[vrooooom]

over a year later... what happened here? Did the ATM work better?

[levl]

Observation are right here. Anything larger than 50% increase over stock IC volume will increase smaller turbo lag quite badly. Seems like across many bmw forums there is a missconcept of suggesting boost leak tests after owners complain bad low end performance....

For example N57D30T1 with Wagner IC will see almost 0.35bar of pressure drop at the same rpm point in same gear, same load condition vs stock cooler. Such drop only exists in low rpm range and occasionally it can even trigger under boost warning . sluggish low end boost dynamics is partly compensated when second turbo kicks in. However city driving will be noticably affected. So this is a trade of for a safer temp.

Anyone with stage 1 I would recommend WMI over IC upgrade

Alternativly you can ask your tuner to compensate lag with higher boost targets or fueling. But again small turbo is too small to fill doubled sized IC fairly quickly . Single turbo N57 has less impact due to turbo's cfm is good enough to handle ic volume increase

[vrooooom]

N55 is a single turbo. S55 is dual. Which IC is +50% of stock. There’s just no data on these aftermarket IC.

[levl]

Originally Posted by vrooooom

N55 is a single turbo. S55 is dual. Which IC is +50% of stock. There’s just no data on these aftermarket IC.

E93 Wagner's EVO1 about 70% over stock. Wagner's evo 2 for f series states 90%. Most Chinese replicas claim 80-90%.

I would say EVO1 or forge ic suites better for stage 1-2 on stock turbos for a daily driver
https://www.forgemotorsport.co.uk/In...hoCZVoQAvD_BwE

[Pepi]

Originally Posted by levl

Observation are right here. Anything larger than 50% increase over stock IC volume will increase smaller turbo lag quite badly. Seems like across many bmw forums there is a missconcept of suggesting boost leak tests after owners complain bad low end performance....

For example N57D30T1 with Wagner IC will see almost 0.35bar of pressure drop at the same rpm point in same gear, same load condition vs stock cooler. Such drop only exists in low rpm range and occasionally it can even trigger under boost warning . sluggish low end boost dynamics is partly compensated when second turbo kicks in. However city driving will be noticably affected. So this is a trade of for a safer temp.

Anyone with stage 1 I would recommend WMI over IC upgrade

Alternativly you can ask your tuner to compensate lag with higher boost targets or fueling. But again small turbo is too small to fill doubled sized IC fairly quickly . Single turbo N57 has less impact due to turbo's cfm is good enough to handle ic volume increase

I was considering purchasing a Wagner EVO II for my Stage 1 tuned 328d, so I’ve been reading through this thread with great interest. The increased lag primarily felt in city driving RPM range is forcing me to reconsider buying it. What intrigues me is the thought of a WMI retrofit in lieu of an upgraded IC. I’ve considered this upgrade before but now I feel that this should be my next mod, before upsizing the IC or going the delete route.

Seems to me that there really are no negatives if setup correctly, with only power gains to be had + reduced opportunity for detonation = win win scenario in my book. I have yet to read about a 328d w/WMI, but surely they’re out there.

Have you installed a WMI system in your car or know of someone running WMI?
If yes do you care to describe your setup?
Any recommendations for which system(s) would be best suited for my 328d?

Thank you kindly for your input!