ATV Drag Racer Forums banner
1 - 11 of 11 Posts

·
Registered
Joined
·
489 Posts
Discussion Starter · #1 ·
anyone on here use them. how helpful are they and how do they work...

I know what they do but how does it measure everything
 

·
Registered
Joined
·
203 Posts
I can alum - coat the inside of my pipe at 1180 degrees!!!!

I see good power at 900 to 1000 on alky.

Ragged edge super power for a couple seconds at 1100.

800 - 950 is a good safe place to be........as long as your not detonating. Detonation seems to hang out at just over 800, anyhow thats how I see it in the 250R alky world.
 

·
Registered
Joined
·
489 Posts
Discussion Starter · #3 ·
QUOTE (turbo bobby @ Sep 7 2008, 06:31 PM) index.php?act=findpost&pid=10219I can alum - coat the inside of my pipe at 1180 degrees!!!!

I see good power at 900 to 1000 on alky.

Ragged edge super power for a couple seconds at 1100.

800 - 950 is a good safe place to be........as long as your not detonating. Detonation seems to hang out at just over 800, anyhow thats how I see it in the 250R alky world.

Thanks bobby. Im thinking about putting one on the new build next year. how do they work.. what all do they read off to you
 

·
Registered
Joined
·
489 Posts
Discussion Starter · #5 ·
QUOTE (dajogejr @ Sep 7 2008, 07:20 PM) index.php?act=findpost&pid=10232Just like anything there is a sweet spot, and each engine is different.
Also...EGTs will vary based on placement of the probe on the pipe itself...

so are these things great to have to really dial your motor in
 

·
Registered
Joined
·
120 Posts
They are widely used by the moddy mountain snowmobilers out West. Ive used them on my ATVs over they years but they arent as handy as they are with a sled- where elevation changes and sweeping temperature differences can tweak your tune.

The biggest mistake people make with them is to not establish a baseline from reading plugs and piston wash. You absolutely must establish a baseline reading 1st. Then you can set about tweaking and fine tuning in your set-up from there. If you just use a general rule that 1250*F is max EGT, you could very well melt a piston like Bobby says above happens to him at 1180*F. You may find your motor will melt a piston at 1050*F, or that it runs its best at 1350*F. Each motor varies and probe placement will also vary and influence what that max EGT allowable will be. They are a nice tuning aid when used correctly.
 

·
Registered
Joined
·
76 Posts
QUOTE (Backcountry @ Sep 11 2008, 05:20 AM) index.php?act=findpost&pid=10539They are widely used by the moddy mountain snowmobilers out West. Ive used them on my ATVs over they years but they arent as handy as they are with a sled- where elevation changes and sweeping temperature differences can tweak your tune.

The biggest mistake people make with them is to not establish a baseline from reading plugs and piston wash. You absolutely must establish a baseline reading 1st. Then you can set about tweaking and fine tuning in your set-up from there. If you just use a general rule that 1250*F is max EGT, you could very well melt a piston like Bobby says above happens to him at 1180*F. You may find your motor will melt a piston at 1050*F, or that it runs its best at 1350*F. Each motor varies and probe placement will also vary and influence what that max EGT allowable will be. They are a nice tuning aid when used correctly.
I have a digitron on my cub. And as everyone says you need to establish a baseline and once you do. tuning is a breeze.....
 

·
Premium Member
Joined
·
1,245 Posts
They are great to have. As for "how" they work. It is just a simple temperature guage that goes in the exhaust headpipe. It reads the temperature of the flame coming out of the cylinder and depending on how hot, or how cool the temp is, it can tell you if your motor is running lean or rich.
 

·
Premium Member
Joined
·
1,953 Posts
And just like Bobby said if your timing is advanced very far you are getting more of the burn done in the cylinder and not coming out the pipe. Thus 1100 degree reading could melt down a piston or with only say 4 degrees of timing that same jetting could read 1300 degrees 6" from the piston face in the pipe. I've used one for over a year or two on a bike and I wouldnt buy one again. On gas I didnt have problems running 1200 deg. I'd just read yer plugs.
 
1 - 11 of 11 Posts
Top