Understanding the MK7 PCV function, retrofitting the MK8 PCV, and why catch cans are bullshit(IMO)

[Nineeightyone]

Bunch of relevant PCV related stuff in the last two trip reports:

https://www.datadrivenmqb.com/tripreports/fastivus2024

https://www.datadrivenmqb.com/tripreports/2024tsccax7

It's really looking like for the later cars, it's looking like the MK8 full retrofit should be a pretty good option for autocross, and probably fit the bill for tracks that aren't littered with multiple long sweeping RH turns over a relatively short lap.

I think 15-16 GTI in particular need to try either an AP or maybe BM valve and *maybe* with a BMS catch can, but if that's no good then straight to a PCV plate.

The Golf R stuff has been much more of a mixed bag.

One interesting thing about the 15-16 vs 17-18 CXCA/CXCB pistons was sort of found here... which definitely could explain why there are such stark differences on the early cars. I suspect it extends to the early CXBA and CXBB 1.8s as well. Basically everything with the 06H 198 151 F piston rings stock looks like it it has a low likelihood of success if asking it to do track or autocross.

https://www.golfmk7.com/forums/index.php?threads/piston-markings-decode.453080/

View attachment 311711

Dummy attempt at translation of this, but looking at the parts website, this seems to basically imply that later cars will have less issues related to rings?

 

[tigeo]

Can confirm. 16 1.8 AP so far so good, but haven't done track yet with it (& probably not anyone soon)

So I had smoking on my 18 1.8 with the AP which was the original. So funny this issue. BL sorted it and now same results with MK8 both in normal and full retrofits.

 

[MonkeyMD]

So I had smoking on my 18 1.8 with the AP which was the original. So funny this issue. BL sorted it and now same results with MK8 both in normal and full retrofits.

Yeah, i think the AP only works on 2015-2016