how is the ignition timing setup on these cars?

[novaderrik]

i'm not asking how to set it- i understand how that works..
i'm more curious about the timing curves- how much timing it has at idle and while cruising in overdrive at 60mph- things like that..

i'm asking because i got to wondering why my T Type only gets 17mpg when i drive it nice. i keep thinking that it needs more timing under light throttle conditions- for a comparison, i've got the timing in the 10:1 vortec headed 305 powered 86 Camaro to 45 degrees BTDC at idle with the vacuum advance hooked up to manifold vacuum, which drops down to 18 BTDC when i pull the vacuum line of the advance canister. it runs great with that much timing under light throttle and i was able to average 24mpg with zero detonation on 87 octane gas (except for Iowa and Missouri- the gas there sucks..) over 3900 miles when i took my road trip from MN to Texas via St Louis and Memphis in June.. anyways, it seems that someone should be able to make a chip with a ton of "off boost" timing that drops back to a more boost friendly setting when the turbo gets spinning and get the best of both worlds- mpg numbers in the mid to high 20's and 11 second 1/4 mile times when the loud pedal is pushed to the floor.. or is there something about the ecm's in these cars that doesn't allow that much of an instantaneous swing in timing?

 

[mikestertwo]

The chips can be programmed with any timing curve you want.

 

[novaderrik]

ok.. but how are they generally setup? when i ordered my turbotweak chip a few years back, i didn't get a choice in how much timing i wanted under light load. it runs better than the stock chip did, but i can't help but always think that the timing is retarded compared to what it should be just going by how it feels.

i might have to hook my timing light up on my car if i ever get it out of storage and drive it this year just to see what the timing is at idle..

 

[TurboDave]

The timing tables are huge! At idle they range from about 25 to 29 depending on load. And cruise, for example they range from about 40 to 43 or more depending on load.