Timing Vs Boost

[Mike 99GSX]

I was reading the recent thread about Dre's new pump gas numbers and something jumped out at me that I didn't know. He said that he is only running 10 degrees timing advance at 27 PSI. I guess I did not realize maybe that the more boost you run, the less timing you should have? Could anyone explain this in a little more detail? For example, on my 50 trim setup, should I be leaning out more at 24 PSI with race gas so that I don't have as much timing. Right now I'm seeing 19 at the top of 3rd. Is there a rough formula for turbo size and PSI vs how much timing will make the most power? If anyone can elaborate I'd love to know. Here's why I ask: Friday I went to the track and ran C16 for the first time. After different advice, I globally leaned out the VPC/GCC settings 4% and turned the boost up from 20 to 24. I ran a 12.38 @ 115 and saw 19 degrees timing at the top of 3rd. Here's the scary part: my EGTs were sky high. Way over 1600 in 3rd and 4th. So I got a little scared and richened it back up 2%. The next run was a 12.25 @ 117, same timing advance and still sky high EGTs. I continued to richen it up my next few runs. The rest of my launches were bad so the ETs didn't tell me anything but the logs and EGTs were still the same. I'm wondering now if I was having such high EGTs from being super rich and that if I would have leaned out alot (say 10%), that it would have brought my EGTs and timing down but I would have made more power? I guess I just got scared to lean the car out with the EGTs that high until I ask what people here thought. Any comments?

 

[Violater101]

Dre is running less timing because he is on pumpgas. You mentioned C16, so you should be able to run decent timing (for me 20-21 degrees) with higher boost levels.

 

[kpt4321]

If you use the VPC/GCC to lean out the A/F ratio, your timing advance will increase.

Dre is running that little timing because he is using pump gas. However, I know several people making close to, if not more than, 400 whp on pump gas, and they are running more than 20 degress BTDC at WOT.

You can run well over 20 on C-16 with your setup.

...Kyle T.