The short version
- A stage 1 tune is all software and comfortably takes an S55 past 500hp.
- More torque means more strain on the crank hub, which can slip with no warning.
- We'd encourage doing the hub first, so the extra torque comes without the risk.
- We'll tune without it if you'd rather, but we'll always explain the risks first.
The S55 responds brilliantly to tuning. A good map transforms the way an F80 M3, F8x M4 or M2 Competition pulls. But there's one job we'd always want to talk about before anyone touches the software: the crank hub.
Why a tune and the crank hub are linked
The S55's crank hub drives the timing chain, and it isn't positively locked to the crankshaft. It relies mainly on the clamping force of its bolt. A tune raises torque, and sharper torque spikes (launches, hard gear changes, wheel hop) are exactly what can make the hub turn on the crank. If it does, the cam timing goes out, and in the worst case the valves meet the pistons. There's no warning before it happens.
So the more power you add, the more sense the crank hub upgrade makes. We explain the part itself in detail in S55 crank hub: what it is and why it slips.
The order we'd encourage
- Health check first. A tune won't fix an engine that's already unhappy. We look at the car's condition, fault history and service history before anything else.
- Crank hub upgrade. We fit the Insane Performance 4-pin, one-piece hub. It takes two working days.
- Then the tune. With the hub sorted, the extra torque comes without the risk.
What a stage 1 tune involves
A stage 1 tune on the S55 is all software, with no hardware changes, and it will comfortably take the car to 500hp and beyond.
We carry out DME unlocks in house, with bespoke ECU calibration as well as bootmod3 (BM3) and xHP. We're also an authorised Celtic Tuning dealer for remaps. Every car is different, and every owner wants something slightly different from it, so tuning is priced on application.
"Will you tune it without the hub done?"
Yes, absolutely. It's your car and your call. But as the people supplying the tune, it's our job to make sure you understand any potential issue before we sell you something that could have expensive consequences. So we'll always talk you through the crank hub risk first. If you're happy with it, we're happy to help.
Prices
The S55 crank hub upgrade is from £2,049 including VAT. Tuning is priced on application, as it depends on the car and what you want from it. We'll always confirm the price for your car before any work starts.
