- Just gonna send it! My man Alex throwing down low 12s on a JB4-only car!

Tune vs. JB4

1y ago


First up, sorry I've been absent from posting. School, life, now writing for Deutsche Auto Parts. But... I still wanted a forum to post something a little more controversial - tunes vs the JB4. Two great solutions for extracting power. But which is better, and more importantly, which is right for you? Today I'm going to get into a number of details about what makes each a more better solution. We'll talk about various off-the-shelf tunes, the Cobb AP, and Eurodyne Maestro as well.

Some Terminology

Flash Tune - A tune solution that overwrites the factory ECU data. This the type that voids your warranty.

Piggy-Back Tuner - A tune solution that plugs into engine sensors and "tricks" the ECU into requesting different values.

OTS Tune - Off-the-shelf Tune. A tune developed by a tuning company, sold as a "standard". Example, every Stage 1 91 Octane Unitronic Tune writes the same (performance) data to the ECU.

Protune - A type of flash tune that is adjusted specifically to the hardware of the vehicle, typically done by a protuner such as Frank Mabo (Eurodyne) or Jon Drenas (Cobb).

E-Tune - "Electronic-tune", a type of protune that is done over the internet, where the owner performs data logs and the tuner sends new files. Common with the Cobb AP and Eurodyne Maestro.

JB4 - The Pros

Let's just say this outright - the BMS JB4 is an amazing tool. No seriously, it's awesome how far piggy-back style tunes have come. Tuning a car consists of three main aspects: ignition timing, boost control, and fuel. The JB4 has pretty much full control of boost and fuel, and thanks to our advanced ECU's, ignition advancement partially covered as well. Not only that, the JB4 is also acts as a high-speed data logging solution, and has a nice app so your phone can act as a real time display! If that's not enough, remove it, and you're good to go in for warranty work.

That beautiful JB4 display!

OTS Flash Tunes - The Pros

SPEED LIMITER! No seriously, the first and most obvious advantage to a flash tune is the removal of a speed limiter. If you're driving a Golf R (limited to 155mph), probably not a big deal. But if you're driving a Mk7 GTI (limited to 124mph) driving on the Outer Loop of Utah Motorsports Campus... yeah, problem.

The next big thing is that tunes requires no adjustment! The whole point of a flash tune is that someone else has already done all the leg work to write a new tune file, hopefully with lots of testing. It's designed to work in variety of conditions for a variety of cars, as long as some minimum hardware requirements are met (example: stage 2 -> downpipe). Now... as we've found this can be a problem as many tunes don't adapt well to altitude... but that's another story!

Flash tunes also include a lot of nice minor tweaks. Driveability improvements such as partial throttle boost. Throttle position to throttle mapping. Fine tuning of timing adjustment. Lower engine temps -- yup, the ECU controls the thermostat. It's not much, but it's something!

Lastly, if you bought a Eurodyne tune or a Cobb AP, you've also got yourself a high speed data logger! In fact, these loggers support more variables than the JB4, namely wastegate duty cycle. All in all, these data loggers are some of the best on the market.

JB4 vs. Tune

So what's the best... and why? Well, it depends on who you are, and what your goals are. Some people in the community are not avid car nerds (like me) and that's totally okay. But, they might still really love the MK7 and want to get the most out of it. For those type of people, I really recommend going the flash tune route. Yeah, yeah, I know the JB4 comes with base maps, but the reality is OTS tunes outperform JB4 base maps. This is because a flash tune adjusts a lot more parameters than just a JB4, so if you're kind of on the fence about messing with a JB4, then go flash tune.

Furthermore, the reality is the JB4 also gives you power, and with great power comes great responsibility! No really, eventually, you're going to wonder, what if you up the boost a little more? And a little more? How much can you add? Is it any faster? It's can become a dangerous addiction, trust me: I have JB4 friends.

Let's be honest, the temptation is WAY to real.

But, what if you are nerdy about this kind of stuff--or have a friend willing to nerd out for you? How much are you really giving up with the JB4? Quite honestly...not much. Especially if you're focused on drags. The JB4 has an amazing ability to extract out power in the cars. Just take look some of the amazing 1/4 mile times with JB4-only cars. Example: Alex (censored) ran a 12.2 @ 113 in a FBO IS20 GTI, with only a JB4 engine tune. That's fast. That's faster than my IS38 GTI (and many other manuals, lol). Bottom line is, most of the time a dialed JB4 is going to be faster than OTS flash tune. You can extract more out of the car but, you do sacrifice some fine tuning elements and have to wrestle with that pesky top speed limiter...

There's also one other type individual I recommend the JB4 to, those who aren't committed to the car, but don't want to leave it stock. If you bought your brand new MK7 and aren't sure about keeping it, and/or breaking it, but you still want something--get a JB4! It's the easily the best bang for your buck mod, especially when you can resell it for about 80% of what you paid! Not only that, it doesn't void your warranty, giving you that peace of mind.

Protunes, E-Tunes and Maestro

Let's not forgot the bottom line is, if you want the most power, or the "best" tune, you get a protune. Maestro has given me phenomenal control over my ECU to get my MK7 dialed to EXACTLY how I want it to be setup. Tons of 1/4 mile records are held by Maestro Protunes. A Protune can make your car into exactly what you WANT it to be, whether that's fast or reliable or anywhere in between. However, if you go in with a naive approach, you're at the mercy of your tuner. I cannot stress enough that if you go this route, at least learn how to read logs to make sure your tuner isn't pulling the pin on grenading your motor.

Upgrade Paths

One kind of separate thing to note is adjusting your tune (or JB4) for new hardware you might get down the line. Tunes typically have a nice upgrade path (Stage 1 -> Stage 2 -> Stage 2+) to support stock hardware, downpipes, and even turbo upgrades. While each costs a little more, you don't have to buy it twice (in fact with Eurodyne you get them all for one price).

My personal opinion is that if you plan on stay stock turbo, it's another point for the JB4. However, if you're looking to upgrade the turbo in the future, go the flash tune route. The problem arrises with boost control with different turbos. There is a specific map in the ECU which correlations boost request and wastegate actuator positions which is different depending on the turbo. While the ECU does adapt, when you swap turbos it can be very hit-and-miss as far as the functionality. From what I've seen, JB4 only 1.8T's with IS20's seem to be okay, but IS38 GTI's with JB4 only seem to struggle more.

Final Thoughts

Both are great options and each are suited to certain people. Just getting your feet wet? Try a JB4. Love your MK7 but aren't tech savvy? Go grab a flash tune. Want to tinker and get the 95% of the power out of your MK7? JB4. Want the absolute best? Protune.