Golf Mk1 GTi Cabriolet

The electronic steering is from a Corsa B, which, over time, suffers from the dreaded “Corsa Steering Angle Sensor Problem", making the car constantly pull to one side. 

The video by EasySteer, where I got the kit, shows how to fix this issue. Corsa Steering Angle Adjustment 

The steering angle sensor box can be seen below next to the electric steering motor. 

The write-up for the process is below: 

• Get the front off the ground and remove the wheels.
• When the ignition is turned on, the Electronic Power Steering (EPS)will drive the steering column depending on the reading of the torque sensor.
• If the position sensor is misaligned, the wheel will be driven continuously in one direction when the ignition is switched on.
• The column has a position sensor at the top behind the steering wheel that will count 30 turns from end to end before it jams. 
• Remove the sensor cover.
• Turn the wheel back to the centre.
• Turn on the ignition, the steering wheel may spin rapidly. Switch off if it does. 
• Rotate the torque sensor fractionally and turn on the ignition again. 
• Repeat this process until the steering is still when the ignition is on.
• Then, give the steering wheel a short tug in one direction and let it settle, then do the same in the other direction. 
• The wheel may continue a little or might bounce back a little. Adjust the torque sensor position until the behaviour is identical in both directions if necessary.
• Repeat the torque sensor setting procedure to ensure the behaviour is identical in both directions. Adjust if necessary. When you are satisfied that the steering is balanced and neutral, turn off the ignition and tighten the sensor retaining screws.
• Refit the Sensor cover, and re-assemble dash covers and screws. 

The catch tank would need emptying once or twice a year depending on the driving, which is acceptable. But as it was venting into the atmosphere, I would get a strong smell of petrol/oil every now and then, which was disturbing while pootling about town.

I read on one of the many Golf Mk1 forums I visit that piping the top catch tank outlet back into the airbox was the way to go, so I gave it a try, and it sorted the problem out. The car feels much smoother on cold starts, and the smells have gone even with the airbox off as the outlet is piped under the trumpet for cylinder one. Since the mod, I have not had to empty the catch tank. 

Honestly, there was no point in a significant car stereo build for this car. Unlike the hatchback, the boot is almost totally enclosed and is very small, so there is only so much bass you can get outta that space and into the cabin. Plus, what little bass could get past the backs seats has been further blocked by the MDF panels that were installed to house the amps 😂 

When the roof is down, it sits on the parcel shelf, creating an even better boot seal and blocking out even more bass. The windbreak stops the wind buffeting back at you from behind but also ensures that any bass frequencies get swept away by the buffeting behind the wind brace. Also, the deep exhaust note is around 80hz and cancels out any bass from the subs when the car is running. 

Fortunately, as ITBs sound so amazing, I listen to them and the exhaust popping on the overruns. The stereo system is just an expansive Google Maps speaker. 

However, when stationary, it sounds so good, so when detailing, you can stick on your favourite jam on and buff/polish/wax/tire black/glass clean away until the battery is flat and the car won't start, and your are stuck at some show in a field. This small pleasure justified the expensive setup for a while, but since I discovered Beats Fit Pro Air Pods with noise cancelling, which I wear when detailing, I started thinking about how much loss of BHP all that weight was causing. 

The setup has changed several times in the car, with various head units and subwoofer amps being swapped out. The most recent upgrade was to remove the Alpine ERA-G320 Sound processor as this unit had shot up in price and was selling upwards of  £1500. As I used the car daily and constantly leave it parked with the roof down, the risk was too great, as a forced removal of the unit would ruin the leather dash. 

The ERA-G320 is an amazing piece of kit. 

The unit was installed in the slot for the ashtray under the heater controls. 

The current setup is: 

Apline UTE-92BT head unit

Focal Access 130a  5” front speakers in AudioScape Door Pods

Back in the day, these were the business and allowed you to fit up to 6" speakers. The OEM smaller version below looks nice, but they are like hen's teeth and going for crazy money on eBay with grills. 

• Blaupunkt  BXQ 320 -4 Channel amp for front & rear speakers
• Alpine BBX-T600 - 2 Channel 300 Watt Amplifier 
• 2 x Alpine 10” Subwoofers

There are some Alpine 4.5” rear speakers. They do not do much, really. Just provide a bit of a fill-in noise in the back. I could only fit 4.5 as the electric window mechanism restricted the space. 

The exhaust system was built and fitted by Tony Banks Custom Exhausts. Tony Banks systems are handmade using aircraft-quality T304 British Stainless Steel with a 2mm gauge wall. They assembled my exhaust on-site using T.I.G welders and only used T316 stainless welding rods of the highest quality. The exhaust is free-flowing with tuned pipes and no restrictions or chambers. These guys are smashing exhausts on everything. Check out their Facebook page.

My 2.5-inch exhaust has a deep note and gently pops and burbles on the overruns (no gunshot bangs). The exhaust note, however, is not as loud as the ITBs, which drown the exhaust out when the engine is rev-ed hard.

They guarantee their exhausts for the life of the car. I brought mine back down after I clipped it and split it, just after the four-branch manifold, on a raised manhole cover, and they added a new flex and flange for only £108. I highly recommend them, but be sure to tell them how loud you want the exhaust note to be, as their default is Aston Martin V8 loud. 

While filling the car with petrol, I noticed rust inside the fuel filler neck. This is a common problem in the Golf Mk1s as dirt from the road gets stuck between the filler neck and the inner wing and slowly rusts the filler neck away. The rust also falls into your petrol tank, which in turn causes all sorts of issues with fueling.

Mine was a mess and came apart in my hand when removing it 😡

The fuel filter and pressure regulator were all clean and had no rusty flakes. These bits are in the engine bay and are easy to access. 

The fuel pump and fuel accumulator are both under the car but accessible. The fuel accumulator and pump brackets are always rusted and falling apart, so replacing these with stainless steel items is a good idea. Crazy Quiffs Mk1 Golf Shop has all the needed parts, but it gets expensive quickly when you start replacing the lines with stainless steel braided ones. I replaced the fuel accumulator, the fuel pump bracket and some of the rubber fuel lines

The rust from the fuel filler neck always ends up in the bottom of the tank. Rather than removing the tank, you can remove the back seat and access the tank by removing the in-tank lifter fuel pump. There is a how-to on the mk1maintenance website that details the process for removing the lifter pump and accessing the inside of the fuel tank. 

Once the lifter pump was out of the way, I spotted the rest of the rust from the fuel filler neck. To get the rust out and clean out the funky-looking petrol at the bottom of the tank, I used the pickup hose from a cheap sandblaster kit with my air compressor to suck the tiny bits of rust & fuel out and spit them into a bucket. The sandblaster kit was from Machine Mart for £21.95

I definitely would recommend this method over removing the tank, as I removed the tank from my Mk1 Tin Top and still was unable to remove all the tiny bits of rust and ended up sucking them out with a bit of tube I taped onto the end of my Henry Vac pipe. I had to replace the vacuum as the smell of petrol did not go away even after the bag was swapped out 😁

The brake servo and master cylinder on the Golf Mk1 are small. 

Like me, most people upgrade the servo to one for the Golf 1Mk2 16v for a better feel, but even this leaves you wanting better brakes, especially if you have gone 4 pots with the Golf Mk2 16v rear disc conversion.  Upgrading the master cylinder to a bigger one will sort out the pedal travel and firmness. 

The T4 22.2mm Brake Master Cylinder - Part No. 357 611 019B or the T4 - 25.4mm - Part No. 7D0611019A  is ideal for brake upgrade on MK1 & MK2 Golfs when using a 9" servo. This master cylinder will work with all MK2 Golf 16v, Corrado, Passat B3/4 MK3 Golf Servos. 

The 25.4mm is perfect for 4-pot callipers and will stop the car from feeling over-braked with too little pedal movement and locking up when provoked. I chose this option as I could easily lock up the 4-pot HiSpec brakes on the fronts with a panicked stomp on the brakes. 

As the servo is bigger and the master cylinder is longer, it takes up more room, but it still just fits. The brake fluid sensor cable could be just a few centimetres longer to make it a perfect fit. 

 The steering on the soft top was getting a bit too heavy to park quickly, and I was spending quite some time looking for parking spots I could get in and out of without having to use full lock. The Easysteer lads had been putting there electric steering kits in Mk2 Escorts and Fiestas for a while now. So I enquired if they could do a Mk1, and they had a kit. 

The Easysteer crew have put together a video on an installation in a Mk1 Golf cabriolet Easysteer Golf Mk1 Cabriolet It fits perfectly under the dash 👇

A standard variable controller is hard-wired with a discreet adjusting knob. It sends signals to the steering ECU (normally sent from the car's sensors). This adjusts the steering and gives the driver complete control of the level of assistance via the adjuster.

The default levels on the controller when it gets a signal from the engine are below. However, as the Golf has no electronic speed pulse you can tap into, the variable adjuster is used to set it to one of the switch points below.

I have set this to the high switch point, which is the low power assistance level, as not much assistance is needed to move the wheels while the car is stationary. In this setting, the steering wheel auto centres and the steering is just a little lighter than a standard Golf Mk1.

The kit is from a Corsa B steering column; the standard Golf column and the pedal box are modified, and the Corsa B motor and sensors are sandwiched in between. The electronics are fairly straightforward to install. There is plenty of space under the dash on the right side to fix the steering rack control box.

The most challenging part of the installation is removing the breakaway or shear bolts that hold the rack in place. I had to drill these out to get the rack off the car.

This modification is worth the installation hassle. It makes parking the car with the 16" Porsche wheels effortless. The wheel can be turned lock to lock when the vehicle is stationary with just a little effort, not quite one-finger effort, but definitely one hand at a time, rather than two hands when stationary.  

The 2.0L 16v engine had so much back-and-forth movement under hard acceleration that you could feel it in the steering. I tried a ploy replacement, but that rattled the dash so much that I took it back out without even driving the car.

The JMR Mk1 Golf 020 rear gearbox mount sorts the problem out instantly with no additional rattles. 

The benefits of the mount are:

It took the best part of 5 years to complete the mechanical rebuild of the soft top

Sometimes, life just gets in the way 😩

It was a right hard slog to get this from the garage where the work was being done. They had swapped over the engine, brakes, suspension and steering rack from my Golf Mk1 tin top, but the electrics and fueling modifications needed doing. It had been stood for 4 years, not being worked on, so the last bits ended up being done by me on Saturdays with some additional days off from work with Martin helping 😀  Finally got it home, but it was not wholly complete. But it was good enough to drive back home and park up for the final bits to be sorted out.

Using the standard Golf Mk1 GTi engine management was impossible with the planned engine upgrades.

The DTA kit at the time was the cheapest and most accessible option. Not many changes are required, with only the crank sensor and the water temperature sensor needing any fabrication. 

The 6a/9a engine block has two mounting points next to the crank where a bracket can be mounted to add the crank sensor. There are various examples of brackets on the internet for this setup. 

The one that was the best-looking is below. 

I used the crank sensor from Ford OE No. 6740816, which was used in the Escort Mk3/Mk4/Mk5 and the Mondeo Mk1. I used the mounting points on the back of the engine rather than the side to mount the bracket and kept it really simple, Just an L-shape with a hole on the short part of the L.

For ignition, I used a  VALEO 245041 Ignition Coil. You can find these on the Peugoet 106, 205, 206 & 405. For the air temp and water temp sensors, I used Bosch 0280 130 039 &  Bosch 0280 013 026. 

The throttle position sensor is 

• Logarithmic Throttle Potentiometer
• Type PF4B - anticlockwise. (Part Number WTP069).
• Shaft drive: Requires 4mm double ‘D’ drive.
• Resistance: 550 Ohm

These were used by various car manufacturers over the years, including the Ferrari F40 1992 (Part No 137206), and once were £50 each, but now, if you can find one, they are expensive (£400-ish). If I had to do it again, I would use a Bosh 0280122001. These came in the Peugeot 106, 306, 405, 605, 805 and  are around £25 or the Ford Sierra RS Cosworth 4x4 & Escort RS Cosworth  throttle position sensor, which used the PF09

The DTA E48 ECU has a digital rev counter output, which does not work with the MK1 Golf tacho as it expects a voltage pulse. I found that the Golf Mk1 & Mk2  1.8T conversion had the same problem as the 1.8T engine also has a digital rev counter output. The guys on the forum used the MSD Tach Adapter to get the old Golf Rev counter to work. In the diagram below, the TACH OUTPUT is the Tach output from your ECU. The Violet wire is the feed to your rev counter in the dash, this is the wire that usually comes from your coil. 

The MSD Tacho was louder than expected and made a ticking noise, which was too loud for inside the car, so I mounted mine in front of the ECU under the scuttle panel in the engine bay where the electronic ignition control module was located. 

The car was originally mapped by John Noble Motorsport when they were in Chesterfield, then again by Chip Wizard when he was in Minlrow Shaw. 

The original power output from this engine was:

• 134 hp @ 5800 rpm 
• 180 nm @ 4400 rpm

After the mapping, the output was: 

• 174 bhp @ 6760 rpm
• 193 nm @ 4729 rpm 

With the engine from the Golf Mk1 Tin Top came the Weber Alpha ITB's 

Thanks to their design and manufacturing, the Webers 45mm ITB provides better throttle response and power delivery over stock throttle bodies. They flow more air and allow for more precise control of the air/fuel mixture. The Alpha Webers specifically are higher-performance throttle bodies that are commonly swapped into tuner/performance cars instead of stock throttle bodies. They help increase horsepower and torque when adequately tuned and matched with other supporting mods. Their benefits include better acceleration, a more linear power band, increased peak power, and greater tuning flexibility compared to stock inlet setups.

The throttle position sensor is a  Magneti Marelli PF4B. These were used in the Ferrari F40 1992 and once were cheap but now cost lots second hand. I found a pair on eBay for 1K 

 I also found a new one in the States for $430 

The Ford Sierra RS Cosworth 4x4 & Escort RS Cosworth used the PF09 throttle position sensor, which looks the same, but two wires need swapping to get it to work with the DTA setup. These are much cheaper at about £60, so it would be wise to swap them out at some point. But if it ain't broke.

The donor MK1 tin top engine was finally installed in the soft top.Originally from an Audi 80, the 2.0L 6a block is identical to the 2.0L 9a block found in the VW Corrado or Passat, apart from the sump and the inlet manifold, as the Audi setup is inline.The head was ported and flowed by Richard at Redline Racing in Brighouse.

New valves, stems, and valves and new hydraulic cam buckets were fitted. Some Schrick split duration cams were fitted, including a Piper Vernier pulley on the timing belt side and individual Vernier pullies on the cam chain side. The original camshafts were 276 inlet and 288 exhaust, & while this produced good power, the torque was almost non-existent until after 3500 rpm, which was great for the track but bad for general road use. Milder cams were needed, so I ended up going for a 260/276 setup.

A new 3-layered metal head gasket was installed.

The cams were added, and Rich from Redline Racing timed everything up.

I installed a Mocal Thermostatic Sandwich plate with a Mocal 16-row x long 235mm oil cooler radiator and a low-temperature water thermostat to keep the engine cool. 

Drove the soft to work every day through the summer of 2007. It was a great summer, and the good weather stayed with us until October.

With the Soft Top finished, it was time to enjoy it as a daily, fairweather driver and hit as many of the shows as I could 😁

This was a small show in Leeds - Aug 2005

Edition 38 - Sept 2005

My Mk1 tin top is in the picture below, in front of the soft top.

Well Lane Turbo Centre - VW rolling road shootout - Oct 2005

VW Mania Belgium - Aug 2006

Elsecar Heritage Centre - April 2007 

A62 Just after Marsden  - Sept 2007

The BODI wind deflector, with its perfect fit, easy installation and high-quality workmanship, is the ideal addition to your convertible. It not only refines your vehicle visually but also offers the best wind protection for a more pleasant driving experience. 

It stops the wind from buffeting back around into the back of the seats and makes driving with the roof down possible when the weather is not perfect. The wind deflector keeps the sound in the cabin and wind noise out and helps keep the heat, which would usually be pushed out by the air buffeting back into the car, in the foot well.  It also makes driving at higher speeds, 70mph - 90mph, possible without needing earplugs and a conversation can be held while maintaining motorway speeds. The overall effect is that you can drive with the roof down on many more occasions. 

The original engine in the soft top was a right mess, it ran, but it was a bit ruff and had been neglected.

I took it out, stripped it down, and sent the head away to Rich at Redline Racing for porting and flowing. Rich fitted a 294-degree Kent GS25 Camshaft with a Kent Adjustable Cam Gear pulled and New valves & valve guides. The hydraulic camshaft buckets were replaced with shimmed ones so the engine could rev up to 8000 rpm. 

The engine was put back together, on the stand and looked at for a day or two before I slapped it back in 😍🥰🤩

I souced some Weber 40 Side Draft Carburettors, which I stripped down, refurbished, and painted black. 

All the old K-Tronic injection systems can be removed from the car when fitting Weber DCOE's. This cleans up the engine bay and makes for a cleaner, uncluttered look. 

I have always been a fan of polished wheels, and after a few trips to Belgium, I noticed that they had a fondness for polished Design 90 wheels, which, with an ET 52 offset, left enough room for 30mm spacers, leaving you a nice ET20 offset which fills the arches nicely. 

However, the wheel that caught my eye was the 928 flat wheels, staggered with a bigger dish on the back. I found some wheels down south, recently refurbished, which made an excellent base for hand polishing.

Took the wheel over to Wakefield for polishing at £70 a wheel, and I was happy with the results.

These wheels really suit the car and help give it a nice, aggressive stance.