KTM 625 SMC Venturi Intake/Airbox
Well, after a year of badgering a KTM tuner in Germany, trying to decipher German and going back-and-forth I FINALLY got my venturi intake.
This thing is NICE, no kinks, bends and restrictions like the stock box, just wide open with a custom-sized venturi and a K&N Xtreme filter. Dyno graphs show another 1-2 HP over an open airbox (the lid removed).
Here are some pics, I'll give you all a seat-of-the pants and dyno review in a few days.
Last edited by 3cRider; 11-28-2009 at 09:33 AM.
Looks good. Waitin on the dyno.
70 Boss 302 sold
69 Original Z/28 restored then sold
80 Yamaha TT 250 gone
06 560 SMR PTT
06 625SMC with Akros
That's look'n like an '05 '06 box?? Do they make anything for an '04? I've seen the pod filter kit (no box at all) and it looks sexy!! However just like you I only see it on euro sites and sadly even though I was borne in Germany I no sprecken.
Install pics! and dyno!!
~Tim
'04 625 SMC
'97 CR500
You can't just post up a picture like that....and NOT give any more info!
So ----- how does the average Joe get one of these.... IS it a EURO KTM part number? or aftermarket?
'06 KTM 625 SMC
'03 Honda 919
Waiting!
~Tim
'04 625 SMC
'97 CR500
Sorry I was out of town for a few days.
It's a modified stock airbox that's been cut apart and opened up with the metal "venturi." If you look at a stock box from the same angle as my pic (from the carb into the box) you can't see into the box, the filter is actually offset.
I stumbled on this airbox a few years ago and it took many months for KTM Sommer to make one for me. KTM Sommer has TONS of stuff for our bikes, including these boxes. The venturi is a flat piece of metal that was bent and welded (it's not a tube). It's pretty nuts.
All said and done it cost me a pretty penny (around $500 USD) but KTM Sommer has/had some of the fastest LC4 racebikes and said this setup really uncorks the stock bottlenecks, even over the Hard Parts lid and a K&N.
When I get home from work I'll dig up the graphs and the info I have on it. Though it had to be translated from German to English. And if anyone want's my contact over at KTM Sommer just shoot me a PM.
Last edited by 3cRider; 11-30-2009 at 11:43 AM.
I spent a lot of time searching and after talking with several teams that raced LC4s (back in the day) this setup seemed to be the best for a streetbike.
Both KTM Sommer and the other LC4 tuners I spoke with advised against removing the airbox all together and fitting just a filter. They both said it lead to uncontrolled air, which in turn made it hard to jet correctly.
They both also mentioned that removing the airbox lid and fitting an aftermarket filter was good, but the design of the factory box was inherently flawed. So, I bucked up and went for this modified box since their research found that a box was needed to better control/contain/regulate (whatever you want to call it) the air but the "kink" in the design needed to be removed.
Long-story short, I'll be doing some back-to-back dyno runs with the factory box/removed lid and this setup to see where the rubber REALLY meets the road.
wow ---- 500 bones.
I sure hope you've done the 'other' mods first..... you probably already have the full Akra....
Have you done any headwork? Are you still running the stock cam?
'06 KTM 625 SMC
'03 Honda 919
Yeah, I have the Akra header/cans, jetting and SAS removed. I Also have Samco silicone hoses and a different countershaft sprocket (those two don't do anything for power) and a few other small things. I thought about a Ralleye cam but the power increase at peak is more than lost under the curve. The way I figure, the ol LC4 is more of a midrange monster than a top-end bike.
The airbox was really expensive but it's the last of my motor mods, unless I can scrape together enough coin for a slipper clutch (but I doubt it).
Last edited by 3cRider; 11-30-2009 at 03:08 PM.
--- I still come and go with the cam thing. I agree with you, I'm nervous about shifting the power curve tooo much.
Though --- for sure plan on getting my 625 head ported and milled (around $300 with a local tuner).... just not sure on the timing quite yet.
I look forward to seeing you dyno graphs on the air-box.
'06 KTM 625 SMC
'03 Honda 919
am wondering.... now that you have the modified box.
Do you think there might be a 'laymans' modification that could do the same thing?
'06 KTM 625 SMC
'03 Honda 919
To be honest, now that I'm looking at it I might be able to replicate it. A lot of the cost came from the filter and second airbox as well as the labor. I'm going to take a closer look and get back to you guys.
def do thatOriginally Posted by 3cRider
Subscribed!
2005 KTM 625 SMC (AKA: Fast Orange)
Rallye cam, ported head, JD jetted.
Videos: Supermoto Trackday | Mulch Mountain | '09 Bronson Rally | Stream Crossing
Now that you've had it on your bike for a while what do you think? Any dyno runs yet?
2005 KTM 625 SMC (AKA: Fast Orange)
Rallye cam, ported head, JD jetted.
Videos: Supermoto Trackday | Mulch Mountain | '09 Bronson Rally | Stream Crossing
Definitely interested
Some people wonder all their lives if they've made a difference. The Marines don't have that problem.-Reagan
Sorry all, the bike still isn't back together. SUCKS! I've been so busy the bike hasn't moved. I'm hoping to eek at least an hour in this weekend, so hopefully in the next few weeks. The minute I get back from my first ride and the dyno I'll post my results!
Sorry all!
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