Sounds like the answer is to play with it and see what works best. I had mine up to 18 before the supercharger and it ran ok but didn't like low rpms, 14 seemed to work best. With the sc I'm at 12 with 2 on the boost retard.
When I first started taking my full weight vert to the track it was a stock long block with GT-40 intake, 70mm TB, 75mm MAF, UD pulley's,and a short belt. My best times with this exremely mild set up were in the 13.50's @ 102mph with a 1.82 60ft. This was with 91 in the tank and timing at 16 deg. It was at Cecil County Dragway and the air was in the low 60's. On the last run of the night I put the timing back to 12 deg and my run was a 13.71 @ 100.5 with a 1.85 60ft. despite the air being about 2 degrees cooler. The next time down to the track the air was in the mid 70's and I tried to run 16 degrees again, but couldnt because of a slight ping. So now on the next trip to the track ( just for curiosity sake ) I started with stock timing, and then bumped it up in 2 degree incriments at a time. I was looking at the MPH more than ET at this point, because that tells you weather your making more power. Air was 67-70 for all runs. 1st run 99.98 mph, 2nd 100.64, 3rd 101.85, 4th 102.10. The 4th run was the best. When I tried to put more timing in for the next run I heard pinging and got out of it. Now I realize that this was done with 91, but it is obvious how much of a change the timing was making. I doubt 87 would have let me put that much timing in.
This topic has me thinking that when my 92 LX is finally up and running I may run my vert to see if there is a difference between 87 and 93 and how much timing each will allow and what the benifits are.
Dont get me wrong my vert will be running 87 with the stock timing, or whatever 87 will allow, but it is now just my weekend cruiser, and Im not looking for every last bit of power.
i was just down at cecil 3 weeks ago. i normaly run 87 octane around town at about 12-13* and it seems to run better that way..last time i went to the track i bumped the timing to 14-15* and put 93 octane no ethanol in and it ran slower at the track..
My car loves 18° intitial and I could get it done on 89 octane with no ping as long as the chamber was relatively clean. When it starts to ping, I run some sea faom through and I'm good to go again. You'd be surprised what 2° difference feels like in my car.
As hot as it gets out here, I can't hardly even run 12* BTDC on either of my 5.0's without getting ping, especially if I run 87 octane. I can't run 87 octane even with the stock 10* timing on days like we've had the past week or so (110*F+). I can get by with 89 octane sometimes, but even then I get a little ping here and there. It's only cool enough to run advanced timing in the late fall to early spring months, but the fact that we also get the crappy ethanol blend of gas from October to May also affects things, as well. I'm so sick of constantly bumping up and rolling back my timing over and over again that I'm just going to stick both my cars at 10* BTDC and just run the cheapest gas that I can that doesn't ping, as that's about as good as it's frickin' gonna get.
Ive got mine at 14 and run 89 in it but have been getting a little noise lately. next time im at the track ill try the bumping it up method and see if i can find a sweet spot with the 89 oct.
I have had mine as high as 16
As hot as it gets out here, I can't hardly even run 12* BTDC on either of my 5.0's without getting ping, especially if I run 87 octane. I can't run 87 octane even with the stock 10* timing on days like we've had the past week or so (110*F+). I can get by with 89 octane sometimes, but even then I get a little ping here and there. It's only cool enough to run advanced timing in the late fall to early spring months, but the fact that we also get the crappy ethanol blend of gas from October to May also affects things, as well. I'm so sick of constantly bumping up and rolling back my timing over and over again that I'm just going to stick both my cars at 10* BTDC and just run the cheapest gas that I can that doesn't ping, as that's about as good as it's frickin' gonna get.
One of those would be nice, but it costs money that I don't have. I can't even afford a set of used tires for my '84 right now. And even if I could afford one of those groovy timing adjusters, I could only justify putting one on teh Notch, as opposed to my other car which is my DD - I don't want to pour a bunch of money into my daily beater Fox and then have some random yo-yo without insurance come along and destroy the car during my 30-something-mile-each-way daily commute.