kenihemi, thanks for the info, very clear explanation. Can anyone with a STS confirm that's how teh STS controller works? Is there some dial that allows you to adjust the pressure to the back of the diaphragm?

 

What would happen if you put a 1psi spring in the wastegate and put an electronic contoller in the cab? You could dial up and boost from 1-???psi.
Is there such a thing as a 1lb spring?

Oh ya, that is how the STS controller works. Wastegate spring pressure and the STS regulator pressure, electric switch to toggle the valve that comes in the kit.
I planned on moving my contoller to the cab, but for now its under the hood on the passenger side firewall.

 

STS boost controller is just like kenhemi says, only its got a switch that turns a solenoid valve on or off allowing flow or not allowing flow to the back of the diaphragm. You still have to craw under the truck and adjust the reg until you get the high setting where you want it. Its king of a PIA. I will have a Greddy Profec B-Spec 2 electronic controller that would let you have a base, low and high settings for sell in the near future, if your interested.

 

My guess is you would blow the motor too easy to up the boost

Don't know about a 1lbs spring, but they make 3lbs springs

 

My supposed 4lb spring makes about 5.5psi on ocassion.
Maybe I'll go to the hardware store and get a real loose coiled spring with the same diameter and stretch it to length and try it out!! NOT!

 

Normally, the STS comes with a .4 bar spring which is 5.802psi; boost gauges usually show about 5.5psi.
We normally dont use the boost controller. You will have a tune for the highest boost you are running. If your tune was for 8psi and you are running 5psi at WOT, then you are running rich. We just make a decision on the boost and put the right spring in.
If anyone is interested this off of Tials website for the 38mm wastegate.
.250 bar 3.626psi small yellow 1.875" dia
.400 bar 5.802psi small red "
.500 bar 7.252psi small green "
.600 bar 8.702psi small blue "
.700 bar 10.153psi large yellow 2.36" dia
.800 bar 11.603psi large red "
.900 bar 13.053psi large green "
1.00 bar 14.504psi large blue "

 

I run a 2 Bar tune and meth. The meth comes in at 10 psi and over 10 psi I'm tuned for meth. Below 10psi I'm tuned for no meth. I run up to 10psi in low boost and higher with the switch on. I run the same timing for both because if I have the switch off I'm not all that serious anyway

All of this is going to change in the near future anyway (probably do 8psi in low and 18-20psi high) when I switch to the twins.