tomasss
former PRVert
- Joined
- Oct 13, 2008
- Location
- Sydney, Australia
The boosted world is still not very clear to me in some points. When I had S70R some time ago, the wastegate hose had burst and as the pressure was leaking I bent all five rods. That set my mind to be very careful when it comes to boost.
Now I want to put an MBC on my B204GT. From what I understood there are generally two engine limitations on the stock setup while increasing the boost:
- jetronic fuel cut, caused by too high reading of the AMM. Can be solved by updating the firmware (chips)
- lean mixture, caused by injectors not capable to deliver more fuel to keep the AFR. Can be solved by bigger injectors/pump.
But still, even if I have chips and bigger injectors, there is third limitation...the mechanical strength of the engine itself.
Can we talk some numbers? From other topics I understood that on stock engine (13mm rods) it is safe to run around 14-15psi of boost, with the chips and injectors it goes usually somewhere around 20psi. Is that the boost where it becomes mechanically dangerous even if it has good mixture? Other threads I have been reading says 30psi..
Also I remember that the mechanic reparing my S70R told me that in low RPM the engine can take less boost while on high RPM it can take almost whatever boost. But the MBC has no idea about the RPM...is there a risk if let's say I tune it for 20psi and then I hit the gas in low rpm?
The object of the questions is B204GT '90...
Now I want to put an MBC on my B204GT. From what I understood there are generally two engine limitations on the stock setup while increasing the boost:
- jetronic fuel cut, caused by too high reading of the AMM. Can be solved by updating the firmware (chips)
- lean mixture, caused by injectors not capable to deliver more fuel to keep the AFR. Can be solved by bigger injectors/pump.
But still, even if I have chips and bigger injectors, there is third limitation...the mechanical strength of the engine itself.
Can we talk some numbers? From other topics I understood that on stock engine (13mm rods) it is safe to run around 14-15psi of boost, with the chips and injectors it goes usually somewhere around 20psi. Is that the boost where it becomes mechanically dangerous even if it has good mixture? Other threads I have been reading says 30psi..
Also I remember that the mechanic reparing my S70R told me that in low RPM the engine can take less boost while on high RPM it can take almost whatever boost. But the MBC has no idea about the RPM...is there a risk if let's say I tune it for 20psi and then I hit the gas in low rpm?
The object of the questions is B204GT '90...
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