A genuine world first · Closed-loop boost control
The custom coded boost model.
A world-first, fully custom closed-loop boost controller for the Hyundai i20 N. Most tunes just turn the factory boost tables up. We went further — we rebuilt how the car controls boost from the ground up and injected our own code straight into the factory ECU.
Why this has to exist
You can't fix it from the tables
"The ECU already has boost tables — why not just turn them up?" It's the trap that's caught tuners on this platform for years. Those tables sit underneath a turbo/air-mass model that estimates total airflow and, as revs rise, bleeds the wastegate open to hold airflow under a built-in limit — so it claws boost back and tapers you off up top, no matter what the maps say.
You can't fix that from the tables; you have to change the ECU's code. Our first release forced past that limiter and proved the ceiling could be beaten. But forcing the factory's open-loop path is crude — no live feedback, so boost drifts with conditions, it's the same in every mode, and safety means leaving margin behind.
So we built the proper answer: a true closed-loop controller — one that reads real boost and holds your target, in every mode, with safety built in rather than bolted on.
Flat · linear · relentless
A curve for every drive mode
The factory modes you already use now do something it never did before. Eco, Normal, Sport and N each run their own tailored boost target — from a relaxed daily cruise to a full-power pull. The stock logic tapers boost away as the revs climb; ours holds your target flat and lets the turbo deliver everything it's got. Tap a mode to compare the boost we command against stock.
Inside the model
The maps that run it
These are the real calibration tables from inside the model — not marketing fluff. Every one is fully tuneable to your car.
Boost target
The heart of the model: exactly how much boost the car aims for at every throttle position and engine speed. Notice how the target builds early and holds flat across the rev range instead of tapering — that's the flat, linear delivery you feel on the road.
Wastegate feed-forward
A smart head start for the wastegate — how far open it sits before the closed-loop controller takes over. Get this close to right and boost lands on target instantly, with the PID only doing the fine trimming. Higher numbers = more open (less boost); lower = clamped down for full boost.
Correction effort vs how far off target
Closed-loop PID
The controller reads actual boost every cycle and corrects the wastegate to hold target. The further boost drifts from where you asked for it, the harder it pushes back — and right on target it does nothing at all, so boost never hunts or overshoots. Accurate, consistent, repeatable — pull after pull, hot or cold.
Proven on the dyno
Power, torque & boost by mode
Back-to-back pulls on a modified customer i20 N — still running its factory secondary cat — with only the drive mode changed between runs.
One tune, different personalities
Dyno Dynamics Shootout · drivetrain factor 1.19 · correction factor 0.96 · boost logged via OBD.
Test car was modified but still had the stock turbo, with a larger turbo expect much bigger gains.
What this really means
These are the real gains
Same car, same dyno, patched vs unpatched, back to back. Through the mid-range the two are effectively matched — peak boost and torque land in the same place. The difference that matters is up top: from 4,500 rpm you will generally start to hit the air mass limit, and the factory logic drops boost, while the Cherry model holds it flat to redline. That shaded zone is where the extra power and torque actually live.
Factory boost logic
Cherry Custom Boost Model
Peak gain, at 6,250 rpm
Representative comparison drawn from the back-to-back dyno runs. Larger Turbos will only amplify these gains.
Engineered end to end
What's built in
Reads real boost pressure every cycle and trims the wastegate to hold your exact target.
A smart starting wastegate position for every condition, so boost lands on target instantly.
Holds the wastegate shut below target so the turbo spools as fast as it physically can.
Caps how fast and far the wastegate can move, keeping every correction clean and mechanical-friendly.
Eco, Normal, Sport and N each run their own boost curve — straight off the factory dial.
Each mode's character is dialled in independently, from spool all the way to redline.
Change the whole boost personality on the move, no reflash, no compromise.
Backs off instantly if boost climbs past a safe margin above target.
An absolute limit the engine will never be allowed to exceed.
If the boost sensor reads out of range, the system defaults to safe — never to a runaway.
Wastegate commands always stay within your specific turbo's safe range.
Written into the factory ROM and switchable on demand — no piggyback boxes.
Runs factory boost control until a throttle and rpm point you choose, then takes over.
Bypasses the stock air-mass ceiling entirely, with no sensor trickery or bending.
Pricing & availability
Dyno-only. Written into your ECU.
The custom code has to be written into the ECU with specialist tools and validated on the dyno — so it can't be done remotely.
with the Cherry Custom Boost Model
$500 above a standard dyno tune, for the extra dyno time this closed-loop model takes to set up and validate.
add it with a retune
Bolt the Cherry Custom Boost Model onto your existing Cherry tune in a single retune session.
We're licensing the Cherry Custom Boost Model to other performance workshops with a dyno. Offer genuine closed-loop, per-mode boost control to your own i20 N customers — get in touch for trade pricing and integration.
Built in-house · A genuine world first
The only limit left is your turbo
Cars with larger turbos see the biggest gains, but even the stock turbo can be improved.
Improve your i20N or i30 Sedan N-Line by being one of the first in the world to get access to this model.