What is the box in a CGQB-powered BiTDI

[Derv_Guzzler]

Hi guys

I have had a look at the threads in the Tech Sub-Forum but alas. I am wanting to compile a wiki about the car (2014 prefacelift CGQB).

I have read on another Audi forum that the box has a manufacturer's code of 8HP55A. this is important a it tells us that the box started as a 8HP55, but then underwent a manufacturer's modification and was then given a new name.
It could also be an explanation as to why a box, originally rated 550Nm, was chosen to be mated to an engine outputting 650Nm.

I also read that Audi have their own code for this box: NVF, but that is to be verified


Can we get some info together and then do our bit to verify this?

[jbmercapple]

You've got about as far as I have.
Everything points to it being the 8HP55 box but like you say, how come Audi have mated it to a 650NM engine? I seem to remember being questioned by someone on this forum when I pointed out his 700+NM tuned Bitdi may cause gearbox problems!

What I think would be a much more interesting project would be to find out if our gearbox could be programmed with the BMW software. As far as I know, they use the same box but with the BMW in house software. This makes it much more quicker changing with no lag.

Perhaps its Audi's slushy, lagging software that lets them use it on the Bitdi!

Good luck in your research

John


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[ukgroucho]

I looked into this a while back and it's hard to get a clear answer.

One theory (from an SQ5 thread on myaudiq5) is that it's the 8HP70 box. I think the SQ5 uses essentially the same engine / gearbox as the A6 BiTdi except that the final drive reduction is different to provide even punchier acceleration - I did find a side by side comparison on the ratios somewhere ages ago.

The other possibility is that it is the 8HP55 but with a different clutch pack. Apparently ZF have a number of clutch packs (5?) that fit the 8HP55 for different applications. Figuring out which clutch pack might reveal some insight into the actual ratings for the gearbox.

[eastmidsdude]

We use the 8HP70 box in our race cars mated to various Land Rover engines

[Derv_Guzzler]

Just wondering if you have the gearbox codes?

When you remove the gearbox from the car, you should be able to find its code etched on the box or in a tab specific. This could provide a clue

I think I found on a French site, that the code for the box in the pre-facelift biTdi (313PS), is NVF. Can you confirm?

[morski]

My bitdi is NVF. Its also written on the PR codes list or on etka with a chassis no.