[Justanotherm340]

[Merami fan]

Ouch... Hope that new part works!

[Justanotherm340]

Originally Posted by Merami fan

Ouch... Hope that new part works!

Thank you 🙏🏼

[chenry]

sh*t sorry to see that - saw your comments in the M340 Gang group chat

watched your clip start to finish - very informative thanks for the share! Looking forward to hearing what you have to say about that new part when it comes in.

[Justanotherm340]

Originally Posted by chenry

sh*t sorry to see that - saw your comments in the M340 Gang group chat

watched your clip start to finish - very informative thanks for the share! Looking forward to hearing what you have to say about that new part when it comes in.

Thank you 🙏🏼 and it happens happy it's just something simple

[TurbroMeca]

What mods do you have?

[Justanotherm340]

Originally Posted by TurbroMeca

What mods do you have?

Catless downpipe
Awe track exhaust
Arma speed carbon fiber intake
Neuspeed rse10 lightweight rims
Brooklyn euro tuned

[TurbroMeca]

Awesome, hopefully it’s back together soon bro!

[Justanotherm340]

Originally Posted by TurbroMeca

Awesome, hopefully it’s back together soon bro!

Thank you 🙏🏼

[evan103207]

Around how much power were you pushing when this happened?

[rrfitness20]

Glad to hear your transmission is ok. Every platform has its weaknesses. Coming from a VR30 platform I went through so many injectors and other issues lol.

[rahimhussainar@gmail.com]

Hey I know this has been a while.

But do you know what symptoms you faced?

I think I may have the same issue but can’t tell.

No CEL or codes. But from 1st to 2nd shift, there is a super loud thud and it’s very violent. All gear shifts after are less and less violent as they go on.

I’m having a lot of other symptoms as well.
Any help would be appreciated. Thank you!

[cyam]

Originally Posted by rahimhussainar@gmail.com

Hey I know this has been a while.

But do you know what symptoms you faced?

I think I may have the same issue but can’t tell.

No CEL or codes. But from 1st to 2nd shift, there is a super loud thud and it’s very violent. All gear shifts after are less and less violent as they go on.

I’m having a lot of other symptoms as well.
Any help would be appreciated. Thank you!

Assuming you are tuned. How does ypur tune "talk" to the TCU? Are you running XHP?

If your tune is downscaling the torque values sent to the tcu, so the tcu thinks its getting less torque than it is - then likely that is causing issues.

The TCU stock, will send a request to the DME to reduce torque when it gets anything over 550nm. Less in gears 3 and 6. Your tune can either ignore that request - which is OK, or it can trick the tcu and downscale the values sent to the tcu - which is bad. Alternatively, it could do as instructed and reduce torque - also ok. If your tuned DME listens to the tcu and reduces torque when requested, then you'd need XHP to remove the torque limits.

My first tune downscaled and I had shudders at a gear change. I immediately figured out what was happening and ditched the tune. I also now run XHP with a different tune. My shifts are fine now.

Hope this helps.

[rahimhussainar@gmail.com]

Originally Posted by cyam

Assuming you are tuned. How does ypur tune "talk" to the TCU? Are you running XHP?

If your tune is downscaling the torque values sent to the tcu, so the tcu thinks its getting less torque than it is - then likely that is causing issues.

The TCU stock, will send a request to the DME to reduce torque when it gets anything over 550nm. Less in gears 3 and 6. Your tune can either ignore that request - which is OK, or it can trick the tcu and downscale the values sent to the tcu - which is bad. Alternatively, it could do as instructed and reduce torque - also ok. If your tuned DME listens to the tcu and reduces torque when requested, then you'd need XHP to remove the torque limits.

My first tune downscaled and I had shudders at a gear change. I immediately figured out what was happening and ditched the tune. I also now run XHP with a different tune. My shifts are fine now.

Hope this helps.

Hey man. Sorry just saw ur reply.

I use xhp. All settings are stock. I’ve run stage 0-3 with several changes in settings.

But still depending on who much throttle I give it, the shifts tend to do a quick shudder.

The only correlation I could find at all for this was log for the torque act. Clutch.

When I logged that, I saw that any time there was a hard heat shift (or anything in smooth on the shift), the values for the torque act. clutch would dip down a bit.

But when the shifts were nice and smooth. That same value would remain relatively the same.

[Randy Johnson]

Of course this happened in NY!!!

[cyam]

Originally Posted by rahimhussainar@gmail.com

Hey man. Sorry just saw ur reply.

I use xhp. All settings are stock. I’ve run stage 0-3 with several changes in settings.

But still depending on who much throttle I give it, the shifts tend to do a quick shudder.

The only correlation I could find at all for this was log for the torque act. Clutch.

When I logged that, I saw that any time there was a hard heat shift (or anything in smooth on the shift), the values for the torque act. clutch would dip down a bit.

But when the shifts were nice and smooth. That same value would remain relatively the same.

You have to know what your DME tune is doing first. If that is downscaling the torque values sent to the TCU - XHP can't help. That's the issue I had and why I ditched my tune. I then got MHD which ignores the torque limits from the TCU and does not downscale. I have had no issues since.

Two ways I could see my first tune was downscaling. First from the torque gauge in the sports gauges. It would hit 500nm and never go above it, even though I knew I was getting over 600nm (The scale went up to 700nm). That gauge shows the exact same values the DME is sending the TCU. I tested this with the XHP torque limits - I set that to 300nm and the gauge only went to 300nm, tried it at 400nm - same. So it does show exactly what the TCU sees.

Secondly with XHP I used the line pressure bump feature which increase line pressures by about 15% - the problem went away. So it was clear. The TCU thought it was getting 500nm when it was getting much more, so the line pressures were too low - thus the occasional slipping and shuddering under WOT. Then switching to MHD - no issues since at all (without using the line pressure bump).

If you are certain your tune is not downscaling torque values, then contact XHP and speak with them I have found them very helpful and responsive.

[rahimhussainar@gmail.com]

Man that is a lot of info!

Thank you so much for the in depth response.

I’ll have to do a lot more research and testing on my own to figure out what exactly is going on.

I’m on stage 2 MHD and stage 3 xhp but don’t know how it affects my car exactly

[cyam]

Originally Posted by rahimhussainar@gmail.com

Man that is a lot of info!

Thank you so much for the in depth response.

I’ll have to do a lot more research and testing on my own to figure out what exactly is going on.

I’m on stage 2 MHD and stage 3 xhp but don’t know how it affects my car exactly

If you are using MHD then it isn't downscaling so the TCU is getting the right info. So I'd dare say its not your engine tune.

I'd speak to XHP and explain your issues. I found them very responsive and helpful.

Might be a good idea to try XHP Stage 1 - that's essentially stock. Stage 2 and 3 can become a bit "harsh". Some gearbox specialists have said stage 2 and 3 will cause premature wear. XHP say it definitely won't. I believe Stage 2 and 3 change how the torque converter works - possibly allowing less slip making the transfer of power more "direct". This has obvious benefits, but maybe in your case it is causing an issue. But Stage 1 is certainly "softer" on the gearchanges in general. See if that reduces your issues.

I don't really know enough to be able to help. I am only going by my experiences and what I have learned. But XHP know their product inside out and may be able to shed more light. You could also speak to MHD - I have found them also helpful and responsive when I have asked them questions.