mk7-cover

Golf GTI Endurance Build – Part One

We are never afraid of diving into the deep end and tearing things apart, but this project was bitter-sweet for us as we are such fans of the MK7 in standard or lightly modified form. However, we wouldn’t be Motion Motorsport without that burning desire to turn everything into a race car.

Grab a brew and take a look at our latest project here at Motion Motorsport.

mk7-golf-endurance

The Car

The car is a MK7 Golf GTI Performance and belongs to Luke Handley; a good friend, current racer and valued customer of Motion. It houses the 2.0 TSI engine strapped to a DSG (Direct Shift Gearbox), and being a performance pack model, has 226bhp as appose to 216bhp found in the non-performance models. It is also equipped with a vorderachsquersperre (a.k.a VAQ – which in English means front differential lock). This allows the car to gain traction around the corners. This is the first Golf to be built on the MQB Platform which we are huge fans of.

The Plan

Here at Motion we never do things by halves – we go to every length when building a car to ensure the best finish and performance possible. We started with a brief from Luke on the championship that the car will be raced in and then set to work!

We aim to build this car into a full endurance spec machine. It needs to complete 2-hour races on a regular basis, but with the reliability and speed to do a 24 hour race if needed.

The series Luke had chosen to run in is the 750MC Club Enduro Championship. A typical race weekend consists of a test/track day, qualifying, followed by a 2-3 hour race. We were aiming for Class B which is a limit of 240hp per tonne. The rest of the regulations are really relaxed which is very exciting as its like an open book and almost anything is possible! The idea here is to build a car capable of being super competitive in both Class B and, in the future, Class A (with a quick change to the engine map) –  evolution!

club-endurance

The Build overview

The car will be stripped back to a bare shell where we can start the fabrication process; air jacks, larger fuel cell, seat and steering column positioning and bias adjusting pedal box mounts, as well as a comprehensively designed and built roll cage. We chose Safety Devices for the cage design and install after their work on the M4 we built for Tegiwa last year. We’ll be working closely with them to create an FIA homologated roll cage that suits our build outlines, along with a few chassis modifications while we’re there!

We plan to keep the engine stock internally to aid reliability and simplicity, but with some breathing mods. We also remove any un-needed items such as the A/C pump and HVAC system. The DSG Gearbox will be stripped for inspection and we will install an uprated differential and new clutch packs. Our aim is to then use suspension components from Yellow Speed Racing, Hardrace and Verkline, along with our own fabricated parts. This will allow us to set the cars geometry optimally, maximising the performance and grip levels the MQB Platform can give us.

Now, let’s get to it!

Part Two

We now have the Golf in the workshop and have made a start on stripping the interior and engine bay to get it ready for Safety Devices. The windows have been removed along with panels, bumpers and trim.

Strip Down And Roll Cage Preparation

The interior has now been pulled apart along with the dashboard, heater box, wiring loom etc (you get the idea!). Weight reduction is well under way with various bits of unneeded bracketry removed including the original seat base frames. This is a long process that requires endless amounts of drilling, grinding and cutting, but is key in shell preparation. This is not only to save weight but it makes the inside a far cleaner and nicer place to be for the driver. It’s also makes it easier for us to clean and maintain!

Fuel tank preparation

When it comes to fuel tanks, there is only ever really one option to consider. Used all over the world in a huge amount of championships, we chose ATL (Aero Tec Laboratories). This week, our fuel cell has arrived which will give us a fuel capacity of 120 litres and the ability to fill from a fuel rig, dump churn, tuff jug or normal fuel pump (dependant on the filler head used). In this instance because of the minimum pitstop time in Club Enduro, we’ll be using a vented Tuff Jugg which fills 20L in around 30 seconds to save some un-necessary expense at this stage but easily upgradable in the future.

We need the extra capacity so that we can go the distance during long races and give ourselves a bigger pit stop window with more usable fuel at our disposal. Dave mocked the tank up inside the car and we cut out its new home! All this must be done before the roll cage is fabricated, mainly because of the obvious problems that putting a maze of tubes inside a car creates for actually working on it, but also so we can see where the cage can sit without having the embarrassment of not actually being able to fit a tank in the space we have left.

Engine Bay

We have removed the engine and made a start on stripping back all the seams, the bulkhead and chassis legs of seam sealer. It’s a task that requires patience, a heat gun, scraper, wire wheel and huge tub of elbow grease! None the less, it’s absolutely necessary and serves to reduce weight while giving us access to the seams so that we can stitch weld the shell.

mk7-engine-bayjpg

Part Three

The Cage

Not only did we ask Safety Devices to produce for us an FIA spec roll cage, we also had them work on a few modifications to the floor pan and exhaust tunnel so we could get the drivers seat further back and towards the centre of the car. The exhaust tunnel in the GTI is pretty large with it being an MQB Platform designed to accommodate different drivetrain layouts (dependant on the model produced). Due to this we were unable to position the seat where we would have liked for the purpose of a better weight distribution, so the decision was made to cut away the exhaust tunnel to allow us a more favourable seating position. Although this is something we’d normally do in house, as SD were fitting the FIA seat mounts, it made sense for them to do the exhaust tunnel work whilst the car was in their hands.

interior-1-resized

Shell Preparation

The car is now back from Safety Devices and as always, they’ve done a great job, really following the brief we had whilst adhering to all of the relevant homolgation requirements.

It’s now time for us to stitch weld the shell, fabricate airjack mountings, add suspension mount strengthening plates to the rear, change the front strut tops,  add various mounting points with weld in bosses and plate any holes that are no longer needed.

Our components have arrived from Yellow Speed Racing which include air jacks and our custom specification coilovers. Dave got straight into the fabrication and has completed the installation of the air jack tubes, as well as making a start on the front top mounts. It’s difficult to gain access to adjustable top mounts on these cars so we have completely cut out the mounting point for the front top mounts. This is to reposition them further back and inwards to allow us to gain more caster and access for quick and easy adjustability.

Along with the long list of jobs at this stage, the pedal box install is complete, the fuel tank box has been finished with mounting points, the rear quarter inner skins have been cut away to allow for filler necks and all of the safety harness mounting points have been drilled and welded. Once we were happy that the car was ready for paint, the painstaking tin tape process begins! We cover all remaining small holes in the shell so that the paint finish is much nicer and prevents water ingress when running in the wet.

Part Four

Paint

The shells paintwork is now complete! We opted for a dark gunmetal grey inside to minimise reflections, which allows the driver to fully focus on the track. We have very lightly stone chipped the underside and arches after taking it back to bare metal, finishing them in gloss white to match the body. Look at the results – they speak for themselves! It’s also always a lovely point in any build to stand back and appreciate the extra time and effort put in.

Heat proofing

Before the assembly stage, we need to get the shell heat proofed. Driving a race car flat out for 2 hours is hard work (even more so if you’re cooking like a jacket potato), so anything we can do to keep heat out of the cockpit is essential. Remember we removed the HVAC system? The only form of cooling we have in here is through the window vents and that creates drag which we don’t want. This is why it makes sense to minimise the heat transferred into the car so we don’t have to worry so much about getting it out!

We have applied heatshield to the bulk head and re fitted the exhaust tunnel shielding. The exhaust down pipe has been heat wrapped and wire lock was used to hold it into place and extra heat matting has been added to the base of the fuel tank around the exhaust system.

heatshield

Part 5

Assembly Starts

 This is the most satisfying point of a build – aside from the finished project – all the prep work that went into getting the shell to this point starts to pay dividends as everything you bolt on fits as it should and gives you the base to start the next stage of the process. The fuel tank and lines, air jacks, fire extinguisher and the battery with all associated pipework and wiring goes in, then it’s time to start the overlay wiring loom.

The overlay loom is built to support the additional systems required such as a heated front screen, fuel lift pumps, fuel level sender, fuel drain, AIM dash, rain light, radio and Cartek isolator.  We had to mount a normally closed relay from the brake switch to allow the engine to start and brake lights to work via a pressure brake light switch. We then removed a lot of the stock wiring loom and un needed modules in the process.

A switch panel replaces the stock radio, the extinguisher nozzles are piped and positioned and a removable KMP steering wheel with shift paddles and radio button is fitted to our re positioned steering column. The dash was heavily trimmed of all un-necessary weight prior to being flocked and fitted along with the seat, Shroth endurance harness, floor mounted throttle pedal and fabricated foot plate which pretty much completes the interior.

Brakes

The brakes on this car were something we discussed from the start as with any race car. When we received the car, it had the stock VW ABS system, pedal box and entire braking system – aside from a pad upgrade in the rear and a Yellowspeed 6 pot big brake kit upfront. Firstly, the issue with this is that the ABS system robs us of braking control when on the limit and the single master cylinder with servo neither helps that nor offers any way of controlling the physical bias of front to rear brake pressure.

So, we removed the stock pedal box whilst deleting the original brake servo along with the complete ABS system (aside from the need for the pump to be there to allow the DSG to function) and installed a Tilton Pedal box with AP master cylinders. This required some fabrication and strengthening of the floor, a bit of head scratching for the brake switch (the brake pedal needs to be depressed to start the car and operate the lights but the stock brake switch is a multi-pin magnetic hall sensor mounted to the OEM master cylinder) but is a HUGE advantage over the stock system. We then replaced the rear calipers and discs with some AP single cylinder calipers (which means no parking brake) and relevant discs to suit the new rear uprights. All of this was tied together with some of our custom length and routed braided lines using bulkhead fittings which eliminates the risk of chafing and allows for easy repair of any corner of the car.

Endurance racing puts prolonged stress and heat on then braking system so keeping the system within the operating temperature of the pad compound and brake fluid is essential. We developed our own brake duct kit which uses all the original mounting points and holes that the OEM fog light uses. These are the perfect solution to brake cooling as well as being a simple swap from the stock light with no modification needed. You can buy these direct from our online store!

Part 6 

The Heart and transmission of the car.

The 2.0 litre engine comes from factory with an IS28 turbo charger we have changed this with an IS38 as found on the Golf R model. This is slightly larger meaning we can run slightly more boost and gain more torque without putting too much strain on the smaller Is28. We have removed and deleted unnecessary components such as the carbon canister and water inlets and outlets to the heater matrix. These engines seem to suffer from heavy breathing on track when hard cornering and braking so we installed a racing line catch can and breather.  

Transmission- We opted for the best differential on the market a Drexler Plated LSD. The box was split apart for inspection and the original Crown Wheel removed from the diff. The original crown wheel is riveted to the diff from factory, so this must be done by drilling the old rivets out. We will keep the VAQ in place as this will still work alongside the Plated LSD.

It was time to mate the transmission and engine together and mount it into the freshly painted bay using VW racing engine mounts.

Motul Engine oil and  DCTF gearbox fluid was used to lubricate the two.

Part 7

 

Front Suspension

With us at Motion Motorsport being a proud supplier and working with Verkline it was only right that this build received the Verkline MQB race subframe and lower arms. The arms have spherical bearing joints instead of Polyurethane bushes, they also have the ability to adjust camber and caster including additional camber adjustment from a billet ball joint.

The T45 tubing Subframe is a work of art. The benefits of this subframe is that its 50% lighter than the OEM subframe. It has only one mounting position so that it eliminates movement. One of the main benefits for us is that it completely corrects bump-steer now that we are running the car a lot lower than stock height.

(pictures of subframe in photo room and on car)

Rear Suspension

The rear suspension was not as straight forward as buying off the shelf items. Firstly, we wanted to get rid of the stock separate damper and Spring arm set up on the rear so that we can use a coilover. To do this we had to think about wheel clearance. We sourced a different VAG rear upright to allow this as the damper will bolt straight to it and not sit on the rear lower arm. We now had to make a custom rear trailing arm to suit the new upright and again we also made this spherical. Unfortunately, we were now left with an ugly re arm not being used to hose a spring or damper and still on stock rubber bushes. With the rest of the car now spherical we had to do something about this. With a little thinking a tubular spherical rear adjustable arm was made. With it being adjustable this now allowed easy toe changes to the rear. A different anti roll bar was now used as the original mounted to the spring arm.

We were that happy with the outcome we now sell the rear conversion kits on our online shop (Mk7 Rear geometry kit) – Consists of Rear upright, Spherical rear trailing arms, Tubular rear spherical arm with subframe and upright inserts and a rear anti roll bar.

(pictures of custom set up and rear end)

Part 8

With all the suspension components built up and installed along with the engine and gearbox. We can now see where to mount all the safety equipment such as. Fire extinguisher and Pipework, Fuel hoses and Fuel drain System.

AN Fittings and Braided fuel hoses were used throughout this build. When it comes to a fuel system we always opt for braided and AN Fittings. This is due to the safety and strength/ rigidity over a normal rubber hose that can easily get rubbed through if it were to become out of place. The AN Fittings can also hold more pressure than a normal jubilee or spring clamp.

(Pics of fuel and extinguisher system)

Part 9

Wiring

 In a race car you only need necessity items such as the items that make the car run and stop. All extras such as speakers, sat nav, airbags, Infotainment systems and interior lighting have been removed along with modules that are no longer needed. All this was a bit of a challenge and a lot of decoding and deleting of certain components had to be carried out. This allowed us to save weight and make the wiring loom a lot neater by stripping back lots of components and de pinning plugs.

Just look at how much we have managed to remove and how much neater it all looks.

Part 10

Geometry and suspension set up

Having worked on the MQB chassis before in the TCR Championship and securing a championship with James Turkington we knew a decent starting point to set this car up. Having already spec’d spring rates and brake master cylinders it was time to play around with corner weights, Camber settings, Caster, bump steer before finalising with the toe settings. There are many many factors that go in to a good handling race car from something as little as a tyre pressure change to roll bar stiffness.

Shake down

We took the car to Blyton Park for a shake down before real track testing got underway. The car was everything we expected and ran faultlessly all day.

750 MC Club Enduro

It has been a strange year with Covid19 and the race season being delayed and cancelled here and there but in the end Luke managed to compete in Club Enduro and the car ran faultlessly all year and finished every single race securing Luke the class B championship win. We are very proud how this car turned out and so happy for Luke for finally getting some trophies for his cabinet.