Torque Management killing my boost!

[Gamester]

Hey guys,

So, for a years now I have been running my Procharger with no real issues to speak of. However, a few months ago, all the sudden the engine torque management has seemed to have declared war on my boost and has even been throwing bad enough codes about the engine torque management to put it into limp mode, which it has never ever done before.

Normally, I will have 9-10lb of boost through every gear with no issues and now I'm lucky if I see 3-4lb. At first, my speed shop guy and I thought that there may be some belt slippage issues again, but we have now eliminated that issue via mechanical fan delete and found a suitable size green belt to fix the belt stretching we were having and that helped some, since when it started there were times with no boost at all, but that did not resolve the issue entirely.

My speed shop uses HP tuner to manage my setup and transmission tuning as well and we have done quite a bit of data logging and testing and are having troubles pinpointing the root cause of this issue. I have read some mentioning of the possibility of disabling the engine torque management itself over at the HP tuner forums...

https://forum.hptuners.com/showthread.php?63996-8-Speed-Torque-management

...,but not sure we should try that or not. Has anyone else around here with boosted 8-speed Rams been through anything like this?

Thanks

 

[nateinva]

Good luck resolving this. You'll probably get some responses here and would also suggest the NA Dodge Facebook group if you aren't already a member. There's several boosted guys that hang out there too.

 

[Joes1500]

This might be a dumb question, but is your blow off valve somehow controled by the tourqe management system?

 

[Gamester]

Don't think so, but we have tried two different ones at this point for testing and issue persists on both.

 

[Joes1500]

I by no means claim to know a lot about the prochargers.

But my thinking is this. The prochargers are belt driven . I don't believe they are variable vein wheels. So they are an independent air pump driven by the engine. Meaning the computer should have no control over the amount of boost the procharger is making unless it is opening the blow off valve.

I would have to think you have a leak, slipping belt, or the procharger itself is having issues.

 

[Gamester]

It's not controlling the amount of boost the blower makes, it is controlling the throttle plate, which means full throttle is not really full throttle, so it some how is stopping the boost as there are no leaks in the system and bypass is working correctly.

 

[Joes1500]

Then I would say something is wrong with your throttle body or the throttle position sensor or your throttle peddle.

 

[Gamester]

We are going to throw it up on the Dyno Saturday after next and do some HP Tuner tinkering to see if we can figure out what's happening here.

Thanks

 

[Stefan N]

how did it go?

 

[huntergreen]

Get this fixed yet ?

 

[Tach_tech]

The torque management will kill power during shifts and during launches to save the drivetrain.

I doubt that’s your issue since it just started happening. My bet would still be a mechanical issue since changing belts and the fan delete helped. What specific codes are you getting?

 

[blackbetty14]

When I tune my boosted LS swaps I use Hp tuners and I always disable torque management. No need for it as it only kills performance for the most part to manage power. It’s not needed if you modded the Engine like you have.

Different platform but the system is the same. Disable it.

But I doubt that’s the issue, my guess is that your having some sensor or data issues causing the ECM to put you in limp mode. Have you verified knock retard or fast knock attack? Sounds like the ECM is getting word that your engine is probably seeing knock or sensor fault and putting the engine in limp mode bc it thinks your engine will destroy itself.

What’s odd is that your not building the normal boost. I ran a centri supercharger on a 5.3 and Centris make boost linear to rpm. The face that your making 1/3 less means your loosing boost as the engine knocking or pulling timing isn’t going to reduce boost, the supercharger makes whatever boost at the same rpm. Perhaps you bent a intake valve or something.

You guys do a leak down test? Pressure tested the cold side piping? Made sure your BOV isn’t sticking or leaking?

 

[wink]

Been through this with my Jeep. First, torque management won't affect boost whatsoever. Doesn't sound like a belt issue with that much loss. Plus it would be pretty obvious with belt dust all over the place. Not to mention belts shredding. My bet is an issue with the bypass valve. Unless a hose is leaking. I literally blew two valves apart on my Jeep when I raised boost. They were good to around 8 psi. Then the diaphragms would self destruct, over time with the higher boost. Try this. Get someone to give it a little gas to close the bypass, while holding your hand over the bypass outlet. The air should be redirected to the throttle body. If you still feel air coming out, you either need a stronger valve, or spring. Vacuum holds the bypass open at idle. The spring is all that holds the valve closed for the air redirect when vacuum is removed. Or if the diaphragm has a hole or tear in it, it needs replacing. But it'll likely happen again if that's the case. I'm assuming you have the standard Procharger bypass valve. Their big red valve is unlikely to have this issue, but it's possible. In my case I did away with diaphragm based bypass valves entirely and went to a piston model. Never had another issue, up to 20 psi.

Good luck!

wink