Alright I finally took my car to the local drag strip, now I only ran it twice since it so busy, but judging by my mods in my sig what do you think it ran... https://www.nopistons.com/forums/pub...#>/BURNOUT.gif



I'll post the actual times after I get a few good guesses, thanks!

it depends on the weight, but 14's?



mike

Low 15's to mid 14's. But still better than a Mustank. https://www.nopistons.com/forums/pub...#>/biggrin.png

14.9 @92. mph

I dunno. I'm gunna say 15.0



Is your 86' engine ported? You have the same stuff i wanna do. And i eventually would like to get her ported. Lot's more Power than.



Any way. yeah i say 15.0

60 foot - 2.27

330 foot - 6.14

1/8 mile - 9.47

1/8 mph - 73.61

1/4 mile - 14.82

1/4 mph - 91.76



Damn good guesses guys... The motor is all stock except for the cone intake filter, and exhaust.



and weight is around 2450... last time i checked

haha, those were good guesses. good time too https://www.nopistons.com/forums/pub...IR#>/bigok.gif



mike

Damn, I am good. https://www.nopistons.com/forums/pub...1047683894.gif

is that on slicks or street tires?



Shift mad yo! https://www.nopistons.com/forums/pub...#>/BURNOUT.gif



Raul

Street tires spinning hard

just normal pump fuel as well?

damn good run time. That's a quick little first gen. my guess was close..lol



And you'll sure as hell kick the crap out of my car! lol

the lowest octane, conoco pump gas... I'm pretty happy with the way it runs, but you always want more (speed that is)

Need to run it on 94 pump gas and see how it goes. https://www.nopistons.com/forums/pub...#>/biggrin.png https://www.nopistons.com/forums/pub...#>/BURNOUT.gif

It will be slower, and less efficient.



What's the best fuel for my rotary car?



ANSWER:



It depends. If your rotary Mazda is equipped with a turbocharger, all the normal rules about octane apply. Use the highest available octane premium fuel for best power and best protection against the ravages of detonation. You may find slighly better fuel mileage using lower octane, but you need to be very careful about using the available power on lower octane. If you are good at exercising restraint, you can save a little money on a long trip using regular, but it's probably best to stick with premium for normal use.



With the NA rotary, the highest octane you should use is US pump (AKI) 87, typically RON 91 outside the US, no matter how heavily your engine is modified. Octane in excess of any engine's actual requirement is always wasted. The issues of purity and additives in more expensive fuels are entirely separate issues. There's no reason not to want either in a NA rotary.



The rotary engine's high turbulence combustion chamber provides a very high resistance to detonation. Its duration of combustion is also longer, remembering that the rotors turn at 1/3 of the tachometer reading, and the slow burn* of high octane is undesirable in it. Pump 80 octane is more than sufficient for most of them. Best power and mileage is usually produced with the lowest available octane.



Many serious rotary racers bring their own low octane gasoline to tracks that supply only racing gasoline. From "How to Modify Your Mazda RX-7", by Dave Emanuel and Jim Downing, HP Books, 1987, ISBN 0-89586-383-9, p 47-8:



". . . the best results are obtained with conservative spark-lead calibrations provided the engine is fed a diet of low-octane fuel. The fact that both 1985 and 1986 IMSA Camel Lights championships were won with low-octane fuel is a rather definitive statement . . . ."

So if you want best performance from your NA rotary, you want lowest octane. The lower cost of it is a nice bonus.



* Note - the time allowed for combustion at high RPM is measured in ten-thousandths of a second. Some literature ascribes lower volatility rather than a slower burn as the characteristic of a higher octane value. In contrast, consider the following: From "14-to-1 compression", By David Green, NASCAR Winston Cup Scene:



"One problem that has developed in the 9.5-to-1 engine is high exhaust temperatures, due to a less-efficient burning of 108-octane gasoline in the lower-compression combustion chamber." (emphasis supplied)

For more information on octane/antiknock characteristic:

Octane Determination, by Gregory Travis

The autos/gasoline FAQ, by Bruce Hamilton, or its mirror.

Chevron's "A Consumer's Guide: Gasoline Octane for Cars"

Mobil's "Gasoline Product Knowledge"

Shell's Fuel "Properties"

Finally the window of what type of fuel to use comes into play...



I've never used anything above 87 in my N/A Acctually i did once.



Any my dyno Readings were 4 HP lower with the 93 pump gas. 3 consecutive runs the lower octane fuel made the engine pull harder. I'm tellin ya. If your all motor.. your better off with low octane. (LOWER PRICE!!!)



my 7 cents

That's great news!!



Raul

Thanks DirectFreak. https://www.nopistons.com/forums/pub...1047683894.gif

Good times and nice info on pump gas. https://www.nopistons.com/forums/pub...IR#>/bigok.gif

Awesome...

no ****?

And here I was running my car on 98 octane. what a dumbass.

pops and flames good though.

You're Octane Rating in Australia is done differently. Your 98, = Our 93.

Either way, just get the cheapest gas you can find.

new on forum! i had thought tha the higher the octane the better the combustion n/a or turbo

The higher the number, the longer it takes to burn, and the more resistant to

pre-detonation (knock). Because of the design of the rotary's combustion chamber,

a longer burning fuel will still be burning as the exhaust port is uncovered, causing

even higher exhaust temps than normal.



Raul

what about advancing the ignition timing?

what about advancing the ignition timing? [/quote]

Then you start to run into timing issues with the tips of the rotors at higher RPM.

And as stated above, it's not necessary unless you're boosted.



Raul

what about advancing the ignition timing? [/quote]

Then you start to run into timing issues with the tips of the rotors at higher RPM.

And as stated above, it's not necessary unless you're boosted.



Raul [/quote]

thanks for that info looking into it!! https://www.nopistons.com/forums/pub...#>/biggrin.png