KTM Performance guide
KTM 350/500
Performance Guide
2017+ · Intake, Exhaust & ECU · Real Dyno Numbers, Not Forum Numbers
What uncorking actually does: real Dynojet 168 numbers, at the wheel
2025 KTM 350 EXC-F
+11.2 hp · +31%
2025 KTM 500 EXC-F
+21.5 hp · +56%
Tested on our Dynojet 168 at 2,300 ft. Intake opened, exhaust opened, fuel corrected. The full ladder, not any single mod.
Why these bikes feel down on power
Here's the thing nobody at the dealer tells you: your bike isn't underpowered. It's restrained. KTM builds a genuinely strong engine, then straps it down with the equipment it takes to pass noise and emissions testing in every market it sells in. That's the price of a green sticker and a plate.
Every one of those restraints is a knob turned the wrong way for power. Pull them off in the right order and you're not adding anything exotic. You're just giving the motor back the air, fuel, and breathing room the engineers designed in and the regulators made them hide.
This is a race build. That's not a warning, it's the whole mechanism.
Every mod on this page works by removing the exact equipment that keeps your bike street legal: the sound restriction in the exhaust and the emissions gear on the engine. That's not a side effect. It's why the power comes back. Which means everything here is sold and described for closed-course competition use only.
We'll be straight with you the way we'd want it. Once that equipment comes off, the bike is no longer legal on public roads, it will not pass an emissions or smog inspection, and it is not CARB or EPA compliant. What you do with your own bike is your call and your responsibility, not ours.
The uncork ladder
Three steps to wake the bike up. They build on each other, so climb them in order. Every one matters. The deep detail on each lives in the sections just below.
The 3-step build
KTM · Husqvarna · GASGASCorrect the fuel
The only step that makes power. More air with no fuel runs lean and cooks pistons. The tune fixes that, built to match your hardware.
Open the exhaust
The stock pipe is choked on purpose. This is the biggest airflow gain on the bike. End cap, slip-on, or full system.
Pull the reeds
Free power, and you delete a part that snaps and eats valves. Little more mid and top, a little intake growl.
Optional: smog delete
Off the power path, makes zero power. Deletes weight and failure points. Do it whenever, or never.
Full smog deep diveSkip the velocity stack
The internet is wrong. It cost us 2 to 8 hp on the dyno. Money to go slower.
Pick your tune or ECU
This category is deep. There are more tuners, flashers, and piggyback boxes out there than we could ever cover, and we've run most of them. These are the three we put our name on for the vast majority of riders. Priced low to high, all three are a great call.
Good · Best value
Ship-In Reflash
$Lowest cost in
Send us your stock ECU, get it back with a full race tune.
- Full race tune on your own stock ECU
- +500 rpm redline, economy cruise, less engine braking
- Dual Race + Enduro maps and traction control
- Lifetime map support
- Set at flash time, no on-the-fly changes
- Ship the ECU in, and again for updates
Better · Flash at home
PV3 Tune at Home
$$Buy the device
Same tune as ship-in, but you flash it yourself in the garage.
- Identical race tune, nothing to ship
- Power Vision 3 doubles as an OBD2 scan tool
- Dual Race + Enduro maps and traction control
- Reflash and update on your own schedule
- Device costs more up front than ship-in
- Set at flash time, no on-the-fly tuning
Best · Full control
GET SX1 ECU
$$$The whole brain
A full ECU with live tuning from your phone, ready to ride.
- Full ECU replacement, ships pre-flashed
- WiGET app: throttle, engine braking, TC, all live
- Map switching on the fly, any speed, any gear
- GPA traction control you actually feel working
- Quick shift, neutral indicator, deeper than OEM
- Highest investment of the three
- Updates still ship the unit back in
Pick your pipe
They all need a matching tune, so ignore that. What actually separates them is how loud, how it hits, and whether it survives a day of tight trail. Swipe sideways on your phone.
| Option | Cost | What you get | Noise | Best for | The catch |
|---|---|---|---|---|---|
|
Best value Pro Moto Billet end cap |
$ | 42 mm outlet, full power potential unlocked, engine runs cooler, stock can and stock look | Louder. Ultra-silent insert available. | Anyone who wants the whole airflow gain without buying a muffler. | Honestly, nothing. This is the pick if you're not going to spend pipe money. |
|
Best all-around Graves muffler |
$$$ | Strong, smooth power through the whole rev range. Up to 1.3 lb saved. | Louder. Removable DB killer / spark arrestor included. | Every riding style, top to bottom. If you're buying exactly one pipe, buy this. | Cost. And the carbon end cap does not enjoy being crashed on. |
| Yoshimura muffler / full system | $$$ | Strong, smooth power through the whole rev range. | Quite loud. Removable DB killer / spark arrestor. | All riding levels. | Nearly stock weight, so you're not buying grams. May melt your turn signal. Fragile carbon cap. |
| FMF 4.1 slip-on | $$ | Full-band airflow, hard punchy hit, up to 1.1 lb saved. | Very loud. Your riding buddies will have opinions. | Supermoto, snow bike, wide-open desert. | Snappy, harsh down low. Not what you want in tight trail. May melt your turn signal. Fragile carbon cap. |
|
It's an option Stock end cap mod |
Free | Some airflow. Cooler running. Stock look. Better than nothing. | Louder. | Riders on a strict zero-dollar budget. | Still very restrictive at a 26 mm outlet, so you're leaving real power on the table. Get it wrong and you've voided spark arrestor compliance. We'd rather sell you the billet cap. |
| Stock cone resonator removal | Free | Mid and top-end gain. | Drone. Genuinely annoying drone. | Fast open-terrain riders only. | Kills bottom-end torque and it's a miserable job. Don't do this to a trail bike. |
|
Nope Intake velocity stack |
$ | Nothing. Measurably nothing. | — | Nobody. | Cost 2 to 8 hp on our dyno. Save your money and buy fuel. |
"Do I need a new map?"
A tune is built for specific hardware. Change enough of it and your map is describing a bike you don't own anymore. Here's exactly when that matters, and when you can relax.
| What changed | New map? | Why |
|---|---|---|
| Stock exhaust → slip-on or full system | Yes | The big one. Your map was fueling for a strangled pipe. The new one flows way more air, so the same fuel over more air means it runs lean. Call us. |
| Stock exhaust → opened end cap | Yes | Same reason, smaller number. Airflow changed, so fueling has to change. |
| One brand of slip-on → another | Usually no | You're already in the open-exhaust world and the map is already built for it. Different cans flow close enough that you'll be fine. If something feels off after the swap, tell us what you've got and we'll sort it. |
| Pulled the reeds after you were already tuned | No | Our maps already account for it. Pull them and ride. |
| Complete smog delete | No | No airflow change, no power change, nothing for the map to do. |
| Sprockets, tires, bars, suspension | No | The engine has no idea you did any of that. |
| Moved somewhere much higher or lower | No | The baro sensor is on it. There's a whole sheet on this, linked at the bottom. |
"My exhaust isn't in the dropdown"
Order it anyway and tell us exactly what you're running. Don't guess at the closest option and hope. Drop it in the order notes or email us, and we'll build the map around the hardware you actually have.
Buying the pipe later? Say so when you order. We'd much rather load the right map today than reflash it for you in three weeks.
What lean actually feels like
Surging or hunting at steady throttle. Popping hard on decel. Hanging idle that won't come down. Running hotter than it used to, headers glowing, plastics getting toasty. More stalling in the tight stuff, not less. If you opened up the airflow and skipped the tune, you're not imagining a single bit of it.
Zero dollars. Twenty minutes.
Try these before you buy anything
Half the stall complaints we hear vanish with these four, and not one of them costs a cent.