I have had some good discussions with a few local nor-cal peeps on this, but wanted to see what other CL members think about octane additives. I have spoken to a few who think NOS formula is the best and a good idea every other fill....

My question to the group - what is the best brand (if any) and how often should I add this?

 

this is interesting. i know in LA there are couple of gas station where you can actaully get 100 octane at about 5 bucks a gallon. usually what those well off people do (you constantly see folks with insane cars there, porsche, ferrari, etc...) is to fill up like 3 or 4 gallons of those 100 octane, and they put in 91 octane for the resrt

 

Yeah - I'm not sure if it makes a difference or not, however I do know that when I get towards the bottom of the tank I hear pinging sometimes. Ouch! Probably the crappy CALIF gas!!

 

yeah i hear that too, that's why i usually keep my car half tank

 

I didn't check CL over the weekend and apparently missed Dyno Day in Fremont. Unless your car is pinging you may not be able to tell a difference between running octane boost and not. We need to dyno test or otherwise measure to really be sure.

In the meantime, I will merrily go ahead and pour octane boost with every tank.

 

Hey Chris - welcome back from tropical paradise! I forgot what you originally told me, what kind do you buy? The NOS street or offroad version?

 

I have been playing around with all three versions lately, the street, offroad and race. I have been running the race for about a month with no obvious ill effects. The car seems to really scoot now, but the weather is colder and I got the exhaust done -- so it's hard to tell.

 

Sorry, for those of us still in the dark, can you please explain how the amount of fuel in the tank causes pinging?

I thought that the pinging was caused by detonation (i.e. premature ignition of the air-fuel mix, which is compensated by the engine computer by retarding timing). Pinging happens when the fuel octane and the ignition timing don't match. I don't really see how having a full tank will make you ping less, unless you're running on fumes, in which case it wouldn't matter what octane you run.

What say you?

 

Well, it must be the sympathetic vibrations resonating from the engine, through the frame to the mostly empty tank -- which acts like the sound chamber of a guitar. Hmmm, don't buy that explanation. How about the amount of air in the tank is affecting the air fuel ratio. Don't buy that one, either? Third time's a charm... That pinging sound is actually the traction control kicking in due to lack of weight over the rear tires.

 

My thoughts as well... although I'm not saying this problem doesn't exist. You might try going getting your gas at a different location. Stations that aren't too busy tend to have the "old gas" that's been sitting around for a while. Especially the premium since most use regular. But since it's only as the tank empties... another possibility;
Fuel pumps that are completely submersed in fuel also run cooler. As the tank empties the pump may become exposed, unable to dissapate the heat. A fuel pump that's running hot won't be as efficient.

"Third time's a charm... That pinging sound is actually the traction control kicking in due to lack of weight over the rear tires."redgs4 actually may be on to something... well at least somewhat possibly related.

When the traction control kicks in, one of the functions is, that it retards the timing to reduce power. Since weight is a big factor under acceleration and while having the TRAC off, the timing is advancing at a rapid rate which can cause this pinging. Of course only due to the crappy CA gas we have! Turbo vehicles are much more sensitive to this.

Since the lowering of octane came into effect here in CA I have come across many turboed vehicles left with no choice but to lower boost or add something to raise the octane level. "Octane Boost" is "Octane Boost" they all claim up to 3 or 4 points. You would think your 91 octane is now more like 94 or 95 octane. Yes, it raises the octane alright, but it hasn't gone past 91.5 octane! Adding more will only make matters worse, it's an additive not a gas. Your car won't run right if you add more than recommended.

I also recommend using unleaded race gas as an additive over any "off the shelf"octane boost. As "rominl" has suggested there are Union76 stations through-out CA. that offer unleaded 100 octane gas. Their website has listings...sorry I don't have the link. 76 race gas can also be purchased in a 5gal can which you can store at home. You don't have to use the whole amount, maybe 16oz per tank should do the trick, I don't know. Figuring a 12 oz bottle of octane boost will cost near $10.00, race gas is a better bargain at $5.00 gal or about .89 cents per 12ounces.

Are there any chemical formula experts out there that may be able to tell us how much 100 octane gas it would take to raise the 91 octane up to 92octane?

Sensei

 

Choritsu-shi,

Please forgive my attempt at humor, Vlad asked a valid but pointed question of my buddy Synergy and I was merely attempting to redirect any bad karma.

With regards to the traction control, when it kicks in there is some sort of "sound maker" in the dash area that makes clicking sounds for audible feedback.

I have read the "UP TO" statement on the octane boosters which is why I stick to the better known brands [NOS, for one]. Do you have any references to back up the only 1/2 point gain? I ask because if you are correct then I can save 10 bucks a week.

BTW -- I did a google search on CA, gas and Octane and found the list of stations selling high octane gas as well as a spreadsheet that tells you how much 100 octane to mix into your tank with the lower octane gas.

Peace.

 

[QUOTE]Originally posted by redgs4
Choritsu-shi,

Please forgive my attempt at humor, Vlad asked a valid but pointed question of my buddy Synergy and I was merely attempting to redirect any bad karma.
No need to appologize, you clearly displayed the 's
With regards to the traction control, when it kicks in there is some sort of "sound maker" in the dash area that makes clicking sounds for audible feedback. hmmn....

I have read the "UP TO" statement on the octane boosters which is why I stick to the better known brands [NOS, for one]. Do you have any references to back up the only 1/2 point gain? I ask because if you are correct then I can save 10 bucks a week.

Sorry I'll be more specifc... the term "1 point" is equivalent to 0.1 octane point... I cannot remember where I read this... it may have been on the back of a particular brand or from one of my automotive readings. In my field of work it has always just been a known fact that I never really questioned. Although I can confidently say through actual experience while testing and owning turbocharged vehicles,(especially high boost applications) adding octane boost has not been enough to compensate for the drop in octane we had. I don't want to discourage anyone from using it, if the race gas is not an option. Again, the negative effects are much greater with a boosted applications than with a N/A engine.

BTW -- I did a google search on CA, gas and Octane and found the list of stations selling high octane gas as well as a spreadsheet that tells you how much 100 octane to mix into your tank with the lower octane gas. (phew!) Well that's a relief, I was beginning to question myself... thanks. The results of any claims can have different results, you should try the race gas and then make your own decission. Automotive techs are considered the experts but in actuallity no one knows their own car better than themself.

So you found a spreadsheet? That's great! Would you be kind enough to give the link on that spreadsheet? Thanks in advance,

Sensei

 

this might help out. Anyone heard of Toluene?

http://noclownz.dnsalias.net/racegas.htm

 

has anyone checked the RON & MON of unocal 76 100 Octane?
100 is the average of the two
in actuality i think Unocal 100 is like 94-5 MON
pump gas is like under 90 i think for MON in cali 91(r+m/2)

chevron burns cleaner
76 makes more power
well in hawaii at least
92octane (r+m/2) lucky i live hawaii!!

 

My wife is from Hawaii and I go back once or more a year. Nice place to visit but I think I would go stir crazy. And with all the "undercover" cops I would not last more than a few months.