17 yz250f 270 dyno graph

NoMuff2Tuff
Posts
192
Joined
2/11/2015
Location
La Place, LA US
12/25/2019 6:53pm Edited Date/Time 12/25/2019 8:57pm

For those looking to see what a 270 big bore with mods does on the Yamaha. The motor wasn't built as an all out race motor, something just about anyone can build on there own. With the help from Derek at HP the motor has a cylinder works big bore kit with the cylinder base cut to get compression around 14.1, balanced crank and Crank Works connecting rod, Bills full exhaust, Jesse Williams cams, 2nd injector and I did all the cylinder porting. It has a GET ecu and Derek did all the tuning and dyno runs. All runs were made on pump fuel. I thought it would have hit a slightly higher peak number but the overall torque curve is pretty impressive. As low as 6500 it already hits 20 ft lbs. The green curve is a brand new 20 KTM sxf 250 for comparison on same dyno. His dyno seems to show lower then other dyno's, most other have the KTM at around 43. I think with oxygenated fuel and more tuning it could hit 46-47 as early as 10,500 which would make for a fun bike to ride or race. A 7-8 hp gain over a KTM at 10,500 is not easy to do. It's about 8 more hp then a stock 17 yzf at 13,500.
5
|
mx216
Posts
725
Joined
3/21/2009
Location
Portland, OR US
12/25/2019 7:59pm
If you hadn't ported the cylinder it might have made more horsepower Tongue
1
NoMuff2Tuff
Posts
192
Joined
2/11/2015
Location
La Place, LA US
12/25/2019 8:57pm
mx216 wrote:
If you hadn't ported the cylinder it might have made more horsepower Tongue
Maybe or maybe it would have made less. Lol
1

Post a reply to: 17 yz250f 270 dyno graph

The Latest