Wastegate/boost controler question.

[Madsimilius]

Will a wastegate with say a 0.7 bar spring and a boost controller set to 1 bar work as well as a wastegate with a 1 bar spring ?
And how much up is it possible to adjust with a boost controller ?

[DSPTurtle]

1. Yes.
2. It depends on your boost controller, wastegate, turbo, etc

[Madsimilius]

i have a K27/k29 turbo , porsche 930 wastegate, and i'm planing to buy a electron bost controler to hook up to my EFI. (solenoid)
Whats the difference ? and which type of controller works best?
I do not want to borrow my car to any of my friends with the 1.2 bar spring that sits in the waste gate now, but want to be able to boost up to maby 1.1 when i want to .

[Miguel Antonett]

The lower pressure controller will determine the bypass (waste), if your spring is set at .7 and your manual controller is set at 1 or whatever higher..., the .7 will open first and should not allow anything higher than that going into the intake.

[sjf911]

Originally Posted by Miguel Antonett

The lower pressure controller will determine the bypass (waste), if your spring is set at .7 and your manual controller is set at 1 or whatever higher..., the .7 will open first and should not allow anything higher than that going into the intake.

Backwards. The spring sets the minimum boost pressure then the boost controller adjusts it upwards to whatever you set.

[Miguel Antonett]

^^^ that's one of the reasons why I don't have or recommend having one...

[RarlyL8]

A boost controller has the capacity to control the action of valve opening better than the spring alone. The controller will block the boost signal to the waste gate until the pre-determined pressure is reached. The resulting "hit" of pressure snaps open the valve. With the spring alone cracking pressure opens the valve before full boost is reached causing some stall in flow.
The flip side is if the boost controller malfunctions and the signal is blocked your wastegate will not open. A very bad failure mode.

[Madsimilius]

I understand that the spring sets the minimum boost.
But what i'm trying to find out here is if 1bar using a 1bar spring will perform any different from 1bar using a 0,7bar spring and a boost controller set to 1bar ?
I'm thinking turbo lag and such.

[Ronnie's.930]

Originally Posted by Madsimilius

I understand that the spring sets the minimum boost.
But what i'm trying to find out here is if 1bar using a 1bar spring will perform any different from 1bar using a 0,7bar spring and a boost controller set to 1bar ?
I'm thinking turbo lag and such.

The post above yours, #7, answers your question in great detail.

[Madsimilius]

Ok, Rarely late wrote this while i wrote mine :P Maby i can get some kind of over boost alarm in case boost controller malfunctions.

One more question though , how much up can i adjust the boost controller ? say i use a 0.7bar spring.
If i can adjust as much as i want, i'll try and find a 0.5bar spring.
As i said to be able to loan it away safely and maby also for cheaper insurance.

Thank you guys

[TurboKraft]

Old rule of thumb: spring pressure + 10psi = reliable adjustment limit.

Newer boost controllers that measure actual boost can reliably regulate higher.

If integrating it into your engine management, use a solenoid valve that defaults to "open" thus reducing boost pressure to the wastegate spring only.

A factory toggle switch makes a discreet Low/High switch, fits perfectly in the dash.

[Madsimilius]

Thank you Chris ! So,, does anyone know where i can buy a 0.4--0.6bar wastegate spring that will work for my wastegate?