Which Wastegate Spring

[CAMB01]

Going to be purchasing an external wastegate to go with my new turbo. There are 2 spring options, 7psi and 14psi.
I'm going to get the G4 LINK ecu to control the boost for me but just want to know and understand which spring would be recommended?

Is going in my racecar so will see boost between 12 and 25psi as i will have 2 boost settings controlled by a switch on my dash from the LINK.

[Shrike]

General rule of thumb is you can run twice the boost of whatever spring is in the wastegate by bleeding off pressure via your EBC solenoid

Lowest boost is whatever spring pressure is

So for 25psi you would run a 12.5psi spring

Id say run the 14psi spring as you will possibly get a small amount of boost drop anyway so depending where you take your boost reference from you may run less then 14psi anyway

If that makes sense

Can go into more detail if need be

I did work out a way to run 5psi-30psi (for my twin charge setup) but it requires 4 waste gates and two solenoids

twin 44mm on the twinscroll mani (14.7psi springs)
60mm welded to the exhaust housing (5psi spring)
solenoid hooked upto each system

When running 5-14.7psi control the 60mm gate and leave the 44mm gates running as normal when running 14.8psi up control the 44mm gates and run the 60mm gate in free boost (so no boost reference point)

Possibly a simpler way of doing it but means if the 60mm gate fails then the max psi run would be spring pressure on the 44mms and 3 gates failing is very unlikely epically when running braided vac hose

(4th waste gate is to allow the SC to be bypassed when it can't provide enough airflow for the turbo)

[Stott69]

As he said^. What wastegate are you planing to use? My turbosmart 48mm came with 4 springs which could be fitted. Some gates can take a combinaton of springs to get your desired pressure.

[CAMB01]

Turbosmart 40mm gate. Only comes with one spring and you have to choose which one.

[Mr Ree]

Would you consider any other WG, or is the TS the only option?

I know they are highly regarded, so I understand why you want one, but I have to admit they really dropped the ball by not supplying them with a large range of springs like Ti-al and Precision do.

Nothing worse than having to compromise on what spring to use, when you can just have it exactly as you want.

[Dell'Orto]

Go the 14psi way, then run 14psi minimum?

[iOnic]

^ This. If you're set on 12psi minimum just run the 7psi spring and use your ebc to bump your first set point to 12 psi and the second to 2x psi and you'll have 3 boost levels. There's no hard and fast rule on springs, I've controlled 30psi on a 10psi spring in a Tial MV-S. It's all about flow.

And that quad waste gate idea just sounds like a nightmare to diagnose any faults in. KISS

[Shrike]

^ This. If you're set on 12psi minimum just run the 7psi spring and use your ebc to bump your first set point to 12 psi and the second to 2x psi and you'll have 3 boost levels. There's no hard and fast rule on springs, I've controlled 30psi on a 10psi spring in a Tial MV-S. It's all about flow.

And that quad waste gate idea just sounds like a nightmare to diagnose any faults in. KISS

Yeah I never said it was a simple idea :p but twincharging is complex anyway haha

Bigger gate for lower boost as it can control the flow better correct

So what if the spring fails from running more then double boost

Freeboosting is not a good idea or would it fail the other way around and allow no boost

Ive just confused myself arg

[CAMB01]

I dont have and wont be using an EBC. The boost will be directly controlled by the LINK ecu.

My current wastegate is a Turbosmart 38mm gate ive had for about 8 years. Still works fine. I prefer Turbosmart to any other brand. Just my preference.

[iOnic]

Ask your tuner what spring they'd prefer to set the link up on to achieve your desired boost level. The way I see it, if your only spring options are 7psi and 14psi and you want to be able to run 12psi sometimes, you're gonna have to run the smaller spring.

[CAMB01]

I'm just gonna compromise i guess and go for the 14psi spring and have 14psi as my low boost.

[Dell'Orto]

I'm just gonna compromise i guess and run 2 bar daily

Might as well

[DexGT]

I dont have and wont be using a Separate EBC. The boost will be directly controlled by the LINK ecu's EBC.

Changed to read correctly