How much timing can one run down in the highway cruising range? Cruising on the highway @ 2000 rpms I'm seeing 33-35 degrees of timing, alittle more or less depending on TPS. Does this have to be tuned on a dyno or can it be done on the street, advance the spark a little bit and then see if there is any knock? Reason I ask this is that Zippy told me a lot of timing down low is key, but I really didn't have any reference point as to what he meant. What is the standard way to tune timing? Do you just increase everything across the board a certain percentage and then look for knock?

 

that sounds about right. Somewhere around 35+ at cruise. Zippy made a timing at cruise thread, dig it up in his profile.

The best way to tune it IMO, would be get on a long straight flat road. Use the DVT feature of efilive and add timing until it starts to try to KR, or does KR, then use that and mold your spark table.

 

the best way would be on a load bearing dyno. just because you dont start to knock doesnt mean you havent lost power. for example you see knock at 35 deg. so you set it at 33-32. there is a good possibility you started to lose power after 28 deg. im not saying it will always be like that but, it will vary and it is something to consider.

 

As much as the truck will allow it, its trial and error

 

I always understood that there is a plateau with which the gains from increased timing stop, meaning that 32* may offer peak hp even if you can squeeze 37* from it without KR. True or not?

 

I was looking at a 2000 vette tune and it has way more timing down low than what I got. I would love to copy that high octane table over to mine once I get my air leak figured out...

 

after 32* you may start to lose power instead of a plateau so, by the time you squeeze the 37* you could lose quite a bit. it will vary but, like i said before, the only real way to know is to put it on a load bearing dyno. for the guys that dont have the cash to put on dyno time they really dont have a choice but, to use the method stated before (advance till knock and then back it off a few degrees.)

 

it wont hurt to try it out. what are your mods?

 

+1.. You lock the rollers at a certain MPH, then adjust the spark up and down looking for the highest HP for each cell on the spark table <2400rpm... You can skip every-other cell... that is the way DC_justin told me to do it... Hopefully in a month i will be doing this on the dyno, with the assistance of a EFI Live instructor!

 

dont you have to have roadrunner to make real time adjustments? It sounds like it would take forever to change timing 1 cell at a time, shut down the vehicle, re load tune, etc.

It has to be done on a mustang dyno?