Quicker Spool Up with External Wg

[Slowboy]

Here is the picture

 

[Kevin Jewer]

Originally posted by larryd
remember with an external gate its all about the spring thats inside the gate.. John was saying something about the external will not open up until the last possible minute.. well thats not true in my case.. I have a 0.7bar spring in my wastegate which is 10lbs and Im running 20lbs of boost so my wastegate is actually opening at 10lbs..

How do you know its opening at 10 psi? If you are running 20 psi boost your WG better not be opening at 10. Sstem efficiency goes to hell, even though airflow goes up. If your setup is working properly your boost cntroller is bleeding off 10 psi so the spring doesnt see the 20 you are running, and its thinks its still opening at 10. Thats how these things have always worked Otherwise you have issues.

 

[larryd]

i know becuase I have an o2 dump tube and at 10psi the wastegate opens up and its loud as hell.. and yes I know its not efficient.. this is why I ordered a new spring for my wastegate.

 

[Kevin Jewer]

Just out of curiousity what size flapper do you have? Since you have a way to be sure it is opening I'm curious about the relationship between flapper size and spring pressure and how it affects the gate leaking. Also, please post what happens with the stronger spring when you get it

 

[set3422]

well if it's not opening, don't know where to blame for my boost lag. I checked everywhere (boost leak test, 155 psi on all 4, no exhaust leaks, checked evc ez, and even eliminated vaccumn hoses for all solenoids).

I'm in the process of ordering a 15 psi actuator from Team Slowboy. I'll let you get the first dip when the new actuator is in. Out.

Originally posted by 95GSXracer
Just out of curiousity what size flapper do you have? Since you have a way to be sure it is opening I'm curious about the relationship between flapper size and spring pressure and how it affects the gate leaking. Also, please post what happens with the stronger spring when you get it

 

[larryd]

Originally posted by 95GSXracer
Just out of curiousity what size flapper do you have? Since you have a way to be sure it is opening I'm curious about the relationship between flapper size and spring pressure and how it affects the gate leaking. Also, please post what happens with the stronger spring when you get it

are you talking to me?? I didnt know the external gate has a flapper.. im still kinda dull on the external gate and how it works.. its a tial 40mm.. Ill let you know how the new sping changes things.

 

[Kevin Jewer]

I mistakenly thought you were on the larger internal and were changing actuators. Makes more sense now. IMO a 10 pound spring is too low for a 40mm gate (it does have a flapper, it just doesnt flap Its more like a typcial valve) running at 20 psi. The spring will help a lot. I have a 13 pound spring in my Deltagate (~32mm) and at 20 psi I sometimes get a strange flutter, like the valve is confused. A stronger spring will correct that as well. Unfotunately the strongest spring they offer is the 13 lb, so I am looking into the Tial 35mm which shares the same flange. But the question is how much it will move the location of my dump pipe, it barely fits as it is... Still, let me know how much the spring rate increase helps so I can decide if I should make the effort or just leave it alone

On a related side note, Another reason for me to switch to Tial and stronger spring rate is that my Profec only allows me to double the spring rate. In other words, with 13lb spring I should only be able to get 25 psi boost on high setting maxed out. In reality I barely get ~23. I have to put a tee in teh WG line to bleed off more air and readjust the Profec to compensate. A 15 lb spring for instance would let me run up to 30 psi, and would make a lot more sense since I run no lower than 20 on the street...

 

[larryd]

same thing.. the profec was only allowing me to hit 20lbs of boost because I have this 0.7bar spring in the wastegate and since I want to run 25 that was kinda hindering me..

 

[set3422]

sup larry. deltagate only offers up to 13psi spring. How about if you combine two lowest ones. Say 0.7bar*2 springs = 1.4bar(~21psi) You can combine springs together, sort of like what RRE is doing.

The external does have a flapper/gate, but doesn't flap or swing. If not, don't know how else you can hold the exhaust gas. The external wg is almost similiar to a BOV. The flapper/gate has a slider joint action (prismatic joint).

I'm too broke to run an external for the moment. The internal gate was grinded of a 38mm chevy exhaust valve.

Originally posted by larryd


are you talking to me?? I didnt know the external gate has a flapper.. im still kinda dull on the external gate and how it works.. its a tial 40mm.. Ill let you know how the new sping changes things.

 

[larryd]

couldnt you just get a generic replacement spring thats stronger then the one deltagate comes with?? like something from the hardware store maybe?

 

[set3422]

you could, but you might have to cut down the spring in order to fit. Cutting the spring will affect the spring rate, so the required pressure to compress or elongate it will not be constant. In other words, the spring behavior will be non-linear. Avoid cutting it. Try to find one that almost has the exact fit for your external wg.

 

[whitegst97]

Ok i installed by 20G today and well the boost is slow, and i have the 02 housing with dump and i hear it open like around 6-7 psi, what kind of external wastegate should i get if i want it to hold the boost pefectly, lets say bout 20 psi. What wastegates do you guys recommend. Thanks

 

[larryd]

Tial 40mm External Wastegate.. you can prolly get away with using the 35 but if you want to be sure the 40 is the way to go.

 

[Kevin Jewer]

Thats an interssting idea to combine the springs like they do with the Tials. But I know with those, you should combine "big" and "small" springs to get the value you want. I dont think the deltagate has two size springs. If they were the same size I would be afraid they would bind as the gate opens. I am going to have to open it up and see what it looks like. Maybe I'll get lucky and find a good match at the hardware store

 

[set3422]

Now you don't have any kind of exhaut backpressure at all. To solve this you will need 15 psi wastegate actuator (talk to MikeH) or go with an external.

Originally posted by whitegst97
Ok i installed by 20G today and well the boost is slow, and i have the 02 housing with dump and i hear it open like around 6-7 psi, what kind of external wastegate should i get if i want it to hold the boost pefectly, lets say bout 20 psi. What wastegates do you guys recommend. Thanks

 

[whitegst97]

So i could use a 35 mm ext. wastegate if i wanna go for like 350 HP to the wheels

 

[whitegst97]

So i could use a 35 mm ext. wastegate if i wanna go for like 350 HP to the wheels, Im going to be boosting no more than 20 psi's, what do you guys recommend, and well do i have to take the manifold out to me the whole or the mounting place for the wastegate or are there certain places where they could do it, on the car

 

[Kevin Jewer]

You have it a bit backwards. If you are tring to use a smaller gate you should be saying you dont plan to run LESS than 20 psi Depends on what turbo you plan to use. Less boost plus larger turbo equals larger gate required. In my case the Deltagate (~32mm) venting all 4 exhaust runners holds spring pressure of 13psi to redline, no creep. Not sure what the difference would be venting only runner one, as most setups do. But I would go out on a limb and say a tial 35 should get down to 20 psi or below on just about any turbo that is considered streetable. Say Greenish and down.

 

[whitegst97]

Ok well im goint to be running a 20G and about 17 to 20 psi's, i dont' really plan on going any less. And im probably going to install the wastegate venting one runner, i think,thats how i've seen it most of the time. So then a 40mm would be my best bet. Thanks

 

[ILOSE]

Hey larry:
You have a profecB right?
If you do there is noway the gate should be opening early if you have the lines set-up properly and the balance set right.

As you already know, the profec b has limited increase percentage. Hence the new spring.

 

[Kevin Jewer]

Originally posted by ILOSE

If you do there is noway the gate should be opening early if you have the lines set-up properly and the balance set right.

Unless its being blown open

 

[larryd]

yes I had the profec b and I had it hooked up wrong. When I got it hooked up right the gate was opening when it was set to at spring pressure which unfortunately for right now is only 0.7bar. I ordered a new spring and Im waiting for it. I now have a Hallman MBC.

 

[KenTSIII]

with out an electronic boost controller... your wastegate will always start to open at lower boost... then open more & more as the boost pressure increases. This is how internal & external gates all work w/ MBCs... the pressure is gradual.. w/ the EBC it holds off the pressure to the WG until the last possible second.. then releases the pressure opening the gate.

 

[set3422]

Well I couldn't get hold of a 15psi wg actuator, so decided to make my own. Check out my Poorman's 15+ PSI Actuator. Make sure you select the right spring rate to be welded on. Any comments? thanks.

Originally posted by set3422
Now you don't have any kind of exhaut backpressure at all. To solve this you will need 15 psi wastegate actuator (talk to MikeH) or go with an external.

 

[95GST]

I have a 40mm flapper and it's too big on my 20G.. the turbine pressure is higher than 16g. With a mitsu actuator it will only hold 11 PSI. Try to turn up the boost to 14 PSI for example and it will drop to 12 by redline. No, not boost leak.. try to shim it and then it creeps to 16. It's this --> <-- fine line between creep and reverse creep! I cannot seem to get my turbo to hold the elusive 14 PSI to redline.


Start with a smaller flapper and stronger actuator and it will probably work. But, I really don't want to mess with it anymore.. external with swappable springs is the way to go.

Adding a spring with somewhat work but you never know what PSI it will open until you attach it, that's why I think a hook setup will be better instead of welding the spring onto the gate