Normally Aspirated? I think not.....

Discussion in '1991 Mazda 787B' started by Paragon Racer, Aug 10, 2002.

  1. Re: Normally Aspirated? I think not.....

    If it was really only that simple.<!-- Signature -->
     
  2. It just doesn't make any sense, most Group C car at the time are Turbo Charged, infact, I can't think of one particular Group C car runs normally aspirated engine. Unlike the Turbo which can control power through wastegate, N/A can't and in Group C where fuel economy is vital, it is more than likely they'll opt for a more fuel economical setup.<!-- Signature -->
     
  3. Re: Normally Aspirated? I think not.....

    Yes the car is normally aspirated. In fact, if you read the March 2001 issue of Road & Track they drive the car and talk about the engine and say that it is a qaud rotor engine and never mention anything about have a turbo(s).<!-- Signature -->
     
  4. Re: Normally Aspirated? I think not.....

    Oh by the way you said that all the cars had turbos but wasn't the Sauber C-111 natrually aspirated? <!-- Signature -->
     
  5. Re: Normally Aspirated? I think not.....

    100% naturally aspirated.
    Has nice variable length trumpets to vary torque at low & high speeda.
     
  6. Re: Normally Aspirated? I think not.....

    yo, what is your real name mr rotary, i think i know u...
     
  7. Re: Normally Aspirated? I think not.....

    <!-- QUOTE --><center><hr width="90%"></center><blockquote><i>Quote from Matthew4300</i>
    <b>Oh by the way you said that all the cars had turbos but wasn't the Sauber C-111 natrually aspirated? </b></blockquote><center><hr width="90%"></center><!-- END QUOTE -->

    After 1991, new rule were introduced that allowed Formula 1 engine for Group C and the the fuel consumption formula was scrapped. So the more successful team all switched to the N/A 3.5 liter formula.

    Now that I think about the characteristic of the rotary engine, being listed as 2.6 liter, the car has actual displacement equivelent to 5.2 liter, so the number aren't as far fetch as it was seen before....<!-- Signature -->
     
  8. Re: Normally Aspirated? I think not.....

    Each rotor fires twice per revolution for the engine, so as they have two power "stokes" per cycle, hence racing authorities consider them as having twice the displacement.

    Considering them as THREE times the piston is a lttle inaccurate though.

    Also, Mazda did some insane developmental work on this baby to make it successful. It is one of very few quad rotor engines I have heard of. (The other one being Racing Beat's 13-G quad)

    So it is not surprising that it is producing such huge power output.<!-- Signature -->
     
  9. Re: Normally Aspirated? I think not.....

    There's 1 bit of the story you forgot there MeanRex7. After the 1991 race, the FIA introduced a rule than banned all motors without a reciprical motion (meaning up and down) so that meant only piston motors were allowed. This continued till 1998 when they revamped the Group C law, thus allowing the Mazda/Kudzu 20B to be raced. C yas!! Mafs!!<!-- Signature -->
     
  10. Re: Normally Aspirated? I think not.....

    <!-- QUOTE --><center><hr width="90%"></center><blockquote><i>Quote from RacingManiac</i>
    <b><!-- QUOTE --><center><hr width="90%"></center><blockquote><i>Quote from Matthew4300</i>
    <b>Oh by the way you said that all the cars had turbos but wasn't the Sauber C-111 natrually aspirated? </b></blockquote><center><hr width="90%"></center><!-- END QUOTE -->

    After 1991, new rule were introduced that allowed Formula 1 engine for Group C and the the fuel consumption formula was scrapped. So the more successful team all switched to the N/A 3.5 liter formula.

    Now that I think about the characteristic of the rotary engine, being listed as 2.6 liter, the car has actual displacement equivelent to 5.2 liter, so the number aren't as far fetch as it was seen before....</b></blockquote><center><hr width="90%"></center><!-- END QUOTE -->
    considering how the 3rd gen RX-7 can compete w/ every japanese TT (most inline 6s) of the mid 90s I consider them to be double the liters. And each rotor equal to about 3 pistons.
    So a V12 N/A in comparison.
    But yeah that engine is mighty impressive
    I wish mazda would had went further with the 3 rotor, and rotaries in general. And other companies at that. <!-- Signature -->
     
  11. Re: Normally Aspirated? I think not.....

    <!-- QUOTE --><center><hr width="90%"></center><blockquote><i>Quote from kenmclaren</i>
    <b>It is said that the Wankel motor of this car was not reliable, seen in couple of races before and after it won the 24 hours of LeMans.

    Heres a question:

    If the engine was not reliable, then how did it win the 24 hour race without major problems?

    </b></blockquote><center><hr width="90%"></center><!-- END QUOTE -->
    Only if not properly tuned, lean it out, it goes bad. Plus this was N/A, and turbos are the main problem for dead engines.
    But this is racing and thats another story. A wankel takes less vibrational stress (no banging up down up down, only a circle) but it makes more heat.

    And you have a pic of RBs 13G, I guess now a 26G ;-D
    BTW Hurley of the UK makes 4, 5, and 6 rotor customs out of 13B's
    Few custom parts and custom eccentric shaft and then you just gotta tackle the fuel, spark, and some ECU problems MUWAHAHAHA<!-- Signature -->
     
  12. Re: Normally Aspirated? I think not.....

    I heard that the engine of 787B is from 2 RX-7s' engines. Rx-7 was still a concept back then.<!-- Signature -->
     
  13. Re: Normally Aspirated? I think not.....

    Nah, the engine of this car is different from that of the RX-7s.<!-- Signature -->
     
  14. Re: Normally Aspirated? I think not.....

    It is said that the Wankel motor of this car was not reliable, seen in couple of races before and after it won the 24 hours of LeMans.

    Heres a question:

    If the engine was not reliable, then how did it win the 24 hour race without major problems?

    <!-- Signature -->
     
  15. Re: Normally Aspirated? I think not.....

    I was wondering if anyone has the pictures of the other 787B, not with the RENOWN livery or color scheme, but the white one with the blue stripe and white/blue banner, number 18 or number 56. Does anybody have any?


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    <!-- Signature -->
     
  16. Re: Normally Aspirated? I think not.....

    <!-- QUOTE --><center><hr width="90%"></center><blockquote><i>Quote from Honda rulez</i>
    <b>I heard that the engine of 787B is from 2 RX-7s' engines. Rx-7 was still a concept back then.</b></blockquote><center><hr width="90%"></center><!-- END QUOTE -->
    Uhm, you have a little to learn about.
    The RX-7 has 3 generations
    Generation Chassis Code Engine Years
    1st Gen SA22/FB3S 12A/13B(GSL-SE) 1979-1980(sa)/1981-1985(FB)
    2nd Gen FC3S 13B/13BT(Turbo II) 1986-1992.5(92 not in US)/1987-1992(Turbo II)
    3rd Gen FD3S 13B-REW 1992.5-Current (not in US after 1995)<!-- Signature -->
     
  17. Re: Normally Aspirated? I think not.....

    the 3rd gen rx7 and the 787b share the same size rotor, the 787b just has 4 instead of 2, the engines are however very different. Compare the engine in the Mercedes S600 to the engine that powered the CLK-GTR to the 1997 FIA GT Championship. One could argue that they started as the same engine, but a hell of a lot of work went into it to make it race-spec, likewise with this powerplant no doubt.

    As for the Sauber-Mercedes C9/C11...they had twin-turbo 5.0-litre V8s based on the 500SL unit. Hence the massive torque output of 590 lbft. They produced upwards of 850hp in qualifying with perhaps 770hp during a race.
     
  18. #18 Real Rotary, Aug 10, 2002
    Last edited by a moderator: Apr 25, 2016
    Re: Normally Aspirated? I think not.....

    <!-- QUOTE --><center><hr width="90%"></center><blockquote><i>Quote from SprinterAE86</i>
    <b>Each rotor fires twice per revolution for the engine, so as they have two power "stokes" per cycle, hence racing authorities consider them as having twice the displacement.

    Considering them as THREE times the piston is a lttle inaccurate though.

    Also, Mazda did some insane developmental work on this baby to make it successful. It is one of very few quad rotor engines I have heard of. (The other one being Racing Beat's 13-G quad)

    So it is not surprising that it is producing such huge power output.</b></blockquote><center><hr width="90%"></center><!-- END QUOTE -->

    Wow, are u ever dumb! The rotors are triangles. Triangles have 3 sides. Each side is a combustion chamber. Therefore the rotor experiences 3 combustion cycles per rotation. Also, each rotation of the rotor the output shaft rotates 3 times. Thusfore, in a two rotor rotary engine there are 6 explosions for each rotation of the rotor, or 2 explosions for every rotation of the output shaft. Don't understand? Look it up at www.howstuffworks.com/rotary-engine.htm <!-- Signature -->
     
  19. Re: Normally Aspirated? I think not.....

    An awesome car. Normally aspirated. Amazing just amazing.<!-- Signature -->
     
  20. Re: Normally Aspirated? I think not.....

    have you seen the new rotories in the RX8, even though the car is hideous, the engine is very nice, high MPG and hich BHP, usually only found in (nonexistent cars).<!-- Signature -->
     
  21. Re: Normally Aspirated? I think not.....

    G'day from down under kids.

    Seems a few people have close to no idea what they are talking about.

    Firstly the guy suspecting the 26B might be turbo charged can't be that stupid. I'm betting he is just stirring the pot. Anybody who knows anything about the rotary Mazda would know the R26B was an "atmo" engine.

    Jim Downing (Downing/Atlanta) took a 26B powered car to Le mans this year (2002). It failed with a snapped gearbox but the air intake was restricted to 48.3mm limiting power to just on 500hp. The turbo cars ran a 43mm intake restrictor.

    For Le mans (as always) the 26B was classed as a "2616cc" engine.

    Also read some guy calling a 13G a 4-rotor. Shame shame shame.

    This should give you an idea......

    10A = 2 rotor production (67-74)
    12A = 2 rotor production (70-85)
    13A = 2 rotor production (69-72)
    13B = 2 rotor production (74-02)
    13G = 3 rotor race (85-02)
    13J = 4 rotor race (88-89)
    20B = 3 rotor production (90-95)
    26B = 4 rotor race (89-92)

    Spomeone else wanted pics of the "other" 787B. As the "Charge" car was the winner, the other cars are hard to find. I only have a pic of it in the background.
     
  22. thanks

    thanks for that great info! Your from Australia or New Zealand right? I have heard that there is lots of REAL FAST rotarys down there, is there? I know some people are making a 4 rotor RX7. Thats crazy! The shifer well be like in the back seat, cause it is moved back 6 inches for the 20B. Sometimes they put the extra rotor in the front, but it requires alot of tearing up and makes it real front heavy.
     
  23. Re: Normally Aspirated? I think not.....

    yea that was really great cosmo, i love it when ppl know their stuff!
     
  24. Re: Normally Aspirated? I think not.....

    Just think if this car had a turbo of 4. ~wow~ i cant even amagin the hp it might make 2,000 maybe more!
    Thiz is some thing they should try! Might get a lil scary but very impressive
     
  25. Re: Normally Aspirated? I think not.....

    That's true, but think of this:

    When one side is filled with fuel/air, it goes like this - suck, squish/bang, blow. 3 stages. (since the squish and bang are simultaneous)
    However, while the 3rd side is sucking air and fuel in, the first one is blowing out exhaust fumes, completing it's cycle. There are only 2 sides of the rotor that still have to bang, since the 3rd side already has.
    There are only two power strokes at a time. The third 'stroke' is full of exhaust gases, which make no more power.

    See MeanRex7's avatar animation. It shows it really well.

    Cosmo, you say the engine was classified as a 2.616L. That means two 1.308L engines. But didn't they double the displacement because of their '2 power strokes' rule?
     

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