worst, I waited for the car to cool down, then popped the hood to have a look around. Puddles of coolant stood in every nook of the front-right corner of the engine bay, though the source of the leak eluded me. I was at least expecting to see a blown hose, but unfortunately, everything looked just fine. Since I knew that more probing was needed, I pushed the car into the garage to let it completely cool overnight.

    The next morning it was time to call in reinforcements. In this case, they came in the form of a Snap-on Cooling System Tester. It’s not uncommon for a coolant leak to only happen under pressure, so a cooling system tester can be used to pressurize the system. The device is pretty simple — it’s just a hand pump, but it’s crucial for testing hoses and fittings. (Thanks for letting me borrow the tester Rob!)

    The pictures below show the process:

    Step 1: Pop the radiator cap from a completely cooled engine:

    Coolant test: Step 1

    Step 2: Attach the right adapter…

    Coolant test: Step 2

    Step 3: Attach the pump, and pump it. Watch the pressure gauge and don’t exceed the pressure your system is likely to run. In my case, I didn’t want to exceed 15 psi (~1.1 bar.)

    Coolant test: Step 3

    Step 4: Watch the coolant spray out the pin-hole leak like a fountain!

    Coolant test: Step 4

    As you can see in the pictures, the leak was pretty easy to find with the right tools, but would have been extremely difficult without them. Fixing it was even easier, and it gave me a nice excuse to flush the system and replace the other hoses as well (I went with higher-strength hoses for the replacements.) Also of note, you may have noticed in the pictures that I’m running a high-pressure radiator cap. (The STi cap is rated 1.3 bar.) This may have caused the blown hose, so do be aware of this when swapping caps.

    If you’d like to replicate this at home, remember that automotive coolant is considered toxic once it’s been run in an engine. Always wear protective gloves when working with automotive fluids, and recycle them appropriately. (See the EPA page on Antifreeze for more on this.)

    [Update]
    Since this repair, the radiator lasted another year before also developing a crack and blowing coolant all over the engine bay. The stock WRX radiator features a plastic top, which was the failure point for mine. Since all the coolant hoses were replaced with high-strength lines, that plastic top may have simply been the next weakest link in an over-pressurized coolant system. Now that the car has an all-aluminum radiator, I’m curious where the next weakest link might turn up (hoping that it’s not catastrophic!)

     

  • erik 10:01 pm on January 2, 2006 | 0 Permalink | Reply
    Tags: automotive

    Jumped the gun

    I guess I spoke too soon about the car being drivable… it’s now stuck in the garage waiting on (unanticipated) parts. It’s one of those times where you did your research to make sure everything would fit together, but when you bolt it up, you find out that there were actually two different part numbers and it just so happens that everyone who said it fit hadn’t tried the redesigned part. And I’ve got the new design. Figures.

    There were a few alternatives available to make it all go back together, but I’m one of those “If you’re gonna do it, you might as well do it right” people, and to do it right meant ordering some different fasteners (that no one in town had.)

    At the same time that the car was apart, I also noticed that it might be about time for a compression and leak-down test.. as it seems I may have some bad rings. Arrg… Not what I wanted to see, but then again, I didn’t really expect the motor to last as long as it did. Hopefully I can still buy some time with it though, as building a new motor isn’t exactly in the budget.

    So just like last year, the holidays are over and the car’s still on jack stands (and it will continue to be there for at least a few more days.) However, I did go ahead and order one of these ATC style fuseblocks for the in-progress rewiring project. I went with the small, 6-fuse unit. Once it arrives, I can finish wiring up the new relays so that I’ll have some fresh 12v to tap. It’s a bit overkill, I know, but I’ve got another project up my sleeves that will require power (and code :-) More details to come…

     

  • erik 6:25 pm on December 31, 2005 | 0 Permalink | Reply
    Tags: automotive

    Grease monkey…

    Last year around this time I was fixing a fuel leak on the car. It was an unexpected repair, and the whole project took a bit longer then planned because I needed parts from shops that were closed for the holidays. This year I decided to once again use the time off to do a little work on the car, only I planned in advance and ordered the parts I would need before hand. “A great plan”, I thought — I’d have plenty of time to get everything working. If only it went so smooth… When working on my car I generally run into the “might as well” problem. Meaning, while I have everything torn apart, I might as well fix a few other things while I’m in there. And unfortunately, I didn’t pre-order those parts. So just like last year, the car’s half apart while I wait until the new year for the local speciality shops to open again. Oh well. At least it’s still drivable this time.

    So what am I up to? Mostly general maintenance. The car’s developed a slight exhaust leak from a variety of places in the exhaust manifold so I ordered new gaskets and cleaned and re-sealed it. It was about time to give everything a once-over with the torque wrench anyway, so it didn’t bother me that much and it’s easy enough to do.

    Next up was a fuel pressure gauge. The changes to the fuel system made last year raised the fuel pressure slightly and I’m not sure how well the stock fuel pump is keeping up. After the original fuel system changes I used a temporary gauge to smoke test it, but I decided it was about time for a permanent installation. Unfortunately, I ended up needing one more hose fitting that just so happens to be uncommon enough for the general automotive shops to not carry it.

    While installing the gauge I also decided that I might as well do the wiring proper and run fresh power to a set of relays driven by various ignition-key positions and whether the headlights are on. Unfortunately, it turned out to be more complicated then I expected to source a decent fuse and power distribution block, so that’s also waiting for next week to be finished. (On a related note, I was explaining this to a friend who commented that buying a fuse box was probably a common thing to do 20 years ago. But I guess people don’t rewire their cars much anymore.)

    The next bit I found particularly interesting. I decided to mount the new fuel pressure gauge in the corner of the dash by the A-pillar. Doing the installation nicely would require a few holes to be made in the factory plastic to run wires, so I went in search of a used piece to cut up instead. I figured that a part like this should be an easy find on eBay, and if not, there are always people buying wrecked Impreza’s for parts. After having no luck with eBay or craigslist, I hit up the usual Subaru discussion boards and found the part selling used for about $25. Then out of curiosity, I called the dealer… who quoted me $25 for the part new. Huh. It is certainly a peculiar market when a scarce used part sells for the same price as a readily available new part. Once the wiring is complete, I’ll start the pillar trimming — and if I’m really lucky, my new phone will be here soon and I’ll be able to photo-document the installation.

     

  • erik 1:58 pm on October 4, 2005 | 6 Permalink | Reply
    Tags: automotive,

    Increasing your mileage

    I saw this on lifehacker yesterday and it’s been bugging me since. In the post, “Increase Your Mileage. Save Gas“, they suggest four ways to reduce your vehicle’s fuel consumption: (1) Slow down, (2) Skip the AC, (3) Inflate your tires properly, and (4) Accelerate Slowly. Being a car geek, these over-simplifications bug me, so I dove into the original article, “Tips to Increase Your Car’s Miles Per Gallon” to see if it did a better job of explaining “why”. It doesn’t, so I’ll give it a shot.

    First a little background (which has to be a bit simplified or it would be a book. Sorry.) There are exceptions, but in general, modern fuel injection systems are load (typically measured by MAF or MAP) and RPM based, and the amount of fuel injected typically increases with both of those metrics. Fundamentally, it has nothing to do with vehicle speed, the AC being on, or your tires. The fuel injectors spray however much fuel is needed to hit a target AFR (air-fuel ratio) for a given engine load and RPM.

    Knowing that fuel injection rates are tied to engine load (and a few more details that I’ll try to throw in), let’s go over this list and explain why:

    (1) Don’t accelerate quickly.

    Accelerating hard wastes uses a lot of fuel for a few reasons. First, you’ve increased engine load; Second, the car is going to richen the mixture to reduce the potential for detonation as heat and load builds; And finally (and this is where it’s going to get messy), you might have switched the fuel injection system from Closed Loop to Open Loop.

    In closed loop fueling, the car’s computer (ECU) is watching the Oxygen sensor and tuning the fuel trims automagically to target a stoichiometric air-fuel ratio of approximately 14.7 parts air to fuel. This ratio is generally agreed to be the most efficient at burning all the available fuel, and it’s also the ratio for which catalytic converters are designed to operate most efficiently. However, the car doesn’t always try to be a non-polluter. In my Subaru, for example, the factory ECU switches from closed-loop fueling to open-loop fueling at approximately 60% throttle (TPS). If you press the gas pedal past this cut-over point, the car no longer targets a 14.7 AFR, but instead switches fueling for maximum power (which in a Turbo car is anywhere from 12.5 AFR to 10.5 AFR depending on the quality of fuel — and yes, the better the fuel, the less you need.)

    (2) Let your car brake itself.

    It’s arguable whether or not engine braking is a good idea mechanically, but it’s generally true that the car needs less fuel under this condition. The reason, once again, is because of reduced engine load (ie., the engine is no longer working to push the vehicle, thus it’s no longer sucking in a large volume of air, thus it no longer needs to spray a lot of fuel to keep that large volume of air at a particular AFR.) The engine may even use less fuel under engine braking then it does when coasting in neutral. That said, the brakes are designed to slow car, not the engine, and the brakes are cheaper to replace, so this isn’t always a good idea.

    (3) Drive at the speed limit on highways and freeways.

    Speed has nothing to do with fuel consumption. It’s load vs. RPM. The simplified reason your car uses less fuel at 55 MPH then it does at 60 MPH is because if you stay in the same gear, RPM’s increase with speed (as does aerodynamic drag, which increases load.)

    Of course, this rule doesn’t always hold true. If you can draft another vehicle, you’ll reduce engine load. Furthermore, gear selection plays a role. 55 MPH in 4th gear will run at a higher RPM and should use more fuel then 60 MPH in 5th; But 55 MPH in 5th gear might not produce enough torque to climb a hill, thus increasing load when you try to maintain that speed without downshifting. You can also sometimes run the car leaner at high RPM’s after you’ve past peak torque output, so increases in RPM don’t always linearly add fuel.

    (4) Use cruise control.

    The benefit of cruise control is it’s ability to be smooth. If you can avoid sudden load, you’ll need less fuel.

    (5) Don’t use the air conditioner.

    First of all, don’t die of heat exhaustion just to save fuel. If it’s 120F outside, you should probably think of your immediate health first. That said, this tip is good at low speeds since running the AC compressor raises engine load. However, this tip doesn’t always hold true at highway speeds where rolling up the windows can reduce aerodynamic drag.

    (6) Accelerate before hills.

    Mmmm… inertia. Going uphill raises load (or climbing stairs wouldn’t be exercise.) Accelerating early may allow inertia to carry you up the hill instead of asking the engine to do all the work.

    (7) Clean out your car.

    The key point here is to lighten your car. It takes less power to move a lighter vehicle, and less power == less load == less fuel (or quicker acceleration on the same fuel.)

    (8) Check your tire pressure.

    Low pressure increases rolling resistance and increased resistance == load. Unless you’re driving in sand or rock-crawling where low pressure == traction (and you’re not going fast enough for it to matter.)

    (9) Change your air filter.

    If your air filter is clogged the engine will have to work harder to suck air through it. Working harder == increased load.

    (10) Get a hybrid car.

    Uh..

    (11) Do more in one trip.

    Doesn’t save fuel per mile, but miles per day, which is also a good thing.

    In summary, if you really want to burn less fuel… reverse-engineer your ECU, study the fuel maps for your car, and drive accordingly ;-)

     

  • erik 10:55 am on October 4, 2005 | 0 Permalink | Reply
    Tags: automotive, ,

    Tailpipe Tally

    TailpipeTally provides an online tool for comparing various vehicle fuel consumption and emissions ratings against the latest hybrid’s (Prius and Civic, for example.) Much to my surprise, my Subaru didn’t score all that bad. Yes, it pushes out more Carbon Dioxide (which while not a health threat, is a “greenhouse gas”), but it produces fewer harmful gasses then the hybrids:

    emissions table

    (via treehuger)

     

  • erik 9:17 pm on January 29, 2005 | Comments Off Permalink
    Tags: automotive,

    Broken downpipe bracket

    It may be hard to see in this picture if you don’t know what you’re looking for, but this is the source of a random metallic clanking noise the impreza picked up awhile back.

    The cause? A broken exhaust mount. This mount never really fit right (which seems to be the status-quo for after-market car parts.) It’s a solid metal mount that connects to the bottom of the downpipe. It didn’t line up once the pipe was installed, but with a little re-shaping it bolted in. The part lasted about 6-8 months before snapping.

    The replacement, which I don’t have a picture of off-hand, was made by modifying a left-over after-market exhaust hanger from a 4Runner that didn’t fit the truck. The new hanger is still stiff enough to keep the turbo from moving, but has a small amount of flex to avoid this problem again.

    I’m not sure what motivated me to post about this, but I have a long list of draft posts in my head that all relate to after-market product quality (or lack thereof) and the apparent in-ability for some of these performance shops to understand their market and launch new products. Many of these small manufacturers miss out on the little details, like: (1) a focus on quality, (2) providing proper customer support, (3) defining a clear product strategy, and (4) properly understanding who their customer is and what need they are trying to solve. They do manage to sell parts though — which I guess is what happens when you’re market is addicted to improving performance.

     

  • erik 2:51 pm on January 28, 2005 | Comments Off Permalink
    Tags: automotive,

    subaru update

    In my post, Cold Weather Fuel Leak, I mentioned that my Subaru Impreza was hit with the infamous fuel leak problem that seems to be affecting many of these early models. I haven’t posted much of an update since then, but rest assured that no self-respecting car hacker would pay the dealer the $400 they wanted to fix this little problem. Instead, the engine bay was properly torn apart over the holidays and the entire fuel system, from the filter to the return line, was replaced with new rails, connections, and steel-braided lines. In doing so, the fuel flow has also been changed from a serial to parallel pattern, the injectors were upgraded with higher-flowing units off a Japanese Impreza, and a few extra engine sensors were wired-in for additional data-logging.

    Everything came back together just fine (with a few extra parts left over for good measure), but I’m still re-tuning the fueling maps. The car runs properly while in closed-loop fueling (meaning the time where output from the oxygen sensor is used to determine fueling), but goes ridiculously rich once the boost comes on (and it moves to open loop fueling.) Since I haven’t had time to debug this, I dropped the boost limiter down around 2psi, and just drive it on light throttle.

    I have a couple theories as to what’s happening, and hopefully this weekend I’ll have enough time to dive into it further. The first possibility is that the injector scaling capability of the UTEC might not be working properly. The second is that several other people with similar setups have reported that in creating a better flowing fuel system, the base fuel pressure has gone up, which is why the injectors are flowing more fuel then expected. The final theory is that the stock fuel pump is no longer able to keep up with the new high-flow system. If this were true, fuel pressure would actually drop as boost comes on, and with low pressure, the injectors would be unable to properly atomize the fuel, thus causing unburnt fuel to leave the exhaust ports and be seen by the O2 sensor as running rich. This one is particularly dangerous. If true, then there is no telling how lean the engine is actually running.

    Fixing the first problem involves software. Proving the second requires a fuel pressure gauge and OBD scanner capable of accessing fuel trim values (neither of which I have.) Solving it probably means an adjustable fuel pressure regulator. The third one is messy. It will also require a fuel pressure gauge, but fixing it will require an upgraded fuel pump and an adjustable fuel pressure regulator. Fortunately a buddy of mine has all the diagnostic equipment we need.

    With something like 10 hours of personal time doing the labor, and another 10 to retune the car, there’s no way I’m actually saved money (if you count time as money.) But where’s the fun in just taking a car to the shop? Besides, I can now tell you what every hose under the hood goes to ;-)

    If you’re interested in taking a wrench to your own Subaru, I’d suggest starting with the following discussion board sites first:

    – NASIOC
    – i-club
    – WRX Hackers
    – ScoobyMods

     

  • erik 12:07 pm on January 27, 2005 | Comments Off Permalink
    Tags: automotive,

    automotive lust

    I’m generally a sucker for automotive p0rn, and these two links don’t disappoint: First is the 2005 Lotus Exige, an amazing little track car that we’ll never get in the States.

    The second is a three-wheel motorcycle concept called the Aprila Magnet. More information can be found on the student designers’ project page, which includes a 3D rendered fly-by video and a link to his dissertation, “Energy which animates the soul; the unique relationship between the motorbike and the rider.”

    I’ll take either for xmas ;-)

     

  • erik 4:39 pm on January 10, 2005 | Comments Off Permalink
    Tags: automotive,

    Interesting new Jeep concepts

    There were many interesting new vehicles and vehicle concepts announced last week (too many to list here), but I wanted to point out these two. The first, the Jeep Gladiator Concept looks like a possible remake of the Scrambler — a Wrangler with an extended bed. Looks pretty well thought out, although a little too nice to take on the trails. The second is the real beauty, the Jeep Hurricane Concept, which is a wicked rock-crawling vehicle with dual engines and four-wheel steering. It certainly looks like my idea of an urban assault vehicle and features an interestingly simple drivetrain.

     

  • erik 2:30 pm on December 27, 2004 | Comments Off Permalink
    Tags: automotive, ,

    – Impreza S203
    Subaru has announced an update to the Impreza S202, called the S203. Think of it as an upgraded STi with the power of a Spec C. The site’s in Japanese, but it still has some nice pics.

    – http://www.superhonda.com/photopost/data/516/559Suparu-med.jpg
    I don’t really know what to make of this, other then hoping it isn’t true. I can’t read the page to know what this is, although it looks to be an example of how Subaru’s latest styling cues might be applied to the Impreza:

    [update 2004-12-28]
    – Subdriven: S203
    Found another article about the S203 — this time in English.

     

  • erik 10:28 pm on December 24, 2004 | 34 Permalink | Reply
    Tags: automotive,

    Cold weather fuel leak

    We were out running errands the other night when the smell of fuel started filling the cabin of my 2002 Subaru Impreza. At first I thought it might be another car in traffic, but quickly realized that the obnoxious odor was coming from my engine bay. One of the Service Managers at a Subaru dealer had warned me about this a few months prior, but I didn’t realize that it was related to the cold weather. Apparently when it’s cold enough outside (which it has been here), one of the fuel hoses contracts and fuel leaks out onto the passenger side of the engine (near the turbo.) Subaru of America has acknowledged this design flaw with a service bulletin, but it’s not considered a recall or warranty work (which I guess means it’s little more than a warning that it happens, and that some re-designed parts are available to solve the problem at the owner’s expense.)

    Before doing anything with the car I searched through NASIOC (North American Subaru Impreza Owner’s Club) to learn more about the problem. Interestingly enough, there have been over 10 other local owners in the past couple days that have posted about the exact same problem. (It’s unusually cold right now.)

    The next day I stopped by a local Subaru dealer only to be sadly disappointed with their interpretation of “customer service”. Since I recently moved, I don’t know where the best places in town are for this kind of thing, but I can tell you that this particular dealer won’t be getting any of my business. They were terrible, which was particularly bad since the local dealer in my old town was amazing. So instead of giving my business to these guys, I’ve ordered the parts from an out-of-state dealer who’s always been pleasant. I also made a point to post to some of the boards about the poor service at this dealer.

    I bring all this up for a couple reasons: (1) If you have a 2002 WRX getting up near 50k miles, there’s a known issue with the fuel line on the passenger’s side of the engine (under the intake manifold.) If you’re still under warranty, I’d go in and complain about a fuel smell just to get the work done. (2) Subaru is aware that this first batch of WRX’s leak fuel when cold, but haven’t recalled it. And finally, (3) I love my car, and everyone I know who owns one loves it too — but all it takes is one jackass (actually two) at a dealer to make potential customers post bad things to their blogs and discussion boards ;-)

    [Update: 2009-01-18]

    There’s a post in the comments suggesting that you can simply tighten the fuel hose clamps to stop the leak. It will take a little effort to get to the right one, but if it works, this will save you from a considerable repair bill.

    [Update: 2007-03-20]

    I’ve noticed that this post (and my Texas heat and a coolant leak post) still get quite a few hits, so I thought I’d add some extra info (and turn comments on, which they should be now.) First, the fuel leak is caused by a short section of rubber fuel line that connects two sections of hard line under the intake manifold. When cold, everything contracts, and there’s a possibility for fuel to spray out from the connection.

    When I took my car to the dealer, I was slightly over 50k miles, and they refused to do the service under warranty. Instead of paying the (rather large) fee to have the dealer swap in new stock lines, I decided to go ahead and install some after-market steel-braided lines myself. Doing this yourself is a pretty big job — you’ll be pulling A LOT of parts out of the engine bay. I’ve included a few photos below to illustrate:

    The engine bay pulled apart. This is what you’re getting into if you decide to do this yourself. Just about everything above the engine has to come off:

    DSCN2268



    Don’t forget that once you pull all those parts off, you’ll need a lot of new gaskets and hoses to put it back together. If you have any other mods or maintenance you were thinking of doing, now’s the time. (Ex., fuel filter, spark plugs, coolant hoses…)

    The intake manifold getting the new fuel lines installed:

    DSCN2280



    Back together:

    DSCN2292



    Note that “back together” means assembled, but with a number of changes. The Perrin doc’s didn’t mention it, but there are a few parts that will no longer fit once the larger, Perrin fuel rails are installed. Most notably are some parts known lovingly as the Green Brackets of Death. The GBD’s are heavy steel pieces that cover the fuel injectors to protect them in the event of an accident. (Breaking off a fuel injector during a crash is a great way to start an engine fire.) The GBD’s will no longer fit once the Perrin rails are on. Once you’ve come to accept this, the next thing you’ll notice is that the left GBD also features some crankcase ventilation hard-line welded to it. By not re-using the GBD’s, you lose this as well, and now you need a new solution for your crankcase breather hose on that side.

    Testing fuel pressure with the new fuel rails:

    DSCN2312



    Don’t try this at home, but with a little painter’s tape, even a test gauge can be visible from the cabin:

    DSCN2315



    [Update: 2008-08-13]
    Here’s the Subaru Service Bulletin (#09-36-03):



    Found it on this thread: http://forums.nasioc.com/forums/showthread.php?t=1421635

    Googl’ing for http://www.google.com/search?hl=en&q=subaru%20service%20bulletin%20fuel%20leak also brings up a lot of info.



    [Update 2010-03-02]

    Looks like Subaru is finally admitting to the problem! I just got this in the mail:

    Letter from SOA



    Perhaps we have the recent Toyota recall issue to thank for Subaru finally addressing this fuel leak.

     

  • erik 11:51 am on December 11, 2004 | Comments Off Permalink
    Tags: automotive,

    An evening with COBB Tuning

    Last thursday, Subaru of Dallas hosted what they called a “High Performance Tuning” session, with keynote speaker Trey Cobb of COBB Tuning.

    The event started with the obligatory pizza and beer, then moved to an introduction of the staff, some history of the new dealership, and a hint at where the dealership is heading. The most notable new information is that Subaru of Dallas is expanding to add an STi showroom, which will stock the entire line of STi parts. This will be the first STi showroom in the Americas.

    Trey’s presentation focused entirely on their R&D process and the new parts they are offering for the Impreza and Legacy. While this wasn’t quite what I was hoping for, it was rather informative. Trey spent a significant percentage of time discussing their new downpipe and the thinking behind it’s fabrication. His first point was about the casting process for the bellmouth housing. It’s two notable features are a taper design that doesn’t interrupt flow coming from the turbo exhaust port (the taper is on the waste-gate side), and a casting made from stainless steel instead of iron (using an investment cast instead of a sand cast for a smoother surface.) The bellmouth housing is then slipped over a 304 stainless steel pipe (with a small internal gap to leave room for metal expansion), which is joined in a zig-zag patterned fusion weld (a TIG weld with no filler metal.) The odd shaped joint was designed for increased strength, which should allow this section to hold up to exhaust heat abuse better then a traditional pipe weld. The bellmouth also features a top-mounted O2 bung, which is conveniently located if you’re not using heat shields.

    The new Cobb downpipe also features a very small catalytic converter. Trey wouldn’t disclose the brand, but emphasized that this is a modern catalytic converter design more popular in Europe then North America. The device is more expensive then traditional high-flow cats, but more efficient and features a lower profile. The downpipe bolts to the factory mid-pipe using the same donut flex joint used by Subaru.

    After addressing audience questions about the downpipe, Trey moved on to the new Cobb uppipe. An uppipe is a pretty simple part, so instead of simply copying the factory design and removing the cat, Cobb focused on optimizing air flow through this section with extensive CAD and fluid-dynamics modeling. The end result is a 100% investment cast stainless steel part. As a fully-cast part, the piece requires no welding, thus avoiding the common joint failure seen in other uppipes. The uppipe is available in 304 stainless, or Inconel 625. Inconel is a more exotic metal that is stronger and more heat resistant then regular stainless. The qualities of Inconel make it a great choice for exhaust headers, but also make it very expensive to tool. Given the higher manufacturing costs, the Inconel part is about $150 more then the stainless piece.

    Trey also pointed out the use of non-stainless, coated studs in their uppipe. He claimed that stainless studs combined with non-stainless nuts are a recipe for seized bolts. Cobb also uses a custom made stud that properly matches the factory bolt lengths, to ease installation and reduce the chance of the studs hitting an after-market downpipe.

    After discussing fluctuations in the raw metals market, Trey moved to the highly controversial (in the WRX world) topic of after-market intakes. After holding out for many years, Cobb will soon introduce a short pod intake for the Impreza. While Trey is still a strong believer in keeping the stock air-box unless pushing over 400hp, he’s recognized that customers want the sound of a pod intake and are willing to purchase a part just for that.

    The common problem with after-market intakes for the WRX is a disruption in airflow over the Mass Airflow Sensor, which then requires extensive ECU tuning to correct. To avoid this, Cobb designed a short intake featuring internal air stabilization channels. While describing the design, Trey mentioned that the new Subaru Legacy GT uses a very similar design in it’s factory intake. Trey only had a 3D printed model of the intake to show, but indicated that the final parts are in production.

    While running short on time, Trey quickly introduced the Access Port. The Access Port is a simple ECU map storage device, which connects to the factory OBDII port, capable of storing and selecting alternate ECU maps for the stock ECU. After this short explanation, Trey quickly moved to a demonstration of his upcoming StreetTuner software. StreetTuner is an engine management solution which enables end users to modify every data point in the factory ECU — in real time. Unlike piggyback or replacement ECU’s, using StreetTuner with an AccessPort gives direct control over the existing ECU, and the ability to modify every tuning aspect available in the factory ECU (ex., low-det and high-det timing maps, the boost map, OLF cutover point, MAF correction, target air/fuel ratios, etc.) The modifications to the ECU are undetectable by the Subaru diagnostic tools used at dealers and don’t require any rewiring.

    The event wrapped up with a door-prize raffle that unfortunately didn’t include any actual car parts. However, I won a Hot Subaru T-Shirt, which was pretty cool. Hot Subaru also has a short blurb about the event.

    Thanks to Trey Cobb, COBB Tuning, and Subaru of Dallas for hosting the event!

     

  • erik 12:00 pm on August 3, 2004 | Comments Off Permalink
    Tags: automotive, ,

    A Python script to calculate UTEC map checksums

    I had a sudden burst of inspiration the other night and wrote a Python script that can read/write map files for the TurboXS UTEC, along with generating or inserting the proper checksum value into the map. For Mac OS X users, I also wrote a BBEdit filter that will stick the checksum into maps you are editing with that text editor.

    If you don’t know what a UTEC is, it’s probably safe to stop reading here. For those that are curious, the UTEC, which stands for “User Tunable Engine Computer”, is a programmable ECU for the Subaru WRX. Until now, there were no Open Source utilities to compute the checksums necessary to upload self-edited ECU maps, nor were there any tools for OS X users at all.

    You can find the readme and pylibutec.tgz file here: pylibutec

    pylibutec.tgz contains some unit testing code, sample maps to validate, the bbedit filter, a readme, and the ‘utec’ module, which contains a script called ‘maputil.py’

    The code was written and tested with Python 2.3 on Mac OS X (Panther) for the 4.1 UTEC firmware. I have not tested on any other platforms, but I would appreciate any feedback, patches, etc., so I can improve the code.

    Mad props go to Pete at TurboXS for explaining the checksum process. His explanation is included in the source code.

    pylibutec is Open Source, licensed under the Creative Commons Attribution 2.0