Felix's Own General Rotary Car FAQ

 

How does a rotary engine work?

What's a boinger?

Why does a rotary engine make as much power as a boinger twice its size?

Why does a Renesis make so much more power than prior rotaries?

How reliable is a rotary engine?

 
Mazda RX-7: IMSA GTU Champion
  1. - 1980
  2. - 1981
  3. - 1982
  4. - 1983
  5. - 1984
  6. - 1985
  7. - 1986
  8. - 1987

No other manufacturer has won such a long string of consecutive championships. The 1979 season was almost the first in the string. Mazda had 199 points to 1st place Datsun's 211. The 1979 season opened with the RX-7 IMSA debut at the 24 Hours of Daytona, where RX-7s finished first and second in GTU. Also in 1979, Mazda won the Champion Spark Plug Challenge with 246 points to 2nd place AMC with 218 and Datsun with 100. Mazda RX-3 drivers took took the first three places in the series' drivers' points race. Results like those take two basic things: 1- Power, to be first, and 2- Reliability, to stay first.

Like any other engine, the cooling and oil systems must be kept up to snuff to maximize reliability. If you let a boinger overheat, a typical result is a blown head gasket. The nature of rotary overheating is that a "head gasket" type failure requires a total overhaul to repair. If you can avoid such neglect, you can expect extraordinary service.

Read what David Lane had to say about RX-7 reliability on the big RX-7 mailing list.

Is the rotary engine dead?

What do the 10A, 12A, 13B, 16X & 20B Mazda engine designations mean?

Why two spark plugs for each rotor?

Why does my rotary Mazda have an oil cooler?

Why does a rotary burn oil?

What oil should I use?

Should I use synthetic oil?

Do oil brands matter?

How often should i change my rotary engine's oil?

Should I mix oil in the fuel?

What's the best fuel for my rotary car?

What gas mileage should a rotary get?

Will removing my thermostat help my rotary engine run cooler or make more power?

When should I shift?

What is an apex seal?

How do i know if my engine's apex seals are ok?

What should my engine's compression be?

How hard would it be for me to rebuild my rotary?

What is porting all about?

What are the differences between 6-Port & 4-Port rotaries?

What is a thermal reactor?

What if I switch to a light flywheel?

How do I get the old flywheel off?

How hard is it to stop oil from leaking?

O-rings? What o-rings?

What's that foamy stuff under the oil fill cap & inside the filler tube?

Why does my engine smoke when I first start it?

Why does my engine smoke when I shift at high RPM?

Why won't my rotary engine start? What can I do to start it?

Why is my rotary engine locked up?

My car just failed its emissions test. Now what do I do?

What's the best way to make my rotary car accelerate quicker?

 
1: Nitrous
aka Nitrous Oxide, "Juice", "The Bottle", "Laughing Gas"
  • Highest HP return on investment.
  • Highest potential to shorten the life of your engine - VERY.
  • Installation can be intrusive and is definitely difficult to keep hidden in an RX-7.
  • Keeping supplied can be very tough. 7-11 & Wal Mart don't sell it.
  • Approximate independent increase range - 25-100%
 
2: Porting
  • Like changing a boinger cam, improves breathing, elevating powerband
  • Like porting boinger heads, improves breathing, elevating powerband
  • Done right, difficult for opponents to detect except via results
  • Requires total engine disassembly to perform
  • Approximate independent increase range - 5-50%
 
3: Exhaust system
  • Constipation reduces efficiency: If you can't get exhaust out, you can't get air in.
  • Very tough to get desired results without a noise increase.
  • Hotter rotary exhaust requires tougher system components.
  • Approximate independent increase range - 5-25%
 
 
4: Induction system
  • The more air you can get in, the more fuel you can burn.
  • Fuel injection usually supplies engine requirements more accurately.
  • Approximate independent increase range - 0-10%
 
 
5: Ignition system
  • Stock Mazda electronic ignition is tough to beat.
  • Approximate independent increase range - 0-3%
 
 
*: Bigger engine
  • An option to which all of the above apply.

    Mazda rotaries in order of increasing displacement:

    • 10A
    • 12A - 20 mm longer than 10A at same basic height and width
    • 13B - 20 mm longer than 12A at same basic height and width
    • 20B - the factory three rotor option.
  • Approximate independent increase range - 15-100%
 
 
*: Forced induction
  • Another option that doesn't lend itself to the order
    • Turbocharger (Exhaust driven)
    • Supercharger (Belt or gear driven)
  • It's not NA any more once you do this.
  • Approximate independent increase range - 25-100%
 
 
1: Gearing
Multiply your engine's torque
  • Tire size. Shorter tires equal more leverage.
  • Rear axle ratio. Shorter ratio (more ring gear or fewer pinion teeth) equals more leverage.
  • Transmissions don't all have the same ratios.
 
 
2: Lightening
Gives existing power less weight to fight
  • Cheap! - Little or No Cost!
  • Air pump & other emissions controls
  • Air conditioning
  • Big tires & wheels weigh more than little ones
  • Flywheel
  • Spare tire & jack
  • Carpet, sound deadener, stereo, other creature comforts
  • Stuff that belongs in the garage
  • Have you weighed yourself lately?
 
 
3: Parasitic
  • Belt pulley diameters.
  • Tire pressure.
 
 
4: Traction
  • Slipping tires & clutch usually mean slower acceleration
 
 
5: Friction
  • Slipperier oil, synthetic or lighter weight, in the transmission & differential reduces power loss
  • Clean, waxed paint
 
 
6: Driver
  • Winners don't just have good equipment, they also have talent, or training, or both.
 

Can I add a turbo to my NA?

Why is rotary exhaust replacement or improvement so expensive?

Why not hollow out the cats?

How do I remove my air pump?

How do I stop the backfiring?

How can I tell if my car has a limited-slip differential?

Where can I race my rotary car?

Corvttes, Mustngs, Firbirds, Camros, Porches & RX7s?

What are the RX-7 "generations"?

Which model RX-7 do I have? How do the various RX-7 models differ?

What other regular production cars have had rotary engines? 2010/05/10

Why did Mazda stop selling the RX-7 in the US?

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So, what are eccentricity and generating radius? See epitrochoid calculations for some technobabble.

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Last Modified
2012/12/20
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