tial WG TOP PORT connection Q's

[andy4g63]

I want to connect the top port of my Tial 44. There is a link of the diagram from Tial:


http://www.tialmedia.com/documents/w3_tial_wginstall.pdf

It is just does not make too much sense for me. I understand everything but how this type of conection will control boost?
the line from the turbo teed and goes into side port and the other one goes thru MBC and connected to top of WG with a TEE to vent ???
From the side I will be pushing against the spring/ in my case dual BIG BLUE, SMALL GREEN /, which is roughly 19psi and then on top after the MBC i have about 21-22 PSI, but this thing has a vent between outlet of MBC and top port of Tial???What is going to happen you think?

I was thinking of split the line from comprssor housing:
First line goes thru MBC/alter signal/ goes into side port getting me around 21-22 PSI
Second line from that split/TEE/ goes on top of WG, but for me to be sure that signal on the bottom will overcome the signal on top port, instal nitrous jet/restrictor/ into second line or just put a TEE/vent / into it, so it is still going to apply pressure,but not high enough to prevent WG of NOT OPENING.

Opinions will be appreciated .Thanks.

 

[Mr Peepers]

Trust me Paul #1, I have done alot of research on this and I have a brand new TIAL 44 from Extreme PSI sitting right in front of me with instructions to use only the side port and VTA the top port with MBC, on the top of the instruction sheet there is a *NOTE* For electronic boost controller installation, use the manufacture's instruction.

Let's break it down into different situations for better understanding.

1. With both ports open, much like leave the fitting on an internal wastegate fitting open, the wastegate is suppose to hold approximately 2x the spring pressure (its ability to hold back exhaust pressure). Example, 14psi spring = 28ish psi of intake pressure.

2. No boost controllers but both top and bottom connected to straight intake pressure, the result is the same as #1, 28psi.

3. No boost controller but with side port connected to intake pressure signal and top port VTA, much like running no MBC with an internal wastegate, the wastegate will hold exact the spring pressure. Example 14psi spring = 14 psi of intake pressure.

4. EBC or bleeder MBC, side port sees intake pressure (which will result in #3), the outlet of EBC or bleeder connects to the top port, for every psi the top port sees, there is one PSI increase in intake pressure. Note, a bleeder MBC will work in reverse in adjustment as in an internal gate environment, the more pressure you bleed off, the less the top port sees, the lower the boost level.

5. Ball/spring MBC, top port VTA and outlet of MBC connects to the side port. No pressure will be sent to the side port until the spring pressure in the MBC is overcomed, just like an internal setup. The reaon a ball/spring MBC doesn't work with the top port is because you have no control over exactly how much pressure to send, either you get nothing or you get everything, unlike an EBC or bleeder MBC. Let's put it in examples of running a ball and spring mbc using the TIAL instruction, assuming the wastegate spring pressure is 14psi.

A. MBC all the way out (no pressure on the ball), top and bottom port sees the same pressure, you get #2, 28psi.

B. MBC all the way in (max pressure on the ball), nothing gets sent to the top port, you get #3, 14psi.

So far so good but the problem is contolling boost pressure in between.

C. MBC set to anything between 0-14psi, as soon as the ball gives, the top port will immediately see the same pressure as the side port, you'll always get #2, 28psi.

D. MBC set to anything 14psi+, the top port will never see anything at all because the side port will open the wastegate before the ball is overcome, you'll always get #3, 14psi.

Hope my explanation isn't too confusing.

Lastly, to get away with using a smaller wastegate spring while trying to run higher pressure, you leave the side port open, 28psi, then for every psi you add to the top port, you get 2psi more in intake pressure.

Many thanks to Oldman

 

[andy4g63]

Actually I am a little confused. Could you break it down for me?
I spoke yesterday with Tial on the phone and tech support guy said that it would work the way is shown on diagram.
I have Hallman Evolution MBC/softer spring I think/. It is all the way open/no pressuure on the spring/. As I said springs are 19 psi after MBC I get 21psi. Will it work/Tial diagram/ and if so how?
Recently I've been experimenting with stiffer springs in my WG and I am very happy with the results.That is why I still keep playing with WG.

 

[Mr Peepers]

The main idea behind using the top port IMO is to effectively create a stiffer spring. If you have the side port connected directly to the pressure source, every psi of pressure that fills the top port will increase the effective boost pressure by the same amount.

Example: Spring pressure is 19lbs and you have 6 psi reaching the top port. Result: 25 psi, 6 psi more than spring pressure alone.

A ball and spring MBC to the top port won't really work in that diagram setup as far as I can tell; you must either use a bleeder type or even an actual pressure regulator. With a pressure regulator, such as on an air compressor, the outlet psi will always be the same no matter what the inlet. For example, 25psi in=6psi out, 20psi in=6psi out. As long as there is more than 6 psi or equal to 6 psi going into the regulator, 6 psi will come out. The result would be 25 psi effective boost as shown above. Of course you can adjust the outlet pressure to whatever psi you wish. With this setup, having the pressure regulator at 0 psi will result in effective boost the same as spring pressure, and increasing the outlet psi of the regulator will increase the effective boost by that same amount. A small vent would be needed as shown in your diagram to be able to lower the pressure back down without the regulator acting like a check valve.

A bleeder type MBC TEE'd off the top port line will increase boost the tighter it gets/less psi it bleeds off. You would start off with it bleeder off as much psi as possible and slowly bleed off less and less(increasing the pressure seen by the top port) until the desired boost pressure is reached.

 

[andy4g63]

Thanks, that's much better.