Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Sunoco Leaded Racing Fuels
View Single Post
  #9 (permalink)  
Old 09-14-2011, 09:11 PM
cobalt327's Avatar
cobalt327 cobalt327 is offline
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 616 Times in 565 Posts
Originally Posted by adam83
I want to know, when picking the right race fuel (which I've never bought before), is this one of those times I should be following the labels exactly for my particular engine, or do I just buy the highest octane one they have for maximum performance?

Now, I have a fresh 440 +30 in a 73 Duster, somewhere between 9:1 and 9.5:1 comp, ported 902 heads, very nice flowing custom hooker exhaust, torker 2 intake, weiand 1" spacer, holley 850 double pumper, turbo action 3500 stall, 30in tall street slicks, 3.93 diff. It's making around 460hp in the higher rpm range, I dont know exactly where I've never dyno'd it, the power is just a guess but I know Im close...

I run pump gas. I want to see what happens with some leaded racing fuel, and sunoco is the brand I looked up and they sell it in Auburn supposedly so Im gonna go get some. According to their chart, their basic PURPLE 110 octane standard fuel would be what I should get, but I want to know, would it be a bad idea to try out the 116 octane RED maximal??

Im not totally clueless, I did read that the Maximal's description, it's for engines up to 17:1 compression and 10,000 rpm, but from lack of experience, I dont know the answer here, IS THIS ONE OF THOSE "BIGGER IS BETTER" SITUATIONS? Should I stick with the recommended fuel, or get the top level fuel?
100 octane gas would be all that's needed w/the CR you're running, provided that estimate is correct or not much higher. 93 may even be all you need.

To find out you need to run at the track using both fuels under the same ambient conditions. Baseline it on the 93 pump gas (this assumes you've optimized the tune for 93 octane), then use the high octane gas and vary the total timing and possibly jetting to see if it picks up ET. Seat of the pants dyno estimations are basically useless when you're talking about 0.10 second changes in ET.
Reply With Quote