ECUflash 9:1 Peak Ignition Timing

[GSXDNA]

I'm going from a stock compression 2.0L to a 2.3L .30 over 9:1. I'm curious how I can expect my peak timing to change.

I've searched around a bit, but haven't been able to find consistent info.

For example, if I was running 35psi (50/50 e85/91) from an hx40 on my 7.8:1 2.0 with 17* peak timing, what peak can I expect to run at 20psi on my 2.3L 9:1?

I know there are many variables here, but I'm just looking for general guidelines for how increasing compression ratio impacts peak timing. Thanks in advance.

 

[2gjlc]

Strokers don't like as much timing. I had my car tuned at English Racing in 92 octane. I think it was like 10 degrees peak timing on my hx35 stroker with the bolt on housing. Now I'm running meth injection and about 6 psi more.

 

[GSXDNA]

How much boost? (and did you mean 6psi more, or 6 degrees more)?

 

[2gjlc]

I was only able to run about 23 psi with a small spike to 25. Now I'm at 31 but it falls to 27-28 on the top end. Sorry, meant about 6 psi more.

 

[2gjlc]

I just got retuned on Tuesday. I can look at the map and see what they set timing to.

 

[GSXDNA]

Yeah, that'd be helpful. Thanks.

 

[2gjlc]

12 degrees peak timing. This is on 92 octane with meth at about 30 psi. Tuned by Aaron at ER. Sorry about the delayed response.

 

[jery1234]

2.3 10.5:1 cr 94 oct + pure meth injection @ 39psi 10* peak timing .