Track whores with MRs?
jk..
Has anyone ever thought of making a 4th, 5th, and 6th gear straight cut gears which would replace the stock helical gears? I'm sure this could solve the problem of breaking teeth and would be much cheaper than doing an entire conversion from 6 to 5 or overhauling the whole 6 speed with a cooling device.
If the WRX 5 speed and STi 6 speed guys have this option why cant the evo guys have the same option?
If the WRX 5 speed and STi 6 speed guys have this option why cant the evo guys have the same option?
Straight cut gears and cyro-treating the gears won't do much for durability. Straight cut gears just end up being noisier than their helical counterparts and may even reduce the durability of a gear as now there is less surface area for the force to act on which also increases the pressure a tooth has to bear.
Cryo-treating and heavy shot peening "may" only increase the strength of the gears by approximately 10%. Longevity of the 6 speed will depend on the torque one is generating, the shock it is subjected to (clutch engagement) less shock = longer life, the "correct" type of lubrication. I would assume wider gears and bigger (deeper/wider) teeth are the only way to improve the durability of the 6 speed to with stand more power.
Keep your power expectation low and you won't have problems.
Cryo-treating and heavy shot peening "may" only increase the strength of the gears by approximately 10%. Longevity of the 6 speed will depend on the torque one is generating, the shock it is subjected to (clutch engagement) less shock = longer life, the "correct" type of lubrication. I would assume wider gears and bigger (deeper/wider) teeth are the only way to improve the durability of the 6 speed to with stand more power.
Keep your power expectation low and you won't have problems.
Straight-cut gears have been known to handle high amounts of torque. Many racecars use straight-cut gears so thats at least some evidence of them being able to handle the abuse power.
If you think about it the teeth in a straight cut gear is stronger because the teeth are straight versus curved. Since the teeth are curved in helical designs, they tend to handle torque for less amount of time versus a straight-cut gear. This is based off the idea that the helical gear has curved teeth and if you actually try performing a stress test analysis on the two gears with the same width, length and material teeth (one being helical the other being straight-cut). You will find that stress levels will be reached in many more spots in the helical design, quicker, than the straight-cut design. Hence the helical gear design is weaker than the straight-cut gear design.
I can't say much for noise, but some people might actually like it.
If you think about it the teeth in a straight cut gear is stronger because the teeth are straight versus curved. Since the teeth are curved in helical designs, they tend to handle torque for less amount of time versus a straight-cut gear. This is based off the idea that the helical gear has curved teeth and if you actually try performing a stress test analysis on the two gears with the same width, length and material teeth (one being helical the other being straight-cut). You will find that stress levels will be reached in many more spots in the helical design, quicker, than the straight-cut design. Hence the helical gear design is weaker than the straight-cut gear design.
I can't say much for noise, but some people might actually like it.
Hey guys, I need your help collecting data from you 6-spd guys that track your cars, failure or not. This is for a school project and would probably serve the evo community very well too. If you could reply to this thread, I'd really appreciate it!
https://www.evolutionm.net/forums/sh...d.php?t=295632
TIA!
https://www.evolutionm.net/forums/sh...d.php?t=295632
TIA!
I recently did a full fluid change, engine, tranny, tc, rear diff... The OEM fluids STINK!
Anyways, I used 1qt of Shockproof Heavy and approx 1.5 qt MT-90 (used as much as necessary to overflow the fill hole). I'm surprised how well it shifts, it already feels smoother than OEM. Seems like a nice blend, hopefully the qt of SP Heavy will add a significant level of protection for those dainty little gears...
As for the oil pumps and radiators, are they rated for a maximum viscosity? I wonder if the uberthick shockproof would be too much and cause the pump to burn up...
Anyways, I used 1qt of Shockproof Heavy and approx 1.5 qt MT-90 (used as much as necessary to overflow the fill hole). I'm surprised how well it shifts, it already feels smoother than OEM. Seems like a nice blend, hopefully the qt of SP Heavy will add a significant level of protection for those dainty little gears...
As for the oil pumps and radiators, are they rated for a maximum viscosity? I wonder if the uberthick shockproof would be too much and cause the pump to burn up...
