Ignition advance curve

[mikemcvaney]

Taking my distributor toget it recurved what do you guys think the total curve should be? That is how degrees total do you think It should have .

 

[WarWagon]

Taking my distributor toget it recurved what do you guys think the total curve should be? That is how degrees total do you think It should have .

It's different for every combo and intention. With the drawthru It's going to be limited a bit with the higher intake temps, pump gas and small turbocharger. Before on my old Drawthru I could not run any more than around 18* total with 93 pump gas and boost at 12#. Now days with my blowthru I can run more but it's still not a a lot. Right now I'm at 20* total and that was the max Ign timing I could run with boost at 22# on 93 pump gas and keep it out of knock but it is right on the edge of wanting too so I dropped the boost back down to 20# and left it alone.

 

[mikemcvaney]

It's different for every combo and intention. With the drawthru It's going to be limited a bit with the higher intake temps, pump gas and small turbocharger. Before on my old Drawthru I could not run any more than around 18* total with 93 pump gas and boost at 12#. Now days with my blowthru I can run more but it's still not a a lot. Right now I'm at 20* total and that was the max Ign timing I could run with boost at 22# on 93 pump gas and keep it out of knock but it is right on the edge of wanting too so I dropped the boost back down to 20# and left it alone.

Did you even run a vaccum advance on your draw threw? or did yoy lockout the disributor at 18 total?

 

[charlief1]

The vacuum advance is only supposed to work under light load. Worry about the max curve but you can disconnect the vac if you want. 18 to 20 degrees seems to be the most anyo f the draw through cars can run safely so somewhere around there is about where you want to be.

 

[mikemcvaney]

QUOTE=charlief1;2909049]The vacuum advance is only supposed to work under light load. Worry about the max curve but you can disconnect the vac if you want. 18 to 20 degrees seems to be the most anyo f the draw through cars can run safely so somewhere around there is about where you want to be.[/QUOTE]You guys understand Iam talking about total timing dgrees above 3000 rpm not initial timing settimgs. Thank you both for input mike

 

[charlief1]

Yes Mike, we do. Even the SFI cars generally run no more than 23 degrees total timing. They have better control of the fuel and ignition and that's why we can't run more than about 20 degrees.

 

[WarWagon]

It's different for every combo and intention. With the drawthru It's going to be limited a bit with the higher intake temps, pump gas and small turbocharger. Before on my old Drawthru I could not run any more than around 18* Total with 93 pump gas and boost at 12#. Now days with my blowthru I can run more but it's still not a a lot. Right now I'm at 20* total and that was the max Ign timing I could run with boost at 22# on 93 pump gas and keep it out of knock but it is right on the edge of wanting too so I dropped the boost back down to 20# and left it alone.

You guys understand Iam talking about total timing dgrees above 3000 rpm not initial timing settimgs. Thank you both for input mike

YES + I use a computer distributor with no mechanical or vacuum advance.

 

[mikemcvaney]

Thank you gentleman I was about to set it at 26 you really helped. Getting ready to install my new headers and turbo very soon.