6HP21PD Extreme Conditions Testing Results

[email protected]

Corporal
Free Vendor
Nov 6, 2016
159
Madison, AL
In maintaining our commitment to transparency and full disclosure of everything we do, we have some pretty impressive extreme testing results to share. We also want all of our current and potential customers to always have all the data needed to make a well informed and educated decision regarding our products.

Ok, so now for the goods...As some of you already know, Jimmie Johnson's PD transmission had a catastrophic failure due to a failed input shaft. Under most circumstances this would be considered a huge set-back and cause for panic but it's quite the contrary. Jimmie was one of our very first Beta Testers to get online so we all agreed to turn him loose to see just how much real-world abuse these new clutches could take before failing. Since we already knew the failure mode of the transmission under extreme loaded conditions, albeit in a controlled environment, we were excited to see just how far this thing could go under some pretty extreme rubber-to-road abuse.

Here are the extreme testing parameters/conditions...
1) No aux ATF cooler (stock system with heat exchanger)
2) Low Viscosity ATF (reduced lubricity and thermal rejection capacity)
3) ATF temps reported at 300F
4) Over 2000 miles of hard launching/brake boosting at 17psi
5) 275 MT ET Street R radials
6) Motiv900 ST
7) Estimated power levels ranging from 650whp to 800whp

While we have determined the root cause of this failure to be due to extreme thermal fatigue of the input shaft, it's extremely important for everyone to understand and be aware of the intent and limitations of this upgrade. This upgrade is not intended for extreme racing conditions nor is it to be considered a complete, silver bullet transmission solution. This upgrade/solution simply addresses the immediately obvious design flaws in the transmission, which everyone knows to be the clutches and bushings.

Now that the clutches are providing significantly more clamping capacity, the stresses are now transferred into other areas of the transmission, or the next weakest link. In this case, it's the input shaft. So, given these results, we are extremely pleased with the performance of the clutches we have provided. Even with ATF temps in the 300F range and 2,000 miles of brake boosted launches with the worst possible ATF for the application and no auxiliary cooling ability, the clutches still had enough clamping capacity to snap the input shaft. That's pretty impressive in our opinion. Bottom line is, these clutches are tough as hell.

Here is a quote from Jimmie himself regarding the failure...

"I was just thinking the other day, almost 2000 miles of launches/brake boosting at 17#, using the factory heat exchanger, low viscosity ATF and temps reaching 300° finally causing the input shaft to snap. It's disappointing to break things, but it's actually impressive considering what it handled for so long AND it was a factory part that failed, not your upgrade. So just keep that in mind and pat yourself on the back for coming up with a set of clutches that work extremely well. People need to understand just how much we trashed that thing and how long it kept chugging along until a factory part broke. It's unreasonable to think parts won't break, but it's important what it can handle before it will break."

Attached are some of the tear-down pics from the failure mode analysis. It's easy to see to see that even though the clutches are absolutely torched, they still performed as intended.

Input Shaft.JPG
C Clutch Drum.JPG
D Clutches.JPG
E Clutches.JPG
 
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dyezak

Major
May 4, 2017
1,764
Plano TX
Curious if you guys are going to continue working on this particular transmission. You're already at $5k for your upgrade on a box that lasted 2k (abusive) miles. From a customer's standpoint this is the tipping point of moving to the DCT system as it stands.

All that said, damn those clutches look bad. Realistically those things were on their way out anyhow after 2k mi even if the input shaft didn't sheer.
 

08_335i

Sergeant
Nov 3, 2016
371
Curious if you guys are going to continue working on this particular transmission. You're already at $5k for your upgrade on a box that lasted 2k (abusive) miles. From a customer's standpoint this is the tipping point of moving to the DCT system as it stands.

All that said, damn those clutches look bad. Realistically those things were on their way out anyhow after 2k mi even if the input shaft didn't sheer.
I think it needs to be noted that these were 2k miles of straight 650-800whp boosted launches and racing. Were not talking the average car here folks. Also, the "upgrades" that are in the transmission from PD, did their job, and held up.
 

08_335i

Sergeant
Nov 3, 2016
371
Appreciate the transparency. I really hope this project pans out in the end... The community needs a solid automatic option.
Yeah, I wish all of our vendors on this platform were transparent. The fact that he released this information, when he didn't have to, shows the type of person/company he is. In my eyes at least. This car is setup to eat it every time it turns on. Drag slicks, etc. And it was ran with shit fluid and without a cooler, and someone it still endured 2k miles of straight abuse. Obviously, I think Jason should look into the input shaft as being the next offered upgrade. But I think for the average DD who likes to do roll racing etc, this transmission will last a LONG time. If you plan on launching the everliving shit out of it every time you stop, then obviously waiting for a hopefully upgraded input shaft, would be the right route to take.
 

[email protected]

Corporal
Free Vendor
Nov 6, 2016
159
Madison, AL
Curious if you guys are going to continue working on this particular transmission. You're already at $5k for your upgrade on a box that lasted 2k (abusive) miles. From a customer's standpoint this is the tipping point of moving to the DCT system as it stands.

All that said, damn those clutches look bad. Realistically those things were on their way out anyhow after 2k mi even if the input shaft didn't sheer.
No clutches within economical feasibility will withstand 300F ATF temps for an extended amount of time, however, ours still had the capacity to snap the shaft in spite of being subjected to 2000 miles of extremely harsh operating conditions. This is why we recommend an auxiliary ATF cooler with a 165F thermostat. Again, these are extremely abnormal operating conditions indicative of the extreme racing conditions that this trans was never meant for. We are just providing results from an extreme worst case scenario with our upgraded clutches and bushings.
 

dyezak

Major
May 4, 2017
1,764
Plano TX
No clutches within economical feasibility will withstand 300F ATF temps for an extended amount of time, however, ours still had the capacity to snap the shaft in spite of being subjected to 2000 miles of extremely harsh operating conditions. This is why we recommend an auxiliary ATF cooler with a 165F thermostat. Again, these are extremely abnormal operating conditions indicative of the extreme racing conditions that this trans was never meant for. We are just providing results from an extreme worst case scenario with our upgraded clutches and bushings.
Thank you for pointing that out. That seemingly obvious fact was lost on me :)
 

jimmie004

Lurker
Nov 15, 2016
14
Savannah GA
I think it needs to be noted that these were 2k miles of straight 650-800whp boosted launches and racing. Were not talking the average car here folks. Also, the "upgrades" that are in the transmission from PD, did their job, and held up.
This is exactly true. I had this set up for drag and that's about all I did since installing the trans. Back to back to back runs, 1st through 5th. It's easy to get caught in the moment of a broken part, but that's when I had to step back a remember just what I had been doing to the trans for the last 2000 miles.

Put an aftermarket cooler on, use true ATF1 and I have no doubt this is the weekend warrior roll race game changer that we've been waiting for. Not only are you getting a solid built trans with a warranty, but Jason's customer service and transparency is second to none (as you've already seen). I have zero reservations about recommending this trans to any and everyone looking for a trans that can handle regular roll racing in upgraded twin or st applications. I wouldn't recommend it if you're looking to set up a drag car though. At least not at this point until an input shaft upgrade can be entertained at a reasonable price.
 
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135Pats

Specialist
Nov 17, 2016
59
MD
I appreciate the transparency here, it's refreshing and builds trust with the community.

Any insight into the ATF fluid that was being used? Pure curiosity on my part.
 
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jayson335i

Specialist
Feb 13, 2017
88
I have one of the beta units and I can second Jimmy. Jason's customer service has been top notch. He has been very transparent since day 1. I barely post on any of the forums reason why I have not posted any data but have provided all the feedback to Jason. As of right now it's holding flawlessly.
 

jimmie004

Lurker
Nov 15, 2016
14
Savannah GA
I appreciate the transparency here, it's reafeshing and builds trust with the community.

Any insight into the ATF fluid that was being used? Pure curiosity on my part.
The fluid used was Pentosin ATF1LV. To be perfectly honest, the container looks the same and I ordered it thinking it was ATF1 and didn't realize it until later. Worked out fine though for the testing as just another piece of abuse. With that, be extra cautious when ordering the ATF1 to make sure it's not LV. LV is cheaper and is usually the first to populate in any kind of search on the web. ATF1 will run you about $56/5L jug and you need 10L. You can visually see the difference of the fluid because ATF1 is amber while the LV is cherry color.

Here is the spec sheet for ATF1:
http://www.pentosin.net/specsheets/Pentosin_ATF1.pdf

Here is the spec sheet for ATF1LV:
http://www.pentosin.net/specsheets/Pentosin_ATF1LV.pdf
 
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nitemare

Private
Nov 5, 2016
35
Jax, FL
Why is it everywhere you go in this community there are trolls? Seems to me someone doesn't understand what brake boosting does to clutches and what trans temps past 200°F let alone an ungodly 300°F will do to a transmission.

Moving on.......

Jason's parts did not fail and nor did the clutches slip because if they were the input shaft probably would not have snapped. Even though the trans got as hot as it did if the clutches were slipping they might have slipped enough to save the input shaft. The trans temps being as hot as they were weakened the input shaft enough to warrant it snapping with the clutches refusing to slip.

I might have a solution to the input shaft without having a custom billet one made. Deep cryogenic treatment has been shown to increase the strength of metal from 50% - 300%. Knowing this lets hypothetically say the stock input shaft is good for 600wtq (with proper trans temps) even if the cryo treatment increased the strength on the low side at 50% that would give us a failure point of 900wtq. Which is well past the rated capacity of Jason's clutches anyway.

So I believe with his clutch and bushing upgrade, coupled with a deep cryo hardened input shaft, trans cooler (keeping the temps below 190°), and proper Pentosin high viscosity fluid you will have a transmission that will handle the abuse of 750whp/750wtq and below. If you are past that point and want to stay auto now would be the time into looking at Andy Divers 4L80E kit or a built DCT swap.

Nick
 

doublespaces

Administrator
Oct 18, 2016
6,959
AZ
Why is it everywhere you go in this community there are trolls? Seems to me someone doesn't understand what brake boosting does to clutches and what trans temps past 200°F let alone an ungodly 300°F will do to a transmission.

Moving on.......

Jason's parts did not fail and nor did the clutches slip because if they were the input shaft probably would not have snapped. Even though the trans got as hot as it did if the clutches were slipping they might have slipped enough to save the input shaft. The trans temps being as hot as they were weakened the input shaft enough to warrant it snapping with the clutches refusing to slip.

I might have a solution to the input shaft without having a custom billet one made. Deep cryogenic treatment has been shown to increase the strength of metal from 50% - 300%. Knowing this lets hypothetically say the stock input shaft is good for 600wtq (with proper trans temps) even if the cryo treatment increased the strength on the low side at 50% that would give us a failure point of 900wtq. Which is well past the rated capacity of Jason's clutches anyway.

So I believe with his clutch and bushing upgrade, coupled with a deep cryo hardened input shaft, trans cooler (keeping the temps below 190°), and proper Pentosin high viscosity fluid you will have a transmission that will handle the abuse of 750whp/750wtq and below. If you are past that point and want to stay auto now would be the time into looking at Andy Divers 4L80E kit or a built DCT swap.

Nick
What would it cost to do that treatment prior to building the trans? What other components can benefit from that?
 

ap485

Private
Nov 27, 2017
49
Houston, TX
Anyone running PD transmission, has tried cryo treatment of the trans internal (input shaft, baskets, etc) yet?

What hardness scale did you achieved (HRA, HRB, HRC,etc)?
 

nitemare

Private
Nov 5, 2016
35
Jax, FL
Anyone running PD transmission, has tried cryo treatment of the trans internal (input shaft, baskets, etc) yet?

What hardness scale did you achieved (HRA, HRB, HRC,etc)?
My PD trans has been running for 800 miles now without any issues. I actually did the cryo treatment on the input shaft. I never tested for hardness. Just make sure it's a true deep dryo, then they hold it for a certain time, slowly bring it back to ambient, then a re-temper at a minimum of 300F to take the brittleness out of the martensite. I had them do 400F just to be safe.
 
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ap485

Private
Nov 27, 2017
49
Houston, TX
My PD trans has been running for 800 miles now without any issues. I actually did the cryo treatment on the input shaft. I never tested for hardness. Just make sure it's a true deep dryo, then they hold it for a certain time, slowly bring it back to ambient, then a re-temper at a minimum of 300F to take the brittleness out of the martensite. I had them do 400F just to be safe.
Many thanks!
 

doublespaces

Administrator
Oct 18, 2016
6,959
AZ
My PD trans has been running for 800 miles now without any issues. I actually did the cryo treatment on the input shaft. I never tested for hardness. Just make sure it's a true deep dryo, then they hold it for a certain time, slowly bring it back to ambient, then a re-temper at a minimum of 300F to take the brittleness out of the martensite. I had them do 400F just to be safe.
Hopefully we will get to see this beast soon!
 
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