Black_Bullet
15+ Year Contributor
- 1,731
- 13
- Aug 22, 2007
-
Brandon,
Florida
I think I may pull it back two degrees also. Its amazing how much timing the guys on the link forums run. Pretty much the same as me. Kevin at Jacks shop here is running 42psi, 1150's, safc/evo maf and seeing 28* at 5* base timing. He has ran it for a long time now and still has not blown anything. Im still using the excuse of how e85 burns slower and needs higher timing levels.
Heres some really good posts I quoted from other people worth listening to on this site to aid in this topic.
95GSXracer said:It's tough to look at absolute timing numbers and take anything meaningful away from them. There are just too many variables... Base timing, placement of the marks on the pulley and the cheap plastic timing belt cover, slop in the crank or pulley key/slot, timing belt tension and amount of stretch, valve springs, cam gears, cam dowel pins, cam angle sensors themselves, spark plug type, actual AFR and distribution in the chamber, and so on. Run whatever timing numbers provide the most power while working within your personal tolerance for risk and goals. It will vary by a few degrees from car to car,
95GSXracer said:The statement that timing makes power is only half correct. Timing just allows you to make the power you should relative to the amount of fuel/air you're burning. Increasing beyond that point will cost you power, and eventually parts. To increase power potential, you need to increase air/fuel flow. The easiest lever here is boost. The tricky part comes in when adding boost requires dropping timing as a bandaid (in other words, more than you would have to drop it due to charge density increase, which doesn't cost you any power). This is where you need to be on the lookout for diminishing returns.
DSMonster said:If you're burning the fuel faster via fast burn chamber that allows higher compression, then you need to start the fire later. You don't NEED as much timing advance. Getting power from timing is not about more timing, it's about literally timing. Timing it right. MBT is the term used. Mean best timing is the best timing for the motor at specific conditions. 3000rpms typically needs LESS timing than 7000rpms because firing off the fuel earlier will cause it to burn up before the piston/rod combo can get to put the most torque on the crank after top dead center. The piston is moving slower. Adding boost, heat, and compression means that the fuel will burn even faster. Hence, turbo motors have lots of timing retard. That doesn't mean that they are losing power from timing retard. That just means that the airfuel mixture is burning faster than it's non-turbo counterpart.

