Re: Pump gas in stock
 

Of course a lot of pump gas has ethanol and I think a lot of it is also oxygenated at different times of the year.

Re: Pump gas in stock
 

Yep. As much as I don't like the cost of racing gas, you're going to need it . That and fuel checks, if you're going to have class runoffs, heads up in the eliminator, qualifying for 128 cars, national records, etc.
Can you imagine what some racers would come up with? Let's see what happens with ERC ,mixed with Nitro, a dash of C25 ...sorta like "gain of function" research ;-)

Re: Pump gas in stock
 

It’s about time we hear from a certain E/SA Camaro racer that picked up ALMOST 3 tenths with a Pro stock ERC blend that he stumbled upon. Not calling him out by any means but MAYBE he will share his story, OR MAYBE not ….

Re: Pump gas in stock
 

Good evening,
Yes pump gas in a low to mid compression engine is faster.
I used to get pump gas to pass by pumping air into it like a fish tank. The oxygen would boil off some of the chemicals in the pump gas and it would barely pass. Then NHRA started asking what I was putting in the gas to make it pass, I didn't have the heart to tell them it was what I was removing. Pump gas is no longer "gas " its fuel! There are some many chemicals in it that there isn't enough room for Gas. So the last time I tried to run it and NHRA told me - NO MORE PUMP GAS.
Its possible at this point that with all the chemicals in pump gas, maybe NHRA feels that they can't police it. Any way Its a heck of a lot cheaper and it would make sense (economically) to use it, but policing it is probably the root cause for not allowing it. That's pretty much my take from what I experienced in the past.

Respectfully,
Henry Kunz 1534 H/SA

Re: Pump gas in stock
 

I guess it isn’t a big deal. I’ll use pump gas when bracket racing and use race fuel at NHRA events. Thanks for the discussion.

Re: Pump gas in stock
 

Darrell, regarding your question about pump gas being quicker than race gas this is my assessment based on study and some actual race experience. Race gas is really about “octane rating” to prevent detonation and not about being more powerful.

With the laws and liabilities limiting lead content the race gas companies had to start using lots of “additives” to boost the octane level, that’s also the sweet smell you get. Today there isn’t much “gas” in race gas, another reason it cost more. These additives hurt power in a couple of ways they burn slow during combustion which changes their pressure rise on the piston and spreads it over a longer period which helps with potential detonation but not power. You typically can run a little less ignition timing with lower octane fuel. Actually the biggest reason is lower octane pump gas typically has more BTU’s of energy per pound than our legal race gas! So in your case with relative low compression you don’t need the octane to counter detonation it then makes sense that it will be faster when used. I proved this to myself when living in Denver as I took race gas out of my stocker and replaced with pump gas and picked up a tenth! This was back before specific race gas’ was mandated by NHRA and the old pump gas was still legal.
Why then do we run race gas? A couple of reasons, when pump gas had to comply with clean air regulations and started adding oxygenated additives, i.e. corn alcohol + other things NHRA’s compliance testing at the time for fuel went out the window. By them restricting us to Race gas they could set tight standards for each and compare when testing at the track, that’s why we have to declare our fuel type and brand. The other reason I suspect is they saw an additional money $$ source from the Fuel companies as each has to pay to be on the “accepted” fuel list.

I'm not saying you cant add "stuff" to gas and make it more powerful such as ERC and VP does with some of there highly originated fuels but those are thankfully not on our approved list as they are harmful and more expensive.

Hope this helps and yes there is more to the story but this is my quick take on your question.

Jim Parsons

(Past FIA international Fuel and Lubricant Committee member)


FYI: I tried sending this to you as a private message but it said you box was full.

Re: Pump gas in stock
 

Excellent post by Jim Parsons.
I knew the basics, but that spells it all out.

Now, for the other experts on this subject, what is the low end brand that will pass , or be passed off as something else? I had heard that, a while back, some guys were using AV 100 LL , and calling it something else on the list. Apparently, NHRA figured this out, and put a stop to it, somehow.
PM me, if you don't want to post this info ;-)

Re: Pump gas in stock
 

The lower the CR the quicker a peak cylinder pressure will decay. If I can have a lower peak cylinder pressure but have it at a point farther ATDC it is possible to have the same if not more turning force on the crank. In many cases peak cylinder pressure is 10 to 14 ATDC where a good amount of that force is trying to push the crank out of the block. Remember how the rod crank angle plays into using cylinder pressure as turning force.

Stan

Re: Pump gas in stock
 

Let me address one other thing regarding fuel. Racers are very creative. The fuel in the cell /tank is not ALWAYS the fuel that the racer submits for fuel check. ….

Re: Pump gas in stock
 

I don't understand............................;-)