On a s550 mustang gt still on stock cats how much timing has everyone been able to see?
On a s550 mustang gt still on stock cats how much timing has everyone been able to see?
On my 15 I would see WOT timing starting ~25-26 raising up to ~29-31 at 7000. On the 18 it’s about 2 degrees less throughout a pull.
Thank you
How about with longtubes? Mine seems to like a lot of timing lol Kinda surprised meOriginally Posted by rhinogt
Have a few buddies with long tubes on hold E85 and see 33-34 degrees and are happy
Yeah that seems to be where mine sits. Thanks!
On 93 octane with intake, headers, and exhaust, I would see 29-31 degrees of timing on my 2015. On E85, it would hit whatever timing I wanted. The question I always had is why do people run so much timing on E85. MBT on the coyote is 29-30 degrees of timing and the rule of thumb is your don't advance pass MBT as there are no returns. On ethanol, you can generally add 1-2 degrees of timing over MBT to gain a small amount of power, but I wouldn't think 4 degrees would do anything at all. I tested 30 vs 33 degrees of timing on a dyno and saw no difference in power. Maybe I'm missing something.
Kris
My buddy runs 34 degrees on his cj 16 mustang and he is just on cat deletes no long tubes or anything and he gets no knock. Who knows if it’s making any power at that point I doubt it or nj has some great 93 lol
On other platforms I have tuned with slightly better flow characteristics to the coyote, you could run 32-34 degrees of timing on 93 octane on these engines, but it didn't make any power past 30 degrees. If anyone has any dyno results they could share to shed some light on the topic, it would be greatly appreciated. As soon as I can, I will continue to test as well.
Kris
https://www.youtube.com/watch?v=jg14wdXg1_g
Its very important to understand MBT spark advance and borderline spark advance and why in certain conditions they are the optimal spark advance(not too little, not too much).
MBT- Too little you are not making maximum torque the engine design can support, too much you are not making maximum torque and creating heat and pressure on the pistons/ bearings/ rods most likely leading to engine failure.
Borderline- Too little you are not making the maximum torque for your current fuels octane, too much and you are causing detonation which is hammering on the inside of the cylinder most likely leading to engine failure. Increasing spark past borderline will increase torque, up until the MBT point. The engine just may not survive the hammering of the detonation.
Last edited by murfie; 06-29-2018 at 03:31 AM.
Reply With Quote