External WGA to control internal flapper.

[forcefed86]

Since finding a decent actuator to control the internal WG flapper had been such a pain I was thinking of doing this.

Take your basic cheap ebay external WGA. ($56)

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Then cut the bottom housing area and tip of the rod off. Then use this mounted to the factory WGA location and factory WGA rod. This should enable you to easily change out springs and use a boost source above and below the diaphram to hold the flapper in what ever position you'd like. Hoping this will give all the benefits of an external gate with alot less work.

I happen to have an old External gate I'm not using, so this is basically a free "Mod" for me. I'll cut it all up and get some pics up this weekend. Unfortunatly my external WG is ancient and will be a bit bulky compared to the design above.

 

[LiquidX]

You won't gain a benefit of an external waste gate unless you use it as an external wastegate. The internal flapper is small and porting it out to put a larger flapper on will allow it to blow open easier. It's due to the design between an internal flapper and external gate.

I'd like to see the pictures of what you are doing though if you are trying to make an actuator with adjustable spring pressures, that would be neat.

 

[polarmoment]

You also wouldn't be able to mount it in the stock location. External gates pull to open, internal gate actuators push to open. You would have to mount it on the opposite side of the turbo to get it to work correctly.

As far as using it as a dual port actuator, I think that would work pretty well. You're not only adding adjustability, but adding area to the diaphragm, which lessens the effect that boost pressure in the housing has on the flapper door relative to the pressure in the actuator.

 

[forcefed86]

You won't gain a benefit of an external waste gate unless you use it as an external wastegate. The internal flapper is small and porting it out to put a larger flapper on will allow it to blow open easier. It's due to the design between an internal flapper and external gate.

I'd like to see the pictures of what you are doing though if you are trying to make an actuator with adjustable spring pressures, that would be neat.

I don't agree. With the proper amount of force holding the actuator/puck arm it won't "blow" open. I'll be leaving my original flapper. I'm going for big boost here. Curently spike to 30+ and settle to 25ish by 6k. Upping my spring pressure and modifying my current actuator helped greatly getting me that far. (garret actuator w/ additional springs)

You also wouldn't be able to mount it in the stock location. External gates pull to open, internal gate actuators push to open. You would have to mount it on the opposite side of the turbo to get it to work correctly.

As far as using it as a dual port actuator, I think that would work pretty well. You're not only adding adjustability, but adding area to the diaphragm, which lessens the effect that boost pressure in the housing has on the flapper door relative to the pressure in the actuator.

Arg, wasn't thinking about that. I may be able to flip the puck arm or weld on an extension going the opposite direction. That way I could mount it in the factory position?


I'll have to look and see if mounting on the opposite side is even an option. I have all my AC and fans still installed so space may be an issue. I also plan on retaining the factory heat shield(s) to help save my alternator. So this may not work after all.


I had also thought of just tapping the brake accum vac source and running that to my current setup. This would provide additional clamping force. Could operate it with an electric vac solenoid. No easy adjustment that way though.

 

[brian9397gsx]

I may be off page here but would making the arm longer that the actuator connects to help control it blowing open?

Just thinking the added leverage, still doesnt help with the swapping of springs but maybe it would help with the problem of the door blowing open?

 

[forcefed86]

I may be off page here but would making the arm longer that the actuator connects to help control it blowing open?

Just thinking the added leverage, still doesnt help with the swapping of springs but maybe it would help with the problem of the door blowing open?

Another good idea! Although you would probably have to adjust the WGA mounting points. It may bind depending on how long you made it. Also throwing on a holset or similar high pressure actuator would help.

But neither aret as easy to adjust as having boost points on either side of the diaphragm. By running a regulator in the car you can have dial the boost to what ever you want on the fly.

 

[400hp93talon]

Going to an external wg is not a hastle at all?

 

[brian9397gsx]

This seems like alot of hassle to run internal gate still.

 

[wkmitsu]

I don't agree. With the proper amount of force holding the actuator/puck arm it won't "blow" open. I’ll be leaving my original flapper. I’m going for big boost here. Curently spike to 30+ and settle to 25ish by 6k. Upping my spring pressure and modifying my current actuator helped greatly getting me that far. (garret actuator w/ additional springs)

I don't think you understand boost creep and why to use an external wastegate over an internal. When you have a high pressure flow field, it will take the path of least resistance to a lower pressure region. In the case of an internally gated turbo, only so much exhaust can flow through the wastegate port until it is a higher pressure region in the turbine housing than the path past the turbine. Once this point is reached your excess exhaust that is supposed to be being bled off by the wastegate port will start flowing through the path of the turbine rather than bypassing it causing the turbine to spin even faster, creating more boost. This is why you get boost creep on some internal wastegate setups. The main reason for changing to an external wastegate is to make a better flow path for exhaust to bypass the turbine. Changing the wastegate actuator to a heavier spring will not do this for you, although it would be a neat design that I wouldn't mind seeing happen.

 

[forcefed86]

Going to an external wg is not a hastle at all?

This seems like alot of hassle to run internal gate still.

I disagree. There is the cost of the new manifold or modified factory manifold. Then the cost of the external WG itself. Then there is the plumbing and finding space to fit it all. You don't want to use cheap ebay manifolds and WG's either. DOing it the way I described you may be able to get away with using the cheap WG because it won't ever see the exh flowing through it.

What isn't a problem for some may be a problem for others. Just depends on the individual setup IMO.

I don't think you understand boost creep and why to use an external wastegate over an internal. When you have a high pressure flow field, it will take the path of least resistance to a lower pressure region. In the case of an internally gated turbo, only so much exhaust can flow through the wastegate port until it is a higher pressure region in the turbine housing than the path past the turbine. Once this point is reached your excess exhaust that is supposed to be being bled off by the wastegate port will start flowing through the path of the turbine rather than bypassing it causing the turbine to spin even faster, creating more boost. This is why you get boost creep on some internal wastegate setups. The main reason for changing to an external wastegate is to make a better flow path for exhaust to bypass the turbine. Changing the wastegate actuator to a heavier spring will not do this for you, although it would be a neat design that I wouldn't mind seeing happen.

I understand and appreciate the input. Although I don't think you understand what I'm trying to do. I am trying to get my turbo to creep as much as possible without welding the gate closed. The more exhaust bypassing my WG hole the better in my situation. I've even ported the turbo housing to assist in the bypassing of the WG hole. My problem is the puck is blowing open to early and never able to adjust itself properly after this point.

As I see it the choices I have are:

Wire the gate closed - Don't want to do this as the back pressure will be ridiclious. Many small turbo drag racers have tried this. Although boost does peak out, it decreased performance.

Limit the total open travel of the gate - This is slightly better than wiring it shut, but will still cause higher back pressure than I would like up top.

Lastly if I set it up with an external gate hopefully it will stop the initial "blow open" and as RPM and exh flow raise the flapper will open progressively more as rpm and exh pressure increase. In theory this will allow less back pressure at the same boost levels and give more power. Much like an external gate.

That's the idea anyway.


I'll also add that the e316g is to small for my setup. Moving to a larger exhaust housing (.63) would make the car a lot faster. I could probably retain internal gating and not have my current issues. . That being said I and others like to see how much we can push these little turbos. For the moment I'm just playing around. This is just a full weight, all option, daily driver. (trapping 119!)

 

[polarmoment]

I may be off page here but would making the arm longer that the actuator connects to help control it blowing open?

Just thinking the added leverage, still doesnt help with the swapping of springs but maybe it would help with the problem of the door blowing open?

That could work. The only thing to worry about there is the fact that the actuator would have to move farther to open the gate the same amount, so he'd need to make sure there's enough travel in the actuator to fully open it. I think he's partly solving the force issue by using an actuator with a larger diaphragm. More diaphragm area means more force per unit of pressure in the actuator, and while the external actuator isn't that much larger than an internal actuator in diameter, there's still a significant increase in area.

Although I don't think you understand what I'm trying to do.

I think you're right. You're not trying to prevent creep, you're trying to minimize the inherent tendency with internal gates for boost to taper off.

You very well could weld the arm on the other direction to actuate it. If there's room on the O2 housing side though, a simple 1/8" steel plate the shape of the outlet flange with extra material to mount the external housing would likely work. I haven't looked at a 4G63 in years though and I don't remember what mine looked like. You do make a good point as well though that the longer arm will help prevent binding.

I had considered doing this on my car as well. Luckily, adding a WG isn't as big a deal since my turbo uses an adapter plate that can easily be welded to. I picked up one of the $70 Turbosmart gates from that blem sale a couple weeks ago. Hell of a deal for a real Turbosmart gate, so I decided to just go the full install route.

 

[wkmitsu]

What boost level exactly are you looking to have the wastegate open, if at all? The way you're describing this it sounds like you're going for infinite boost...

Have you ever considered a setup like this...

 

[forcefed86]

Assuming I could size my turbine housing perfectly to my engine you would be correct. Problem is that would also create a lag monster(huge rear housing). Usually turbine housings are made smaller than optimal and incorporated with a WG for this reason. With the small housings back pressure is the enemy. (bottle-necking exh flow). Although this may increase boost pressure it restricts power substantially. Something similar to running a 1” exhaust pipe on a 400hp engine. Even though the motor is capable of lager numbers it will never get there with choked up exhaust.

Not going for infinite boost. But with my setup the 16g is close to maxed out. It won’t be able to supply enough cfm for my engine to make much more than 30psi

From what I’ve seen the big names in the 16g world run, I’m aiming for around 30 psi to 6800 or so. Many are making slightly more than this with larger (2.3) engines. Examples of these can be seen in the drag race section of this forum. Ideally at lower rpms’ I’ll want the WG completely shut, as exhaust flow and rpm increase the puck slowly opens since the additional exhaust pressure is not needed to maintain the desired boost level.

Setting up an external gate on the dump is a cool idea. My limited space in that area would make it difficult. Not to mention the price of a decent gate. This isn’t costing me anything. If I was going to spend the cash on a setup like that I’d just go with a larger turbo. An internally gated precision 50 trim would bolt right on.

 

[tkelly27]

http://www.lightweightmiata.com/forsale/P6224659.JPG
T3 T3/T4 To4e Turbo Dual Port Wastegate Actuator 30 D - eBay (item 380104072996 end time Mar-05-11 07:03:15 PST)

They sell those, did you know that? Was I in time to save the poor little ebay gate from the hacksaw? Odds are good you'll save yourself a lot of headache just dropping the $40 and trying that one.

 

[forcefed86]

http://www.lightweightmiata.com/forsale/P6224659.JPG
T3 T3/T4 To4e Turbo Dual Port Wastegate Actuator 30 D - eBay (item 380104072996 end time Mar-05-11 07:03:15 PST)

They sell those, did you know that? Was I in time to save the poor little ebay gate from the hacksaw? Odds are good you'll save yourself a lot of headache just dropping the $40 and trying that one.

If you read the add it tells you the bottom port is a vent. It is not sealed. That is a scam.

 

[tkelly27]

Turbonetics 30326 Turbonetics Internal Wastegate Accessories

Why did that prevent you from looking for real ones?

Hacking up the external gate is probably going to be more trouble than it is worth. Assuming you can cobble it together properly, you're going to have that giant flying saucer assembly in the way of everything.

If you had to put it to use, I'd get a new O2 housing flange and make yourself a 3" O2 housing and use the external gate the way it was meant to be used.

 

[forcefed86]

Turbonetics 30326 Turbonetics Internal Wastegate Accessories

Why did that prevent you from looking for real ones?

Hacking up the external gate is probably going to be more trouble than it is worth. Assuming you can cobble it together properly, you're going to have that giant flying saucer assembly in the way of everything.

If you had to put it to use, I'd get a new O2 housing flange and make yourself a 3" O2 housing and use the external gate the way it was meant to be used.

I'm happy that is what YOU would do. I'm really not concerned what you think, or how you think an external gate is "meant" to be used. I modify and adapt things as I see fit. If you don't like it, don't do it.