Monitoring haldex torque split

[CloakAndSwagger]

First post

I've recently started racing my 2018 S3 at autocross, and am planning mods for coming events as well as for tracking in the near future. Anyways, I've been doing research on the haldex and was wondering if there was any way I could monitor the torque being sent to the front and rear axle through OBD... or perhaps connecting a voltage meter to the haldex pump? The only related post I could find talking about this was https://www.audi-sport.net/xf/threads/haldex-torque-split-level-on-the-dis-a3-s3-quattro.339117/ and there isn't really enough there for me to go off of.
Thanks!

 

[Harvey]

@CloakAndSwagger you might find this useful https://www.haldexcontroller.com/en/products/haldex-controller

 

[CloakAndSwagger]

Just use VCDS.. it shows voltage and there is even graph

Thanks for the info!

 

[CloakAndSwagger]

@CloakAndSwagger you might find this useful https://www.haldexcontroller.com/en/products/haldex-controller

Thanks for the reply Harvey. I have looked into Haldex controllers, but I would rather just monitor the torque split rather than change it. It seems that pretty much all the options out there are made for drag racing/acceleration performance, with there engagement during general driving being a gateway to damage.

 

[CloakAndSwagger]

Why exclamation mark? ‍
If your differential is weak.. The bearings they get seized by frequent high speed or sudden acceleration
It can be replaced.. I need to do it but need to find someone who could help me to take it of and disassemble whole thing and replace bearing below..
Mine rear diff bearing is seized and it is very noisy... Metal grinding
Your pump don't suffer or haldex its job is pretty much to only attach and disconnect from rear diff

My haldex unit is in good working condition, I’m just trying to monitor the rear diff engagement percentage so I can setup a display showing how much the torque split front and rear is.

 

[wuta3]

You can't monitor rear torque power separated from front unfortunately as car calculates front and rear power all together on your dash..
The pump is working every 20 seconds. that's just fluid circulation.
You can only read below how it works and you can use your imagination and create understanding how rear power is engaged Link is for RS but they mentioning A3 and S3 as well when you read it all through.. in RS3 the all quattro thing is doing much quicker as engine is stronger... but same way.
The clutch in rear is engaged in dynamic mode and comfort mode and in efficiency mode and auto mode is dislodged until you don't step on it..
Article is new-ish so rear diff picture in RS3 is more advanced but system how it works is all same in A3 or S3

A matter of lateral: the torque splitter in the new Audi RS 3

The new Audi RS 3 (Combined fuel consumption in l/100 km: 8.8 – 8.2 (26.7 – 28.7 US mpg); Combined CO2 emissions in g/km: 201 – 188 (323.5 – 302.6 g/mi)) represents the epitome of unadulterated driving dynamics. This is Audi’s first vehicle to feature the RS Torque Splitter, which distributes...

www.audi-mediacenter.com

I think an A.I wrote this.

You can use VCDS to log haldex pump power demand which correlates to haldex engagement of the rear. What it means in terms of concrete power transfer has a few more variables than just pump load, but it'll give enough for an estimate.

Aside from pump current draw you can also read Haldex clutch status, which you can use to backup graphing of engagement.