opinions on race gas...

[highintenzity4]

Almost done putting the motor back in and now its time to start thinking about which fuel to use...Im running a 60-1 turbo with a built motor and plan on running about 30psi... The 3 fuels Im thinking of going with are c12, c16, and the sunoco standard leaded fuel which is i think 110octane... Thanks guys.

 

[92awddsm]

C16. It was designed for turbo/supercharged/nitrous applications where the c12 is more for just high compression-n/a applications. And the sunoco 110 is in the same boat as the c12. You might be able to get away with the lower grade fuels as long as you have a good tune and a fairly efficient fmic but why chance it when the c16 is available. I was able to run cam2 purple, 114 octane at 28 psi with my 60-1 but any more boost was stating to cause knock. The only reason I did that was because c16 wasnt available to me at the time.

 

[TalonJohn94]

Have you ever heard of "Rocket" racing fuel. It is for sale at a Tri-Par station in Slinger, Wisconsin - by the Slinger Speedway?

I don't know if it is leaded or not. I want to use it, but don't want use leaded fuel. (even though I have no catalytic converter - I heard of plugged fuel injectors)

 

[danielbui]

leaded fuel will kill any O2 sensor or wideband. the car can run on leaded fuel but not recommended.

any grade race fuel (even 101) is better than 87, 88, 89, 90, 91 octane fuels.

 

[Kev90sc]

I will vouch for leaded fuel killing O2 sensors. Has happened to me twice. C16 is excellent fuel but will kill an O2 Fast!

 

[mirkoelek]

I will vouch for leaded fuel killing O2 sensors. Has happened to me twice. C16 is excellent fuel but will kill an O2 Fast!

how fast? i do have wideband too.
1 galon of c16 should be ok(just for one night of drag racing) , right?

 

[sweet97]

I've run anywhere from 2 -5 gallons of Sunoco 112 leaded in every tank this summer with no ill effects on my 02's, stocker and wideband. I understand denso makes an 02 that will take leaded fuel. 1 gallon of c-16 should not cause damage. I use 2 gallons of the race and it makes a world of difference for tuning and power.
Worst case is I buy replacement 02's. Replaced the stock one simply because I did not know it's age. The wideband 02 has held up fine. For a night at the track I would use the best fuel I could get and not worry. I do believe we have sunoco 100 octane unleaded around here also. mark

 

[mirkoelek]

is there big diference between c16 and 101 unleaded

 

[92awddsm]

is there big diference between c16 and 101 unleaded

It depends on how much boost you plan to run and what ic you have. 101 would be good for street at higher boost levels but It will not work at 30 psi on a 60-1 unless you have water injection(or equivilent) and a good tune.

I see all these people post about how leaded gas is bad for the o2 but how many of you have a 60-1 and plan to or have run 30 psi? I personally would rather replace an o2 sensor than 4 pistons but that is just me. I have also ran about 20-25 gallons of leaded fuel through my engine with the same o2 sensor and have yet to have problems. Like I stated before, go with the c16 or go in for a rebuild. At those boost levels, you will need either one or the other.

 

[paul s]

I'm running the 60-1(gt13) at 24psi and 94octane sunoco unleaded and only get very minimal knock(3 counts 1deg) at top of 4th 6500rpm when its very hot out..

 

[sweet97]

^92awddsm just answered this thread's questions!^ Mark

 

[mirkoelek]

i was going to run 25psi with evo16g, stock internals

 

[92awddsm]

I'm running the 60-1(gt13) at 24psi and 94octane sunoco unleaded and only get very minimal knock(3 counts 1deg) at top of 4th 6500rpm when its very hot out..

I also run 24 psi but on 93 with very little or no knock. I have found that over 25 psi, fuel choice becomes a big concern. Again, it basically boils down to how efficient is your set up. Not just ic but cylinder head porting also plays a big role in it.

i was going to run 25psi with evo16g, stock internals

Every car is different so the best info I can give you is run the 101 and start increasing boost slowly. Keep tabs on knock and timing while you are increasing boost to see whow well it responds. You will probably end somewhere around 22-23 psi but then again, you might be able to run the 25 psi with no problems. But, the c16 should get you there without any issues as long as you are tuned for it.

 

[sweet97]

Paul and 92awddsm at what rpm are you guys reaching 24 psi? Also 92awddsm what does head porting have to do with fuel selection? I have a Buschur stage 3 head so it is ported and polished. Not many miles, less than 1000. I am selling my 60-1 and am going to run a Holset HX-35/40 which I have sriven a bit but it blows open the stock 1G bov over 19psi but I just bought a Forge BOV through GREperformance. It's a beautiful valve, polished billet aluminum and has 4 springs and 2 shims with which to make adjustments so I will be able to run 23-25 PSI with a coupld gallons of 112 octane added. Just can't see what the head work does to affect the choice of fuel. Great to learn something new! Thanks guys. Mark

 

[92awddsm]

Paul and 92awddsm at what rpm are you guys reaching 24 psi? Also 92awddsm what does head porting have to do with fuel selection? I have a Buschur stage 3 head so it is ported and polished. Not many miles, less than 1000. I am selling my 60-1 and am going to run a Holset HX-35/40 which I have sriven a bit but it blows open the stock 1G bov over 19psi but I just bought a Forge BOV through GREperformance. It's a beautiful valve, polished billet aluminum and has 4 springs and 2 shims with which to make adjustments so I will be able to run 23-25 PSI with a coupld gallons of 112 octane added. Just can't see what the head work does to affect the choice of fuel. Great to learn something new! Thanks guys. Mark

Head porting affects the efficiency of the engine. With good port work, the fuel atomizes at a faster rate with less puddling which in turn also helps reduce detonation. Also, a smoothed combustion chamber also reduces hot spots which reduces detonation. If the intake charge is completely atomized, and no hot spots in the combustion chamber, generally you can run a lower octane fuel than you could normally run in a stock engine.

When I speak of hot spots, those are the sharp edges in the combution chamber or on the pistons that come from either a rought casting or just from machine work that was done to them. These sharp edges hold extreme amonts of heat and can cause detonation as soon as fuel reaches them.

And for those that dont know or are just a little confused, detonation is more known to the dsm community as knock. It is caused from preignition(before the piston reaches tdc) of the fuel/intake charge. This can be caused from excess droplets of fuel(not completely atomized), sharp or rought areas in the combustion chamber that will hold excess heat(hotspots), high ignition timing, too hot of a spark plug, excess boost, lack of fuel, too low of octane fuel(lower the octane, the lower the flash point), and a mutitude of other things. If anyone wants to know a little more, pm me and I will try to explain the best I can of what I know.

 

[loweperf]

Head porting affects the efficiency of the engine. With good port work, the fuel atomizes at a faster rate with less puddling which in turn also helps reduce detonation. Also, a smoothed combustion chamber also reduces hot spots which reduces detonation. If the intake charge is completely atomized, and no hot spots in the combustion chamber, generally you can run a lower octane fuel than you could normally run in a stock engine.

When I speak of hot spots, those are the sharp edges in the combution chamber or on the pistons that come from either a rought casting or just from machine work that was done to them. These sharp edges hold extreme amonts of heat and can cause detonation as soon as fuel reaches them.

And for those that dont know or are just a little confused, detonation is more known to the dsm community as knock. It is caused from preignition(before the piston reaches tdc) of the fuel/intake charge. This can be caused from excess droplets of fuel(not completely atomized), sharp or rought areas in the combustion chamber that will hold excess heat(hotspots), high ignition timing, too hot of a spark plug, excess boost, lack of fuel, too low of octane fuel(lower the octane, the lower the flash point), and a mutitude of other things. If anyone wants to know a little more, pm me and I will try to explain the best I can of what I know.

I think your post just needs a little more clarity. Detonation is referred to as knock but it is not from preignition. Preignition is igniting the fuel mixture before the spark occurs,not before TDC. Detonation is the uncontrolled burning of the mixture. Preignition can cause a knock but most knock people hear is from detonation.

 

[Maglin]

I think your post just needs a little more clarity. Detonation is referred to as knock but it is not from preignition. Preignition is igniting the fuel mixture before the spark occurs,not before TDC. Detonation is the uncontrolled burning of the mixture. Preignition can cause a knock but most knock people hear is from detonation.

This is true.. I was going to say the same thing. I used to think pre-ignition caused most knock but it turns out the uncontroled flame front on the top of the piston bouncing back and forth from one side to the other is what causes detonation. Also Pre-ignition usually ends up with a holie piston or a rod through the block.

 

[92awddsm]

I think your post just needs a little more clarity. Detonation is referred to as knock but it is not from preignition. Preignition is igniting the fuel mixture before the spark occurs,not before TDC. Detonation is the uncontrolled burning of the mixture. Preignition can cause a knock but most knock people hear is from detonation.

If I wanted to write a book, I would have clarified everything that I wrote. I was just trying to give a brief explanation of what I was talking about.

Preignition is a form of detonation. Preignition is also an uncotrolled burning of the fuel mixture. If it was a controlled variable, it wouldnt happen. I stated before tdc instead of before spark to help some of the unexperienced understand easier.

But just to clarify for you, preignition is when the intake charge ignites before the ignition system sends current to the spark plug. This can happen anytime before tdc since most ignition systems will fire the plug anywhere from 5* to 35* of crankshaft rotation before tdc. Now, isnt that easier to understand?

Now, detonation is like preignition but the charge ignites in a more explosive manner. at the same time, preignition is also ignited in an explosive manner, just not quite as much due to the lower cylinder pressures. Detonation usaully happens within 5* of ignition. Either way, both cause the same problems but preignition is more likely to damage engine bearings. Both will cause knock and both will burn pistons and break rings.