Tial wastegate springs?

[sixgun86gn]

I have been having serious problems building boost at the track and need some info.

I have changed the converter and at 0 psi I am getting 3000 rpm,and around 3500 @ 10 psi with a 76gts.

I am told that the converter is still too tight,but I am also thinking that maybe under spoolup that the exhaust pressure is pushing the wastegate open.

I took the spring out of my tial F46 wastegate and it is a single blue spring.

According to tials website,this is a 13# spring.I am thinking that at WOT and 0 psi the wastegate may be pushing open.

I did a search and saw a suggestion in another thread to use a double spring setup for 15.9#.

Is this the standard?

I don't want to launch at 20 psi just yet,but would like to be able to control boost to lower than 15 for possible changes in track prep.

Should I order another spring to keep the wastegat shut?

What are some of you using,and does anything I've posted make sense?

 

[Robert Wilson]

I have been working on a car with a Tial V44 gate and was having similar problems. I made a pressure relief valve like the one in the link and it helps.
boostcontrol
(You have to scroll down to see the actual valve)

 

[sixgun86gn]

I forgot to add that I use an MSBC1 boost controller which uses solenoids as bleed valve.

 

[Robert Wilson]

I forgot to add that I use an MSBC1 boost controller which uses solenoids as bleed valve.

The car with the Tial V44 has the AMS 500 controller. The Tial spring currently in the wastegate will allow as low as 8 psi launch boost with the accelerator on the mat (no 2 step). We launch it at ~14psi by turning on stage one of the controller with the transbrake button.
The advantage of the relief valve is that it does not let any pressure act on the wastegate diaphram until the relief pressure is reached. I keep the relief valve adjusted close to the target launch boost so the gate stays shut as long as possible.

 

[S2V6RACER]

Who told you the converter is too tight? 3000 is about as loose as I would want to see for spooling a 76 turbo.

 

[sixgun86gn]

Who told you the converter is too tight? 3000 is about as loose as I would want to see for spooling a 76 turbo.

Thats what I noticed from other posts I have seen from others. The 3500 rpm @ 10psi doesn't sound right though.

What I am thinking is that maybe at wot on the brake,the exhaust pressure is maybe pushing the wastegate open without any pressure on the topside and the boost is slowed.

Possibly causing the boost to climb so slow gradually as it has to overcome the exhaust pressure on the poppet?

Does that make sense?

Could I have enough exhaust pressure at WOT and 0 psi to open the gate from inside the header?

Like was posted the spring is only 13# according to Tials website.

 

[sixgun86gn]

The car with the Tial V44 has the AMS 500 controller. The Tial spring currently in the wastegate will allow as low as 8 psi launch boost with the accelerator on the mat (no 2 step). We launch it at ~14psi by turning on stage one of the controller with the transbrake button.
The advantage of the relief valve is that it does not let any pressure act on the wastegate diaphram until the relief pressure is reached. I keep the relief valve adjusted close to the target launch boost so the gate stays shut as long as possible.

Thats exactly how my MSBC is supposed to be working,the hoses are all run according to the instructions.

I guess what I am trying to find out is if there is a point where the exhaust pressure can overcome the spring without any pressure built up on the top side of the gate?

How exactly is yours run? do you have any pics?

 

[Robert Wilson]

No pics handy but here is a diagram.

 

[sixgun86gn]

No pics handy but here is a diagram.

Thanks,just ordered one of those things. I think it will help alot.

Definitely will let me know if the spring is being pushed by the exhaust.

 

[GNVYUS 1]

How will a 14psi spring open before it builds 14psi of pressure in the pipe let alone you have manifold pressure pushing the top of the wastegate to keep it shut? If you're seeing your set total boost up top then most likely it's not the gate and could be other issues like leaks, tune etc.

I don't know anything about your build or tune but 3500 at 10psi on a 76GTS doesn't seem too crazy for a 231ci without a 2 step or nitrous launch.

 

[sixgun86gn]

How will a 14psi spring open before it builds 14psi of pressure in the pipe let alone you have manifold pressure pushing the top of the wastegate to keep it shut? If you're seeing your set total boost up top then most likely it's not the gate and could be other issues like leaks, tune etc.

I don't know anything about your build or tune but 3500 at 10psi on a 76GTS doesn't seem too crazy for a 231ci without a 2 step or nitrous launch.

It is a 250ci and I have a 2 step.

At zero boost there would be no boost pressure on the top side of the wastegate.

If the exhaust pressue is above the 13# springs ability to hold shut,why couldn't it be pushed off the seat before any boost is at the wastegate?

The total boost has nothing to do with the amount of time it takes to rise.

If the wastegate is cracked open early in spoolup the spool would be slowed way down,but total boost would not change.

 

[sixgun86gn]

Does anybody have a pic of how the vacuum lines are routed on thier external gate?

 

[d90dan]

If you want to see what the wastegate creeping open is like, disconnect the top port and leave it open. Get on the brake and watch the boost. I compared this to plugging the top port on my own car. You should see a huge difference, if not then you probably have issues with the gate. Got a spike with it plugged, so be ready to get out of it.

Don't know if this helps?

 

[GNVYUS 1]

Sixgun, at 0 boost you still have a 14psi spring pushing down on the gate so it's not going to creep open.

What D90dan is describing is what will happen when you run purely off the spring which will slowly open as it gets closer to 14psi, but if you put the line on it the scenario changes with manifold pressure helping out.

What I meant by the total pressure was that if you're seeing what you want up top then you're not seeing a spring creep issue down low since the lines on and it's seeing the proper pressure up top. Usually there's an opposite problem, the gate creeps past the set point up top due to evacuation issues to and from the gate.

With the 250ci and the two step I think you're seeing what you're supposed to be seeing with the 76GTS at 3500, most likely it's a T4 .82 exhaust housing right? You might need to add more timing at launch etc.

PM guys like

JZ SS 1500
Don Wang
Cheeseburger
Otto
Bison
Ted A
Cal Hartline

I've seen posts by them with big turbo's on Stage and 109 blocks.

 

[sixgun86gn]

Sixgun, at 0 boost you still have a 14psi spring pushing down on the gate so it's not going to creep open.

What D90dan is describing is what will happen when you run purely off the spring which will slowly open as it gets closer to 14psi, but if you put the line on it the scenario changes with manifold pressure helping out.

What I meant by the total pressure was that if you're seeing what you want up top then you're not seeing a spring creep issue down low since the lines on and it's seeing the proper pressure up top. Usually there's an opposite problem, the gate creeps past the set point up top due to evacuation issues to and from the gate.

With the 250ci and the two step I think you're seeing what you're supposed to be seeing with the 76GTS at 3500, most likely it's a T4 .82 exhaust housing right? You might need to add more timing at launch etc.

PM guys like

JZ SS 1500
Don Wang
Cheeseburger
Otto
Bison
Ted A
Cal Hartline

I've seen posts by them with big turbo's on Stage and 109 blocks.

Yes we've tried more timing and some fuel changes and it helps a little.

I think I had my hoses routed wrong,now.

I had the top side being fed from the turbo and the bottom coming straight from the intake,rather than T'd off from the turbo boost fitting.So I guess I'll find out when i take it out on the street and put it up against the brake.

 

[GNVYUS 1]

Ah that makes sense.

My basic setup on my Tial is

Turbo to Manual Boost Controller

MBC to lower part of Tial

Most let the top nipple vent.