I you are running higher than standard boost (e.g. 13 psi) throught he use of boost jets or similar will safety boost still run at 7 psi or will it run at at 11 psi (based upon a standard normal boost of 9 psi).

7 psi

hi,

just looking at the scematic,for the wastegate solenoid valves,the way i see the system working is that under normal(no boost jets)conditions you have

a pipe from behind the throttle to the solenoid(pipe 1),

a pipe from the solenoid to the actuator(pipe 2),

and a pipe from the soleniod to before the turbo(pipe 3),,

in full boost mode the solenoid bleeds of a certain amount of air off through pipe 3 and in safety boost mode you get a direct feed straight to the actuator.

so if you put any restriction in pipe 1 you will alter safety boost settings aswell!!!

i think boost will be 2psi under max boost with boost jets.i.e:-13psi =11psi in safety boost

if anybody else knows different please explain how???

Ok ok ok,

 

Both replies are correct LOL

 

Basically, under safety boost circumstances, the actuator is fed directly by the intake pressure. If you put a boost jet in, it will restrict the flow in this line. The effect you will see is the boost rising to a peak and then falling back down to 7psi. The only effect a boost jet will have on the boost, under safety boost conditions, is to slow the actuators responce down, allowing the boost to build beyond the set point b4 it has chance to open the wastegate, but will then catch up to bring the boost back to 7psi...

 

Make sense??? Hope so!!!

 

CheerZ,

 

Andy

Thanks Guys,

 

I get the idea. But I'm still a little perplexed about what is going on with my Z.

 

Before she went in for a new cylinder head the boost guage would read approx 13. Now it only reads just over 10. ConZult shows that I have an intermittent problem with the detonation sensor circuit.

 

I'm pretty sure that 10 isn't a bad reading corresponding to saftery boost of 7 psi because it always read that at full boost prior to the boost pressure upgrade when I had the turbos replaced.

 

Could a collapsed cat have any effect on boost pressure?

yup, collapsed cat will affect boost pressure.

 

in my experience, boost pressure will rise very slowly, under load, as the turbo cannot spool up quickly enough. happens on merc CDi's a lot.

 

 

 

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I feel the need, the need for speed!