machinehead

It seem like when I run on race gas (C16) I get different readings on my wideband and have to change my fuel settings to go with it. Anybody else notice this, or is my wideband screwed up?

mkoch1

That makes sense, different octane gas is going to burn differently. If you tuned for regular gas a run race gas you should be fine. If you tune for race gas you can get a little more power out of it but you will need to retune before going back to regular.

I am sure you know but the lead in c16 will kill your cats and O2 sensor.


mark

tcb100

You positivly need to tune differently for different octanes. I had my car dyno-tuned on 93 and all was well, until I put in 108 unleaded and was unable to launch without sputtering. I suspect was drowning the thing in fuel because 108 burns more slowly.

I went back to the dyno with race fuel and all is well now. I use Farrell's three position PMS so setting two is for 93 octane and 12 LBS. and three for the track with race gas & whatever boost I can make.

I sent emails to every race gas manufacturer and never got a concise answer to your question but I think my experience is common.