Possibly our favourite creation yet. This is something very special, and very unique. Taking Subaru's now discontinued Impreza Boxer Diesel, and ramping it up to STI spec.Here we have All Wheel Drive, over 200bhp, and nearly 400lbs ft of Torque. A unique STI wide-body modification, not available on the Impreza Diesel platform as standard. This car is quite simply the best fast diesel hatchback in the world - the only fast diesel hatchback that doesn't spin its front wheels like crazy as soon as you go past 180bhp...List of Modifications to standard Subaru Impreza 2.0 Diesel200Bhp Remap Originally remapped by Litchfield Imports to 180bhp, and then increased up to 200bhp locally which required additional modifications such as the clutch, intercooler spray, BP ultimate diesel and 3" exhaust. 200bhp really strains the DPF, which regenerates every few days. The aim is 225bhp with a motorsports spec DPF and uprated internalsAt 200bhp, when the DPF allows, which isn't very often, the car is blindingly fast off the line, and I had an Evo IX FQ-340. That says the potential of this engine and drivetrain.I hope to have a dyno done at some point, but I can't until I sort out the DPF.Revolution STI 3" Stainless Steel DPF-Back Exhaust This exhaust system is intended for the 2008 STI. It fits perfectly, but on a WRX you would need to cut the rear bumper for the additional tailpipe. The exhaust is quiet, but very burbly when the DPF regenerates. Over the 180bhp remap, the 3" exhaust has really helped make a noticeable difference.08 STI Brembo Brake System with Godspeed Brakes Two-Piece Front Discs & EBC Redstuff Brake PadsA very expensive modification, but well worth it. The brakes on the car now stop the car easily from high speed in pouring rain in no time, whereas previously the car would have probably suprised me with taking a tad longer to stop than I would have judged.KW Variant 3 CoiloversReplacing the BC Racing coilovers are what most tuners agree are the best street performance coilovers you can get. Made of Stainless Steel to prevent corrosion, and using external oil reservoirs and pre-load springs. Bump, Rebound and Ride Height are adjustable. The difference between these and the BC Racing coilovers are very noticeable. The KW's are just much better quality with a lot less problems. We used GT Worx camber plates on the front and standard top mounts at the back, albeit with the rubber replaced with polyurethane.GTWorx Front Camber PlatesImported from the USA, these are pretty much the best camber plates you can get. The KW Racing coilovers dont come with top hats / camber plates, so this was a natural choice to pair with them.Sachs Uprated Clutch Pressure Plate and Clutch DiscOne of the reasons the Boxer Diesel shouldn't be remapped above 180bhp is the stock clutch will die that day. Hence installing this uprated version. It will be interesting to see if it can take any more power.Custom Reinforced Clutch ForkWRX forks tend to break, so we have added steel in the places where it was breaking.Cusco Master Cylinder BraceTo prevent firewall flex which makes the brake pedal sloppy.Uprated Transmission (Coated Synchros and Billet Selector Forks)Any more power in the boxer diesel will eventually hurt the transmission. We have had a tungsten carbide coating put on 3/4/5 and 6 gear synchros, which improve shift times massively, and also new billet selector forks on 1/2 and 3/4 as our 3/4 stock one snapped. The transmission suffers from the usual WRX flex, so new bearings were needed at 40,000 miles, but there is no cure for that.OZ Ultraleggera 18x9" Alloy WheelsAt only 8.7Kg for an 18x9" wheel, OZ Ultraleggera are one of the lightest wheels on the market. Offset is ET55, and these are fitted with a 19mm hub-centric spacer/PCD converter to alloy fitment of 5x114.3 wheels to 5x100 hubs.Lightweight Single Mass FlywheelCustom made by Clutch-Specialists.co.uk this flywheel replaces the Dual Mass Flywheel which is prone to failure and costs over 900 quid to replace from Subaru, not including labour. A bit of extra vibration at low RPM is worth it for much better throttle pickup. Probably the single best modification for increased acceleration, but beware, it does give a definite race feel.Pedalbox Throttle Pedal Sensitivity Adjuster.This is a funky device that connects between the accelerator pedal sensor and the ECU. Very easy to install, takes 20 seconds. The Boxer Diesel has a very sluggish accelerator pedal, and this box firms it up nicely. Meaning you can press the pedal only 1/4 and the car gets going, whereas previously it wouldn't get going at any rate of knots until about 1/2 pressed. This goes someway to mimicking the STI's SI-Drive, but without the additional change in engine mapping.Custom Intercooler Spray SystemI rigged this up myself. I used a T connector to divert off the rear window washer, and ran this tube up to the bonnet scoop, and used B&Q plant misters to spray the intercooler. I put a switch on the rear wiper, accessible through the rear trunking on the bootlid, so that could be turned off most of the time, and some on/off valves on the tubes to the intercooler spray and the rear window washer. This means that you can twist the rear window washer switch and the intercooler is sprayed until you let go, yet the rear washer doesnt come on, nor does the rear wiper. It's important that a mixture of 80:10:10 Distilled Water:Methanol:Isopropyl Alcohol be used. We tested variations of the mix and that produced the most power.The intercooler spray produces masses of additional power when you spray before a standing start. We have checked time and time again, and without the intercooler sprayed before take off, the car is much slower. Cusco Front Strut BarThis was something I found on ebay. I notice a small increase in turn in stability.Perrin 22mm Front Anti-Roll Bar with Polyurethane Bushings & Rallitek EndlinksThis bar, intended for 08 WRX needed a slight modification to fit, but it worked wonders for the handling of the car.Update 17/10/12: Removed due to STI aluminium wishbones conversion, which requires STI version of the anti-roll bar.STI Spec C 19mm Rear Anti-Roll Bar with Polyurethane Bushings & Rallitek EndlinksThe STI spec C bar fits with no issues, and really helps control body roll and improves handling vastlyAluminium/Polyurethane Engine Pitch StopperA problem I was having even after the 180bhp initial remap, was that on take-off from a standstill, the whole front of the car would bog terribly. We figured this was down to the movement of the engine. Installing this item helped massively, and I dont find the car bogs down anymore.Group N Transmission Mount & Whiteline Crossmember Bushings These are intended for the 08 WRX 5-Speed. The STI 6-Speed Mount wont fit. The WRX 5-speed Mount however fits perfectly and when combined with the crossmember bushings, completely firm up the shifting and allow the car to accelerate hard, whilst changing gears with a lot less lash.Beware these items dramatically increase the NVH in the car. For us the increase in engine noise was welcome - it make the car sound much more powerful. The Vibration is not an issue as it fades away after a week or so, but we did find we had to add anti-vibration mounts to the center exhaust heatshield to remove a loud vibration that the heatshield developed, as it is connected directly to the crossmember.PST Carbon Fibre Propeller ShaftMade for the 08-2011 WRX, but fits the Diesel fine. This item significantly gives back wheel horsepower lost due to the AWD setup. Increased throttle pickup, and one of the best modifications that can be done to the diesel to increase its acceleration. This item is expensive, but worth it.Powerflex Positive Power Bushings (Rear Subframe)These inserts fit into the rear subframe bushings, and stiffen up the rear subframe. Without these, the car will clunk badly when accelerating hard due to the gaps in the rear subframe bushings. This removes that play and transfers the clunk into additional power.Whiteline Rear Sway Bar BracesThese braces give support to the rear anti-roll bar (sway bar) supports, removing the flex inherent with the stock perches.DAMD Flat Bottom Steering WheelThis is a smaller diameter black leather red-stich flat bottom steering wheel that re-uses the standard air bag and controls. Why bother? The smaller diameter will increase steering weight, which will remove the light feel of the Impreza's steering, and the flat bottom will stop my jeans ripping the bottom of the wheel when I get in and out of the car. The Steering wheel looks and feels fantastic. Subaru Legacy STI Short Throw Shifter (Cable-Type)Sold as an upgrade for the US-spec Subaru Legacy for years 2010-2011 only, this is a short throw version of Subaru's 6-Speed Cable-Type Shifter, that fits the Boxer Diesel Impreza, and I assume the Forester, perfectly. The standard shifter is very poor in the Impreza, and this unit is night and day, with a much more precise feel and a vastly improved throw distance. Installation was incredibly easy, and we were done in a couple of leisurely hours.The part number is C1010AJ100, and is only listed for 2010-2011 US Legacy 6 Speed Petrol MT. It does however we have proven, fit the 2008-2011 Impreza and Forester Boxer Diesel. More information below.2011 STI Aluminium Front WishbonesFor 2011 Subaru replaced the rear bushing on their aluminium wishbones with a pillow-ball type connection. This offers much better steering control and cuts down on steering wandering on bumpy roads during acceleration and brakeing.Powerflex Polyurethane Front Bushing for WishbonesA replacement of the stock rubber bushing with polyurethane version. The rear bushings on the 2011 STI wishbones does not need to be upgraded as it is a pillow-ball joint, and no longer a rubber bushing.Whiteline Bump Steer and Roll Center KitWithout this, the car wanders quite badly on uneven road surface because it has been lowered, meaning that without this kit, the suspension geometry is wrong.Whiteline 22mm 08 STI Front Anti-Roll BarThe conversion to STI wishbones requires the use of the STI Front Anti Roll Bar, so we removed the WRX one and sold it. The endlinks however fit both WRX and STI. We went with Whiteline this time because it was about 100 quid cheaper than the Perrin, but no obvious loss in quality.Pirelli P Zero 255/40/18 for SummerProbably the most important modification for performance. These tyres are phenomenal and there was an immediate effect after installing them. Expensive but well worth it. They are very expensive due to the width.Pirelli SottoZero 225/40/18 for WinterJust to be on the safe side, I switch to winter tyres from October to April. These are Pirelli's winter tyres, and whilst not as brilliant in the snow compared to others, they hold their own in the snow whilst, most importantly for fast car owners, being the best at cold weather spirited handling. Whiteline Steering Rack Bushings, modified to fit.Intended for WRX 08 , we actually found that the Boxer Diesel electric steering rack is mounted with bushings that dont even fit the bolts. There is a good 5mm of open space around the bolts. We used the bushings which fit in the same places they would on the WRX, but we found that we needed to cut and insert an extra layer of polyurethane around the bolts to make it fit snugly. They made a massive difference in the cars steering. Before the steering was quite sloppy, now it is nice and tight.Goodridge Stainless Steel ClutchlineI'll be honest, I cant tell the difference but the stainless steel braided WRX or STI clutch line fits perfectly, so why not!Stainless Steel Braided Brake LinesThe stainless steel brake lines make more difference to the brake feel that the Brembos did. We know this because we installed the Brembos first and couldn't undo the nuts on the brake lines so we had to have a dealer install them a week later. The Brembos stopped quick, but they didnt feel any better through the pedal, no firmer. The stainless steel lines made the brake pedal very firm and responsive.Custom STI inspired leather interior with sports seatsThe Boxer Diesel comes with the same seats as the JDM STI and the UK WRX, so we had them converted to leather, and added red stitching and the STI logo. Full 2011 WRX STI widebody conversion by Smart Techniques Ltd using OEM parts and custom quarter panel modificationMajor body work, but it worked suprisingly well. We used oem STI parts at the front, and fiberglass conversion kit at the back. The quarter panels require blending into the car, which I thought would be a nightmare, but the local body shop did that and painted everything for �1600. The STI wing mirrors fit perfectly, and the boxer diesel even includes the wiring in the plugs to make the indicators on the mirrors work!Special ThanksThe following people have all helped contribute to the building of this car:Wayne from Walldonway.co.uk Very helpful supplying subaru genuine parts and information. He has done all this by me emailing him, and then he posts the items to me. Which is fantastic and a great help not having to visit Subaru dealers constantly for parts pickups! Also quick with requests, nothing seems to big a deal for him to sort out!Wesley from Smart TechniquesWho did all the bodywork and painting for usThe JackalAn expert engineer from TRB Ltd who has fitted every single item here under my guidance and solved many many problems outside the box. This car is an ode to him!