MBC Around N75 valve?

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Tom93

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Hi chaps, been having some weird issues with my car lately thought it was missfiring so basically focused on the fuel/ignition system and now ive realised that the problem has been boost all along. Basically my boost is all over the shot the needle on the gaige is almost shaking and the cars stuttering with it, but then it hit me that ive known the whole time about this MBC Around the n75. Its on a reciept from the company that mapped it as they fitted it to stop boost spikes... What do you guys think? I also do have some flat out 3rd gear logs of boost to upload later.



The boost almost goes in both sides of the mbc...
 
Who mapped it and why do they need to patch up boost spikes using one of them orrible contraptions
 
Was mapped by a local company called RK Engineering, seem to be highly regarded, but its just seemed a bit of a bodge than a cure :/
 
Got a log, basically shows its not making specified boost :/



Also found out the MBC is ran in parallel to the N75, common on the audizine forum... Pic just so you can see.

Also measured the resistance of the N75, was 30.6ohms...
 
I'd be unplugging the n75 electricly and binning the mbc till you can get a decent map and health check. Mbcs are good at capturing boost spikes but if you are not meeting request it could be either bleeding boost off or your turbo is dead and unable to meet request. Assuming turbo and engine healthy then you need it mapped properly by someone not stuck in the 90s
 
But sometimes it runs perfectly fine, it doesnt always not meet the requested boost...
 
n75 in limp mode will still be able to drop it into actuator pressure when its unhappy..... plumbed like that
with a boost request of 2550 (max) its not surprising it needs some sort of cap, if they did'nt know how to do it in software (easily)
 
What is your suggestion mr badger? Im currently going over all the pipe work looking for leaks or anything that could be giving me issues, also going to try another N75 valve in a bit...
 
audi upgrades
Ok so went for another drive, if i hold the car flat out in 3rd, from 2500rpm upto 6000rpm theres a couple of stutters everytime, but sometimes it stutters loads and other times it stutters loads then the boost drops back to a stable 0.5bar, which i assume is the N75 limp mode/actuator pressure? I have a sneaking suspicion that im going to need another remap :/
 
The company that mapped it call themselves VAG Specialists :eek::eek:
 
Tom93 said:
What is your suggestion mr badger? Im currently going over all the pipe work looking for leaks or anything that could be giving me issues, also going to try another N75 valve in a bit...
Click to expand...

the mbc is'nt required with suitable map..
if its dropping into limp mode it should also be flagging a faultcode.
Have you checked
 


Thats fresh today. Maybe i am having coilpack issues and this is unrelated...
 
Car had new plugs anyway but after some research apparently the BKR7E plugs are recommended for mapped cars so i got some of those, and also my bargain 2.0tfsi coils turned up today, so banged them in and the car is smooth as butter, no more hesitation or weird boosting, goes upto 1.6bar and holds.



Also dug out some of the receipts for a laugh, i didnt pay any of this, one of the previous owners must of...





 
audi upgrades
I do plan on a badger remap one day, just want to get a few more mods done first to make the best out of it...
 
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