Jesus Christ!!!!!! Talk about rotary illiteracy. Just go to your local speed shop and buy VP Racing fuel, you will feel the difference. For everyday use get 93 octane. When a rotary engine knocks at high RPM's it means that the engine is lean on the secondaries. LEAN IS BAD FOR HOUSINGS AND APEX SEALS!!!!!!!

 

My previous rx7's(Both 86 models) I ran nothing but 87 octane. Now I have a 91 NA, I still run 87, but the other day I used some 93 and noticed a few things. The idle was perfect, the car started in under a second and ran incredibly smooth the whole time. I am curious as to if there is a difference between the series 4 and 5 on the fuel issue, because the 91 has more pros than cons on premium(and my timing is not advanced at all

 

Exactly! I noticed the same improvements in my 91' NA when running the 91 octane.

 

Remember guys the higher the octane the more clean it will burn.

 

Hey, i was wondering how you would advance the timing if your using the higher octane... ??? And i nomally put in around 92 to 97 octane... The higher the octance.. the more hotter the gas burns... I also have a 91 vert and how do you advance the timing? and how much... will it help out in low end tourque ?.... I need more low end tourque...

 

Illiteracy? Goddamnit! First, LEAN is not bad for ANYTHING in a rotary. Perhaps bad in a boinger due to high EGTs, but LEAN does no harm. DETONATION does harm. PREIGNITION does harm. LEAN does nothing but parhps lead to the previous two cases. If you want to spend $4/gal on your N/A rotary, be my guest. But you don't know what you're talking about. Ask Jim Downing for God's sake! He runs 85 (r+m)/2 octane fuel in his N/A racecars!!!

You're an idiot.

READ THIS THREAD: https://www.rx7club.com/forum/showth...threadid=44906

I'm SORRY to flame (again) but a simple SEARCH would have avoided the spread of even MORE misinformation on this forum.

Brandon

 

Actually, higher octane usually burns a bit cooler due to incomplete combustion and lack of BTU's, but that is not always the case. You will need to try different brands of gas to see what you get on your EGT gauge. I wouldn't recommend advancing your timing unless you have the proper experience and equipment to do it safely. An aftermarket EMS and a local engine-smart mechanic would be a good way to start.

These links will give you a better basic understanding of the subject. Hehehe, please try not to injure yourself when your jaw drops upon learning that higher octane gas usually yields LESS performance.
http://www.howstuffworks.com/question90.htm
http://theserviceadvisor.com/octane.htm#1

 

Yes, your Profile says that you are a male, but it also says that you are an engineer, so I hope that you will understand why both of those statements are in question at this point.

Several forum members have already attempted to explain the octane rating numbers to you, but you seem to be more intent on criticizing everyone rather than listening.

The stock compression ratio for the Series 4 NT is 9.0:1, while the Series 5 NT is 9.7:1. Your responses will also vary due to tuning, engine condition (hot spots), local meteorological conditions, region (pump gas varies with different state and country regulations), season (winter gas is usually different), and the fact that the average Joe doesn't understand that the octane rating is purely an anti-knock rating and has nothing to do with clean burning (combustion efficiency), power (heat energy BTU/lb), or cool burning (latent heat of evaporation).

 

Cool.. thanks... hey, read my thread just posted "Help: Low end torque"
I need help on that subject...
thanks Evil Aviator

 

Why the hell do you use 93 on a daily driver? STock NA cant burn the high octane

 

87 is fine for a stock motor. You don't need anything more unless you have SERIOUS mods.

 

Yeah... well, now you should be even MORE sorry to flame. WARNING #1.

Brad

 

*more power, but need to use higher octane if advancing*

- kahren

This is a direct quote from a different thread..I am not trying to flame, but why ask us what we run, then tell us we are wrong? And if you are knowledgeable on the subject...Why ask at all?

Rat

 

The lowest one.

 

'nuff said

 

Well, most of you should of read my rev'ing thread that I posted earlier.
My end result was using higher octane because I thought I was knocking at 7k.
Well, I've been using 91 or 94 since then. But I find the car don't rev as high as before. So I changed back to 87 today.
My car pulls nice to redline now.

My reasoning:
Injectors were dirty. Since higher octane burn cleaner and hotter, it cleaned out the engine + injectors. While it is cleaning, obviously it made the car run better. But after it's clean. It's better to go back to 87.

That's my theory.

 

it seems a few of u seem that u are knocking at high rpms, that coudl be due to carbon buldub and raised compression from stock, thats why when u tried higher octane u saw improvement cause u were not pre igniting the fuel before the spark went off anymore. higher octane WILL make your engine run more "stable" in this case. higher octane does not burn "cleaner" as some of u guys put it...it MIGHT run better in YOUR car if maybe your timign is slightly advanced or u have buildup in your motor and therefore higher compression. chaning octane numebrs will usually effect either low end or top end , dependign on wha tu prefer and to make the engine last longer depending on your driving style. but these are all minor point and no one cares about this. that is why engineers that desing these motors and diffrent octane fuels are called engineers. i guess my search on who used which octane , well , was pretty much worthless , because i didnt not get much feedback other then a lot of flaming goign on. oh well . happy rotoring, u are the weakest link, goodbye

Jrat
---------
*more power, but need to use higher octane if advancing*

- kahren

This is a direct quote from a different thread..I am not trying to flame, but why ask us what we run, then tell us we are wrong? And if you are knowledgeable on the subject...Why ask at all?
--------
what thread? and umm i belive my original quastion was what octane u use, but this thread has turned out to be something else now.



evil avaiator
------
Several forum members have already attempted to explain the octane rating numbers to you, but you seem to be more intent on criticizing everyone rather than listening.
-------
i never asked about octane rating numbers and what they do, my quastion was plain and simple, "what do U fill up with". and the same applys here that this discussion is not what i was lookign for. and the misinformation posted throughout this thread is ridiculous. i hope guys
who did not understand the concept of octane are now enlightened and
know what octane to use.

 

Yes, but you had nothing to do with enlightening anybody. All you did was bait for what you viewed as incorrect responses, criticized them, and then waited for others to add their enlightening responses and links. Please refrain from using this format in the future. If you have any technical information to impart, then simply post it.

 

umm lets see, my quastion was "what do u fill up with" a simple numebr such as 87, 89 or whtever it is u put in your car woudl do. my quastion was NOT "how do internal combustion engiens work, and plese help me select the right octane"> SO, that means the answer i was looking for is a 2 digit number. not paragraphs of text people flaming each other and trying to explain one another what they think/know or information they got some other place. if i did criticize anyone, which i dont think i did btw, then my fault it is, but once again this thread has failed to serve its function. i did not want to post any technical information of any sort in this thread. we shall meet again

 

 

87 octane - for over 47,000 miles now. Car is stock n/a as the post originator was looking for =)