Automotive Industries
02-20-2003, 06:29 PM
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Automotive Industries
The following is an article from Automotive Industires February 2003. A coworker of mine gets it and he knew I had a RX-8 pre-ordered so he gave it to me.
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02-21-2003, 12:19 AM
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'04 RX-8 GT Silver R/B
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Originally posted by tribal azn
mind typing it out for us?
mind typing it out for us?
Technology marches as such a forced pace that engines seldom get a second chance to prove their mettle. When Studebaker ceased flat-head engine production in 1960. they were gone for good. Straight eights and inline threes also went the way of the buggy whip. So the second coming of the rotary engine under the hood of Mazda's new RX-8 is truly remarkable. The combination of a unique engine with an unprecedented bodystyle represents more creative thinking than the auto industry has seen since the Tucker Torpedo.
The rotary bounced back because a hard core of Mazda enthusiasts was convinced its merits deserve one more play on the automotive stage. To it's everlasting credit Felix Wankel's is fundamentally simpler, smootherand more compact than 4- or 6- cylinder engines with comparable power. But, as is the case with all mechanical devices, there are negatives. Past rotaries demonstrated questionable reliability, high fuel consumption and difficulty meeting emissions standards.
For the Mazda RX-8 to be successful, the rotary had to clean up it's act AND compete favorably against some of the best piston engine powerhouses on the market. Eight years ago just as the third generation RX-7 began migrating into the history book, Mazda engineers produced a thoroughly reconfigured engine at the Tokyo Motor Show. Their major breakthrough was relocating the exhaust ports from a peripheral to a lateral position.
Forty years ago, when Mazda began devolping the rotary under NSU license rights, exhaust outlets were oriented radially to avoid coking - burned oil deposits in rotor sealing grooves. At the start of Mazda's rotary revival program, engineers solved that concern with improved seals and drastic reduction in the amount of oil injected to lubricate the seals. This paved the way to side exhaust ports, precisely the breakthrough the rotary needed to achieve major gains in power, fuel efficiency and emissions.
While piston engine designers struggle to pack in more valves and larger fluid passages, their rotary counterparts enjoy ample free-
someone else's turn... I cannot type this whole thing.
02-21-2003, 12:29 AM
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Originally posted by Cylo
page 1
Technology marches as such a forced pace that engines seldom get a second chance to prove their mettle. When Studebaker ceased flat-head engine production in 1960. they were gone for good. Straight eights and inline threes also went the way of the buggy whip. So the second coming of the rotary engine under the hood of Mazda's new RX-8 is truly remarkable. The combination of a unique engine with an unprecedented bodystyle represents more creative thinking than the auto industry has seen since the Tucker Torpedo.
The rotary bounced back because a hard core of Mazda enthusiasts was convinced its merits deserve one more play on the automotive stage. To it's everlasting credit Felix Wankel's is fundamentally simpler, smootherand more compact than 4- or 6- cylinder engines with comparable power. But, as is the case with all mechanical devices, there are negatives. Past rotaries demonstrated questionable reliability, high fuel consumption and difficulty meeting emissions standards.
For the Mazda RX-8 to be successful, the rotary had to clean up it's act AND compete favorably against some of the best piston engine powerhouses on the market. Eight years ago just as the third generation RX-7 began migrating into the history book, Mazda engineers produced a thoroughly reconfigured engine at the Tokyo Motor Show. Their major breakthrough was relocating the exhaust ports from a peripheral to a lateral position.
Forty years ago, when Mazda began devolping the rotary under NSU license rights, exhaust outlets were oriented radially to avoid coking - burned oil deposits in rotor sealing grooves. At the start of Mazda's rotary revival program, engineers solved that concern with improved seals and drastic reduction in the amount of oil injected to lubricate the seals. This paved the way to side exhaust ports, precisely the breakthrough the rotary needed to achieve major gains in power, fuel efficiency and emissions.
While piston engine designers struggle to pack in more valves and larger fluid passages, their rotary counterparts enjoy ample free-
someone else's turn... I cannot type this whole thing.
page 1
Technology marches as such a forced pace that engines seldom get a second chance to prove their mettle. When Studebaker ceased flat-head engine production in 1960. they were gone for good. Straight eights and inline threes also went the way of the buggy whip. So the second coming of the rotary engine under the hood of Mazda's new RX-8 is truly remarkable. The combination of a unique engine with an unprecedented bodystyle represents more creative thinking than the auto industry has seen since the Tucker Torpedo.
The rotary bounced back because a hard core of Mazda enthusiasts was convinced its merits deserve one more play on the automotive stage. To it's everlasting credit Felix Wankel's is fundamentally simpler, smootherand more compact than 4- or 6- cylinder engines with comparable power. But, as is the case with all mechanical devices, there are negatives. Past rotaries demonstrated questionable reliability, high fuel consumption and difficulty meeting emissions standards.
For the Mazda RX-8 to be successful, the rotary had to clean up it's act AND compete favorably against some of the best piston engine powerhouses on the market. Eight years ago just as the third generation RX-7 began migrating into the history book, Mazda engineers produced a thoroughly reconfigured engine at the Tokyo Motor Show. Their major breakthrough was relocating the exhaust ports from a peripheral to a lateral position.
Forty years ago, when Mazda began devolping the rotary under NSU license rights, exhaust outlets were oriented radially to avoid coking - burned oil deposits in rotor sealing grooves. At the start of Mazda's rotary revival program, engineers solved that concern with improved seals and drastic reduction in the amount of oil injected to lubricate the seals. This paved the way to side exhaust ports, precisely the breakthrough the rotary needed to achieve major gains in power, fuel efficiency and emissions.
While piston engine designers struggle to pack in more valves and larger fluid passages, their rotary counterparts enjoy ample free-
someone else's turn... I cannot type this whole thing.
:D
02-21-2003, 02:17 AM
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Originally posted by RXhusker
What happened to the perfect 50-50 weight distribution?
Article quotes 52-48.
What happened to the perfect 50-50 weight distribution?
Article quotes 52-48.
02-21-2003, 09:40 AM
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Pages 2 and 3
Here is some more:
I apologize for any mistakes. I didn't have time to check the transcription for errors.
-dom determining the size and position of their induction and exhaust ports. To create a normally aspirated new-generation rotary that beat the outgoing turbo version on all counts, Mazda engineers doubled the size of the exhaust ports and increased intake area by nearly 30 percent. Positioning the part array (two or three intakes and two exhausts per rotor)to eliminate overlap improved idle-stability, dramatically reducing both emissions and fuel consumption. (As in a piston engine, overlap is the short circuit by which spent gasses invade the fuel-air charge.) To take maximum advantage of the new-found volumetric efficiency, the mass of the rotors were trimmed by 11 percent and the flywheel was lightened by 20 percent. Elaborate resonance-tuned intake passages with computer-controlled shut-off valves were devised to force feed the rotating combustion chambers throughout their expanded rpm range. On the exhaust side, piping was made as large and as straight as possible to minimize flow restriction. Secondary air delivered by an electric pump after a cold start was added to speed warm-up of the RX-8's catalytic converter.
While they were at it, Mazda engineers gave their RENESIS (the rotary engine's genesis) powerplant new fuel injectors providing better atomization, longer-lasting iridium tipped spark plugs, a drive-by-wire throttle, a mass air flow sensor (replacing the previous speed density means of fuel-air-ratio control), double-loop exhaust oxygen sensing and a much smarter 32-bit powertrain control computer. The payout is a power peak raised by 2000 rpm (to 250 hp at 8500 rpm), a 90 percent reduction is exhaust emissions and EPA combined fuel economy figures over 20 mpg. Two engine configurations are offered. The "standard" edition, with two intake ports per rotor and a 7,500 rpm redline for use with a four-speed automatic, delivers 210 hp and 164 lbs-ft of torque at 5,000 rpm. The "high-power" version inhales through three intake ports per rotor, winds to 9,000 rpm through a 6-speed manual transmission and produces 250 hp at 8,500 rmp and 159 lbs-ft of torque at 5,500. After such brilliant work by the engine department, RX-8 program manager Noboru Katabuchi was duly inspired to create an equally remarkable car to carry the reborn rotary engine. Recalling the origin of this new species, the 30-year Mazda veteran reports, "What we needed to suceed the RX-7 was one car suitable for three diverse markets - Japan, Europe, and the U.S. In 1998, we began considering various possibilities with ideas solicited from out advanced-engineering branches in those three locations. Our goal was a four seat RX-7 with all the driving pleasure that concept implies. Within a year, our idea how to achieve this was accepted and the program was approved for production."
Asked how this radically different vehicle fits into the grand Ford Motor Co. scheme of things, Katabuchi-san is quick to point out, "While Mazda's front-drive products are integrated with Ford's model plans, the new RX-8 platform is exclusive to Mazda. We intend to use this foundation for other sporty cars in the future. The platform was engineered with broad capabilities to yield an RX-7 derivative, a convertible bodystyle, and, if necessary, cars powered by conventional [non-rotary] engines."
Mixing sedan and sports car genes to create the first true crossover car is risky business. Instead of the desired stallion with extra seating, there's a distinct possibility of ending up with a donkey. The key to the RX-8's success literally hinges on its rear door design, a system Mazda calls "freestyle." Notes Katabuchi, "We needed four doors to provide more convenient access to the rear seats than is possible in a conventional 2+2 coupe. But using conventional door hinges and a B-pillar would have stretched overall length by 200 mm (7.9 inches). Taking that approach, the basic proportions depart from the sports car range and begin looking like a four-door sedan, which we definitely didn't want. So we chose the pillarless arrangement and selected the freestyle name because the RX-8's rear seat is so readily accessible."
While interlocking rear doors are common practice in pick-up trucks and a feature Saturn has used for a few years in its coupe, Mazda has truly advanced the state of the closure art with the RX-8. Instead of tip-toeing past rising safety and occupant protection expectation with a barely legal design, Katabuchi's team aimed for the rafters with five-star capabilities in every impact-related area including lateral collisions. In place of a fixed B-pillar, there's a moveable one cleverly integrated within the forward portion of the rear door. A steel tube that latches into the roof and the side sill is supplemented by the three "catcher pin," one located in the front door, two in the rear door, which engage sockets built into the RX-8's sills. A large reinforcement plate forms the root of the vertical tube and spreads concentrated side-impact loads over the one-foot-long section of the sill. Wrapping around this stout heart of high-strength steel is an aluminum skin used to give the rear door a light, easy to open feel. Carting the hinge axis 10-degrees from vertical also reduces the effort needed to open the door from inside the vehicle. A swing angle of 80 degrees (versus 67 for the front doors) gets the short, thick rear doors out of the way for efficient ingress and egress. Seat-mounted side air bags help guard front occupants torsos and side curtains provide head protection for all four passengers. Achieving the rigidity needed to support a sports car aggressive moves with gaping holes in the side areas was no small feat. Key structural features are a [something] backbone through the center of the interior, deep-section sills, three crossmembers to stiffen the transmission tunnel and single-piece......
I apologize for any mistakes. I didn't have time to check the transcription for errors.
-dom determining the size and position of their induction and exhaust ports. To create a normally aspirated new-generation rotary that beat the outgoing turbo version on all counts, Mazda engineers doubled the size of the exhaust ports and increased intake area by nearly 30 percent. Positioning the part array (two or three intakes and two exhausts per rotor)to eliminate overlap improved idle-stability, dramatically reducing both emissions and fuel consumption. (As in a piston engine, overlap is the short circuit by which spent gasses invade the fuel-air charge.) To take maximum advantage of the new-found volumetric efficiency, the mass of the rotors were trimmed by 11 percent and the flywheel was lightened by 20 percent. Elaborate resonance-tuned intake passages with computer-controlled shut-off valves were devised to force feed the rotating combustion chambers throughout their expanded rpm range. On the exhaust side, piping was made as large and as straight as possible to minimize flow restriction. Secondary air delivered by an electric pump after a cold start was added to speed warm-up of the RX-8's catalytic converter.
While they were at it, Mazda engineers gave their RENESIS (the rotary engine's genesis) powerplant new fuel injectors providing better atomization, longer-lasting iridium tipped spark plugs, a drive-by-wire throttle, a mass air flow sensor (replacing the previous speed density means of fuel-air-ratio control), double-loop exhaust oxygen sensing and a much smarter 32-bit powertrain control computer. The payout is a power peak raised by 2000 rpm (to 250 hp at 8500 rpm), a 90 percent reduction is exhaust emissions and EPA combined fuel economy figures over 20 mpg. Two engine configurations are offered. The "standard" edition, with two intake ports per rotor and a 7,500 rpm redline for use with a four-speed automatic, delivers 210 hp and 164 lbs-ft of torque at 5,000 rpm. The "high-power" version inhales through three intake ports per rotor, winds to 9,000 rpm through a 6-speed manual transmission and produces 250 hp at 8,500 rmp and 159 lbs-ft of torque at 5,500. After such brilliant work by the engine department, RX-8 program manager Noboru Katabuchi was duly inspired to create an equally remarkable car to carry the reborn rotary engine. Recalling the origin of this new species, the 30-year Mazda veteran reports, "What we needed to suceed the RX-7 was one car suitable for three diverse markets - Japan, Europe, and the U.S. In 1998, we began considering various possibilities with ideas solicited from out advanced-engineering branches in those three locations. Our goal was a four seat RX-7 with all the driving pleasure that concept implies. Within a year, our idea how to achieve this was accepted and the program was approved for production."
Asked how this radically different vehicle fits into the grand Ford Motor Co. scheme of things, Katabuchi-san is quick to point out, "While Mazda's front-drive products are integrated with Ford's model plans, the new RX-8 platform is exclusive to Mazda. We intend to use this foundation for other sporty cars in the future. The platform was engineered with broad capabilities to yield an RX-7 derivative, a convertible bodystyle, and, if necessary, cars powered by conventional [non-rotary] engines."
Mixing sedan and sports car genes to create the first true crossover car is risky business. Instead of the desired stallion with extra seating, there's a distinct possibility of ending up with a donkey. The key to the RX-8's success literally hinges on its rear door design, a system Mazda calls "freestyle." Notes Katabuchi, "We needed four doors to provide more convenient access to the rear seats than is possible in a conventional 2+2 coupe. But using conventional door hinges and a B-pillar would have stretched overall length by 200 mm (7.9 inches). Taking that approach, the basic proportions depart from the sports car range and begin looking like a four-door sedan, which we definitely didn't want. So we chose the pillarless arrangement and selected the freestyle name because the RX-8's rear seat is so readily accessible."
While interlocking rear doors are common practice in pick-up trucks and a feature Saturn has used for a few years in its coupe, Mazda has truly advanced the state of the closure art with the RX-8. Instead of tip-toeing past rising safety and occupant protection expectation with a barely legal design, Katabuchi's team aimed for the rafters with five-star capabilities in every impact-related area including lateral collisions. In place of a fixed B-pillar, there's a moveable one cleverly integrated within the forward portion of the rear door. A steel tube that latches into the roof and the side sill is supplemented by the three "catcher pin," one located in the front door, two in the rear door, which engage sockets built into the RX-8's sills. A large reinforcement plate forms the root of the vertical tube and spreads concentrated side-impact loads over the one-foot-long section of the sill. Wrapping around this stout heart of high-strength steel is an aluminum skin used to give the rear door a light, easy to open feel. Carting the hinge axis 10-degrees from vertical also reduces the effort needed to open the door from inside the vehicle. A swing angle of 80 degrees (versus 67 for the front doors) gets the short, thick rear doors out of the way for efficient ingress and egress. Seat-mounted side air bags help guard front occupants torsos and side curtains provide head protection for all four passengers. Achieving the rigidity needed to support a sports car aggressive moves with gaping holes in the side areas was no small feat. Key structural features are a [something] backbone through the center of the interior, deep-section sills, three crossmembers to stiffen the transmission tunnel and single-piece......
02-23-2003, 12:45 AM
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a mass air flow sensor (replacing the previous speed density means of fuel-air-ratio control
-pete
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