Okay so i have a 96 1.8T and have fitted the MBC now, when setting it up i was boosting to 18psi but after 2 or 3 WOT boosts it would buck the a bucking bronco, figured the boost was too much so turned it down and it only seems to cope with 10psi maybe 11 spike. I do not have it chipped so i figure it is maybe bucking (feels like you have slammed the brake on and straight back off again or jolting back and forth like you sometimes see learner drivers doing) because the timing is not advanced enough to allow enough fuel into it compared to the forced air but i'm not too sure. My mate had the same car which also was not chipped and he was hitting 14psi spiking at 16 without any side effects like this so its making me think there maybe something else too.

Any Ideas would be much appreciated. It is rapid compared to the stock 7psi before i fitted MBC but only until boosted a few times when the kangaroo impressions are in full swing.

 

would my DV cause any issues? i have a Forge Split-R valve set on hybrid so it recircs and dumps too. This was setup for standard boost and i have not stiffened or eased spring tension since upping the boost????

Any ideas would be a help....Please?

 

If you're gonna use an MBC you really need to have it chipped first. The stock ECU will only provide enough fuel for stock boost levels, and when you start making more pressure, and increase the airflow without injecting enough fuel into the engine, it's gonna cause problems. With a chip, the computer is programmed to adjust the fuel delivery as boost increases.

 

thats sort of what i was thinking but just wondered if it could be anything else too. seems to run ok up to 10psi so will set it there until i can get the old girl chipped.

cheers

 

What he said is accurate. Leave the boost alone when stock