flat track ds450 09

[crums8]

any one have there bike set up for flat track? i have mine set up for enduros but have to get him ready in 4 weeks for the start of the new flat track season.

Mods curantly doing to engine are:
13.6 cp race piston
PC 111
Motoworks full exhaust Moded end
50mm throttle body
Another exhaust cam
epoxy ported cylinder head. chasing around 50hp any extra would be tops.

Am chasing input more on suspension set up, tyres ect. but any input would be great. Am currantly also making up a lowering link for the back. our track out here is oval about 300meters in length. current gearing is 15-39 but will probable drop the front down to a 14 depending on how the engine turn out after mods.

[fast rap]

nice, sounds like a runner!!!

[crums8]

oh yeah forgot to mention that this is on dirt lol.

[ds450power]

who did ur throttle body boring and what it cost ya

[blaster99]

I belive you can but the TB straight from can-am.

[fast507]

I have set up a few bikes for flat track. There are a few things that determine the set up:

1. Are you racing ovals or a TT-type horseshoe config with left and right turns?
2. USA or foriegn? (counter clockwise or clockwise oval)
3. What class are you running? ( Some classes run a Knobby tire, no-swaybar rule.)

I set a trx450R up for a guy who runs locally. We did a std-travel setup with P.E.P.'s and went with stock width arms on the left side and a +2 arm on the right side to bias the weight to the inside of the turn. We also offset the Lonestar MX axle on the rear with the spacers as well. We used a modified Dura-Blue sway bar and adjusted the "jack" in the front end with threaded hiems on the bar and shock preload. I'll try to find some pics. I know American Star Manufacturing will make setups like this for you, call and talk to Mike tell him Jason from VA rec'd. them. They currently don't have a DS arm in their catalog but they are very reasonable about fabbing things up for people. Some people will run a -1" or -2" swing arm to get the bike to rotate in the slide, but we went with a stock swinger and P.E.P TT linkage kit. We always tried to keep the chain adjustment on the rear carrier in a manner where the axle rode at the highest point in the adjustment which netted us an add'l 3/4" drop in the rear.

Josh found this bike to be very Stable and fast and has won a few races between here and his duty station in Alabama. (military) He says he can enter the corners on most tracks on full power and use the front brakes to pitch the bike and the throttle to modulate the slide. Once he squares up to the corner exit he just feathers the clutch enough to let the tires grab and he fires off down the next straight. We have experimented with staggered tire setups for tight 1/4 mile tracks but he runs neutral now. A 300M oval is very tight. I'm assuming a Kart track?

[crums8]

yea it is a cart track. We run anti-clockwise only and it is just an oval track all left turns. Hume performance bored out the standed TB, cost me 180 AUS.(Yea im in Australia down under lol) i am also getting a set of wider A arms off the mx model. Will have to work out what to do with the shocks on mine. they will probable be to shoft with those arms?

[ds450power]

also did u have ur plastic adapter from head to tb opened up to 50mm? and did u have to open up the intake port on ur head at all?? and what intake are u running

[crums8]

i havent bolted it all back together yet, its still all apart, waiting on the piston. should be here tomorrow. standed tb measures 46mm at the butterfly. on the manifold side and butterfly it is all 50mm now. looks like it will match up with the manifold ok. on the filter side tb is bell mouthed. starting @ 50mm where the butterfly is and goes out to about 58mm. i am going to polish this for flow. i am thinking of getting rid of the whole air box and running a filter straight on the tb? anyone done this? any better?

[ds450power]

i think thats a bad idea, u may get more flow going direct mount, but i think a well designed intake boot/tube creates velocity and thats what we're after for making more power