i'm trying to figure out what spring rate to go with on the wastegate. any input would be awesome. ie.. what the difference is, how to figure out the best one for my application. not i heard from so and so this one is badass.

bump

 

Well first

You need to know what size turbocharger you're going with

With that in your head, figure out how much pressure (PSI) you'll need to run in order to achieve the power you want.

You wastegate is just a tool to divert exhaust and to help keep your turbine spinning at a certain RPM steadily, so you don't have bad things like boost creep or boost spiking.

1 Bar = 14.50 PSI
.5 Bar = 7.25 PSI

The spring will fully open at whatever bar you want it to. This is all relating to your intake manifold pressure. There is a vacuum line that goes from your intake manifold to your external wastegate. When it reaches a certain pressure, the spring makes wastegate fully open at that amount of pressure.

You can however use a boost controller from there if you undersize OR just get another spring. It's that simple.

 

ok so if i'm running 21 psi i need a 1.5 bar? or will the boost controller allow me to run more with a smaller wastegate. the reason i ask is my manifold has a wastegate flange for a 38mm. and the highest i has seen is 1.0 bar on a 38mm wastegate.

 

It's more reliable to just get the spring than try and delay your actuator signal for an extra 7 PSI.

But pretty much yes.

Let me do some searching real quick...

Dude, right on Tials website...

This is for the 38 mm

http://www.tialmedia.com/documents/w3_tial_38_sp.pdf

 

sweet thanks. now i need to find a 1.5 bar spring for a 38mm wastegate.

 

Read the caption on the bottom of that page...it has to be a dual spring setup.

 

yah i just read that, now my question is how does a boost controller work, if i run a 1.5 bar wastegate and decide i want to only run 18 psi for daily driving. would the boost controller allow the valve to open at 18psi. or how does that work

 

You can't go backwards, only forwards.

A boost controller would change your actuator signal to make it later.

 

ok so in my situation it would be better to run a lower spring rate and a boost controller. the reason i say that is i want to be able to lower or raise the amount of boost i run. btw i plan on using a mechanical boost controller

 

huh, i learned something on this thread. thanks Adam

 

Yeah that's feasible as long as the boost pressure you're aiming for isn't 2x the wastegate spring's limit, you should be fine.

This is also another reason you should pick a moderately larger turbocharger, lower pressure with higher CFM flowing capabilities.

You're welcome. Anytime.

 

thanks for all the help adam, this is a learn as you go project for me, so far it has been lots of learning and no go. but that will all chage when the new motor is in next week .

 

I've been there with my sunfire...I know exactly how you feel. That's another reason I'm not a ******* to people when they ask questions like yours, everyone starts from somewhere.

I also suggest buying some books, that will help you alot and it's inexpensive.

 

yah i just bought an awesome tuning book, it's all on pdf file. it's locked right now with some security feature. but i'm gonna get passed that and post it on here for everyone to read.

 

Whats the name? I might have it