running 110 or 112 octane??
07-12-2011, 08:10 AM
#11
5th Gear Member
Join Date: Nov 2005
Location: MN
Posts: 4,412
E85 has more than proven itself in boosted applications. It's not that uncommon for a boosted vehicle to pick upwards of 40hp (unbelievable as that is) for E85 over 93 oct, with only the supporting fuel mods and a tune to optimize the difference in MBT and the resistance to detonation.
07-12-2011, 08:19 AM
#12
3rd Gear Member
Join Date: Mar 2010
Location: KS
Posts: 555
I run 103 octane unleaded for nothing more than the extra safety of decreased chance of detonation. Extra timing on a race tune, boost, nitrous, all of these push the detonation limit and higher than pump octane fuel greatly helps reduce this.
If you do use it your car must be specifically tuned for that fuel as the stoichiometric ratio is different than pump gas, with that said most leaded fuels like VP's C16 is very close to the pump gas rating of 14.7-1. My car ran like crap on a Bama tune using VP's MS103 until I had Bob Kurgan write a tune specifically for that fuel, after that it has been quicker and even more consistent than ever before.
If you do use it your car must be specifically tuned for that fuel as the stoichiometric ratio is different than pump gas, with that said most leaded fuels like VP's C16 is very close to the pump gas rating of 14.7-1. My car ran like crap on a Bama tune using VP's MS103 until I had Bob Kurgan write a tune specifically for that fuel, after that it has been quicker and even more consistent than ever before.
07-12-2011, 10:06 AM
#13
3rd Gear Member
Join Date: Feb 2008
Location: Delaware
Posts: 801
On spray, you actually will gain from a higher octane. You can run more timing and the cylinder temps will fall. Like jrod said, on spray or boost many decent setups will reach the limit of pump gas and detonation becomes a huge concern. I would stick with vp or sonoco fuels, anything under 110 should be fine with a retune
07-12-2011, 11:58 AM
#15
5th Gear Member
Join Date: Nov 2005
Location: MN
Posts: 4,412
On spray, you actually will gain from a higher octane. You can run more timing and the cylinder temps will fall. Like jrod said, on spray or boost many decent setups will reach the limit of pump gas and detonation becomes a huge concern. I would stick with vp or sonoco fuels, anything under 110 should be fine with a retune
07-12-2011, 02:48 PM
#20
3rd Gear Member
Join Date: Mar 2010
Location: KS
Posts: 555
VP fuels MS109 is approx 105 octane. Leaded fuels are fine on a limited usage basis such as racing only. Regular use will eventually trash the sensors and cats, but it is not like the first gallon that goes through will ruin them.