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Monday 8:30am - 5pm Tuesday 8:30am - 5pm Wednesday 8:30am - 5pm Thursday 8:30am - 5pm Friday 8:30am - 5pm Saturday 9am - 12pm

FB Tuning

All things Subaru... We specialise in tuning and performance upgrades, ECU remapping, servicing and repairs. Find out more at www.fbtuning.co.uk

We're a specialist Subaru servicing centre located just outside High Wycombe, Buckinghamshire. FB Tuning offers Subaru servicing, tuning and performance upgrades. Services include:
• Servicing & Maintenance
• Tuning & Performance Upgrades
• Handling, Suspension and Braking Modifications
• Custom ECU Remapping
• ECU Diagnostics
• Geometry and Wheel Alignment

12/04/2026

2004 STi in the workshop recently for a replacement engine and associated upgrades after rod bearing failure. The failure occurred at speed on the motorway and subsequently snapped a rod, which resulted in a catastrophic ending, with the engine seizing solid and destroying itself..! 😳

A new factory 2.0 forged piston SCDB short block was sourced, along with a replacement set of 2.0 AVCS heads which were fully rebuilt and reshimmed, prior to assembly with ARP 11mm studs and RCM Headgaskets, new AVCS inlet pulleys, RCM vernier exhaust pulleys, modine heat exchanger, 11mm oil pump, GpN pickup pipe, and rebuilt vf35 turbocharger mated to a set of tubular headers with Venturi uppipe.

New components, gaskets and seals were used throughout to ensure this upgraded OEM+ motor will stand the test of time..

Once fully run in, the car will be back to us for final ECU calibration, and should go on to give another 100k+ miles of reliable service.

If you’re looking to refresh, rebuild or upgrade your existing Impreza engine, feel free to get in touch with us..

29/03/2026

2005 UK STi with OE 2.0 engine, GTX29 Gen2, Process West TMIC and supporting mods, that I road tuned last year went to the dyno at SurreyRR last week for a power test

20% methanol map, standard ecu tuned using Carberry SD ROM

06/01/2026

A nice car to start 2026..!

Impreza RA-R in for a Cambelt and waterpump change, service and checkover.. 😎

I feel proud and accomplished to be into the 15th year of FB Tuning with over 25 years of Subaru specific experience. I am eternally thankful for all the support from past and present customers over the years, without whom I would certainly not have made it this far..

11/11/2025

Hawkeye SpecC track car in for mapping today. Fitted with a newly built 2.1 with uprated cams, MDX turbo, PW TMIC, and all the right supporting mods.

It’s always a privilege to be asked to tune a freshly completed build.. 😎

05/06/2025

Freshly imported, standard low mileage Hawkeye JDM STi in the workshop for mapping to suit UK 99RON fuel.

Always a pleasure to tune JDM cars.. 😎

18/12/2024

T25 build progress update..

I’ve just collected the D25 cylinder heads from the machine shop where they’ve been acid washed, fire faces skimmed, guides fitted with K-Line repair inserts, seats cut and valves refaced and lapped into the seats - ready to start on the assembly work.

First job was to wash the castings and blow out any remaining swarf from the skim process - The machine shop do clean and hot wash once they’ve finished but there’s always some hiding in the water jacket..! Then tapped and plugged the secondary air ports as they won’t be required and removed all the gallery plugs to flush out the oil feed channels that feed the cam bearing journals and lubricate the buckets.
Once cleaned up I then dummy built the valvetrain with valve>bucket>cam to get a ball park valve clearance measurement, as cutting the seats always brings the valves closer to the camshaft and closes the clearance up. Valves were then removed and ground + chamfered the tips to suit. Final shimming and precise adjustment can then be completed once the heads are bolted down onto the block, as the cam follower buckets are individually sized.

Stem seals installed and then the heads could be built up with valves, springs, retainers and collets.

Using the Cams and springs from the original 2.0 JDM heads in combination with 2.5 D25 castings to make a ‘hybrid’ head will be a much improved solution for this engine over the originally modified 2.0 castings. The combustion chambers are much better suited to the 99.5mm cylinder bore of the 2.5. The 2.0 JDM cams have a much better profile than their EDM equivalent, and the 2pin AVCS cam sensors need to be retained to run on standard 16-Bit ECU management.

I previously fitted a set of drop-in Omega RCM forged pistons to a brand new EJ25 SCDB short motor so i fitted an ARP 11mm headstud kit to the block, installed the heads with a pair of Cosworth MLS Headgaskets, ARP lubed all the fasteners in the right places and torqued the heads down to spec.

A lot of time and effort goes into engine assembly work. It needs attention to detail and everything has to be meticulously clean and done just right, especially so when dealing with a 2.5 motor..!

01/12/2024

T25 Update..

I’ve made a bit more progress on the T25 over the last few days.

Engine removed from the car and stripped, with the aim of refreshing and reusing the cylinder heads and reusing as many of the existing anciliary parts as possible. Even though the engine was running with evidence of headgasket failure, unfortunately it’s plagued with issues some of which are just down to poor workmanship from the previous build..

The bottom end has suffered a partial seizure most likely to a cooling system overheat, and the camshafts have picked up on their bearing surfaces in the cylinder heads, which unfortunately renders that engine as not an economically viable option to rebuild.

I have sourced a pair of D25 heads which have a combustion chamber profile that is more suited to a 2.5 than the original 2.0 and the plan is to swap all the valvetrain and cams over and carry out a few small modifications that allow the later design head to work in what was originally an early 2.0 AVCS car

New heads are at the machine shop for overhaul - K-Line the guides, cut valve seats and skim the fire faces.

Whist waiting for the heads to be done I’ve installed a set of Omega forged pistons to a new EJ25 short motor, polished all the camshaft bearing journals in the lathe, and stripped, modified and rebuilt the oil pump.

Happy with the progress so far, and I’m hoping to get some more done over the next couple of weeks between jobs that are booked into the workshop

19/11/2024

2001 STi into the workshop today for centre differential replacement.

With 150k on the clock the car had started to suffer from excessive drag and diff wind up + clonking noises from the gearbox, which had become most apparent when making slow manoeuvres on full steering lock.

The diff unit was changed with the gearbox in situ, and at the same time I also replaced the transfer case main carrier bearing and propshaft output seal.

18/11/2024

The Litchfield T25 was a limited edition car produced in low numbers from 2003. It used the JDM STi (and optionally the Spec-C) Impreza as a base, imported to the UK new and converted with a forged EJ257 short motor, hybrid turbo charger, Milltek 2.75” exhaust system with Sports Catalytic Converter, Upgraded Fuel Pump, revised ECU mapping, gearbox modification and Whiteline handling upgrades. Various other optional upgrades were also available from new, including aftermarket wheels and upgraded brakes

The MK1 blobeye was available as a 5x100 and then 5x114 model. Subsequent Hawkeye model was offered as a T20 using the stock JDM STi engine, and as a T25 running a fully built Cosworth motor.

I have recently acquired a MK1 T25 #007 which is in need of some love and recommissioning work. The body is solid with no rust and overall the car is in great shape , having obviously been well loved and garaged for most of its life. I’ve already had some paintless dent removal work carried out to tidy up the usual carpark dents in the doors, and the Speedline 18”wheels have been refurbished.

Almost all of these cars have suffered from the usual 2.5 engine related issues over the years, and this one is no exception. It’s been rebuilt more than once by previous owners and currently isn’t in the best of health. Over the coming winter months it will receive some TLC and be treated to a new forged short motor, cylinder heads will be overhauled and whatever else it needs to put it back to as good as, or better than new condition..

Watch this space for more updates as I make some progress with it..

03/01/2024

2005 WRX in the workshop today for a replacement Cambelt and water pump, RCM Aluminium pulley set, new belt covers and associated hardware..

All the bolts holding the Cambelt covers had previously been overtightened, and in the 7 years since the job was last done a bit of corrosion had set in, which caused all the captive nuts in the rear covers to spin and prevent the bolts from coming out.. That turned a simple Cambelt job into quite a bit more work..

21/11/2023

Hawkeye Spec-C Type RA in the workshop today for surgery..

Engine out to complete a few repairs and replace the clutch, flywheel and turbocharger that couldn’t be removed in situ..

Address

Unit 7, Woodway
Princes Risborough
HP270NN

Opening Hours

Monday	8:30am - 5pm
Tuesday	8:30am - 5pm
Wednesday	8:30am - 5pm
Thursday	8:30am - 5pm
Friday	8:30am - 5pm
Saturday	9am - 12pm

Telephone

+447595493581

Website

http://www.fbtuning.co.uk/

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