[LA1Z24]

Some of you may know, that e70 caused my 6th gear to start slipping on my ZF8. This car has just over 100k on it, with it's first trans service ever being done by me at 72k, with Liquid Moly ATF (don't do this).

It began with overboosts in 8th gear. Halim fixed it, but then I had the same issue when downshifting into 6th aggressively. I sent him some logs and he replied Nope, not the engine tune. He made some mutterings about torque limits and I was on my own again. I contacted XHP, who were a bit more informative. A 50RPM loss of power (slip) inside the tranmission, has the TCU tell the DME to cut boost.

I used my Autel Maxisys Ultra to graph the turbine speed in the transmission, along side the output speed. Sure enough, on hard shifts into 6th, the turbine speed with spike about 50rpm before the engine cut power.

PDS is 2 towns over from me. I began emailing Eric about my transmission, wants and needs. He suggested the stage 0, and their super street torque converter. Stage 0 is rated for 750hp, and 750lb ft of torque. Numbers even a big boost kit will struggle to achieve on a stock block.

It took 17 days to build my transmission and torque converter. The install took about 3 hours. The break-in period is 3-500 miles of stop and go. I'm at about mile 90 now. Suggested service interval is 20k miles. His words were, waiting to 30k miles for fluid service is a bad thing on this transmission. The converter stall speed has been raised 150rpm. It IS noticeable. First gear is kind of mush. Once second gear hits though it takes off hard.

I was also told by Eric, that XHP line pressure bump will kill this transmission, and stock transmissions fairly quickly. He says there is a seal in the back of the transmission that holds all the line pressure. When you bump the pressure this seal fails pretty consistantly. I was also told XHP stage 3 is too much. Stage 2 absolute max. I am currently running stage 1 to remove torque limits.

When this thing grabs gears it's pretty wild. It happens in an instant. Stage 1 xhp on this built trans, shifts harder than xhp stage 3 on a stock trans.

That's all for now. I'll update this thread more as the break in period comes to an end.

[thejeremyman9]

Good info. One question - When you say the line pressure bump, you mean the additional option beyond the OTS maps specifically for line pressure bump? Its a separate check box, and i think XHP has a note that its typically not needed. Just making sure i am thinking of the same thing.

[LA1Z24]

Originally Posted by thejeremyman9

Good info. One question - When you say the line pressure bump, you mean the additional option beyond the OTS maps specifically for line pressure bump? Its a separate check box, and i think XHP has a note that its typically not needed. Just making sure i am thinking of the same thing.

Yes, the separate checkbox in flash options labeled "line pressure bump". The line pressure bumps that are baked into the tune are 'ok', but the additional check box is a no if you want the transmission to last.

https://photos.app.goo.gl/5yt2bDGH4z9iKmEz8

[harkes]

Would be VERY interesting to hear what xHP has to say about this!

christoph@xHP

[LA1Z24]

Originally Posted by harkes

Would be VERY interesting to hear what xHP has to say about this!

christoph@xHP

Id like to see what they say too. I'm done with my 500 mile break in period. Last night an SRT8 Grand Cherokee tried to play. He was sorely disappointed.

[el_couzin]

Originally Posted by LA1Z24

trans service ever being done by me at 72k, with Liquid Moly ATF (don't do this).

Don't do the trans service or don't use LM ATF?


Could you elaborate a bit more on why?

[thejeremyman9]

I am also curious on how the increase in stall speed feels/drives. Does the converter feel extremely loose during normal driving? Is it something you would avoid if doing something like autoX?

[LA1Z24]

This is PDS's official statement on XHP.

https://www.puredrivetrainsolutions....ions-about-xhp

Don't use the Liquid Moly ATF, even though it says it's compatible. OE fluid all the way.

I have never autocrossed, so I don't really know the specific requirements you'd want in an automatic transmission in that scenario.

On the initial drive, taking off in first gear seemed loose. I felt the car did not react as responsive as it normally did. This is driving normally like a sane person mind you...Break in period. 2nd gear and higher all felt the same driving normally.
Yesterday, I am out of the 500 mile break in period, so I've been easing into it more. At half throttle when 2nd gear hits, I wouldn't say it's violent, but it noticeably more responsive than before the converter was built. When the RPM is up, the converter is MUCH tighter. I've had the rear end come loose a couple times now on cloverleafs during the break in because the connection between your throttle pedal, and the output of the car are much tighter. Meaning it reacts much faster to your pedal input. I hope I was able to answer your questions. This weekend I'll get some gopro footage of it banging gears.

[thejeremyman9]

Originally Posted by LA1Z24

This is PDS's official statement on XHP.

https://www.puredrivetrainsolutions....ions-about-xhp

Don't use the Liquid Moly ATF, even though it says it's compatible. OE fluid all the way.

I have never autocrossed, so I don't really know the specific requirements you'd want in an automatic transmission in that scenario.

On the initial drive, taking off in first gear seemed loose. I felt the car did not react as responsive as it normally did. This is driving normally like a sane person mind you...Break in period. 2nd gear and higher all felt the same driving normally.
Yesterday, I am out of the 500 mile break in period, so I've been easing into it more. At half throttle when 2nd gear hits, I wouldn't say it's violent, but it noticeably more responsive than before the converter was built. When the RPM is up, the converter is MUCH tighter. I've had the rear end come loose a couple times now on cloverleafs during the break in because the connection between your throttle pedal, and the output of the car are much tighter. Meaning it reacts much faster to your pedal input. I hope I was able to answer your questions. This weekend I'll get some gopro footage of it banging gears.

Thanks for the info, was kindof wondering if it would almost feel like slip at first due to higher stall when you aren't used to it, or would feel like a "looser" connection between pedal input and car output, but sounds like the opposite.

[Boostedphil698]

Interesting what you said about xhp. I was looking to go the route of the stage 1 transmission from PDS (they recommended a higher level for xdrive cars.) So, are you saying to not go past stage 1 at all on these transmissions?

[LA1Z24]

When the RPM is low, the converter feels looser, but once you get over the stall RPM, it tightens up much firmer than stock.

PDS says to not go past stage 1, on their built transmissions. I can see the need for stage 1 on AWD cars. The shock load from launching will be huge.

1stockf30 on IG had their stage 2. He was slaying everything up and down the east coast in a luxury line b58 xdrive. You name it he killed it.

[LA1Z24]

Today, PDS posted a new product on Instagram...

A trans brake kit for "All ZF8's"

[n55david]

Originally Posted by LA1Z24

Some of you may know, that e70 caused my 6th gear to start slipping on my ZF8. This car has just over 100k on it, with it's first trans service ever being done by me at 72k, with Liquid Moly ATF (don't do this).

It began with overboosts in 8th gear. Halim fixed it, but then I had the same issue when downshifting into 6th aggressively. I sent him some logs and he replied Nope, not the engine tune. He made some mutterings about torque limits and I was on my own again. I contacted XHP, who were a bit more informative. A 50RPM loss of power (slip) inside the tranmission, has the TCU tell the DME to cut boost.

I used my Autel Maxisys Ultra to graph the turbine speed in the transmission, along side the output speed. Sure enough, on hard shifts into 6th, the turbine speed with spike about 50rpm before the engine cut power.

PDS is 2 towns over from me. I began emailing Eric about my transmission, wants and needs. He suggested the stage 0, and their super street torque converter. Stage 0 is rated for 750hp, and 750lb ft of torque. Numbers even a big boost kit will struggle to achieve on a stock block.

It took 17 days to build my transmission and torque converter. The install took about 3 hours. The break-in period is 3-500 miles of stop and go. I'm at about mile 90 now. Suggested service interval is 20k miles. His words were, waiting to 30k miles for fluid service is a bad thing on this transmission. The converter stall speed has been raised 150rpm. It IS noticeable. First gear is kind of mush. Once second gear hits though it takes off [...]

What did you go with exactly and how much was it?

[LA1Z24]

Originally Posted by n55david

What did you go with exactly and how much was it?

Stage 0 and their super street torque converter. Bumps the stall speed up 250rpm. You can tell. When driven like a sane human, it sounds a bit like a riced out automatic car. Lots of noise, not much happening. When you romp on it...You can tell there is something different going on.

Both cost me $4500. I did the installation myself.

If you email them, Eric is who you will be in touch with. Tell him Jay from Robs Auto Service in Smithtown sent you.

[n55david]

Originally Posted by LA1Z24

Stage 0 and their super street torque converter. Bumps the stall speed up 250rpm. You can tell. When driven like a sane human, it sounds a bit like a riced out automatic car. Lots of noise, not much happening. When you romp on it...You can tell there is something different going on.

Both cost me $4500. I did the installation myself.

If you email them, Eric is who you will be in touch with. Tell him Jay from Robs Auto Service in Smithtown sent you.

Looks kike the price has gone up but very cool. I may look into it.

[LA1Z24]

I looked at the site earlier, it was the same price. 3500 for the trans.

[Eschmacher]

Originally Posted by LA1Z24

I looked at the site earlier, it was the same price. 3500 for the trans.

With the high stall converter it's now $5250.

[lens]

Originally Posted by LA1Z24

I was also told by Eric, that XHP line pressure bump will kill this transmission, and stock transmissions fairly quickly. He says there is a seal in the back of the transmission that holds all the line pressure. When you bump the pressure this seal fails pretty consistantly. I was also told XHP stage 3 is too much. Stage 2 absolute max. I am currently running stage 1 to remove torque limits.

When this thing grabs gears it's pretty wild. It happens in an instant. Stage 1 xhp on this built trans, shifts harder than xhp stage 3 on a stock trans.

That's all for now. I'll update this thread more as the break in period comes to an end.

A bit strange, have they specified what quickly is

I've been running stage 3 since release, with most probably over hundreds of launches and I've put maybe 80k miles since then?

Haven't had an issue with the transmission yet, mind you, I've never done any service on it yet and I'm almost at 180k miles.

[LA1Z24]

Originally Posted by chaungo

A bit strange, have they specified what quickly is

I've been running stage 3 since release, with most probably over hundreds of launches and I've put maybe 80k miles since then?

Haven't had an issue with the transmission yet, mind you, I've never done any service on it yet and I'm almost at 180k miles.

You should read the entire text. The quote is about the LINE PRESSURE BUMP feature which is not enabled by default. In fact even XHP says the LINE PRESSURE BUMP is not for every day use. They say only to use it when your transmission is already slipping.

[thejeremyman9]

After reading their post about stage 3, i eventually went down to stage 2 for the trans flash. It feels exactly the same, but i might sleep a little better at night lol? I was considering stage 1, but there were zero revisions to the stage 1 map since initial release. Probably because it doesnt really change things (except torque limits), but still i like stage 2 as a middleground map that actually had recent revisions.

[harkes]

Been running all stages for several months. I eventually ended up at Stage1. Dont like any of the changes xHP has made on the drivability really haha

Interesting read about the line pressure bump. I have been running that since it was released. Might be time to disable that and see if I get any slip.

LA1Z24 I dont have any slip (to my knowledge) but 20-30% of the time I get a hard shift into 6th. My values are somewhat outside the tolerances. Do you know what need rebuilding? Valve box/mechatronic or clutches/brakes?

[lucasborka]

Originally Posted by harkes

Been running all stages for several months. I eventually ended up at Stage1. Dont like any of the changes xHP has made on the drivability really haha

Interesting read about the line pressure bump. I have been running that since it was released. Might be time to disable that and see if I get any slip.

LA1Z24 I dont have any slip (to my knowledge) but 20-30% of the time I get a hard shift into 6th. My values are somewhat outside the tolerances. Do you know what need rebuilding? Valve box/mechatronic or clutches/brakes?

The option line pressure bump only bumps the pressure when needed. Which is rarely needed on the N55