It’s taken just two years, but Project GTI is almost exactly the car I always wanted it to be.
If you caught the last update, you’ll know that the car was just about to go under the knife at Regal Autosport, and would probably expect the work to have long been finished. Of course, you would be correct. Sitting down to write this, I’ve been back on the road with the car for around 10 days, having already completed some long distance and a variety of driving with the freshly installed Integrated Engineering parts.
However, I’m going to go back to where we left off previously and go through the whole build process. Before I travelled to Regal’s workshop in Southampton, England, we had already fitted the new Integrated Engineering cold air intake and breather plate. This left four considerable jobs still to be carried out: installation of the intake manifold, K04 turbocharger system, uprated front-mount intercooler and tuning.
Before we got underway, Regal spent the time to check the car over to ensure they were working with a healthy example. Some baseline power readings were made on the previous setup so we could accurately assess what gains would ultimately be made. With its stage two software, the car put down 247bhp and 250lbs/ft on Regal’s Mustang dyno with 95RON fuel (US 91 octane equivalent, but more on that later). In my experience, Mustangs are very consistent dynos and exactly what we would need when the time came to tune the car. The most important part was that we were going to be comparing like for like on the same system.
The first part of the process to be tackled after the health check was the intake manifold. The factory intake manifolds on the 2.0-litre TSI engines are renowned for being a little bit fragile; made of plastic, they’re known to crack, leak and the runner flap system inside them to completely fail. Plus, they’re ugly as hell, so there’s that.
With it removed, we – mostly Ben at Regal – were able to inspect the condition of the valves on the intake side of the engine. TSI engines are direct injection, so no fuel is sprayed over the valves during the combustion process unlike port injection. Instead, the fuel is sprayed directly into the cylinder.
Because the factory PCV system mists unburnt fuel and oil vapours back into the intake manifold, it means that the valves can get covered in carbon deposits. We’ve removed this PCV system and is the main reason behind running the IE breather plate and catch can setup, which prevents this from happening. Still, there was around 40,000 miles worth of build-up from the previous owner.
Luckily, they weren’t that badly coked up, but it made sense for them to be cleaned with the manifold off. Soaking them in petrol overnight made the job infinitely easier when Ben got in the next morning.
So much so in fact, that he already had them cleaned by the time I arrived. The carbon deposits are drawn out of the valve chamber during this process.
With the valves cleaned, he was already at the end of the process of transferring parts over from the old manifold to the new one. Because of the difference in the runners, the fuel rail mounting bracket needs to be trimmed for it to fit on the new intake. Integrated Engineering supply a diagram of this bracket, with a guide of where to trim and how much material to remove so there’s no guess work involved.
For some reason, this part of the installation was the bit that worried me the most. I guess it’s just because you don’t (or at least I don’t) see the intake manifolds on these getting changed very often. Still, it was just another day in the office and the process was as smooth as you could hope for.
The reinstallation of the new manifold was as expected – no issues with fitment or fouling lines and no modifications required (save for the fuel rail bracket detailed above); it was like installing a factory part.
With everything put back together, Ben started the car and was able to ascertain that everything was fitted properly and running correctly. This is an important part of the process during a series of upgrades, as it makes troubleshooting much easier. With everything running as it should, the engine didn’t even throw a CEL; we were now able to move onto the next phase of the upgrade..
Would Sir Like Some Boost?
With the intake installed and operating correctly, focus moved to the other side of the engine. The Mk6 GTI is factory-equipped with an IHI K03 turbocharger, which is a small but efficient unit. However, we had reached the limit of what it could achieve (at least without sending it into the stratosphere).
Red was in good company at Regal over the course of its week-long visit, which also happened to be the run-up to Players Classic. So it was a particular busy week for the team.
The original turbocharger came out with little fuss, asides from two very tight exhaust-side bolts. With both units on the bench beside each other, it made it much easier to see the difference between the K03 and K04.
With the K03 on the left and K04 on the right, you should notice a difference, despite my apparent inability to photograph them at the same distance. What I can tell you is that the K04 is just that little bit bigger in the places that count, allowing it to move a considerable amount of air more than the K03.
Integrated Engineering also pre-machine the housing to accept the GTI’s diverter valve in the same location as the K03, so it doesn’t have to be relocated elsewhere in the engine bay.
It’s not a very photogenic install, as so much happens out of sight, but the installation was once again perfectly straight forward. If I remember right, Ben did mention that there’s much more room to work around the Mk6 TSI bay versus the Mk5 TFSI. They are similar chassis and engines, but I guess the packaging has improved between the evolutions. A new exhaust manifold gasket was used during the process.
Either way, everything was buttoned up and reconnected in a surprisingly short amount of time.
We (read: Ben) then refilled the engine with fresh 5W40 Mobil Super 3000 (I’m keen to stick with 5W40 for a while, having recently changed from 5W30) and installed a new oil filter.
Once more, the car was started – but not before being cranked a few times to move oil through the engine and into the upright filter – and run up to temperature whilst its vitals were monitored. Every connection was double checked to ensure no leaks, and once Ben was happy the car was shut down for the night.
Another good day’s work done.
Staying Cool In Southampton
The by-product of producing more power is heat, which is the biggest killer of engines. While I might live in a very mild climate, it seemed that Mother Nature was keen to remind us that it can, on occasion, get hot on our side of the world.
With outside temperatures of 30°C/86°F, it felt somewhat appropriate that the last item to be tackled was the intercooler.
While not particularly difficult, it is a comprehensive installation with the whole front of the car needing to be stripped. Even at this stage, with the bumpers and lights removed, you’re still only about half way there.
Mounted between the air-conditioning condenser and the water radiator, the factory intercooler is usually recommended to be upgraded once going beyond stage two levels of performance.
Again, it’s only really when you see the new and old side-by-side that you can appreciate the differences.
The Integrated Engineering intercooler was designed to use every inch of space allowed in the factory mounting position, without having to modify or trim anything. It’s a perfect fit. Despite this, you can see the extra overall thickness in the intercooler compared to the stock item, which allows for 54% more core volume than factory.
Maybe the most dramatic difference is in the end-tanks, especially with consideration for the materials used and the size. The end-tanks play their own role in helping to dissipate heat, with alloy being more effective at cooling than plastic.
There’s also a considerable size difference on the inlet and outlet side of the intercoolers.
But the biggest difference is the IE FDS (Flow Distribution System) setup, which distributes charge air uniformly across the inlet side of the intercooler, in comparison with others which just rely on natural air flow. As a result, IE claim that their FDS increases heat dissipation by 65% versus other intercoolers.
Installation being the opposite of removal, Ben set about piecing the car back together for the final time.
It’s a shame that this is about as much you can see of the new intercooler when all is said and done.
With the provided silicon hoses attached and tightened, it was almost the end of the hardware installation.
Working directly with Integrated Engineering in Salt Lake City, Utah, IE advised us to fit the car with a new MAP sensor prior to them remote tuning the car. From several thousand miles away.
With this final piece installed, it was finally time to see just how much of a difference there was. Happiness, nervousness and excitement were all at the fore of my emotions at this point. This was what I was waiting for.
The thing about living in the future, is that you don’t really realise it until it surprises you from time to time. IE had shipped over their PowerLINK which would communicate with my car – in fact, it’s now locked to my car – and play a pivotal role in the tuning process.
The OBD2 device allows the software to be quickly and easily uploaded to the car. Some weeks before, I provided IE with my ECU details, with which they set about creating a base map for my new setup on 95RON fuel. While UK enthusiasts can avail of up to 99RON at the pump, Irish drivers can only acquire 95RON. Basically, my choice at a service station is either 95 or diesel. Nothing else.
This obviously puts me at a disadvantage when it comes to making peak power, as 95RON is approximately equivalent to 91 Octane in the United States. However, as the car would be tuned for 95RON from the get-go, it would ensure that I’m getting the most from it while still protecting the engine at the same time.
At the end of the day, this is still my daily driver and only car, so there’s no point in making 400whp if it only lasts a week. Reliability and drivability were going to be key to this tuning session.
With the base file uploaded to the car from IE’s server, it was time to start. After warming the car up, Ben gently brought it through the rev range, closely monitoring every detail imaginable. Once he was happy that everything was in good order, the first power run was performed.
With that first distinctive pop-pop-pop of its new hard-cut rev limiter, I waited for the car to decelerate before the first power figures popped up on screen. 320bhp with 310lbs/ft on the very first run.
It just so happened that the ambient temperature wasn’t conductive to huge power numbers, but even at that, I was already ecstatic. I now owned my first 300bhp+ car.
Another run was performed for logging purposes, before the car was let cool down and both Ben and Chris Stewart (that’s Mr. Regal Autosport) examined the data in front of them. They made some notes, before sending them and the logs across to Integrated Engineering, who in turn sent back a revised file. The speed at which this happened was just incredible.
With the car having cooled sufficiently, the new software was installed and the data gathering process began once again.
Another pull was done, followed by another with the car delivering consistently the same results. Temperatures were steady, despite the ferocious ambient heat.
This time, the numbers increased to 330bhp and 325lbs/ft. The really, really impressive part, however, is the shape of the new power curve in comparison to the previous state of tune. For reference, the dotted lines are before and the solid lines after, with red representing horsepower and blue representing torque. That’s a staggering difference in performance and a complete change in the driving characteristics of the car.
The tuning continued with both Regal and IE working to develop the perfect map for the car, which would deliver power and reliability. In particular, Regal wanted to allow some overhead in the tuning should I ever pick up bad fuel. A margin of error if you will.
I got the car back that night, just to put some easy miles on it and see if any issues arose, before returning to Regal the following morning for final data logging and fine tuning.
The final day was a perfect reflection of my experience since arriving in Southampton at 5:00am that Tuesday morning. With the bulk of the work done, it was just a belts and braces kind of day as every upgrade was pored over once again, the data re-examined time and time again, and the last runs on the dyno performed before the car was fully released to me.
At the end of the day, the car consistently delivered 321bhp and 312lbs/ft run after run after run, which is a result of +74bhp and +61lbs/ft. More so, there’s a completely different power curve, with the car making in excess of 300bhp from 5,250rpm all the way to its 7,000rpm rev limiter. At the bottom of the rev range, I’m making 250lbs/ft (which was my previous peak torque figure) from 3,000rpm. Where before, there was a good shove at the bottom, but it all fizzled out beyond 4,000rpm. I’m now carrying power all the way to the limiter.
Under normal daily driving circumstances, the car is still as docile as it always was. It’s efficient and refined, averaging 35mpg on a long run and is still the same, nice car that it always was. That hasn’t changed.
What has changed is when I decide to go a little harder on the loud pedal; the rate at which it gathers speed, coupled with the shifts from the DSG and supported with a proper soundtrack from the intake and exhaust, is breathtaking. I cannot believe it’s the same car. There’s virtually no turbo lag, and with the new power band it feels like a completely different car to drive. Previously, there was a hint of turbo-diesel to the car, a big rush at the bottom followed by the power band going off a cliff as the K03 ran out of puff. But no more.
Out of curiosity, I measured its performance – on a private road – from 60-100mph which took 5.9 seconds including a full tank of fuel, a full boot and a full back seat worth of luggage. Going by these figures, it puts it in some serious illustrious company. But at the end of the day, it is still just a Golf.
Just a rather quick one.
Cutting Room Floor