Internal or External Wastegates?

[tunermt]

What’s everyone’s personal preference for wastegates (Internal wastegate vs external wastegate) and why?
Please no bashing each other, I’m interested in everyone’s opinion on wastegates here.
I personally lean towards external wastegates 90% of the time as they flow great, almost all use vband connections (gaskets/hardware pre turbo is always a failure point) and can be recirculated if noise is an issue.
That said internal wastegates also have their place, keeping things simple/cost effective when compared to external wastegate options.

Super throwback video of my KA24e-T with a Tial external wastegate having some fun in AZ.

[tunermt]

My Sr20det e30 with an internally gated evo8 turbo.
**I must admit I?m itching to swap out for a g30 and 44mm wastegate (both vband of course).


My S13 KA24e-t running a Tial external wastegate:
https://youtu.be/ssTjGgQQrdE

[tuzzio]

I've always ran external wastegates as I like the noise when they're open.
I've also seen internal wastegates not be able to flow and cause boost spikes etc.

I'd also say 90% of the time, an external wastegate is the better choice.

[jedi03]

+1 external would be the better route...however, i run internal due to cost and simplicity lol

[tunermt]

For external gates i will personally only use Tial wastegates or Turbosmart wastegates. Over all the years of tuning all sorts of different engine configurations i've always had a great experience with both Tial and Turbosmart wastegates.

[inferno s14]

personally running a single hypergate 50 Turbosmart on my 2JZGE S14.
never had an internal wastegate setup and probably never will, Although you can have a much cleaner and lightweight turbo manifold with an internal wastegate turbo and save $500 - $1000 depending on how many wastegates you run.

[SoundEfx]

After having experience with both, Audi B5 S4 and boosted Nissan Sentra, my preference will be external. If or when it goes bad, you can simply change it and get back on the road.

From what I've seen, internal ones are not that easy to get to and having to change the whole turbo is never fun.

[silviaks2nr]

External gate, recirculated into downpipe. None of this out the hood BS

[jedi03]

internal are very easy...the flapper rarely goes bad, but based on the v-band and normal location I see from external I do see the ease of external as well!

[tunermt]

Originally Posted by silviaks2nr

External gate, recirculated into downpipe. None of this out the hood BS

I?m down to vent behind the firewall but also not a big fan of out the hood

[jr_ss]

Originally Posted by silviaks2nr

External gate, recirculated into downpipe. None of this out the hood BS

1 month of open dump was all it took for me to change my setup to a recirculating setup. It was so obnoxious.

[e1_griego]

+1.

Novel for a few weeks.

Recirc'd for many years now.

[tunermt]

my S13 with external gate vented has always treated me well and not annoying. I do use a 3 port EBCS "electric boost control solenoid" to hold the gate completely closed until 12psi though so you don't hear anything from the wastegate until you really put your foot down and make some real boost.
I find with this setup i don't ever hear the external gate until i'm accelerating hard in which case i don't mind the extra sound at all, even enjoy it. (If it were starting to open earlier and make noise during light/medium acceleration i'd get sick of it real fast!)

[Kingtal0n]

External for control

Recirculated for comfort



If you want to hear it anyways use a cutout. That provides the pressure drop to turbine necessary for increased power and noise on demand. Then close it when you get a headache.

[tunermt]

I personally don?t like the sound of cutouts (post turbo) little to open downpipe sounding for my taste. I?d much rather hold a turbo smart wastegate closed with an EBCS for quiet low load driving and let the wastegate scream/open only a couple PSI below target boost.
(Something like your single turbo V8 or any large displacement engine with a ?smallish? turbo this option isn?t so reasonable as the large displacement will spool the turbo/force the wastegate open at much lower rpm/throttle inputs which definitely gets noisy fast.

[Kingtal0n]

Oh I agree 100% the noise is unbelievable. I use ear plugs when I have that thing open. And the raw sound of it.... Not pretty until the turbo really spools.

Its more just for idle conditions, the cam lope around parking lots and stuff. warns people the car is there too, helpful and in traffic. More of a show item than go item for my purposes. Everytime I destroy somebody they want to know whats in the car 'yo what the fuck is that!' pretty funny, so I Pop it open for 30 seconds without saying a word and the look of raw confusion and disbelief is worth having it.

What it really needs is a muffer on the cutout side. But there is no room under there. I really want to try a flowmaster 40 series for the tone, that classic sound ya know? But where I'm going to put it... One day I'll think of something. Meh got bigger things to worry about

[tunermt]

Originally Posted by Kingtal0n

Oh I agree 100% the noise is unbelievable. I use ear plugs when I have that thing open. And the raw sound of it.... Not pretty until the turbo really spools.

Its more just for idle conditions, the cam lope around parking lots and stuff. warns people the car is there too, helpful and in traffic. More of a show item than go item for my purposes. Everytime I destroy somebody they want to know whats in the car 'yo what the fuck is that!' pretty funny, so I Pop it open for 30 seconds without saying a word and the look of raw confusion and disbelief is worth having it.

What it really needs is a muffer on the cutout side. But there is no room under there. I really want to try a flowmaster 40 series for the tone, that classic sound ya know? But where I'm going to put it... One day I'll think of something. Meh got bigger things to worry about

On that note I had a good friend put a sport bike muffler on his external wastegate. Haha sounded much ?softer? until the lil muf exploded and lost all its guts.

[tunermt]

Expanding on the external wastegate there’s the Turbosmart Egate
This free Haltech DCMD offer sure does make it tempting, always wanted to run one of these on my sr.

[PoorMans180SX]

External are great with older turbo designs, but EFR?s and the G-series have wonderful internal gates that are good enough for everything but kill mode. I don?t see a reason to run external on these turbos unless you?re trying to push the limits of flow.

[tunermt]

Originally Posted by PoorMans180SX

External are great with older turbo designs, but EFR?s and the G-series have wonderful internal gates that are good enough for everything but kill mode. I don?t see a reason to run external on these turbos unless you?re trying to push the limits of flow.

I have tuned more than few engines running internal wastegate EFR turbos and while they do work ok the little internal wastegates are indeed a restriction in some cases (not all though).
Examples:
- On an S2000 (built f22 engine) I tuned running an internally gated twin scroll EFR turbo kit the internal gate could not quite flow enough which choked power and led to some less than ideal boost control. Completely manageable but not nearly as efficient as the same setup using larger external gates.

- On my personal S13 (built KA24-T with ported cylinder head) i ran/tested the first EFR Full-Race received while i was working there. Again the turbo did work well BUT the small wastegate could not keep up and i had to tune around some boost creep issues, again nothing unmanageable BUT not the ideal setup. Single external Tial MVS wastegate instead and boost was rock solid/steady.

[240boosted]

I live my g30-770 with 45mm tial external wastegate it sounds so mean

[tunermt]

Originally Posted by 240boosted

I live my g30-770 with 45mm tial external wastegate it sounds so mean

That's a great combo! On an SR or RB or something else? What turbine housing did you go with for your G30 770 turbo?

[tunermt]

Recently tuned a STi with a built EJ25 running a GTX3576R and a tial MVS wastegate. In this particular example the MVS wg was vented to atmosphere* While this is not a nissan SR, KA, RB or other turbo engine the boost creep concept still directly applies.


The log above has under 2% duty cycle for the 3 port boost solenoid which means the engine will run at the lowest possible boost AKA "wastegate spring pressure". You can see the white line (boost) climbs quickly then tries to "level off" as the wastegate opens at ~15psi. However do to the MVS wastegate being a bit to small for the EJ25 and GTX3576R turbo combination you can see the boost continues to climb from 15psi up to 20psi by 4800rpm at which point it starts to taper back off as the turbo/engine combo becomes less efficient. 15psi creeping to 20psi or 5psi of boost creep is more than ideal, at most 2-3psi of boost creep would be considered acceptable. Now keep in mind this 5psi of boost creep happened in only 3rd gear, as the engine is loaded up/ran at WOT (wide open throttle) in 4th, 5th and 6th gear the engine will be under load for longer resulting in even more boost creep than we can see happening in the 3rd gear pull. If you look further to the right in the log you can see as the car continues to accelerate in 4th gear the boost creep becomes more severe and boost creeps 6psi over wastegate spring pressure before 4800rpm.
In this case there are 3 options:

1. add a second MVS wastegate or replace the existing MVS with an MVR or other 44/45mm wastegate (increase volume of flow through the wastegate/s is the correct way to address a boost creep issue.)
2. Lower the spring pressure in the wastegate. This will allow the wastegate to open earlier making it slightly easier to manage the boost creep and keep "peak boost" at the target. (this is a band-aid fix as the setup will still have boost creep it will still creep up just from a lower starting point. Example: 15+6=21psi VS 11+6=17psi. The 3 port boost solenoid is then controled by the ECU to increase boost from 17psi to the target boost however there are still some limitations when it comes to target boost at lower RPM as you MUST still account for the boost creep.)
3. recirculate the wastegate dump to the downpipe. (this will only help lower creep 1-2psi) as the wastegate bleeds pressure into the DP the pressure differential on the turbine wheel is decreased even further than if the wastegate was vented to atmosphere.

[feito]

any of you tried the new garrett WG? they look very promising

[tunermt]

Originally Posted by feito

any of you tried the new garrett WG? they look very promising

Yes they work great! Very compatible to the Tial MVR imo

[tunermt]

Tial MVR doing hard work on the track in this turbo M3