And I picked up almost 3 mph but my ET. dropped by 1.5 tenths.

Interesting. I ain't a drag racer but I am assuming ET is the bottom line. Here's a BTT for ya.

That is a big change. Not sure what your ET is but if the car is very fast at all then that is a bunch of horsepower that you picked up.

8.67@154 with 35 degrees timing
8.70@157 with 32 degrees

60 foot is a little off @32 degrees. 1.23
60 foot is 1.18 @ 35 degrees

So it wants timing to get the car moving and retard after. Get a high speed retard. You can probably add another 2-3 degrees at the hit and then pull the timing back out .

I like the mph@32 degrees

.3 quicker with more timing but slower mph.

.03 not .30. And where is the 1.5 tenths in the first post

????

X2

What ignition system do you have. You would be surprised what would happen if you have a way to ad timing down low and take it away up top.

It might not want timing to get the car moving, he might be making more power with less timing and overpowering the tires. I'd keep the timing at the lower number and try to get it too hook.

I have an MSD 6al-2 ,set the timing with a laptop.nThe timing is adjustable every 100 RPM.I have NOT found the sweetspot YET!

Your situation parallels one I witnessed first hand today. Cab was down and made several pulls on a chassis dyno at my friend`s shop. We were trying to get a plug reading on e85 and installed one new spark plug in #7 that was one step colder. The car lost 100whp on a A B B A test. We put the other plug back in and the last "A" pull was right back to normal. 100whp due to one spark plug. That really blew my mind. It is amazing what you can pick up or lose with minute changes. I am impressed that you picked up that much mph with a timing change.

I am thinking he meant .015. One and a half thousandths. Ron

Whats the combo ? Eng , heads , cam and so on ? Ron

It's a 4.200 bore
3.79 stroke with a 6.50 rod in a 48* block.
16:1 compression.
I'm ballz deep in this engine.
Fully CNC ported W9 heads now.
A little to much maintenance to run but this combo screams.

I need a little more gear to spin it harder.
68 Dart that weighs 2955lbs.

I'm getting too old. Grabbed the wrong time slip and slowest pass was 8.82@156.90 with a dead hook with 32 degrees timing.

In my limited experience, very high CR is more sensitive to spark setting. Decades ago, Yamaha road racers set spark to .1mm (.004"), and warned riders that if using WOT below 5,000 RPM the engine would lock up. It did, but it was faster if you're careful.

That's a good running combo for sure but like you said it comes with a cost. High fuel costs, high RPM, original build costs, new and better stuff coming out all the time so we upgrade for a few hundredths, and constant rebuilds. Probably a big reason I'm dragging my feet on my 572. Mines a budget build compared to what the hitters are running and my income is going down faster than it is going up. Heck my Friends are running 4.60's at my local tracks 'heads up" series and drive them often.