Here is my Venom duner WR449cc motor (Red) line and a KTM Outlaw 450mx-er... mods are BB 554cc 12.1 or 12.5 piston, 806 cam (top end KTM cam), Sredrum 44mm with venom Rat stack, Polaris slip on pipe/ stock header, RW intake. Both made 55HP but as you can see the low to mid is freaking insane on the KTM!!!! Now we just need to save some $$ for a +1 head.

wow nice runs man. imagine yours as a 554 BB, i think you would have better numbers than the ol ktm

I do have a 534cc yfz as well, but will wait till this up coming wednseday to get the run files to properly over lay them. My 534cc was a 62/42 motor.

I just looked and it was 62/42 on my 534cc with non drag pipe.

Cool comparison Terse. Man that thing starts pulling early. Maybe the paek numbers arent there but id say thats a pretty good build. Bet its alot of fun to ride. One would think with some different stuff you could stretch out the band to peak a little more. I want to see your bigger build over layed. Might make that build look kinda shabby after all!

62/42 you got huh? Man that was pretty good. I thought it was kinda hard to get that much torque out of the YFZ's....

thats insane torque for a yfz. get that graph overlayed! lol

Wow, nice! if you could keep that bottom end and add/carry the tq/hp on top on the KTM that would be ridiculous!

Grey

My 522cc yfz with the Venom pipe made 60/44 and 62/42 with a more top end pipe.

cool Erik ..so do you have a KTM now as well or is it someone elses ?

It's my buddies quad. He bought it new and wanted something totally different then the regular 450's out.

I just own the 2 yfz's.

Good stuff eric, thanks for sharing

So does the Polaris/KTM have a stock head, no porting at all just a BB, piston and KTM Cam?

Correct.

100% stock head

Thumper Racing BB kit pump gas piston. They call it the 570cc kit but it actually is a 554cc.

KTM cam

Sredrum bored out stock 39mm carb to a 44mm with Venom Rat stack

YFZ Ron Woods intake no box with 250r filter...... as there is no room for any other intake.

Next up will be a +1mm IN/EX ported head.

Cool stuff. Curious to see what a ported head and +1's will do to that KTM.

Thanks for posting it up.

Oh.... didnt realize it didnt have a ported head. Send it off to Venom and see what it does after that.

Pretty wierd that a company calls a kit a 570 and its really only a 554..... Talk about a little miscalculation or straight up deseption. Thats WAY off!

their stock 525 is only a 510 too.

mild cam, stock porting...

that KTM looks real nice... ...

the KTM port is pretty much there from the factory...

here's some info on that 806 KTM cam:
intake
9.19 mm / .362 duration 237 degree
exhaust
8.97 mm / .358 duration 234 degree

here's stock 04/05 450R port flow vs. stock KTM port flow..

factory port....

we just dynoed a ktm 505 sx bone stock with just a dasa pipe it made 54hp at 35lbs of torque. i built pump gas honda makes 54hp at 33lbs. plus the ktm will rev all the way to 11000 with out dropping off in power. the bikes are pretty sick from the factory. Chad so are the heads like an aftermarket chevy head. there all already done from stock. or is there power to be had?

Thanks for the add in Chad with the flow chart and picture.

Just so every one knows this is the RFS motor... not there newer dual over head cammed motor.

Yes they are off on their cc sizes but why that is...... along time back they had there 510cc (I for get the exact cc size) motor in their dirt bike and then switched the bore to stroke ratio, head design, cases etc.... but kept the same cc size the same... to make it easier for people to order the parts that they needed for the newer motor design they changed the name to 525cc. So the BB companies just add the bigger bore cc to the name of the motor 525cc to 570... even though it is a 554cc.

About the ports too, they are a two angle valve seat design, and after talking to a pro KTM Pike Peak hill climb builder/ racer here in town and other builders who have actually ported these heads.... the only way to change up the bowl area on stock valves is to blend them.... with no angles, or go to a +1 head and run a 3-5 angle set up.

Garret,.. there's more from stock,... not a whole lot without busting through, but enough to get it to +1 in all four corners like tersejr suggests...

good numbers im building a 600 out of my outlaw with +1 valves and the 8/33 cam or the 8/07 cam
custom dasa exhaust,43.5 carb and a few other things
tersejr can you hook me up with a intake picture i have the velocity setup

Ok, I may have messed up with cam I named. Is the KTM top end cam the 807, and the mx guys prefer the 806 right... if so my friend has the 807.

I'm not sure if I have a picture of the intake. However it is the YFZ Ron Woods no box version and the smaller welded section of the tube that the hose to carb clamps to, is cut off... so it is the larger diameter all the way. It is also pointed down ward as this was the best we could figure it would fit. We also made a chain splash guard to keep anything from flinging off the chain and on to the filter.

For what it's worth on the dyno in Okie we tested a 250r filter clamped to the carb direct and seen 1hp over stock, but then ran the YFZ Ron Woods intake (pointed up with the Ron Woods filter...seat off) and it made 5hp over the 250r clamped on the carb.... so intake runner length is very important on this motor. However we could not get the filter to fit any where, and had to use a 250r K&N on the tube. Seems to work very well.... however not the best for wet or muddy conditions at all.

so is the filter and intake under the seat and above the sub frame or did you move the battery and snake it by the shock.im moving my battery up front like the outlaw irs models and going to have side mount exhaust instead of centermount

Moving the battery will work alot better, but we left the battery where it is and the filter is down under the frame cross brace (not over) and pointed towards the swing arm pivot. I'll see if I have any pictures of it for you.

that would be great if you have a picture

Ok this is the best I got for now. You may need to full screen it or something..... I hope it helps.