Will running 100 - 107 octane damage any sensors on my 96 e320? Also those that do run race gas what brand are you using?



TIA

Chad

 

I don't think it'll damage your sensors, but I also think you would be wasting money - it won't give you any extra power.

Make sure it has no lead, or you'll screw up your cat.

 

No ricer answers please. Everone who has ever been envolved in racing should know that 89 or 91 octane compared to 100 unleaded is a big difference. When you have a faster burning fuel it pushes the rotating assembly alot harder and faster which means more horsepower, now a flat hood ornament or "euro" lamps is a waste of money. I don't mind paying to play but I want to minimize damage to my 02 sensor, cat and anything else that might be an issue. Also if anyone is reprograming the fuel and timing values on chips let me know.

 

ricer?

I'm pretty sure higher octane means the fuel burns SLOWER, e.g. the less tendency to knock.

http://www.howstuffworks.com/gasoline3.htm

As long as your engine is running at the optimum advance (e.g. is not retarded due to the knock sensors) higher octane fuel does no good.

Higher octane will allow you to run higher compression, but most engines (except that experimental SAAB engine ) can't change their compression ratios.

Of course, I could be all wrong. ANyone else?

 

Well, after researching a little more,
http://www.diabolicalperformance.com/hotrodoctane.html
It lloks like that in some cases higher octane DOES make a difference.

These guys tested up to 114 octane fuel in a 360 Mopar.

114 octane had 2% more horsepower than 91.

But if you read carefully, again they say that the power increase was because the octane boost hindered ABNORMAL combustion.

So maybe you have some abnormal combustion (knock) going on?

 

If I do have any knock I don't hear it. Usually the computer will adjust the timing if the knock sensor goes off. I'm not expecting the race fuel to add 50+ horsepower but 10 would be nice. With 91 octane available as the highest rating at most pumps here I'm going to have a little knock retard (KR) happening. I don't want that I would like to have it dialed in perfect and consistant for the occasional 1/4 mile run.

 

Ok, I will try some sunoco GT109 should make a big difference a little over $4 a gallon. I only need to use about 5 gallons though. I won't be mixing it with the 91. This is what they recommended at my race gas supplier, designed to be sensor safe

 

I dont belive you will see much of an improvement at all in your time slips, especially on a 320, the computer will not add timing with respect to fuel octane, it is designed to retard timing. And to add, dont knock someone because of a suggetion and call them a liar, thats not fair.

 

what post did you read?

 

Oops, I meant dont call people ricers.

 

I just thought it was funny. I'm not sure I've ever been called a ricer before. I'm not sure what it was that caused Chad to label me that way.

But the octane thing IS confusing and lot of people have misconceptions about it.

 

I run 101 unleaded race gas when I hit the dragstrip. Primarly, to help avoid any possible detonation when I turn up the boost to 9 on my 10:1 compression engine (although I think I have my A/F ratio pretty dialed now, so I'm at pretty low risk even without it). However, I would say that it does help shave about a tenth off of my times over the 92 that I normally run on the street. At least that's been my experience. But remember that I'm running a custom turbo setup with altered timing, so I don't know if it would do much in a stock non-forced induction engine?

Jason

 

By turning up the boost you are essentially increasing compression. Race gas certainly makes sense in your case.

 

You might see a couple of Hp if you run the race Unleaded fuel at 100-103 octane.

And it might help your car run slightly cooler due to the properties of the unleaded race gas, but that is about all.

Jeff
AFM Champion 1998 & 1999
Thunderhill Lap Record Holder (motorcycle)