Wastegate Spring

[SLOWEGG]

Quick question, what spring rate should we get for a external tial wastegate if you're running about 9psi?

Do we get something lower and use a boost controller to raise the boost or get something closest to the ideal psi? Or either will be fine?

[DLO01]

Either is fine.

Get something lower and use a controller to increase to your desired level.

[1996ek1]

While yous are talking about wastegates.
I've read some confusing things about gates, and i think i read if i wanted to run like 15 PSI on a T28 turbo, i would get a smaller wastegate or something like that.

I'd only want to run 5-6 PSI on a ballbearing T28, so that means i would want a larger gate doesnt it?

And what would yous recommend? like a 38 mm tial or something like that? or a different brand?

[SLOWEGG]

A larger wastgate will control low boost better.

[1996ek1]

A larger wastgate will control low boost better.

thanks
And what wastegate would you recommend?

[TODA AU]

Quick question, what spring rate should we get for a external tial wastegate if you're running about 9psi?

Do we get something lower and use a boost controller to raise the boost or get something closest to the ideal psi? Or either will be fine?

For simplicity's sake & minimum cost, if no other boost level is required.
Use the spring that coresponds to the desired boost level.

Should you use a lower poundage spring & employ a boost controller to increase the pressue,
This will give you the advantage of having a high & low setting which many people enjoy.
That said, you aught to bare in mind that you can only control boost to be stable at double the wastegate spring pressure.
If you want a low boost of 5psi & a high of 9psi.
You're limited to using 4.5psi to 5psi spring (as an example)

Should you want to run more boost in future.
Use the spring rate that you want your minimum boost to be.
Double that, will be your stable maximum using an electronic boost controller.
Eg: Turbosmart E-Boost II or similar.

Ie: Minimum boost 9psi (using 9psi spring) & max stable boost via boost controller would be 18psi.

Hope that helps,
Cheers

Adrian

[SLOWEGG]

Thanks adrian that clears alot of things up.

[b18c_crx]

how can u tell what rate ur wastegate spring is?

[SLOWEGG]

Check on the manufacturer of your external wastgate and see how they determine theirs. For tial its by colour and sizing.

[Limbo]

cool that's what i'm gonna be doing


For simplicity's sake & minimum cost, if no other boost level is required.
Use the spring that coresponds to the desired boost level.

Should you use a lower poundage spring & employ a boost controller to increase the pressue,
This will give you the advantage of having a high & low setting which many people enjoy.
That said, you aught to bare in mind that you can only control boost to be stable at double the wastegate spring pressure.
If you want a low boost of 5psi & a high of 9psi.
You're limited to using 4.5psi to 5psi spring (as an example)

Should you want to run more boost in future.
Use the spring rate that you want your minimum boost to be.
Double that, will be your stable maximum using an electronic boost controller.
Eg: Turbosmart E-Boost II or similar.

Ie: Minimum boost 9psi (using 9psi spring) & max stable boost via boost controller would be 18psi.

Hope that helps,
Cheers

Adrian

[Limbo]

any one know how to check the spring rate on the internal waste gate?

[DLO01]

You will only be able to tell by a boost gauge. As boost is adjusted by Actuator - Gate adjustment shaft.

[TODA AU]

any one know how to check the spring rate on the internal waste gate?
Most machine shops will have a valve spring tester which will tell you.
Of DIY...
Remove the spring from the wastegate (external gate only, don't ruin an internal gate diapragm)
If you put the spring on a set of scales,
Zero the scales then compress it.
(Eg: you could use a drill press or something similar to give smooth compression instead of your hand)
The pressure required to compress the spring will be indicated as weight.

For internal gate, go to your local fishing store & buy a set of fish scales.
Attach this to on end & the other (body of internal gate diaphragm) in a vice.
Pull away... :thumbsup:

Hope that helps,
Cheers

Adrian

[Limbo]

cool thanks, dun worry i think i'll just bring it your way and ask.

The turbo kit is coming together great just waiting on a PFC and some intercooler pipes i'm ready. ETA 21st of December, cos i got time off ;)

[andrewwwwww]

while were on the subject of wastegates.. for arguments sake.. if i was to have a turbo with an internal gate and had a manifold on which i had an external gate.. is it possible to use both? (not both at the same time) ive just got this crazy idea and wna know if it will work...

[DLO01]

Yes you can do that. Don't know why you would though.

[andrewwwwww]

i want to leave my external gate with a screamer on it but i also want to be able to silence my car when i need to.

i think i can do this by just setting the external gate to open at a higher boost than the internal gate and let the internal do all the wasting.. then when i dont have to be quiet i could just set the internal gate to the higher boost level and scream all i want..

i think i might need 2 boost controllers though.. :confused:

[DLO01]

Okay, I see what you mean.

And sounds like the way your doing it will work too. :thumbsup: