went to the track today for some test runs. I recently swapped in a smaller spring into my wastegate because I plan to install a new boost controller. after my first test run, I noticed my MPH was way down and my ET wasnt that great. it was really hot out today so I thought maybe that was part of it or there was some heat soak going on. on the next run I notice my boost wasnt reaching what it used to when I had the larger spring installed, even with the boost controller on. it was still a good 5psi off. I had to turn the boost controller way up about 15% for it to hold boost with the smaller spring where it normally does when I had the larger spring installed. is this normal when installing a smaller spring? you have to actually turn up the boost on your boost controller in order for the spring to hold?

 

What PSI were the springs ?

 

the original was 9psi, the new one is 5.8psi

 

by smaller spring i assume you mean lighter/lower psi. so yes you will have to increase the boost contoller duty cycle to reach higher boost. 15% on different springs will create different boost levels.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dpetro1 &raquo;</TD></TR><TR><TD CLASS="quote">by smaller spring i assume you mean lighter/lower psi. so yes you will have to increase the boost contoller duty cycle to reach higher boost. 15% on different springs will create different boost levels.

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thanks. can you explain duty cycle for the boost controller? I know the concept with injectors, so I assume its similar with a boost solenoid.

 

in all honest im not sure. i mean i know the solenoid controls the airflow but how exactly duty cycle or whatever you wanna call it works, id like to know too.

 

duty cycle on anything is % of on time vs off time. yes your settings will be different with a different base. so in your boost controller, it is a solenoid actuated air valve, it is pulsed fast like your injectors. the faster it pulses, the more boost it dumps or presses down on the top. 80% means it is open 80% vs 20% of given time.

i am pretty sure that it is with any ammount of time. i know on my old welder it had 15% duty meaning it can run full bore for 1.5 minutes out of 10 before it needs to cool down, it was a little buzz box with no fan.