The long term GTI has just passed the 9000 mile mark and our hot-hatch certainly seems to be hitting its stride. Our last update was nearly 3000 miles ago and I had just installed the Bilstein coilovers and some shockingly good additions from the VW parts bin. But before that, at right around 5500 miles, I noticed a substantial improvement in fuel economy. I had been getting 22 mpg around town and was struggling to hit 30 mpg on the highway. Our driving is, in my opinion at least, predictable and repeatable, so more than likely it wasn't attributable to any change in use or conditions.
For 500 miles before the suspension, tires and wheels, I was suddenly hitting 25 mpg around town and could easily do 34 mpg on the highway. That isn't conservative highway driving either. After the modifications, the economy improvements have remained, if not even improved slightly on top of that. The lower stance has undoubtedly improved aerodynamics and the decreased rotating mass from the Neuspeed wheels can't hurt either.
For this update, I decided to add more power, a bit of noise and add an information display to monitor more of the GTI's vital signs during all the changes. If you looked at the teaser section of the last update, you undoubtedly saw the boxes from P3 Cars and Neuspeed. Obviously I'm not making huge changes, at least at this point, but hope to see some substantial improvements.
First up was the P3 VIDI Gauge; I call it a gauge but that's a bit of a misnomer. VIDI actually stands for Vent Integrated Digital Interface. It's a bit of a mouthful, but is a better description of the product. This is actually multiple gauges in one clean, oe-like unit. For standard operation, the VIDI pulls all of its information from the cars OBDII port. At the push of a button, the user can cycle through: boost/vacuum, coolant temperature, intake air temperature, exhaust gas temperature, throttle plate position, vehicle speed, RPM and charging system voltage. There is also an option to add a mechanical boost sensor as well as additional spots for 0-5 volt sensors of your choice. The unit also features a peak recall and 15 second record function so you can perform test runs and not have to worry about staring at the readout.
I won't go over the entire install here, but I can tell you, if you have the mechanical aptitude to change a spark plug, you can install this gauge. I had it in the car and working in roughly 15 minutes using basic hand tools and almost no profanity - I did drop a bolt between the seat and the console so one or two words may not have been family friendly.
This is my first time having a P3 VIDI in my own car. I've used them in feature cars before, but never had the time to really play with them. So far, I would list this in the no-brainer column of modifications. It's easy to install, it provides most of the useful data you could want, it looks great and with a retail price of $469 it might actually be cheaper than buying individual gauges. We will have to add the mechanical boost sensor later, especially if we want to keep tabs on how much boost the Neuspeed Power Module is adding.
Why you ask, well Neuspeed has come up with a work around to usual process of ECU flashing. Instead of adding software to yours cars control unit, the Power Module intercepts and adjusts signals from the car's MAP and boost sensor before getting to the ECU, think of it as a Jedi Mind Trick for your cars engine management. This won't make quite as much power as a full ECU flash but the upside is that all the factory safety measures are still in place and fully functional. The ECU is still controlling timing and fueling and keeps them within factory specifications. Literally all that the Power Module is changing is boost pressure. The only downside, is since the PM is "tricking" the ECU, the boost signal the VIDI is getting through OBDII is what the car "thinks" it's producing.
The $400 Power Module is relatively straightforward to install, but will take a bit of patience, especially the first time. The Power Module itself mounts directly in front of the battery with Velcro. One wire loom runs to the MAP sensor located at the front and top of the engine on the intake manifold and installs in minutes. The lower boost sensor is a little tougher to reach. We followed the instructions and installed the unit from the top. This involves snaking your arm down the front passenger corner of the engine bay, unplugging the boost sensor and connecting one plug from the PM to the sensor and one plug to the wiring harness. Doesn't sound too hard, but the entire operation is done blind. Sadly, you can't see a thing from looking down from the top. The first time you do the install, I would recommend jacking the car up, removing the belly pan and attacking it from the bottom. You will be able to see everything that is going on and it will prepare you if you need to take the PM off in the future, say for a trip to the dealership.
Next up, we installed a $450 Neuspeed P-Flo air intake. I've owned more than a few of these over the years and I've always been impressed with the quality and fit. As usual, the P-Flo replaces the factory airbox and plastic intake tube with an open element filter surrounded by a heat shield and a mandrel bent tube. Our kit also includes and adapter and smaller filter for the secondary injection system. Again, install is a breeze and can be done in less than 20 minutes.
The guys at Neuspeed say your car will take roughly 20 miles to adapt to the upgrades. The obvious difference is the sound from the P-Flo. The stock airbox muffles just about all of the intake noise from the turbo and the diverter valve is completely silent. With the P-Flo, you suddenly hear everything the turbo is doing along with some of the fluttering and whooshing sounds of the diverter valve opening and closing.
The Power Module is rated at a 35 hp and 70 lb-ft peak gains on 91 octane gas. ECU flashes will often play with the electronic throttle and do a few other things to make added performance more obvious. With the Power Module, it's only going to add more boost when the stock car would normally be at its limits, so it isn't so obvious in normal use. With congested roads and the car being fast to begin with, our GTI doesn't spend much time at wide-open throttle, even during canyon driving. Hopefully we will get the car out to the test track shortly to see what it really does with some testing equipment.
As mentioned in an earlier installment, Project GTI will be a constantly evolving thing. We want to try products of different price points, complexity and performance goals.
We have multiple boxes from the suspension giant ready to test out on our GTI. Many enthusiasts will opt for the simplest approach to get stiffer spring rates and a lowered ride height. We are going to try out H&R's Sport Springs to see how they work with the stock VW dampers. While we are at it, we will try swapping the factory wheels back on and using a set of H&R Trak+ Wheel spacers to make those wheels flush out the fender wells a bit better.
As another addition, we have both front and rear anti-roll bars that will eliminate some of the cars body roll without necessarily having a negative impact on ride quality. We are hopeful that they will not only decrease roll, but hopefully change the balance of the car and to get rid of the understeer, something we haven't been able to accomplish using just the Bilstein coilovers currently on the car.
We have a few more products we are looking forward to getting on the car, but we don't want to make promises we can't keep. You'll just have to watch this space for future updates and be sure to check on our website as well. We usually run out of space in the magazine, but have yet to come anywhere near running out of electrons.