JBM Performance

21/10/2026

387bhp and 557Nm from this Mk5 Golf GTI DSG 🌶️

Running an Audi S3 BHZ engine with a Stage 2+ K04 conversion, anti-surge core, upgraded actuator, VIS HPFP, Direnza intercooler and Trackslag turbo-back exhaust.

There’s custom code in both the engine ECU and DSG on this one.

The custom code keeps boost under closed-loop control at higher boost levels, allowing the ECU to keep correcting actual boost against the target. Want to change the tired looking air filter later on? Worried about different boost levels between summer and winter? No problem! The ecu will take care of it. There’s also boost by gear and switchable overrun pops and bangs in sport/manual mode.

The DSG had started showing signs of slipping when we began to increase the boost, so the clutch pressure strategy needed attention too. We changed the program logic to make the extra clamping available in every gear, with up to 16bar when the torque demands it.

All developed and tested on our dyno in Sheffield.

Follow for more.

11/10/2026

2020+ BMW ECU unlocking and tuning 🔓

This 2022 BMW 330e was with us for an unlock only, allowing the owner to flash their own OTS tune using MG Flasher.

We offer unlock-only and tuning services for supported MG1/MD1 ECUs at our Sheffield workshop.

Message us with your reg and tuning plans to check the options for your car.

JBM Performance

07/10/2026

Stop-start faults and a squeal on this 2020 Audi Q7.

Its 48V mild-hybrid system uses a belt-driven starter-generator to recover energy into the battery and restart the engine during stop-start operation.

This one came in with a dashboard warning and a squeal when the starter-generator tried to operate. The engine then cut out and couldn’t be restarted by it.

Pressing the start button would still start the engine using the separate conventional starter motor. So being able to start it manually didn’t mean the starter-generator was working.

We replaced the 48V starter-generator, drive belt and tensioner. Swipe to see the removed parts and the replacements fitted.

Got similar symptoms on your Audi? Message us with your reg and what it’s doing.

JBM Performance

04/10/2026

Stock or mapped? 👀

The owner of this Mk7.5 Golf R thought it felt quick and wanted to find out whether it had already been tuned.

A couple of runs on the dyno later, this one turned out to be stock. Best run was 312bhp and 381Nm.

Would you leave it stock or go Stage 1?

We also offer custom engine and DSG tuning for MQB cars at our Sheffield workshop. Message us with your reg and current spec to discuss the options.

29/09/2026

330bhp and 468Nm from this 2012 VW Scirocco R - but the dyno graph only tells part of the story.

Before tuning, we carried out the mechanical work it needed:

• ACL big-end bearings and centre main-cap thrust washer upgrade
• Balance-shaft delete
• Walnut blasting
• Injectors cleaned and rebuilt with uprated filter baskets
• Cambelt, water pump, plugs and cam follower

Once the engine was ready, it went on the dyno for a custom Stage 1 calibration.

The intake already fitted hadn’t been properly accounted for, so we corrected the MAF scaling and torque model first. Boost control was then reworked to remove the oscillation, followed by the cam timing strategy, worth around 25bhp on its own without affecting drivability.

282bhp / 384Nm ➡️ 330bhp / 468Nm

The baseline was recorded after the mechanical work, so the difference from how the car drove when it arrived was greater than the graph suggests.

Got an EA113-powered Scirocco R, Golf R or Edition 30? Send us your reg and current spec and we’ll tell you what we’d recommend.

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📧 [email protected]
🖥 jbmperformance.co.uk
📍 Sheffield
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27/09/2026

VW Caddy 2.0 TFSI K04: 357 hp / 484 Nm

The owner bought this Caddy already converted to 2.0 TFSI, then carried out the K04 conversion himself. It came to us for repairs and Stage 2+ tuning.

Before tuning, we found fuel leaking past the high-pressure fuel pump shaft seal into the engine oil. As the oil warmed up, the fuel evaporated and the vapours were drawn into the intake through the PCV system. The result was an excessively rich idle and fouled spark plugs.

We fitted a new genuine HPFP, refitted the VIS Motorsport internals, changed the oil and filter, and confirmed the fault was fixed before tuning. We also corrected the valve timing and replaced the rocker cover.

On the dyno, it went from 258 hp / 318 Nm before calibration to 357 hp / 484 Nm after. Swipe to see the graph.

JBM Performance

23/09/2026

16/09/2026

How much power can you safely make from a Littco L450 on 95 RON E10?

This Octavia vRS came to us for a proper Stage 3 calibration after having the supporting hardware fitted:

• Littco L450 hybrid turbo
• Wagner Gen 3 intercooler
• Autotech HPFP
• RacingLine R600 intake
• Scorpion 3" downpipe
• Sachs organic clutch and flywheel
• NGK competition plugs

The target from the customer was 400 to 450bhp.

The important bit though was the fuel.

The car was running 95 RON E10, so this wasn't a case of winding everything up until we found the biggest number the L450 could produce.

What the turbo is capable of and what we're comfortable asking the engine to do on lower octane fuel are two very different things.

After developing the calibration on our dyno we finished at:

401bhp / 527Nm

Strong power throughout the rev range, good torque delivery and, most importantly, a calibration we're happy with rather than a number produced purely for the dyno sheet.

The calibration also includes map switching, boost by gear and advanced traction control. As it's a manual car with an uprated clutch, the clutch-to-start requirement has been bypassed so it can be started using the brake pedal instead.

There is more available from this setup on better fuel. The car will be coming back on 99 RON, plus a full 3" cat-back to replace the stock exhaust, which should give us considerably more room to work with.

So what would you do? Leave it at 401bhp on 95 RON, or put 99 in it and see what the L450 can really do?

Follow for the 99 RON follow-up.

13/09/2026

Not every bolt-on combination works perfectly out of the box.

This 2025 Mercedes-AMG A45 S came in for KW V3 coilovers, supplied and fitted by us, along with:

• Camber and caster-adjustable top mounts
• Carbon-ceramic brake discs and pads
• Brake-cooling ducts

During our final checks, we found that the backplates supplied with the aftermarket brake-cooling ducts sat too close to the new carbon-ceramic discs.

With components of this value, even slight contact is not worth the risk. The aftermarket duct setup will therefore be removed and the OEM ducting reinstated before the car leaves us.

Swipe through for a closer look at the suspension and braking setup.

KW V3s or carbon ceramics, which upgrade would you choose first?

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JBM Performance

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📞 0114 276 8193
📧[email protected]
🖥www.jbmperformance.co.uk
📍Unit 4, Fieldhouse Way, Sheffield, S4 7SF
⏰Mon-Fri 8AM-5PM
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08/09/2026

Power is the last part of the job.

This 8P RS3 has been through quite a bit of work with us over the last year, with the aim of getting everything right mechanically before we started asking more from it.

This time it was finally onto the dyno.

Baseline: 348bhp / 473Nm
Finished: 395bhp / 588Nm

A gain of 47bhp and 115Nm, but the peak figures don't really show the biggest improvement. The torque curve is a completely different shape, with a lot more available below 3000rpm and through the midrange.

The MED9.1.2 ECU was RSA patched and then calibrated in house on our dyno specifically for the car. The DSG was tuned alongside it, with revised shift behaviour and shift points, changes to the launch strategy and additional clutch clamping pressure where the extra torque requires it.

Hardware wise it's running a Wagner Evo 2 intercooler, 034 intake and Milltek cat back.

There's actually more left in it, but intake temperature was becoming the limiting factor. The radiator and A/C condenser are blocked enough to restrict airflow through the cooling package, so the intercooler isn't getting the airflow it needs during repeated dyno runs.

Rather than chase a bigger number while temperatures continue to rise, that's where we left it.

It's also worth putting that 348bhp baseline into context.

Before reaching this point we've carried out walnut blasting, ultrasonic injector cleaning and testing, plugs, coils, servicing and transfer case repairs on the car.

It's also had a complete upper and lower timing chain set, oil cooler and oil filter housing work, along with repairs to the Haldex system.

On this visit we fitted a new auxiliary radiator, replaced the electric water pump bracket and repaired the changeover valve connector before carrying out the ECU and DSG tuning.

So while the dyno graph shows another 47bhp, the difference compared with how the car originally came to us is considerably bigger than that.

Get the car healthy first, then tune it properly.

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📞 0114 276 8193
📧[email protected]
🖥www.jbmperformance.co.uk
📍Unit 4, Fieldhouse