1G Wastegate size help

[BoostedS256]

I’m a newb when it comes to choosing the correct size so help would be aprreciated. My setup is a s256ett, wastegate off the o2 housing with 3in exhaust, car runs 28 low and 32 high via ebc. Currently has a Chinese Godspeed wastegate(no clue what size)that I wanna toss before it fails!

So what mm do you guys recommend and what spring do I need for the psi I’m running? Thanks!

 

[1990TSIAWDTALON]

Tial 38 or 44 with the appropriate springs for your desired WG setting. Most gates have a chart with them. They can be tough to take apart and put back together so get a buddy if you can for extra hands.

 

[BoostedS256]

38 or 44 huh? Why not a 40? Since my low setting is 28psi that means I would put 14.5psi springs into the wastegate correct? Or do I set it to my higher setting and do 16psi springs? Thanks

 

[ThunderChild]

Generally cost vs effect. I haven't checked recently, but I assume the extra cost for limited improvement of a 40mm would be better spent to go towards a 44mm.

For wastegates, you really can't go too big as long as you can afford it.

Most of your limitation seems like it would come from the wastegate location and the orifices that lead to it being too small. Make sure to port them as much as you can.

 

[Vegas Smith]

38 or 44 huh? Why not a 40? Since my low setting is 28psi that means I would put 14.5psi springs into the wastegate correct? Or do I set it to my higher setting and do 16psi springs? Thanks

The only reason (most likely) that you have 40mm and 38mm is proprietary differences between the companies. I imagine TIAL has a copyright on the 38mm. You'll be fine running anything you buy, but why not get the 44 if you can fit it.

 

[donniekak]

Don’t waste money on a big gate with your setup. A 38 and 60 would both flow the same on your setup.

The gate can only flow as much as the wastegate hole in the turbine housing.

 

[ThunderChild]

I agree with @donniekak.

Normally I'd say get the bigger gate if budget suits, but unless you have a bigger turbo and/or manifold to suit, it won't do you any good in an O2 mounted location.

 

[BoostedS256]

that makes sense thank you guys 38mm it is!

 

[brian9397gsx]

Also the spring you use also depends on how you are controlling boost. If its electronic and you are using both ports on the waste gate you can just put in the lightest spring. If your just using a manual boost controller your generally limited to a max 2x your spring pressure. So I'd do the 16lb spring in that case.

 

[BoostedS256]

Also the spring you use also depends on how you are controlling boost. If its electronic and you are using both ports on the waste gate you can just put in the lightest spring. If your just using a manual boost controller your generally limited to a max 2x your spring pressure. So I'd do the 16lb spring in that case.

It’s a 2 setting electronic turbosmart but it only runs off one of the bottom ports on the gate so figured I’d still just do the 16lb spring?

 

[brian9397gsx]

Yep you would treat it like a manual boost controller since your only controlling one port. Since you're electronic I'd put your bottom port directly to boost and run the controller on the top. Youd be able to control boost a lot better. At least that's how I've always done it then you can toss the lightest spring in and add boost to the top to hold it shut and control it with the ebc cutt cycle.

 

[BoostedS256]

Yep you would treat it like a manual boost controller since your only controlling one port. Since you're electronic I'd put your bottom port directly to boost and run the controller on the top. Youd be able to control boost a lot better. At least that's how I've always done it then you can toss the lightest spring in and add boost to the top to hold it shut and control it with the ebc cutt cycle.

To be honest you lost me a little there , lightest spring as in 14 for my 28psi setting? Where should I pull boost from for the top port?What’s a cutt cycle?
How come it seems to hold boost fine right now even tho I’m only connected to one port on the gate?

 

[brian9397gsx]

Lol yeah it will dont matter the way you've got it works fine. I've used 8 lb. Springs in the past and with controlling the top port I could get it to hold up to 25