We Built the ULTIMATE KTM 350 SX-F!

We're always been fans of the KTM 350 SX-F, but the latest generation (2023 and '24) has really taken a giant leap forward in power and handling. We were so impressed with it, in fact, that we included the 350 SX-F in our 2023 450 shootout and it fared quite well against the larger machines thanks to its superb handling and easy-to-ride, free-revving engine that makes the bike feel much lighter than a full-sized 450.
This year, we decided to see just how great we could make the 2024 KTM 350 SX-F, so we dropped it off with Jamie Ellis at Twisted Development (www.td-racing.com) to see what he could coax out of the engine. Twisted Development is legendary when it comes to building race engines, and we asked him to give us some great power gains without sacrificing durability so that we could ride and race the bike all year without worrying about a rebuild. TD ported the cylinder head, decked the head to raise compression, and performed a Newen CNC valve job. TD has a proprietary piston made to perfectly match these modifications and the top-end mods were completed by a TW high-flow venturi system in the intake. Vortex Ignitions are highly regarded in MX, and Ellis is a master of programming them. The package includes 10 TD maps, and we were stoked to learn that the stock dual map switch, traction control, and quick shift functions are all maintained. As delivered, our machine had the two most popular options pre-loaded into the handlebar switch; both with maximum power, but one with very little engine braking. Ellis does have a full-race performance package that includes diving into the lower end of the engine, but keeping our wishes in mind he opted to stop there. The Yoshimura RS-12 exhaust we've been running for the past year was maintained, as Ellis agrees that it is the best-performing aftermarket exhaust for the Austrian 250s and 350s. Due to the higher compression of the engine, VP Pro 6 Racing Fuel is required to keep the engine purring nicely.
For a suspension upgrade, we turned to enzo racing for what we feel is. the best handling upgrade you can make to any Austrian machine: the enzo KYB spring conversion kit. The kit converts WP front inner and outer tubes to accept the KYB AOS internal damping system. KYB AOS cartridge, rebound rod, compression base valve with standard caps, bottoming cones, springs and standard spring perches fit into the standard WP inner and outer tubes with the installation of the special machined conversion axle lugs by Technical Touch.
Out back, the standard WP shock was modified to complement the fork and valved for our test rider's weight and ability.
Twisted Development Cylinder Work: $1100.00
Twisted Development Piston: $475.00
Twisted Development High-Flow Venturi Intake $35.00
Vortex ECU: $1059.00
Yoshimura RS-12 Titanium Exhaust: $1299.00
enzo racing WP KYB Fork Conversion Kit: $1755 to $2173
enzo racing Shock Revalve: $220 plus parts and oil
www.td-racing.com
yoshimura-rd.com
enzoracing.com

[@scotteckerman3047]

You need to mention that statistically, riders have better lap times on a 350 vs a 450. The bottom line is always something you should dwell on.....!!!

[@philipsmith6152]

If Yamaha made a 350 enduro bike, it would be their biggest selling offroad bike in the world !!!

[@moto3463]

Love the Yoshi exhaust looks good

[@crwing7307]

As a long time 350 rider, I can definitively say…once you get a 350 you won’t go back. Go ahead and get this bike. It’s fantastic

[@WesReeves87]

This makes me want to get ride of my ‘22 450 for a ‘24 350 😅

[@kurtheidelbach]

Definitely wouldn’t be disappointed

[@jcbenson01]

I went from a ‘21 450 to a ‘22 350 (same frame/chassis) and I absolutely love everything about the 350

[@_that_native_artist_boy_]

hey great video, i do have an idea/request for one though, where do you guys get replacement parts for those bikes? like cluch levers and grips and stuff.

[@esdrehtsich9289]

Great video ! Comparing your laptimes on this bike and a 2024 450 would be so interesting….. maybe you have the chance to do it… Would be worth another video 👍👍

[@swapmotolive.]

Great idea. I can tell you from lap times at the races, though, that I am a couple of seconds quicker on this than the YZ450F at most tracks...

[@mxracer158]

I'm in the market and I think I found my xmas project. Thanks for the video. I've been eyeing a 350 for a bit now.

[@MotoMatt418]

Get it. The 350 rocks. I came off a Yamaha 450 for it.

[@mxracer158]

@@MotoMatt418 thanks for the feedback.

[@mrossi4778]

I rode a 350 sx-f for years. Never thought that a 450 sx-f would be much easier to ride, but it is. You have to wring the 350 out much more. When you do this, it is so aggressive. The 450 is so linear and so easy to ride. I will never go back to the 350

[@zachh8148]

ride the new generation and you'll change your mind. it's a lot different. i have a remapped vortex and it's just as fast as a stock ktm 450

[@chrjamrho]

would love to hear your thoughts on this bike compared to the new 2024 spring fork 350 xcf off road model

[@dirtshaker4616]

This is the bike I’m looking at as we speak! Donn, being a friend of Frappy Mike do you have any hook up’s? 😂

[@Mineratron]

Turned off as soon as they ditched the AER fork… I run 15MY cones on one 300 and 23MY AER on another. I like both for different reasons. Would rather see an objective overview of the 24MY SX and AER performance. Apologies if I’ve missed it, just saw what’s in the feed. 🙃

[@IntuitiveUniversity]

AMA Pro Classes are overwhelmed with top 10 guys. Time for 250, 350 and 450 guys. Fail of the point out system fixed.

[@quadcityracing]

Yes, air the 3 class races and do all the heats with race day live

[@matthewtoes6433]

Whats the horse power gains of the Twisted Development's Enginne work the ktm 350 has the same amount of power as the honda why would Pat foster feel not easy up against the 450 might not get the best start But even the best pro's can not hold onto a 450 thats why they roll & coast to save energy no dissadvantage with the 350

[@motionfactoryracing5914]

Just need some Motion Footpegs to finish that build off;)

[@ottokirk2325]

Great bikes, shite sounds. D'oh! I'll take the YAT of my 200 & 300 SX's...No Choice

[@kirkdunn1379]

if japanese made them they would sell every last one.......

[@Motoinc]

That YOSH sound like crap

[@soxh8ter]

The most expensive bikes on the market for no other reason than greed. I will never buy a KTM

[@MotoMatt418]

lol not at all factual. You don’t have to buy one, but look at one close up in person. The fit and finish may surprise you..