MBC on its way, but some clarification needed

For those of you not faint of heart, who believe the Volvo 480 should have more torque and horsepower, find all you need to know in here.

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o.mcadam
480 Newbie
Posts: 14
Joined: Mon Jul 11, 2011 11:31 pm

MBC on its way, but some clarification needed

Post by o.mcadam » Sat Jul 23, 2011 8:15 pm

A MBC is on its way to me, but i was still a little uncertain about a few things.

Having read through thousands of threads on here ive learnt that the ECU will cut fuel above 13psi.
But ive also read people say that when they fit the MBC they only turn it up to the end of the yellow section.

Now my Gauge reads in lbs/in2 which is PSI, and the maximum is 14psi.

What else needs to be upgraded to turn the boost up to about 11 or 12psi? Surely the end of the yellow section is about 8-9psi?

Im not looking for massive gains, just enough to put a smile on my face. :hopping:

Robou
Knows an Aerodeck isn't a 480
Posts: 270
Joined: Sun Jul 08, 2007 11:34 pm

Re: MBC on its way, but some clarification needed

Post by Robou » Sat Jul 23, 2011 9:52 pm

The ECU will judge too high a boost as a defective system and react with a limp mode. If you cheat the ECU in making it see less boost than actual it will adjust injection and ignition to what it sees so the motor will run too lean and ignition timing may cause knocking. To an extend this all will be compensated by the lambda- and knocksensor, but this is not a situation to be happy with for several reasons. The MBC will not have any positive influence, whatever type.
The only way to overcome this is by altering the ECU.
If your gauge were linear and if it would show the actual value you can yourself figure out. But gauges, if not from a lab, act in their own way. The only reference point is the needle pointing at with motor off, this is very certainly 0. (In gauge speaks.)
Too old to bother
480 Turbo midst '91

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