size matters...my 08 has a 38mm tial

 

What size is the typical wastegate on a turbo with the it built in like a 62mm turbo?
Do twins require a larger one?
If so do you need a special small turbo when using turbos with it built in when running twins.
I appreciate the info

 

one thing at at time. yes there are advantages. there are also disadvantages. sizing depends on how the system is gated (to atmosphere or to the primary) as well as power goals. turbine wheel and exhaust housing size need to be taken into account. too small can be as detrimental as too big for an external gate. no regarding the special small turbo.

 

I want to be in the 550-600hp range.

Can you use a small turbo like a 57mm as the secondary and lets say a 80mm as the primary and run a large enough wastegate that the small turbo doesn't become a restriction?
I know a 80mm isn't necessary for the power I'm looking for just trying to wrap my head around what works and what doesn't.

 

i wouldn't even be considering an external gate at that power level. your stock turbo and an s472/475 or other equivalent turbo will cover that.

Yes... kind of but you would still be poorly matched and one would stop producing power and there would be a dead spot in the middle of your power band and then the 80 would light so it wouldn't be a good combo still. More of what wastegates allow you to do is have enough air for 600 hp and enough fuel for 700 hp and make up the difference with help from nitrous and wastegate the extra gasses around your turbo so you don't over spool it

actually this has been done a few times with good results as long as the gate continues working. my set of compounds is on a similar thought process with a small turbine in the secondary. just gate around it and drive the large primary.

 

Yes... kind of but you would still be poorly matched and one would stop producing power and there would be a dead spot in the middle of your power band and then the 80 would light so it wouldn't be a good combo still. More of what wastegates allow you to do is have enough air for 600 hp and enough fuel for 700 hp and make up the difference with help from nitrous and wastegate the extra gasses around your turbo so you don't over spool it

 

I personally am going with an external gate not only because I want to spray but I also like the tunability that they give you. The cool factor of one is also helpful in my choice and I love screamer pipes so it's a no brained for me

 

I noticed that non gated turbos are about 3 to $400 less expensive witch the $ could be put towards a manifold with a external gate port .


PS. the cool factor is something to consider for sure!

 

6 in one hand and a half dozen in the other. packaging can be a pain for external gates but not usually an issue with a mild set up.

 

It seems that wastegates are designed more as a relief valve rather than a divereter valve.The exhaust has to make a right turn .They don't seem to have good flow characteristics.
I think if the exhaust could be "diverted" to the primary with a smoother pathway more performance could be seen .If the relief is to the atmosphere the flow doesn't matter so much but if the diverted exhaust is being used to spool the primary maybe a better flowing valve could make a diff!?
Maybe a butterfly type?
I could see where the control of the valve is a challenge with all the heat and pressure though.

This Diesel stuff just gets in my veins and Its hard to keep the gears in my head from turning!

 

Waste gates ARE a relief valve. The exhaust having to make a 90, meh, probably isn't a big deal honestly.

You can absolutely have a smallish secondary and a larger primary, of course there are other things to consider above and beyond "one's big, one's small" but it's been done before, it'll be done again. And I drive one of them daily (but with three waste gates, so my cool factor trumps all!)

So yeah, your 57 and 80 could be done, it's not that easy of course and I'm far from a turbo guru, but...yeah.

 

it is being used as a relief and a diverter in my case. i have a s366/68 for a secondary and an s4t as a primary. ron allen has one of the best known set ups that worked very well.

 

Jlbayes have you had your rig on the rollers?
Sounds like your makin some good power.

I want good responce I'm thinking a 60mm is as about as big as I'm going go on the secondary.I haven't figured out the primary size yet.
DAP sells a 60 fmw with hx40 housing for $1049 I think would be a good start for twins in near future.

 

not since the compounds were put on. will get numbers this year.

 

If you are going to use a crazy carl kit get the 12cm or 14cm gated housing as they are the correct length for his kits.