What does it mean to give your engine a tune? Don’t confuse it with tune-up; it’s not the same thing.
Tuning is a broad concept, but given the response to my recent turbocharger and supercharger explanation piece, I thought it would be beneficial to discuss how a tune relates to a turbocharger, as this is also a common query.
I’ll use my own personal car, a 2018 Volkswagen Golf Sportwagen featuring a 1.8TSI turbocharged engine, as an example. In stock configuration, the engine produces 170 horsepower and 184 lb-ft of torque using regular fuel. These are respectable numbers, but they’re not ground-breaking. There are a variety of other manufacturers that offer engines with similar displacement but better results. I can, however, get these numbers up pretty easily to approximately 242 hp and 273 lb-ft with a tune. That’s a huge power improvement, which leads to two questions: How is this possible? And should you even do it?
As previously discussed, a turbocharger is an air compressor that forces more air into the engine, which allows extra fuel to be added. The turbocharger’s internal turbine wheel is driven by the engine’s escaping exhaust gases and can easily spin up to 150,000 rotations per minute (RPM) if left unchecked. RPM is controlled by a wastegate that opens and allows the escaping engine exhaust to bypass the turbine, thereby decreasing rpm. On contemporary vehicles, the wastegate’s open-and-close cycle is controlled by the vehicle’s Powertrain Control Module (PCM). The amount of boost developed is relative to how long the wastegate remains in its closed position.
Since software-hacking has been around for decades, there are private individuals who have figured out ways to bypass manufacturers’ original security lockouts. Just like your cellphone, which can be “jailbreaked” to run non-native applications, so can your vehicle’s software. When the software is modified, factory parameters are rewritten to keep the wastegate closed for a longer duration, resulting in elevated boost pressure. These rewritten programs can offer horsepower gains from the mild to the extreme. For approximately $600, I can have my vehicle produce the above-mentioned horsepower with no hardware changes; only software. The immediate downside being that I will have to now run mid-grade gasoline. But is this the only downside?
Manufacturers don’t think so. They have set the parameters within their PCMs to run at optimal settings, balancing fuel economy with engine and drivetrain longevity. From their perspective, overwriting the manufacturer settings indicates that the owner doesn’t care about fuel economy, nor do they care about prematurely wearing out their vehicle. So why should they offer a warranty on modified products?
I agree with them. If you modify your vehicle, you should not expect to be able to walk into a dealer and expect full coverage. Most manufacturers can now detect tampering with their PCM’s software and will set a flag in their databases indicating the vehicle has been tampered with. This will void any warranties and also void any future drivetrain extended warranties or recalls.
A developing problem pertains to the resale of these tuned vehicles. Since it’s the car that’s flagged in the manufacturer’s database and not the previous owner, unsuspecting consumers are buying vehicles that have been tampered with. The used vehicle they just bought may have warranty exclusions that they were not made aware of at the time of purchase. When you are buying a used vehicle with a turbocharger, this adds a new level of complexity. While it is not terribly common problem right now, it could become a bigger issue as more and more vehicles are equipped with turbochargers.
Your automotive questions, answered
Hi Lou,
I’m not quite sure what question to ask about this.
My car is a 2013 Buick Verano 2.0-litre turbo with a modest 98,000 km on the clock. About a year ago, the side-detection (blind spot) system began to fail and finally died. I was quoted $2,200 by a dealership for repairs (two sensors, rear wiring harness, installation, programming), which I declined. It’s a nice feature, but I have been accident-free for over 45 years without it using the old-fashioned shoulder check. The dealership disconnected the sensors, but the “Side Detection System Failure” message on the console cannot be disabled.
A year later, now that my wife and I are retired, we have decided to downsize to one vehicle, and the Verano is to be sold. However, my local service centre here in Manitoba tells me that it cannot pass a safety check without this system working. That doesn’t seem reasonable to me, but I’m struggling to find a way of verifying. Replacement sensors are only available from GM Parts and are close to $600 each. I feel trapped. How do you recommend I proceed?
Best regards,
Andy N
West St. Paul, Man.
The Manitoba Public Insurance website provides a link to their Certificate of Inspection (COI), which must be completed by a licensed auto-repair facility in order for any resident to obtain insurance. Taking a close look at that form, I see no section that details a pass or a failure for blind-spot, distance or radar side detection. From there, I looked up Manitoba regulation 31/2019, which the COI references. While this a very long document, I attempted to find any passages that refer to your specifics, but I couldn’t locate any.
The issue is the message on the dash displaying “side-detection system failure,” with the likely scenario being that the inspection station is playing it safe and failing the car because they think they should.
Your choices are to visit another inspection station, and if they fail it, ask them to show you the exact passage in the above-mentioned provincial document detailing the specific failure. Or you can just grin and bear it, and have the issue fixed. Selling any vehicle with warning lights on the dash will always cause your resale value to plummet, probably by more than the cost of the repair.
My final thought is on why you are being asked to change two sensors. I find it highly unlikely that both sensors have failed. Perhaps revisit this issue with the notion of just changing a single sensor to get the system functioning again so you can pass the safety. I’m sure most local garages can handle this repair and offer you a huge cost saving.
I have a 2013 Toyota Matrix automatic with about 74,000 km. The car develops a sound every time it goes up a local mountain or mountain pass that appears to come from the rear end and sounds like a bad muffler. The dealership can’t figure it out (it isn’t the muffler, and they have done an exhaust-system leak test), and when it happens, there is no apparent loss of power. It seems to be based on the elevation rather than the incline, as it never happens going up steep hills at lower elevations around Vancouver.
Thanks,
Cam M
Vancouver
Wow, that’s a strange one, Cam. Obviously it has to be related to the reduced air pressure at higher elevations. Given this, all engines struggle with the changing air pressure and have to work a bit harder the higher they go. Your vehicle’s barometric sensor will indicate the changing pressure to the main Powertrain Control Module (PCM), and the PCM will adjust the fuel pressure accordingly.
My guess is it has to do with the way the fuel is being burnt or, in this case, not being burnt as efficiently, which will effectively put a slight bit more raw fuel into the exhaust. More raw fuel in the exhaust would make the catalytic converter work harder and hotter, which may result in an air-flow disturbance through the tailpipe.
Clearly I’m reaching here, as it could be any one of a thousand different things causing your noise. The one thing I can say, though, is that it probably isn’t an indicator of any harm being done to your vehicle.
Lou Trottier is owner-operator of All About Imports in Mississauga. Have a question about maintenance and repair? E-mail globedrive@globeandmail.com, placing “Lou’s Garage” in the subject line.
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