Wastegate bar Size

[natedog2088]

How do you decide what size bar to get on an external wastegate? And what does the psi number relate to

 

[92awddsm]

It is based off of the minimum boost you plan to run. 1 bar = 14.7psi.

 

[99gst_racer]

Yes, as stated above, the spring size (psi) that you pick will be the minum amount of boost that you can run.

For example, if you order it with a 1.1 bar spring, you wont be able to turn your boost down below about 16 psi.

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[Staytuned]

For the record 1 bar = 14.5 psi. And your right about all the rest.

 

[99gst_racer]

For the record 1 bar = 14.5 psi. And your right about all the rest.

haha, I beat you with the graph.

 

[Staytuned]

Hahaha ya I saw that right after I posted. You're quick Paul.

 

[Clutch GSX]

So what is the advantage of going with a large bar? Wouldnt everyone just get a really low bar just in case they wanted to run low boost. The bar doesnt limit the max amount you can run right? Im just confused why there is a choice at all.

 

[99gst_racer]

So what is the advantage of going with a large bar? Wouldnt everyone just get a really low bar just in case they wanted to run low boost. The bar doesnt limit the max amount you can run right? Im just confused why there is a choice at all.

In my experience, the wastegate begins to show less control after I reach a boost level of double the value of the spring or more.

Example. I had a 1-bar spring and a TurboXS MBC to raise my boost level to 20 psi for a pump gas tune. My boost would never exceed my preset, and I had excellent control. Then I made a trip to the dyno to get a good race gas tune, and I raise the boost to 27 psi. It would constantly spike to 30-32 psi and then fall to my preset. This was due to having such a small wastegate spring and the fact that I needed to rely so much on the boost controller to get to my desired setting.

As a rule of thumb, I have always said to never run more than double the rate of the wastegate spring.

I now run a double-blue spring set-up, so I consider my boost range to be 20 psi to 40 psi.