Been confused by the petrol market
I was on the Sunoco race fuels web page looking at gas and with no alcohol allowed and a diaelectric doo da of 15 or less for LSR gas class
sent them a enquiry.
, the boys from sunoco fuels got back to me today,
Re my Honda CB 750 MG750 I sent them engine specs , dyno chart and also a computer engine analysis etc class gas rules etc
Their responce;
Mark:
From an octane perspective your engine could use any of our fuels. But if you are limited to no alcohol, that eliminates a lot of fuels. We do list the alcohol content of the fuels that have alcohol in them.
On the unleaded side, you could use Optima or 260 GTX. Given the heat, I'd recommend the 260 GTX if you want to run an unleaded fuel.
If you are looking for a leaded fuel, Supreme would be a good choice. It's fast burning which works well in higher-RPM applications.
Re. timing, you don't need to push the timing to the point of detonation. As you're probably aware, there is an ideal timing point for each fuel and air/fuel ratio. A fuel should have sufficient octane to allow that ideal timing point to be reached. High octane fuels will allow timing advance beyond that ideal point, in which case the fuel will still prevent detonation but you will be wasting energy and heating up your motor. So, especially if you run Supreme, don't push the timing to the point of detonation, as I'm sure that point will be well past the ideal timing point.
Thanks for the inquiry,
Mike / Sunoco Race Fuels
For me his last comments were good as on my engine software analysis it showed I had a detonation problem right through the midrange and warned me to back of the advance until 7 or 8 grand ( redline 10,500 rpm) then bring it on. Thats probably why he is making the point on timing.
Anyway I'm happy , I will give the the Pizza Supreme a go,
ciao Johno