Steve Weiner-Rennsport Systems

In the context of racing gasolines, thats not always true. Detonation supression/resistance additives are a major part of the composition of racing fuels for certain, but its an opportunity to add more energy to the formulation and there are several products for doing so.

Race fuel manufacturers are naturally retiscent about discussing the proprietary nature of their products, but sometimes you find engineering personnel who are willing to be helpful and I've had some success at that.

Amber Gramps

DARISC, I'll be down in the morning and will take you behind the woodshed if I have to...

we are going to have breakfast at jay's on carlsbad blvd around 10:30-11:00
I'd love to see you there. it's across from the old Neaman's.

altonj

Well, I am not sure where the answer lies in this argument....

But, I am dynoing my new motor here shortly. I have 94 octane pump fuel available and the dyno shop has VP racing fuel available on the spot. (not sure the octane but will find out)

So, maybe I should tune the motor on the 94, as that will be its steady diet, and then drain the remainder, fill with VP and put it back on the dyno. I am pretty sure the VP is at leat the equivelant to the stuff Douglas is buying at the pump.......

When I do this, and it will be a month or so, I will post the results...........


Cheers

Graufuchs

Sorry doug didnt wanna get your butt dyno in trouble..thanks for the picture though

Amber Gramps

I'm talking the differance from 91 to 95ish. it's a crap shoot. it could be 93 or 97 really don't know. up into the 100(highest legal in california) and 110 range I don't know what it will do....other than be unholy responsive. after driving my chevy astro all week, jumping into my 911 all hoped up on speed(the car, not me) I wake up monday morning with a sore neck. It is such an on/off wide open launch to drive that it hurts.

post the results. I did get a print out from one of my butt dyno runs come to think of it.

Amber Gramps

not sure if this is it butt maybe

DARISC

[QUOTE=Steve Weiner-Rennsport Systems;4471003]Detonation supression/resistance additives are a major part of the composition of racing fuels for certain, but its an opportunity to add more energy to the formulation and there are several products for doing so. /QUOTE]

Yes and yes. My point from the beginning (which is back in the original thread)has always been that WITHOUT adding more energy to the formulation, such as with one or more of the several products to which you refer, simply raising the octane # DOES NOT yield more power, but rather, as you say, only provides greater detonation resistance/suppression.

I strongly doubt that the 100 octane pump gas that Doug has been buying at a gas station has any of these power increasing additives, but is rather the same gas as the 87 and 91 octane gas coming out of the same pump, differing only in having a 100 octane # and will therefore have the same specific energy as the two lower grades since I suspect that it is not custom formulated "race gas", just 100 octane pomp gas - and without the race gas additives to which you refer, will not, CANnot, produce more power than the two lower octane mixes.

Respectfully,

David

Doug - I DO agree on your choice of restaurants. Jay's Gourmet is great!

Steve Weiner-Rennsport Systems

Hi David:

Almost all of the current 100-104 octane unleaded race fuels sold nowadays DO contain additives to improve throttle response and drivability.

If you get an opportunity, call some of the manufacturers such as Sunoco, VP, and Trick. If you get the right person, it will be worth your time.

This subject is FAR more complex than it appears and there is a lot more to the story.

DARISC

That's interesting to learn, Steve.

It leaves me with the question, "Is 100 octane gas, when sold at the typical gas station that we are familiar with (e.g., Doug's station), indeed race gas? Or is it, with exceptions, simply 100 octane pump gas?"

If the former is true, I stand corrected and edified - but Gawwd!, what a price to pay every tank full for, how many hp, ft/lbs?

David

Steve Weiner-Rennsport Systems

Some manufacturers such as Sunoco offer 4 unleaded gasolines; some of which are EPA legal and some are intended specifically for racing. Read this:http://www.sunocoinc.com/site/Consum...UnleadedFuels/

The differences are Specific Gravity, Reid vapor Pressure, and of course, how they behave in the engine (chemical makeup),.......

One would certainly need to know what brand & product Doug is buying to understand what to expect. You are certainly right about the price, but IMHO is all an indictment about the sorry state of normal pump gasolines currently sold in this country. Most of them are now akin to Sperm Whale Urine,...

Mike Murphy

Ahhh, maybe this is a clue as to why racing fuel smell sweet (like perfume) when it's burned at the track, while regular gas smells like...

Amber Gramps

did I start this fire?

David, we got to Jay's about 1:00 not 10:30 as I had hoped. chicken salad and three or four iced teas and I was back on the road to home (I was retreaving the contents of my forgotten undie's drawer fron the condo.)

believe it or not I didn't juice up on car crack before the trip as I had hopped, and you know what, the car still hauls axes. VP Racing is the brand and "Street Blaze" is name of the gas. Is it needed for street driving, no way. Was it fun last week when we drove out to Julian, oh ya. It turned my normally on/off throtle in to a throtle that can read my mind and get the job done the moment I ask, not in a second, but now! Right now! When I say it hurts my neck, this car wants to snap my neck off and make it flop from side to side...no joke.

I gotta take girls to the track. National #'s are on the line

Mike Murphy

When I built my 400 cu.in. smallblock Chevy (that's 6.6 litres for you euro folks) engine, I had ordered 9.8:1 compression pistons. What came were 10.8:1 pistons, and because my budget was limited, I could not afford to have the mechanic redo all the balancing with new pistons, so I left it that way.

That was a mistake.

The car ran well for the first few hundred thousand miles on 93 octane, but then carbon started to build up and I could hear the engine pinging under load. It was only when I ran 97 octane fuel that the car ran without Pinging again...

If someone swears by "butt dyno," then the only way to prove that is to run on a real dyno.

Steve Weiner-Rennsport Systems

Dynos do not measure transients; i.e. throttle response.

We have both engine & chassis dynos and both are valuable tools, but they do not quantify what happens when the throttle is opened up,....

Mike Murphy

So are we also talking about part throttle conditions?

I guess we're ultimately talking about combustion here, which is at the heart of the matter.

This reminds me of the book that "Smokey Yunick's Power Secrets." He says (am I'm paraphrasing here):

"Go into a dyno room, fire up the engine, warm it up, set to full load and then turn off the lights. What you'll see is a dazzling light show of misfires, arcs and tiny explosions from both the spark plug wires and the exhaust system."