The HP Book "How to Modify Your RX-7" takes about those championships and how they used fuel in the low 80's octane rating and premixed which also lowers the octane rating too. They mention they were the only race team using the low octane fuel and everyone laughed until they started winning then everyone switched. Made believers out of the rest of the teams.

 

What school is it? I just found the chart on a google search. I studied in-cylinder combustion for my masters degree at Wisconsin. Most of my friends went to Ford and GM too. I just couldn't give up Colorado for Detroit (or even Ann Arbor).

 

Yes, they do. If you look at the chemical make up of methanol and ethanol in the linked chart above, you'll see they both have oxygen in their chemical structure. They are added to gasoline to help reduce CO in cars that don't use oxygen sensing. An oxygen sensing fuel injected car just sees the extra oxygen as a lean mixture and adds more fuel.

 

Don't blame ya. I lived in one of the burbs around Detroit for nearly two years and decided to move out of state.

The link http://www.me.mtu.edu comes from Michigan Technological University which is located in Houghton, MI in the upper penninsula.

 

looks like we've got a bunch of lawyers here!!!!!

 

Having just read articles on carbon in rotaries and then fuel octane I thought that I should share some history.

Charles F Kettering the inventor of the self starter for the automobile credited his assistant Thomas Midgley Jr. with developing anti knock gasoline.

The following are the words of Kettering. "Ever since we had put the self starter on the automobile, engineers were inclined to blame the engine knock on the battery ignition which was part of the starter. About 1913 we had done some work on the cause of this difficulty but for lack of time it was laid aside. Thomas Midgley and a group of us talked this over one Saturday at lunch and I said ""Why don't you get the old apparatus out of my closet and see what you can find out?"" Engine knock in those days was supposed to be caused by either ignition or carbon. Our preliminary studies had showed that there was more to it, so the first job that Midgley did was to devise a means of determining just what it was.

On the afternoon of February 2, 1923 a car drove into a filling station in Dayton Ohio and the driver said, "Give me five gallons of that new Ethyl Gas advertised on the sign." That simple event is important because it was the first sale of this anti knock gasoline to the public."


PRIOR TO THIS TIME

All engines were slow speed and had explosion chambers built into the head. I read a few years ago that the model T Ford had a four to one compression ratio.

A piston engine has slow piston movement for a long duration while close to top dead center. The old fuel would ignite and hammer on the piston but the piston had not yet turned to the crankshaft two o'clock position so lots of knock and little torque was derived from the fuel.

The new Ethyl fuel had additives in it and the ignition of it was slower so it was a more elastic combustion and this would press against the piston creating more torque.

Now we have the rotary engine that has an explosion chamber that increases in size immediately upon ignition and we should want to use the faster burning fuel.

Another problem with the higher octane fuels is the additional additives that could increase carbon problems.

Just my thoughts and a little bit of history on the matter.

Cheers

Ken McKenzie
www.starapex.com




03-27-04 05:49 AM

 

so if my rx7 is stock i should go with lower octane but if its turbo higher? i need this in english im lost....

 

The answer is that either way there is no need for high octane gas in rotaries. The difference, if any, will be very limited as far as performance is concerned.

Save your money and stick with the 87.

 

Why would he want a styling-challenged poor man's Porsche?