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For those looking for another option instead of being taken for a ride. And having wasted your money on false claims. First id like to say the 722.9 trans has really impressed me in how much tq and power this thing can hold, the stick clutches can handle a monstrous amount of power when a good tcu tune is added. But for a lot of us that love to put down good quarter mile times , we need to brake boost. And this is where the outputshaft gets abused which after a while may eventually snap. To increase strength I’ve sent out 80% of the 722.9 internals to be cryo treated then micro polished. The cryo treatment is said to increase strength by 30% . The micro polishing helps with quicker smoother gear engagement, better heat transfer , and a cooler and butter like operating trans. I believe this is the first anyone has taken the time to build the 722.9 . If they have it was never posted . Why? Because all these companies just want to keep alll The good info to themselves.
30% increase in strength - Is this tensile, shear, torsional, yield, compressive....
What about the reduced toughness?
This is super cool
I would expect it is Ultimate Yield Strength. And yes, when you heat treat steel you harden it and while it raises the UYS it does make the material more brittle. So while it can then handle more power at a higher elastic limit, it will snap quicker if you exceed that new limit at the top of the elastic modulus.
So yes. There would be some trade off. But if you strengthen it beyond the maximum torque that you will ever deliver to the output shaft you should be OK.
Whereas with the stock shaft you can exceed the UYS a bit for a finite number of occurrences before it finally fatigues enough to snap.
This cryo process is all still a bit unproven territory for the 722.9 output shaft and I am excited to see if it truly has benefit. It might indeed.
For anyone unaware, the OP here is a seasoned guy and is likely on the verge of the fastest W212 in the world! Will be running well under 10 quite soon.
For clarity I am only speaking on the Cryo angle. The micro polishing is another discussion.
Good luck OP! You have been a pioneer in this platform. And we all appreciate your efforts and transparency!
And yes the toughness does drop somewhat as toughness is the area under the stress strain curve. So while the elastic modulus goes higher from heat treatment, the curve shape for entire curve, to include the “plastic” deformation does lower a bit the area underneath it and therefore less toughness.
Above, I meant to say the elastic limit in the new heat treated shaft is raised. By doing this the UYS is raised while still in the elastic region. However the nonlinear portion of the curve beyond elastic limit is lowered giving less area under the overall curve and less toughness.
The real question is will the “net” result be an advantage over time.
We all eagerly await!!
I realize this is all sounds a bit convoluted. Because it is! Lol. Metallurgy is very give and take science.
Noob question here.. I serached and the wiki says the MCT version of the 722.9 is just a regular 722.9 without the converter.
Is that true for internals and gear ratios? I have a 722.9 out of an E350 that I am ready to throw away.. But if they are the same.. might be worth to keep the internals just in case.
Thx fellas!! My attempt is to just find real proven results and not call a trans bullet proof like other companies that do nothing more then take your money . Knowing that if the trans becomes stronger the weaker link is next . I’m actually attempting to make the weaker link anything else other then the internals of the trans. I’d much rather have to replace broke axels over outputshaft any day. And if this micro polishing speeds up shift or just merely helps each gear engage smoother it was well worth it . Also micro polishing helps with heat dissipation and better lubrications on the gears themselves. If this works . It will be a game changer for even stock turbo cars. We are talking possible 9 sec car because now we can come off the line much harder
Noob question here.. I serached and the wiki says the MCT version of the 722.9 is just a regular 722.9 without the converter.
Is that true for internals and gear ratios? I have a 722.9 out of an E350 that I am ready to throw away.. But if they are the same.. might be worth to keep the internals just in case.
I wanted to share my updates with everyone . After some real world testing, with over 4k miles and over 20 hard brutal launches, attempting to snap my output shaft . Well I'm happy to say, i still haven't been able to break my output shaft! Using 3k rpm brake boost method, with limited slips LSD front and rear for maximum traction with radials, I haven't been successful in my attempts. You can chalk that up to whatever you like. I'd like to think the treatments are indeed working and have increased the strength of my transmission. Response of my shifts are fast, crisp. In my attempts I realized the clutches I had were slipping after a tune that was in around the 850 wheel hp mark. And as I loaded tunes that were more aggressive the slip became even more apparent. Since I wanted to tear the trans apart to inspect the parts anyway I figured it was the perfect time to now source clutches that actually hold some serious power. After spending a lot of time i decided to go with stage 1 reds which hold even more tq then gpz but no one has ever used them . After buying them I realized I wanted something more custom, so I then started sourcing individual clutches that are dual friction that do not come with any kit . Dual friction increases material and surface area providing even more clamping force. After all said and done I was able to successfully install dual friction clutches that will hold more power then any clutch kit on the market can give me. Results are even more impressive then before I dropped the trans. Faster shifts, super crisp and when it engages you can feel the car spring fowArd. These clutchs grab and HOLD! Even when I ran 41 psi absolute of boost which is 26 psi for those that don't use absolute, it didn't slip one time. Example of single sided friction disc Gpz vs red stage1 . Stage 1 being greater then gpz
14 E63, 05 E55, 03 Evo 8, 08 F250, 06 R6R, 92 Talon TSI, and instability
Originally Posted by Cifdig
I wanted to share my updates with everyone . After some real world testing, with over 4k miles and over 20 hard brutal launches, attempting to snap my output shaft . Well I'm happy to say, i still haven't been able to break my output shaft! Using 3k rpm brake boost method, with limited slips LSD front and rear for maximum traction with radials, I haven't been successful in my attempts. You can chalk that up to whatever you like. I'd like to think the treatments are indeed working and have increased the strength of my transmission. Response of my shifts are fast, crisp. In my attempts I realized the clutches I had were slipping after a tune that was in around the 850 wheel hp mark. And as I loaded tunes that were more aggressive the slip became even more apparent. Since I wanted to tear the trans apart to inspect the parts anyway I figured it was the perfect time to now source clutches that actually hold some serious power. After spending a lot of time i decided to go with stage 1 reds which hold even more tq then gpz but no one has ever used them . After buying them I realized I wanted something more custom, so I then started sourcing individual clutches that are dual friction that do not come with any kit . Dual friction increases material and surface area providing even more clamping force. After all said and done I was able to successfully install dual friction clutches that will hold more power then any clutch kit on the market can give me. Results are even more impressive then before I dropped the trans. Faster shifts, super crisp and when it engages you can feel the car spring fowArd. These clutchs grab and HOLD! Even when I ran 41 psi absolute of boost which is 26 psi for those that don't use absolute, it didn't slip one time. Example of single sided friction disc Gpz vs red stage1 . Stage 1 being greater then gpz
Any chance of you offering a rebuild "kit" of all of the parts necessary to rebuild the trans?
Any chance of you offering a rebuild "kit" of all of the parts necessary to rebuild the trans?
At the moment, it's just something that I'm not focusing on. But perhaps in the future . I can tell
you this, for anyone that thinks there's not more to this trans other then just clutches, they are wrong. Building this trans to the extent I have, really showed me how much stronger and faster this trans can be.
I just started rebuilding my CL63 trans and came across your post about the double friction plates. Can you share the SKUs of these that are not Raybestos, I would love to have my trans as strong as possible, having that I also will plant a supercharger and maybe the torque will come to the limits of a regular friction plate if I don't plan ahead.
11-26-2021, 10:35 AM
