awilson40

So ,
After tons of searching, I have never seen anyone actually post a side by side comparison of dual port vs Single port.

I'm running a Greddy EBC with a Tial wastegate in Single port mode.
Has anyone actually had the above configuration and switched to Dual Port?
Things I read on other sites say that with the Tial, dual port isnt required due
to the valve being held tight against the seat by spring and exhaust pressure.

Comments ?
Thanks

chrenan

I'm curious to hear thoughts on this as well. I run a lindsey
dual port wastegate in single port mode using the stock setup
cycling valve to control boost.

minho78

+1. Ohh and I'm looking for a Tial in good condition.

Thom

I replaced a fresh stock wastegate with a Tial plugged in single port mode, no difference whatsoever.
In dual port mode, the turbo (re)builds boost more quickly when upchanging gears, the difference is significant enough to be feelable.

I'm not sure how an EBC can even be used correctly in single port mode?

kahlveen

I'd say that in general for the tial, the valve is held more tightly against the seat than in the stock wastegate (how tightly depends on the spring one chooses). But the exhaust pressure is actually working against the force of the spring that's holding the valve closed. The benefit of the dual port configuration is that the positive intake manifold pressure being produced acts to aid the spring in preventing exhaust pressure from opening the valve before your desired max pressure is reached.

Please correct me anyone if I've got this wrong!

User 52121

When I was looking at the two WG's side by side (TiAL vs. stock) - the TiAL flows backwards compared to the stock unit.

The stock unit, exhaust flows through the WG body and around from the backside of the valve (much like an intake valve on a cylinder head.) With the TiAL unit, the exhaust flows the other direction, from the face of the valve up through the WG body (just like an exhaust valve in a cylinder head.) So with the stock WG closed, the WG body is full of exhaust gases. The TiAL, the only time the exhaust flows through the WG body is when the WG opens. Which could explain why the stock WG has cooling fins all over it and the TiAL does not.

So it seems that with the TiAL, the exhaust flow would work to keep the valve closed. Whereas with a stock WG, the exhaust flow would work to push the valve open. Regardless, I'm sure you'll get the best boost response running a TiAL in dual-port mode, though I would still expect quicker-than-stock response running a TiAL in single port over a stock WG simply for the fact that you won't have exhaust pressure pushing against the backside of the WG valve.

kahlveen

You're right that the Tial flows backwards compared to the stock unit, but the Tial valve also moves in the opposite direction. It moves into the body whereas on the stock unit, the valve travels out of the body. I believe that in both cases, the exhaust pressure pushes the valve toward the open position.

If the exhaust pressure worked to keep the valve closed, I don't see how it could be opened with intake manifold pressure alone as it does. Intake manifold pressure would somehow have to exceed exhaust pressure (don't think this is possible) as well as the pressure from the spring that would both be holding the valve closed.

jb-kix

how do you put the tial in dual-port mode?

kahlveen

In the diagram from my previous post, you can see that there are two ports to which pressure can be applied (top and side). In dual port mode, the side port will receive the full unrestricted intake manifold pressure (works to open the valve). The top port will receive a fraction of that pressure (works to close the valve) which is used to set your desired boost level. Here is basically what's going on:

Say for example you want to reach 16 psi intake manifold (boost) pressure and that your spring exerts 23 psi of closing force on the valve. When 16 psi is reached, (we'll assume that exhaust pressure is equal to intake pressure) you now have 16 psi of exhaust pressure pushing the valve open, 16 psi of intake manifold pressure pushing it open (from side port), and 23psi of closing force from the spring. That's 32 psi opening force and only 23 closing force. There is 9 psi more worth of force acting to open the valve. This is where the top port comes in. Since you want the valve to open once 16 psi is reached, you would set this to just less than 9 psi. Now when 16 psi intake manifold pressure is reached, the downward force on the valve is slightly less than the upward force and boost should not increase.

86 951 Driver

How are lindsey's wastegates compared to the Tial?

awilson40

Ok Guys, Here is the data logging of Single Port vs Dual port.
No setting changes on the EBC were made, this is an apples to apples comparison and I see that Dual port mode yields no difference.
I measured the time in 3rd gear from 2450 rpm to 6100 rpm and its 10 seconds
in both configurations. Initial boost is a little higher, but if I adjust this down to 15.5 lbs, then I think it would be the same.

The first Graph Single Port
The 2nd Graph is Dual Port

DivineE

Perhaps someone will post a couple of pictures up but having held one in each hand I'd take the tial.

teamcrossworks

Correct me if I'm wrong but:

The only difference between the two is:

A dual port will let you adjust the regulated exhaust pressure going to the turbo greater then the spring rate while the single port is really stuck constant at that spring rate pressure (does that make sense?)

I've rebuilt a number of stock wastegates and changed the spring to a stiffer rate and have had great success. I prefer this method or single port style because I still maintain the CV and stock protection. People who had modified their cars to bypass the CV probably would benefit from the adjustability of the dual port style.

just my 2 cents...

teamcrossworks

And I can't see much difference between a Tial and a LR dual port. They both do the same thing well.

awilson40

The Below screen shot is after fine tuning the EBC for Dual Port connections.

This is a 4th gear run but I ran out of road and couldnt take it to redline.