2G Building a stronger 5 speed transmission

[Talon96fwd]

Hopefully you guys come up with something. I love all this brainstorming going all in this conversation. If something comes out of it count me in. I’m currently on my 5th trans and recently purchase another trans from jacks. NO FUN!

 

[rabenne]

Wow! I can't imagine what it takes to go thru that many transmissions. Do you race it constantly?
I am saving for some straight gears when I destroy this trans (and my hoard of spare evo3 parts). I haven't broken a transmission in my 14 years DSM'ing - but I also have never been on a track. I did try to use a "good used" trans from a member on here when I did my AWD swap, but I only made it 14 miles before it locked up and left me stranded (destroyed bellhousing). I don't count that as me breaking it*

@Talon96fwd - I highly doubt anything will materialize from this. I would guess there are already people developing the hub and slider. I will deal with the gear whine when that day comes (assuming I can get those parts in the future - anybody's guess).

 

[llxkevinxll]

The gear whine I think is can be lived with, especially if you stick with the factory 5th gear for your long drives and freeway cruising. My real concern/question for those that do run the PPG set is what is it like to drive on the street? My car sees maybe 2500-3000 miles in a year so it is far from a daily. But it is street driven. I have no issue spending the money on a dog box if it means I can keep driving my car but how badly does the dog engagement affect drivability?

 

[Vegas Smith]

I actually just bought another 1g awd shell locally. I'm really serious about making it a high hp auto build and toning down my red one to an evo3 turbo build. I've heard many people say the 16g is the hardest on these transmissions. I can't see how that's true. Anyone have an opinion on that?

 

[Canadian_CD9A]

I actually just bought another 1g awd shell locally. I'm really serious about making it a high hp auto build and toning down my red one to an evo3 turbo build. I've heard many people say the 16g is the hardest on these transmissions. I can't see how that's true. Anyone have an opinion on that?

The 16G on E85 would be prone to the big torque spike but it's not the worst offender. Any setup that can make 500+ lb-ft for a sustained duration (basically a bigger turbo, likely a stroker) is going to be the worst.

 

[twicks69]

I have one remaining evo 3 3/4 hub and slider I am using for modeling and will get quotes on machining, but I need it EDM'ed or broached or both. It will be a while to make, but it will at least let me do rebuilds on pre-1992.5 gearsets and resume stage 1/2/3 builds. I have zero issues driving a dogbox on the street, just use the clutch in between shifts, no biggie. I already have a loud ass car with a huge turbo, a twin disk, loud exhaust, etc. The noise of a straight cut gearset is the least of my concerns.

 

[rabenne]

Tim, I am glad you are working up a design for the hub and slider! That is exciting for everyone! If there is anything I can do to help, let me know. If nothing else, I have a pretty good network of machinists and machine shops. I cant share the documentation, but I can certainly make suggestions based on the type of work being done. Happy to help any way I can...

The more I think about this, the more I just want to sell my built evo 2 trans and buy a ppg setup...

 

[Talon96fwd]

Wow! I can't imagine what it takes to go thru that many transmissions. Do you race it constantly?
I am saving for some straight gears when I destroy this trans (and my hoard of spare evo3 parts). I haven't broken a transmission in my 14 years DSM'ing - but I also have never been on a track. I did try to use a "good used" trans from a member on here when I did my AWD swap, but I only made it 14 miles before it locked up and left me stranded (destroyed bellhousing). I don't count that as me breaking it*

@Talon96fwd - I highly doubt anything will materialize from this. I would guess there are already people developing the hub and slider. I will deal with the gear whine when that day comes (assuming I can get those parts in the future - anybody's guess).

I made 630whp and 500tq on a 2.0 liter. My car has seen the track once and that was at a roll racing event. Broke 3rd gear doing a pull on the highway . Not sure how that occurred while already rolling. Going auto is no fun by just pressing a gas paddle is not a option for me. Do straight cut gears help more? If I post my receipt can you tell me what’s the longevity?

 

[bastarddsm]

Everyone assumes straights are stronger than helical. It's not that simple. Strong is a broad term, and gears being a dynamic element there is a lot to it. In many cases helical is a stronger gear.

 

[DSMPT]

I have one remaining evo 3 3/4 hub and slider I am using for modeling and will get quotes on machining, but I need it EDM'ed or broached or both. It will be a while to make, but it will at least let me do rebuilds on pre-1992.5 gearsets and resume stage 1/2/3 builds.

Tim,
Recently I was told by a parts supplier in Japan that the discontinued EVO 3 3-4 hub/slider might possibly be available again in next year. yet I haven't confirmed it with Mitsubishi and I don't believe it too much. But if it's true, that a good news. Do you have any info about that?

 

[twicks69]

I have not heard anything of them making more, I have regularly put in order requests and they just bounce back as obsolete.

 

[rabenne]

Everyone assumes straights are stronger than helical. It's not that simple. Strong is a broad term, and gears being a dynamic element there is a lot to it. In many cases helical is a stronger gear.

Very true. A straight gear vs helical (size on size and all other factors being equal), the helical wins due to more bearing area in meshing. Two parallel lines (faces of the gear) are joined in the shortest distance by a line perpendicular to those lines. Any angle deviation from perpendicular will result in a longer line to connect those two faces. Basically, the tooth profile is "wider" when they are angled.

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The advantage of the straight cut gears is primarily reduced/no axial loading, right?

 

[DSMPT]

I have not heard anything of them making more, I have regularly put in order requests and they just bounce back as obsolete.

They normally reply as discontinued, too. But this time I heard back as available in 2020. I think it's just a mistake but I will update it here in case if I get any further info. Thank you.

 

[twicks69]

I contacted my Mitsu rep for further info.

 

[jakelandry]

Glad to see people haven’t given up on this yet. Every time I get on here and see a new trans thread I get my hopes up.

 

[bastarddsm]

Very true. A straight gear vs helical (size on size and all other factors being equal), the helical wins due to more bearing area in meshing. Two parallel lines (faces of the gear) are joined in the shortest distance by a line perpendicular to those lines. Any angle deviation from perpendicular will result in a longer line to connect those two faces. Basically, the tooth profile is "wider" when they are angled.

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The advantage of the straight cut gears is primarily reduced/no axial loading, right?

Yes, but I think you are geometrically limited when you have a narrow face width and want a larger pitch gear (bigger but less teeth) - i think.

Helical generally has more contact ratio, which helps smooth the load transitions, and improves fatigue life.

 

[twicks69]

Mitsu responded that MD747378 has no new news, been obsolete since 2014. That is the Evo 3 3rd/4th hub and slider.

 

[Ben-Stian]

Mathias Boldt,Boldt Racing in Germany can make you straight cut 3- and 4th gear (I bought the 4th gear from him years ago as my 4th gear stripped teeths to many times...) You have to ship him your old axles/gears as he machines them and put new gears on. Did not break any 4th gears after that. Had lots of low 10sec passes on them and dyno as well. Just under 700 whp and 750 nm.

 

[rabenne]

Hopefully it gets developed so as to keep people on the road. Salt is on the roads here in Racine as of this morning, so I am parked until spring. I may sell off my evo 2 trans and call you about a PPG setup before long. I would prefer to take the hit selling a perfect working, built, used, trans compared to breaking it and starting from (potentially) nothing.

 

[DSMPT]

Mitsu responded that MD747378 has no new news, been obsolete since 2014. That is the Evo 3 3rd/4th hub and slider.

Yeah that's the part number I asked my supplier. Thank you.

 

[rabenne]

@Ben-Stian

How much did they charge you for that service? Sounds like an interesting compromise. No issues with other gears for you?

 

[Steve92talon]

Well I feel lucky now having a 92 and a 90 transmission not a latter trans to work with.

 

[FAQGSX222]

Absolutely information overload! This should be a thread for everyone else that wonders the same thing. The amount of in-depth parts knowledge and what parts work and how rare they are. I want to thank everyone who added to help guide myself on what can be done in the garage and what HAS to be professionally done. I’ve got a ton to research and plan for the future,

 

[bastarddsm]

@Ben-Stian

How much did they charge you for that service? Sounds like an interesting compromise. No issues with other gears for you?

It ends up being 2500-3000 by the time you pay all the customs bs. I don't think it's a great value. There were a few guys that had issues with pitting. The profile looks like it is a pretty low pressure angle, which is good for case spreading loads,but bad for tooth strength. They look like they are 14.5*, and it really leaves me with the feeling that they are cut on a mill with a form cutter, and a dividing head. Probably 8620, and not finish ground. That's not great for gear quality and life. He won't answer any questions as to material or process, so I would be leary.

For guys on the fence about a ppg cause of the noise ect. I was just out for a cruise in mine, in 5th gear it's really pretty quiet. I have a very quiet exhaust, and you can barely hear the whine over the exhuast. Driving around town shifting isn't bad at all. It's a 3 step process. 1. go to neutral 2. pause 3.complete the shift quickly. If you time it right, it goes in the next gear silently. Downshifting can be a pita. When it's warm and at low speed its not too bad. WOT shifting is a breeze.

The one part that sucks for me, is it's all or nothing if you are getting on it. On the street I enjoy rolling into it, and lazily shifting it. Can't do that. If it's got any kind of RPM, you basically need to take it all the way, and jam the next gear.

The last part I don't like is I think first gear is too tall for a medium power heavy street car.

 

[rabenne]

That is very interesting about the PPG set. I have heard it is sort-of all or nothing with the shifting... I only drive on the street so it is certainly something to think about. Thanks, Bastard.