rocketeer928 - My 2003 VW Jetta TDI

• DC Stage III+ Clutch and 17.5 lb. Flywheel
• Fratelli Bosio Power Plus 764 Injector Nozzles
• 11-mm Injection Pump
• VNT-17/52 Garrett Hybrid Turbo (commonly called VNT-17/22 turbo)
• 3-Bar MAP Sensor
• R32 Air Intake and R32 MAF Housing up to the PD150 TIP with TDI MAF filament
• PD150 Turbo Intake Pipe with DEI Titanium Exhaust Wrap
• PD150 Intake Manifold with Allard Power Pipe
• 2½-inch lower and 2-inch upper intercooler pipes
• APR-Tuned Front-Mounted Intercooler
• 0.658 5th gear
• 2½-inch downpipe with catalytic converter and straight-back exhaust without muffler
• Dieselgeek EGR Delete and by-pass Oil Filter, Short-shifter, and Panzer Skidplate
• Dynaflow CCV Filter
• TDI Frost Heater
• McNally Boost and EGT gauge
• Enkei RSV 17-inch wheels with Yokohama 235/45R17 tires
• Koni FSD struts and shocks with Koni Sport Springs
• Diesel fuel cooler using a transmission cooler
• PD Lift Pump with LCR Modification
• Lower Rear & Upper Front Stabilizer Bars

Last December, I went to Jeff Robertson’s house in Red Lion, PA and had him place the RC5-ASV-Euro-Tune on a secondary ECU (See Post Nr. 621). My primary ECU already had RC5 on it with EGR readiness activated, so as to pass Connecticut emissions (See Post Nr. 375). I was happy with this tune, but wanted more power, so I opted to switch to the RC5-ASV-Euro-Tune.

A TDI Club friend who currently resides and works in Deutschland put me in contact with a German guy named Günther (last name) who tuned his ECU specifically for his car. My friend had shipped his TDI to Deutschland, and he needed a new tune to pass strict TÜV emissions standards, among other reasons. I’m sure some of you know who this TDI Club friend is, but I’m choosing not to be specific so as to protect the innocent. My friend’s Jetta TDI has nearly the same power modifications as I have on my Jetta TDI.

I decided to have Günther work with me to also tune my TDI specific to my modifications with the hope of an increase in horsepower and torque, while at the same time reducing the amount of soot and smoke generated. In e-mail exchanges I had to communicate with Günther in German. Because I lived in Deutschland for a year back in 2006 - 2007, I know a little Deutsch, though I am far, far, far from being fluent (not even close). So, I relied on Google Translate and my friend to help me.

I bought a Galletto 1260 ECU Flasher, so that I could take Günther’s files that he was to e-mail to me and upload them onto my ECU. However, the first challenge was to remove the RC5-EGR readiness-Tune from my ECU. Jeff Robertson places a dongle chip on his more advanced tuned ECUs, presumably so his files cannot be downloaded and copied. I can understand that. As a businessman, Jeff needs to protect his files to make his living. So, I sent my primary ECU to Günther in Deutschland to remove the RC5 chip and its dongle chip, and replace it with a standard OEM chip that could be programmed. I wasn’t comfortable performing the soldering myself, which is why my ECU went across the pond and back. It was a bit of an ordeal because on the customs form I had labeled it as an “Automotive Part”. I was trying to be honest. That caused the ECU to get stuck in customs for 3 weeks and a tax to be applied.

My ECU was sent back to me with the stock 90 HP / 155 ft-lb tune programmed onto the newly installed chip, and ready to be worked upon. I also have the RC5-EGR readiness-Tune chip and its dongle chip, which I may try to sell.

Each time Günther sent me an updated tune file to try, I had to log data with VCDS in 3rd and 4th gear from 1500 RPM to 4500 RPM. I think Günther likes to limit his tunes to around 4500 RPM for safety reasons, since my TDI tops out around 4600 RPM. Overall, I tested 18 tunes from the beginning of September through mid-October. Some of the tunes had to be adjusted due to idling and smoke issues. Günther had me log Groups 008, 011, and 006. The best Günther-Tune is 2 seconds faster than the RC5-ASV-Euro-Tune from 60 - 160 km/hr (37 - 100 mph) in 4th gear. However, I feel that the RC5-ASV-Euro-Tune is quicker upon acceleration from a standstill.

Since there was not a New England Dyno Day TDI Club GTG scheduled this fall because of poor turnout last year, on Thursday, October 27, I made an appointment with Dent Sport Garage to compare both the RC5-ASV-Euro-Tune and Günther-Tune on the dynamometer. I drove the 3+ hours to DSG because that’s where I have my dyno baselines from 2008, 2009, and 2010 during past NEDDs.

In the below graphs there is only shown a single pull. However, for each dyno test, three pulls were performed with no variability between pulls. Also, this dyno is a heartbreaker, which translates into lower than expected results, and it was a humid, rainy day.

Here are the results for the RC5-ASV-Euro-Tune:

The stock engine is rated at 90 HP / 155 ft-lb (210 Nm) torque. At 162 HP / 235 ft-lb. (319 Nm) torque, this translates to an increase of 80% HP / 52% ft-lb torque. Maximum torque is not reached until 3300 RPM, and there is an odd dip between 2400 - 2900 RPM.

Here are the results for the Günther-Tune, including the VCDS logs:

3rd Gear:

4th Gear:

The stock engine is rated at 90 HP / 155 ft-lb (210 Nm) torque. At 159 HP / 264 ft-lb. (358 Nm) torque, this translates to an increase of 77% HP / 70% ft-lb torque. The torque power band is smooth, the area under the curve is good, and it maximizes at 2650 RPM. The horsepower is about the same as the RC5-ASV-Euro-Tune. I was a bit surprised and disappointed, as I had expected the horsepower to be a little higher with the Günther-Tune. The smoke was considerably less, as there is more fueling (59.8 mg/str) with lower boost and no surging (see below).

Here is a comparison of the boost and torque between the two tunes:

Though the boost maximizes at a lower PSI, the Günther-Tune spools up quicker and stays rather steady as compared to the RC5-ASV-Euro-Tune. I have always complained that my 17/22 turbo coughs when hitting the accelerator, and I suspect that the fluctuations between 2000 - 2500 RPM is evident of that coughing sound I hear. I wish the turbo was smooth at the low RPMs.

Here is a direct comparison of the RC5-ASV-Euro-Tune and Günther-Tune:

The maximum horsepower is similar, though the Günther-Tune has a bit more power at lower RPMs. Obviously, the torque results are different.

Here is a direct comparison of the RC5-EGR readiness-Tune, RC5-ASV-Euro-Tune, and Günther-Tune:

I was shocked to see that the RC5-EGR readiness-Tune provides similar horsepower and much improved torque as compared to the RC5-ASV-Euro-Tune. For the RC5-EGR readiness-Tune, at 155 HP / 290 ft-lb. (393 Nm) torque, this translates to an increase of 72% HP / 87% ft-lb torque. Now I feel like I wasted my money getting the RC5-ASV-Euro-Tune, since it doesn’t seem to perform as well as the RC5-EGR readiness-Tune. I didn’t get the power increase I had expected and been told I would get. Hmm...

Though a bit busy, here are all the dyno results on my Jetta TDI from 2008 through 2011:

I’m sure on a cool, dry autumn day, the numbers above might have been higher. Every time I dyno at DSG, I leave a bit disappointed. Maybe I'll do another dyno in the future on a dry, crisp spring or fall day. DSG is 3½ hours one-way from my house.

squire89 said:

so that's the dyno run....how do you compare real world driving experiences with the two tunes?

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NHgranite said:

Don't forget your HELMET !!

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rocketeer928 said:

Too bad it's not a diesel.

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IndigoBlueWagon said:

Your numbers are eerily similar to IBW's Fuelly Numbers. I do drive a few more miles per year, however.

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Eerily, Peter?

I'm pretty sure that you drive faster on the highways than I, even though our percentage of highway vs. local driving is nearly the same. I also notice that your mileage was very consistent over the past year, while for me there is a big dip down into the 30s in the summer because I was doing all those test runs while perfecting my new, Deutsch Günther-tune.