octane questions

ghanlon · 08-22-2001, 08:39 AM

A few weeks ago while participating in a board discussion "lower octane fuels make higher power" I was informed by Natchamp
(mark) that adding octane boost 104 to a tank of premium (91 octane) would only increase my octane level to 91.2 or 91.5.
I checked into it as he suggested. I emailed Gold Eagle Marketing Dept. (They distribute the product) and they ensured me that I defanitly was getting an octane increase around the 100 mark as I had expected. (In actual use, I put in about 1.5 containers for every full tank)
So guys who is right here. Am I getting my chain yanked by Gold Eagle or are Natchamps figures wrong. I would really like to know because if this stuff is doing little good I will stop using it at 10 dollars a container.
I had also mentioned that my car is an 81 930
and the sticker in the gas cap states minimum 98 octane. One other member asked if that was american or european spec? Whats the differance? Can someone help me out here?
Thanks everyone
Gary

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ghanlon

nhromyak · nhromyak's Garage

Are you sure your car specifies 98 OCTANE?

I think it says 98 RON (Europe spec). I believe this is the equivalent of 91 or 92 OCTANE.

BTW: if you do run higher Octane, then you should be able to run some higher boost. I am sure one of our many fine engineers on this board will have a better answer for you.

Have FUN!

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Nick Hromyak
'85 Carrera 7 & 9 Fuchs
Havin' Fun in Sacramento

lsolon · 08-22-2001, 09:54 AM

Here's my take on this issue and it doesn't pertain to a porsche. I have an 88 saab spg-turbo. I have modified it to a point where I'm now seeing around 200hp compared to 165 which was stock.Remember this is a 4 banger w\145,000 miles. I run 92 everyday. It runs very good with that gas. If I add octane boost("the outlaw", which I think is the best) I'm able to boost higher(18.5-19.5psi) and sustain the boost pressure longer than with just 92 octane(15-17psi). Not sure what increase in octane I'm getting by dumping this stuff in but, I can feel a great deal more power. The question is:"do you feel a difference by adding this to your tank?"

lsolon · 08-22-2001, 09:56 AM

Forgot to add this:http://home.kscable.com/ssutton/miata/engine/toluene.html

Check it out

Bill Verburg · Bill Verburg's Garage

Some reading for you;

http://www.vtr.org/maintain/gasoline-octane.html

http://home.kscable.com/ssutton/miata/engine/toluene.html

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Bill Verburg
My Home Page

My Pelican Gallery page

My Porsche Owners Gallery Page

ghanlon · 08-22-2001, 11:54 AM

The label in the cap says min 98 ROZ/RON.
Thanks for the lesson. As far as noticing the power increas its hard to tell. When I punch it hard and the turbo kicks in it always feels like a rocket on rails. Thanks for all the info .
Gary

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ghanlon

89Targa · 08-22-2001, 05:35 PM

I read the Toluene document that Isolon and Bill posted. Sounds like the advantage of higher octane (for a non turbo car) is reducing the need to retard the spark. Seems like there would be a point of diminishing returns when the octane is high enough that the spark no longer needs to be retarded (maybe I am the one who is retarded). Any one with an idea as to when that point is reached for a stock ignition system? Maybe it is the "minimum" octane rating for a particular model year car?

Tom

Natchamp · 08-22-2001, 09:57 PM

Ghanlon, aside from the effect and need for higher octane debate, my statement and claim is correct and I stand by them. I originally posted those, and others I beleive, urls for information. Just do a search on octane boosting on the net and you will have more information than you need. NONE of the off the shelf boosters will raise your octane more than the points they claim. The key word here is points, which is not the same as whole numbers. There are only 2 real good ones (NF and Nulon) and both are in Australia. I contacted Nulon and they are not set up to export to US. Check out this link:

http://www.vtr.org/maintain/gasoline-octane.html

I decided to try Tolune because of the numerous reasons in the research. Try it at your own risk. I am still in the process of tuning the Beast and haven't tried it yet but should shortly. I want to get it running good on normal gas first with out putting yet another variable into over 2,000 tuning points!

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Mark
The Beast
mark@hargett.com

Dave951M · 08-25-2001, 03:01 PM

I've been following this discussion a bit. From what I've been able to find, it does seem that toluene is the main ingredient in most of the off the shelf boosters. I just worked up the courage to try it myself today. I put one gallon of toluene in the tank of my 951 and topped it off with 92 premium at Chevron. The tank on the 951 is about 16 gallons. The result thus far- no noticable change for about the first 10 miles or so. Then there was a definate change, the car feels faster, the turbo does spool up about 500rpms lower than before and the exhaust note sounds a bit different. This is entirely anecdotal evidence to be sure, but it does seem to help.

Dave951M

Natchamp · 08-26-2001, 09:20 AM

Dave, did you use any type of lubricant? You onlt ran @ 6% so its not that big a deal but you might consider adding some if you go any higher. The general consensus I found is that 10-30% is a safe range. Some people use marval mystery oil bucause it lubricates well and burns clean too.

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Mark
The Beast
mark@hargett.com

Dave951M · 08-26-2001, 06:45 PM

Mark- I've used Marvel Mystery Oil in other sports cars and it's pretty good stuff when getting on the ragged edge of reliability. I don't see any reason why it wouldn't help here too and I'm going to mix it when I go to the 12% level. The reason I'm trying this out is that I intend to start modifying my 951 now that the original mechanical issues are resolved. Having a fuel that I KNOW is over 100 octane makes for that little bit of insurance against knock and detonation when dialing up boost levels. From my past experience in the SCCA and wrenching, the assertion of one of the websites that all racing gas isn't created equal is absolutely true. Maybe that's due to slow turnover of the stock perhaps. Anyway, it's just a step in the process, this week I'll cut a set of wastegate shims from .030,.060, and .090 stainless on the laser at work and order a set of chips, only which ones remain undecided.

Dave951M

Natchamp · 08-26-2001, 08:55 PM

Dave, sounds great. All you need is a Haltech!

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Mark
The Beast
mark@hargett.com