Flex fuel sensor + wastegate spring
 

For those guys running the flex fuel sensor. What wastegate spring are yor running (or springs if dual wastegate). Im just trying to figure out if there is a spring that will work for both low and high boost when the flex fuel sensor transitions. If I have to switch wastegate springs to achieve high boost then I really dont find an use for the flex fuel sensor. looking to run 15-16 psi on 91 pump. and 30+ on e85. Thanks guys

Sense you cant lower boost below the wastegate spring rate. Then I would start with a 15 psi spring

I'm running dual gates with 15 psi springs and running 28 high boost no problem.

Another option would be to use a 4port boost solenoid. Then you can run up to 4 times the WG spring pressure

I'm running an old Greddy wastgate with a 12 lbs spring. 38mm.
I think when you run big boost all the time, your wastegate really doesn't have to be that big.
I don't have any problems with creep or over boosting. The Haltech does a pretty good job at that.

Exactly. If you want to run a ton of boost you dont need a big wastegate because you need to direct more exhaust to the turbine. So no need to be able to vet a ton of exhaust gases.

I have twin 44mm gates and can run 8lbs with no creep to redline.

Sweet thanks guys. I have a dual gate short runner manifold. So it sounds like I can run 1 bar springs in both for pump gas and base boost with no creep. Then use the boost controller to turn up the boost 30+ on e85 on my pt6766. With the wg being able to open fine with the flex fuel sensor doing its adjustments. If not can someone correct me. Thanks again.:icon_tup: