Turbo timing curve
 

Curious what the turbo guys are running for timing under boost. Im running a 440” (4.185” bore x 4” stroke) with Edelbrock old style chamber heads. 10-1 compression with Butler spec’d solid roller. Blow thru on E85. What kind of initial timing and timing under boost is everyone running?

505cid, 10.5:1 DCI RAV Heads, C16 fuel.

9:1 - Initial 6 degrees @ 22 psi 23 degrees . 30 psi 18 degrees . 35 psi 13 degrees. With the new Edelbrock head. The older design head was different you can use more timing..

What fuel are you running Charlie? Did you mean 36 initial? That where I’m at but I’m pulling more timing right now to be safe. I’m at 18* at 18 psi and down to 14* at 25 psi. Plugs looks decent but I think I can add some timing.

I run 20 degrees under full boost at 17 psi currently.
I’m at 34 cruise and I get 17 mpg. W 160 lb hr injectors.

What your combo? What fuel are you running?

What plugs are you guys running? I’m using NGK R5671A-10.

When i said 6 initial i meant at idle . Im at 34 degrees cruising . I use E85 fuel.

If you ask me you're timing settings are really conservative with the old style E head.

With the older version head i was at 23 degrees @35 psi . But dont listen to me , work up into it by reading your plugs. Im sure you already know this but i just have to say it.lol

At 25 psi i was at 24-25 degree ( old head )..

I use 8 heat range plug. I have used #7's in the past .. Only on E85 fuel ...

Here's one of my center plugs also another picture of it with the threads cut off so you can see the ring . it's just under an eighth inch in width ring around the base.

Locked at 32 with the btm pulling back to 22 at 15psi. 8.7-1 compression with 93 pump gas. I also add meth injection starting at 8psi.