90,000 Miles and APR Update

Looking at the latest activity on my blog, I can see that there’s been hardly any activity at all! I’ve been busy doing other things: LIFE. 🙂  The car has surpassed 90,000 miles without any significant issues. It continues to be a great commuter car as well as a travel car and workhorse. One of my largest summer projects was to purchase a shed, place it, and then move everything into it from out of a storage unit. The baby trailer was definitely the hero of that endeavor, as was the Dutton-Lainson winch that I featured recently. I don’t think I’ve shared anything about the shed. So, I’ve shared a few photos in the album below. I’ve also done some work on my subwoofer system, supported a bicycle event, removed my “rear seat delete,” had the paint corrected and ceramic coated, and updated my APR software. I’ll share details below.

I think most of you are here to read about my thoughts on APR’s software update. After all, why would APR update their Mk7 tunes NOW, four years into the Mk7 lifecycle? Wouldn’t they have gotten it right before mass-release in 2015? Apparently, there’s only so much development that can be done in-house. The rest comes as feedback from customers with a wide variety of daily-driven cars gets to APR. APR was also acquired by Driven Performance Brands in 2017, which has made new tuning tools available to them. They reportedly used new-to-them sophisticated instruments to make improvements to the tune. Read a little about their methods on APR’s website.

One sporadic problem I had seen with my tune was the occasional pre-detonation, sometimes referred to as “Low-Speed Pre-Ignition,” or LSPI. It wasn’t frequent enough to be a burden, nor predictable enough to collect data logs to send to APR. It tended to happen below 3500 rpm, a place where I have a bad habit of accelerating briskly without downshifting, thanks to 20 years of driving TDIs. I think doing that with a trailer in tow might have made LSPI more likely to happen, but not always. I decided to give the new tune a try since my wife and I were about to take the trailer on an 1100-mile road trip to retrieve our daughter from Parris Island, SC. I’ll share more about that trip soon.

Many in VWVortex have expressed their disappointment with losing ~30 lb-ft of thrust at the low end… or perhaps it was discontent from airchair commenters over the prospect of losing low-end torque. Some have commented that their car feels faster at the top end. Looking at the dyno graphs alone (I have APR’s old and new graphs, shared here), one would think that there’s a huge loss in low-end torque and about a 1-hp gain at the top. I’ve crudely plotted APR’s “v2” numbers in green dots on top of their old comparison plot. APR has stated that these dyno runs were done on different dynamometers at (obviously) different times. So, it’s not an apples-to-apples comparison. All I can share is the results of my butt-dyno, which is finely calibrated.  😉

Sure enough, I did notice a drop in low-end torque. It’s not terrible, but it is enough of a loss to notice it. However, the car now pulls noticeably harder above 5000 rpm. In fact, it continues to rip right on past 6000 rpm. I don’t know if it peters out swiftly at 6500 rpm, bounces against a rev limiter, or goes ’til it blows. I prefer to not drive my car like that. Regardless, the top end blast is certainly noticeable! The peak values on the dyno plot above show only a 1-hp difference. However, the difference is closer to 15 hp at 6500 rpm. And, remember, these were dyno’d on different dynamometers. So, the difference could be more. I’m not here to say “The upgrade is great and you should get it.” Instead, I’m saying that the loss of low-end torque isn’t terrible and it’s compensated at the top end.

My only complaint concerns the different accelerator pedal feel. Driving as before takes more accelerator pedal travel. At first, it feels as though the car is less responsive. Once I adapted to giving the car “more gas” during acceleration, I then felt as if it was more “difficult” to maintain a cruising speed. I think my brain and ankle had been trained to “keep the pedal here.” As a result, I often find myself driving slower than planned if I’m not around other traffic. It’s sort of dumb, and a petty complaint, but it’s my reality of driving until I fully adapt to the new tune. Perhaps it will serve to help prevent unwanted encounters with the police? But probably not!  😀  It’s worth recognizing that I can avoid this problem altogether by using the cruise control more often.

On the bright side, the new pedal mapping may be contributing to better fuel economy. Think about it: If the ECU is not requesting as much fuel or boost below 3000 rpm, then it stands to reason that the car may burn less fuel when cruising in top gear. All I know for now is that I averaged 28.7 mpg *with air conditioning* on a recent trip with myself, my wife, two Marines, and some bags in the car; plus, the trailer with four stuffed seabags (50-lb each?), two stuffed garment bags (30-lbs each), two light duffles, and bags for my wife and me. I suspect our combined vehicle weight was around 4700 lbs! My informal calculations estimate that we had 700 lbs of “meat” and baggage in the car and another 800 lbs in tow. Therefore, I think 28.7 mpg is fantastic! BTW, we got 33.6 mpg on the return trip with just me, my wife, our baggage, and the trailer, for a trip average of 30.5 mpg. I’ll do more testing without the trailer and share my results.

I mentioned that I had done some work on the subwoofer system. I removed the equalizer from the subwoofer setup and replaced it with an AudioControl LC2i. An LC2i is an active, high voltage, high impedance line converter with adjustable bass restoration circuitry. I didn’t need to restore any bass. Instead, I set the LC2i to allow maximum bass and then adjust the sub-bass from the front seat using a Rockford Fosgate PLC2 Remote Punch Level Control. The new setup sounds great and has freed enough space for another ham radio chassis.

I also supported another bicycling event last month. I won’t bore you with the details. It pretty much looked just like this one. Finally, I had my paint corrected and ceramic coated. It was an expensive job, but well worth it. The seemingly random photos that I’ve shared above show an excellent shine, even in the photos where the car is quite filthy. The detailer did a full paint correction and ceramic coating using Sonax Profiline products and then went over it with Carbon Collective Oracle coating, for a total of three coats. He said the coating should last three years. It looks fantastic, especially after a rain. Bird droppings just glide off with rain or a quick hosing.  🙂  I’ve shared some photos below. I’ll share more about our recent road trips soon. I’m also approaching the car’s three-year anniversary and will give a full report, both here in the blog and in a YouTube video.

Livin’ the Life!


About Scott

I grew up near Houston, TX and served in the U. S. Coast Guard for over 30 years. I have an electronics background and continue to work in the electronics engineering field. I taught myself the basics about automotive systems as well as how to perform some of my own maintenance (cars and bicycles). I became involved with Amateur Radio and computers in 1995. The explosion of technology has made my job and several of my hobbies quite interesting. My hobbies include Volkswagens, bicycling, photography, electronics, amateur radio, web management, and reptiles. Visit my websites to learn more.
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