5 speed power capabilities with boost
05-01-2014, 06:25 PM
#5
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I don't know why these guys are being such dbags when all you did was ask a simple question.
The stock 5 speed is kind of a glass case and will break pretty early, like around 5-8 psi. The rods, on the other hand, are super strong, good for 20+ psi. People put Miata rods in all sorts of other engines as upgrades. Little race secret for ya
The stock 5 speed is kind of a glass case and will break pretty early, like around 5-8 psi. The rods, on the other hand, are super strong, good for 20+ psi. People put Miata rods in all sorts of other engines as upgrades. Little race secret for ya
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05-02-2014, 08:13 AM
#6
Trae - it depends on the year of the transmission.
90-93 5MTs are generally luck of the draw - some go at around 150hp, others have been documented to 475hp for hundreds of track hours.
Starting in 94 and going through the 97MY in North America (98MY everywhere else), they pretty much all became butter. 175hp is generally the limit, some have gone to 200hp. There are no documented '94-'97 transmissions running over 215hp long enough to get a good dyno pull in.
To fix this problem, mazda re-looked the 5 speed, but since they ran out of time for the '98 model year, they adapted the old RX7 trans to the Miata in North America for only the '98 cars. Those RX7 transmissions are beasts - there are only 2 documented cases of the '98 RX7 trans going in the Miata, both well over 650AWHP.
Starting in '99, Mazda had generally fixed the problem, and all of the 5 speeds from 99 through end of production are generally expected to hold 450-500 HP for the life of the car. The '99 and on transmissions use different mounting points, though, and are not compatible with any previous Miatas without also replacing the entire front subframe and using the shorter PPF.
90-93 5MTs are generally luck of the draw - some go at around 150hp, others have been documented to 475hp for hundreds of track hours.
Starting in 94 and going through the 97MY in North America (98MY everywhere else), they pretty much all became butter. 175hp is generally the limit, some have gone to 200hp. There are no documented '94-'97 transmissions running over 215hp long enough to get a good dyno pull in.
To fix this problem, mazda re-looked the 5 speed, but since they ran out of time for the '98 model year, they adapted the old RX7 trans to the Miata in North America for only the '98 cars. Those RX7 transmissions are beasts - there are only 2 documented cases of the '98 RX7 trans going in the Miata, both well over 650AWHP.
Starting in '99, Mazda had generally fixed the problem, and all of the 5 speeds from 99 through end of production are generally expected to hold 450-500 HP for the life of the car. The '99 and on transmissions use different mounting points, though, and are not compatible with any previous Miatas without also replacing the entire front subframe and using the shorter PPF.
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05-02-2014, 10:46 AM
#14
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I'm actually using diesel in mine right now. It required different spark plugs but the torque output is increased by about 38%. It also lets you belch giant clouds of black smoke when you floor the throttle, which is pretty cool.
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05-02-2014, 10:58 AM
#16
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Quit complicating the situation with facts.
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05-02-2014, 12:20 PM
#20
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Go with the 4spd, much stronger and better for boost because of the longer gearing. The 4spds only came on the 89' model year so you have to look a bit, but they are out there (most people "upgrade" them to the 5spd because they are stupid).
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