Fitted a mbc to a 1.8t aeb, no boost contol just stays at 0.5 bar ish???

Ryan Mcconnell

Registered User
Hi, I fitted a manual boost controller today to my a4 1.8t aeb. The problem is that it does not seem to matter where I turn the boost controller to. The boost gauge always reads around 0.5 bar or just under at full throttle, which looks about the same as with n75 on, although the car feels a lot better and is faster no doubt. It occurs to me the n75 could have been faulty and the manual boost controller could just be sh** it, was cheap; or a boost leak. I fitted it between the turbo nipple and the waste gate nipple and left the n75 plugged in, have I done something wrong? Any ideas/help?
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
VCDS Map User
The thing you did wrong was fitting an MBC.

Get the car tuned properly.
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
VCDS Map User
Well clearly either your MBC is **** or piped in wrong, but i suspect you'll find that even if it were connected properly, as soon as you achieved "a bit more boost" the ECU would realise theres something wrong and cut fuel.
 

Arrkon

Back in a "B"
Staff member
Moderator
Regional Rep
Kev, surely the AEB, not having a MAP sensor, would only base this on MAF reading, so could scaling the MAF work?

That said though, having run with an MBC on mine, it made part throttle driving a nightmare, it was either flat out or nothing... Not reccomended
 
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Ryan Mcconnell

Registered User
A small change in boost wont trigger the cel its not as tho im trying run 1.5 bar just bit a more than standard. Regardless of the mbc being **** or me setting mbc up wrong if thats case the car does drive smoother and it feels faster sorry is faster. i once kinked a vacum line by mistake on golf agu when fitting a boost gauge which made it run at 1.0bar .At the time i had no idea what it was supposed to boost at as i had never had 1.8t before i drove it for months never got the cel resricted power nothing the turbo did start go four months down the line but other than that it had no probs and it had 160000 on the clock.
 

Oranoco

Registered User
The electronic controller will dial out the additional boost you're trying to add. The only safe way to up the boost is to remap/chip it. Do it right or the results can be expensive
 
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