Question about variable engine timing on 4.6 dohc

[Mach828]

All of the tunes I've gotten seem to have a set WOT timing. I have somewhat limited knowledge when it comes to tuning but it seems like all the variable timing tunes are adjusted using variable cam timing. (3v and coyote engines)

I'm about to get a tune for e85 for my Vortech Mach 1. I want to limit power in the 5k+ rpm range because I will be well over 500whp on my stock 115k mile engine, but I want increase the weak mid range power by adding a lot more timing. Can I have my tuner decrease ignition timing based on rpm? Its a v2 s trim running about ~9lbs. I run it on the street at 15 degrees on 91, and add some 110 leaded when I hit the track and bump it up to 18 using my SCT xcal 3. The xcal 3 has an rpm based timing advance/retard so I just add timing in the 0-4k and 4k-6k fields, and decrease in the 6-8k field.

Here is what I'm thinking for the tune. Thanks for your input!

up to 4k - 19 degrees
4k to 5k - 18 degrees
5k to 6k - 17 degrees
6k to 7k - 16 degrees

 

[01yellercobra]

We can adjust timing as well. It's RPM and load based. That's how I set up my timing table. Down low when it's out of boost I have a very aggressive timing set up. As the load and RPM increases the timing reduces. I'm around 15 degrees at WOT right now. I added 2 or 3 degrees at part throttle. It made a difference in how the car felt.

 

[DSG2003Mach1]

what slow98 said

you should see the difference in something like a Lightning with a properly ramped timing curve vs one without, the 60' will be a huge and if those trucks dont 60' they dont et

 

[Mach828]

Thank you for the information. I suspect that creating a "properly ramped" timing curve is something that takes a lot of extra time and work. Maybe that is why most tunes I've seen just stick with a max safe WOT timing and apply it across the board. When I played with the timing based on rpm using my xcal3 the car picked up half a second and 5mph.

Found this article which was pretty helpful:
http://info.efidynotuning.com/saftot.htm

Thanks again! Now I can go into my dyno tune more informed.