C12 vs MS98 vs Mix?

80Jr and Sr, 125 Senior, Stock and Masters

Moderators: Brian Traw, Mike Hewitt, Tom Dunlap, John Bartos, Rick Miller, Garrett Boone

Post Reply
Patrick Roth
The master poster
Posts: 149
Joined: Thu Oct 13, 2011 5:47 am

C12 vs MS98 vs Mix?

Post by Patrick Roth » Fri Jan 15, 2016 2:40 pm

It's been a while since the last activity on this forum so I'm hoping to start a little debate. What are people using for fuel? Straight C12? Straight MS98? Or a mix?

When I ran a 99 cylinder, I used straight MS98. I never had any issues from leaning out the main jet.

Now that I run a 01 cylinder, I am mixing 50/50 MS98/C12. I started out with straight MS98 and I never had any issues but was always cautious in pushing the limit. I tried running straight C12 but the spark plug had a bunch of deposits and couldn't get it to burn very clean (albeit I didn't tinker with it too much). It's my understanding the best ratio is the lowest octane that doesn't detonate and am curious if others have found the "magical" mix ratio? 50/50 is convenient to deal with, but in speaking with others it sounds like several are running less C12 (ex: 1-2 gal C12 to 3-4 gal MS98).

For what it's worth, my fastest lap times were when I was running straight MS98 (01 cylinder) but I'm hesitant to chalk this up to the fuel...

Jean Michel Gaston
The master poster
Posts: 207
Joined: Fri Mar 04, 2011 9:13 am

Re: C12 vs MS98 vs Mix?

Post by Jean Michel Gaston » Tue Jan 19, 2016 11:52 am

straight 98 for me. No issues. I'm slow, don't listen to me

Patrick Roth
The master poster
Posts: 149
Joined: Thu Oct 13, 2011 5:47 am

Re: C12 vs MS98 vs Mix?

Post by Patrick Roth » Tue Jan 19, 2016 4:11 pm

Ha!!!

david mckee
The master poster
Posts: 101
Joined: Sun Dec 30, 2007 11:12 am
Location: hockley texas

Re: C12 vs MS98 vs Mix?

Post by david mckee » Wed Jan 20, 2016 5:29 pm

I hear coconut oil works real well ! ;)
David McKee

Harry Ramirez
Posts: 19
Joined: Mon Nov 11, 2013 3:42 pm

Re: C12 vs MS98 vs Mix?

Post by Harry Ramirez » Tue Feb 09, 2016 7:58 am

Aha, coconut oil!

Running straight C12 with 0 issues regarding detonation or spark plug deposits. When we run too lean there's no damage, just performance issues.

Scott Boone
The master poster
Posts: 285
Joined: Sat May 05, 2007 11:23 pm
Location: Houston, Tx

Re: C12 vs MS98 vs Mix?

Post by Scott Boone » Thu Mar 10, 2016 9:22 pm

c12 for sure. you can get same power from both without the fear and cost of detonation.

Brad Johnson
The master poster
Posts: 335
Joined: Wed Aug 08, 2007 1:59 pm
Location: Magnolia, Texas

Re: C12 vs MS98 vs Mix?

Post by Brad Johnson » Thu Mar 17, 2016 5:44 pm

If the club sticks with SKUSA rules, they've changed the spec fuel to C12 only. No more option.

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest