uncaged
Newbie
I talked to a dyno shop locally that said they could do sleds. They have to clamp the tester to the crankshaft. What do you need to get the primary off?
Also, from experience, I know that if you run the engine for a while without a belt on, the sensor on the jackshaft cuts the computer because it sees the engine revving high and the jackshaft not spinning. How do you bypass or fool that sensor to dyno tune?
Any other things to consider?
Thanks!
Also, from experience, I know that if you run the engine for a while without a belt on, the sensor on the jackshaft cuts the computer because it sees the engine revving high and the jackshaft not spinning. How do you bypass or fool that sensor to dyno tune?
Any other things to consider?
Thanks!
RayKnobs
Expert
- Joined
- Feb 24, 2010
- Messages
- 396
- Reaction score
- 1
- Points
- 141
- Location
- Rochester, NY
- Website
- 315er.net
How do you cool the engine?
07STI_Matt
Pro
Just get the tool for the primary. It pops off in 10 seconds. Not sure on the jack shaft sensor
07STI_Matt
Pro
Just get the tool for the primary. It pops off in 10 seconds. Not sure on the jack shaft sensor
marpolsdofer
TY 4 Stroke Guru
There are two ways to dyno. By the crank shaft or by rolling a steel drum by the track.
RIGIDONE
TY 4 Stroke Master
- Joined
- Jan 5, 2009
- Messages
- 1,300
- Reaction score
- 81
- Points
- 738
- Location
- SYRACUSE, NY
- Country
- USA
- Snowmobile
- Pro S Switchback
I think the thing they hook to the crank shaft of the sled adds resistance so its not like it is spinning freely... again emphasis on "i think"..
Yes.When Aaen did mine he never had a problem same as any other sled.Sled shouldnt shut down unless it gets hot.You can help that by tying into cooling system or fan might be enough especially if its cold outside.With most dynos the motor just acts as a hydraulic pump.They measure the power and control it by controlling the fluid.Ulmer has a Chassis dyno which will measure actual power to the ground.Big difference since alot of power is lost between motor and ground and chassis dyno allows clutch tuning to get more power to ground.
uncaged
Newbie
Thanks for the replies.
I installed the fan kit on the radiator, so not too worried about overheating since they'll have the normal blower setup.
The dyno shop only has the hydraulic fluid coupling to put resistance on the crankshaft. In reality, I'm not so much worried about absolute HP numbers (at the track) as I am about making sure I get the A/F mixture dialed in right.
Interesting that nobody had the jackshaft sensor issue. When I put on a pipe I took the belt off so I could rev it to listen to the sound. It threw a code and cut the ignition (like a limp mode), looked up the code and that sensor was why. Put the belt back on, jacked the rear, ran it and it cleared the code. Just figured that would happen while crank dyno running, maybe not?
I installed the fan kit on the radiator, so not too worried about overheating since they'll have the normal blower setup.
The dyno shop only has the hydraulic fluid coupling to put resistance on the crankshaft. In reality, I'm not so much worried about absolute HP numbers (at the track) as I am about making sure I get the A/F mixture dialed in right.
Interesting that nobody had the jackshaft sensor issue. When I put on a pipe I took the belt off so I could rev it to listen to the sound. It threw a code and cut the ignition (like a limp mode), looked up the code and that sensor was why. Put the belt back on, jacked the rear, ran it and it cleared the code. Just figured that would happen while crank dyno running, maybe not?
