So I just bit the bullet and bought a IPP stage 1 shortblock. I am wondering, will I still be able to use the "copy thru" ignition timing on the Haltech for the vacuum columns, or will the timing curve be significantly different with the lower compression?

Also does anyone have a Haltech map (timing map specifically) for either an APS Xtreme, GTM 2871R, or JWT700/850 turbo kit running at least 15 psi of boost?

 

If all you did was lower compression alittle then it shouldn't affect your current timing map in vaccume too bad, unless you changed the displacment or it was a drastic drop in compression. You may want to add some timing in at idle/vac. to compensate for the lower compression though. Sounds like you"ll need some dyno time to fine tune, or a nice long straight road

 

i always used copy thru and i havent really seen a haltech map that doesnt.

your timing map wont change much with the built motor. just take your map and add 2 degrees to all the boost cells. like 10-12 at max trq and around 16-18 at max boost

 

That's what I was hoping for, I just wanted someone else to confirm it. I will leave copy-thru on then, and wont waste my time tuning vacuum on the dyno.

Also those timing numbers you gave pretty much are exactly what my 0.5 bar column looks like currently, with the 1 bar column about 6 degrees lower (I only run .5 bar right now so anything above that is "untuned").