Outer Limits 4x4 Board

Am thinking of what to run when i make the big spend on a turbo, Thought i should put some thought into internal/external but dont know ......

what are the pros and cons?
what works best?
why will it work best?
who has tried both?

cheers

If your turbo don´t come with a wastegate, run a external .. I have good experiences with both .. sighly simple with internal one I thought.

ok, thanks

external will allow you to gain a little more HP if you want in and also another problem you can run into on internals is that they can burn the wastegate off and they wont boost like they should cause they don't seal properly just like a crook valve in your head. externals are a little bit more hassle to plumb in the exhaust manifold. im runnin both internals at the moment and haven't had trouble yet.

You wont go too wrong with an good internally gated turbo, reliability wise. Nearly every OEM turbo has an internal wastegate.

One of the biggest advantages of an external is the boost control is significantly better, they will regulate boost pressure more consistently througout the rev range. Some internals can cause boost spike/overboosting through insufficient flow, which can cause issues.

External wastegates also sound shit-hot, therefore attracting 25% more women.

If you run under 15psi an internal gate will "usually" have no problem controlling it.

You'll only need an external gate if an internal one isn't big enough.

For over 99% of diesel applications an internal one is plenty. It's another ricer petrol upgrade that doesn't apply to the majority of diesels.

Normally an internal for a diesel wil be fine, large Hp petrols require external gates or boost control will be an issue, spikes.

The size of the engine, power output, boost level and turbine housing size all come into play as to the required wastegate size.

Joel

internals creep, no matter what you do, they will never seal as good as the valve and seat in an external. so your turbo will spool better, and never overboost either.







and you can dump the gate into atmosphere at the engine bay

Stoive wrote:internals creep, no matter what you do, they will never seal as good as the valve and seat in an external. so your turbo will spool better, and never overboost either.







and you can dump the gate into atmosphere at the engine bay

With BOV you can solve it ..

Boost creep is related to the flow of the waste gate. Internal or external won't matter as long as it is the correct size. Most people will never even notice th difference in performance between an internal and external, so while an external will work better it is on aturbo deisel it wouldn't be worth the extra stuffing around.
High boost is easier to control than low boost due to less gas needing to be bypassed around the turbo. With a low boost (<12psi) it doesn't take much energy to change the speed of the turbo compared to the energy required when making high boost. (>14psi)
I think people simplify the whole wastegate size / localation / turbo / boost equation. It is not and easy thing to get right unless you are copying what has been done before. And most people who claim to know what they are talking about, have very limited knowledge of why it works so can only rely on the experiance of what has worked in the past. So their advice will be spot on if you copy what has been done before but if doing something different EXPECT it not to work first time up.

Stoive wrote: and you can dump the gate into atmosphere at the engine bay

Why would you want to do that?
If it's petrol you've got gases hot enough to melt things.
If it's diesel you've got gases that might be hot enough to melt things, but will cover everything in soot.

I don't see wastegate creep as being a problem, unless you're trying to get high boost using an inline boost controller and a weak wastegate spring.
Boost creep is something I actually prefer in a diesel. As revs rise and VE drops, having boost climb slightly can keep progressively lowering EGT's.

Has anyone used those cheap external wastegates off ebay.....and what spring do i put in 10 psi or 15psi ect ??? hows that work

I'm using one and it appears to be fine. You just need to be aware they are cheap and so can be a bit unreliable so you need to monitor things. If they get stuck closed you could blow you motor up!

nzdarin wrote:I'm using one and it appears to be fine. You just need to be aware they are cheap and so can be a bit unreliable so you need to monitor things. If they get stuck closed you could blow you motor up!

I think i will save and buy a turbosmart one lol