I was using a ebay fake tial and the lowest psi i could get was 18 pounds, i purchased a real tial 38 with a 8.7 spring and with the boost controller turned all the way down the lowest i can get is 19 pounds? wtf? I want to get to 15-17 pounds for 91, im on c16 right now. What spring do i need? thanks.
Tial 38 wastegate spring help
- Thread starter cfish462
- Start date
83ttypecooled
Active Member
- Joined
- Sep 14, 2003
Hi,
I don't want to sound ignorant, but just what is a "tial"?
I don't want to sound ignorant, but just what is a "tial"?
I don't think your problem is the spring. Have you ported the wastegate hole on your PT61 to match the down pipe? If not, that is a must.
83ttypecooled,
Tial is a brand of external wastegates. The 38mm is a direct replacement for the old ATR wastegates and Turbonetics Deltagates.
83ttypecooled,
Tial is a brand of external wastegates. The 38mm is a direct replacement for the old ATR wastegates and Turbonetics Deltagates.
Um that hole is blocked off at the dp. see link:
eBay Motors: BUICK GRAND NATIONAL GNX T TYPE DOWN PIPE (item 120126848645 end time Jun-06-07 09:37:46 PDT)
Could that be the problem?
eBay Motors: BUICK GRAND NATIONAL GNX T TYPE DOWN PIPE (item 120126848645 end time Jun-06-07 09:37:46 PDT)
Could that be the problem?
I was thinking you had GN1's other external DP with the gate mounted right on the DP similar to the old ATR, Cotton's or my Mease external DP. If your gate is mounted on the passenger side header I really can't comment as I have no experience with that setup. RUQWKNF would be the guy I look to for help. Good luck
- Joined
- May 26, 2001
This is a tough one if the wastegate is located on the passengers side header and not on the turbo. One thing we need to know is, what turbo are you running?
There are a couple of does and don'ts when it comes to mounting it onto the header or crossover pipe.
The tubing that feeds the wastegate needs to have the same ID of the inlet of the wastegate. Discharge needs to be the same ID as well.
Make sure the wastegate is not mounted to the header backwards, (The inlet is on the bottom of the wastegate, not the side)
If you have a short piece of tubing that comes off the header and feeds the wastegate, you don't want it to just be at a hard 90* right angle to the main pipe or header. You want the connector pipe to be at a slight angle (IE: 45-60*) to help facilitate a smooth exhaust flow into the wastegate. What can happen is, if the pipe is at a 90* right angle, the exhaust can bypass the wastegate almost entirely and cause you to have a run away or creeping boost condition and or no boost control.
Make sure that you indeed have the 8.7psi Small Blue spring inside your wastegate and not a doubled up Large and Small spring combo. Check this before you order anymore springs. I have seen in the past where the boxes were mislabeled and the wastegate would have the wrong spring vs what the label on the box said. What would really blow would be to order parts that you don't need because you already had the correct spring but it needed to be modified. (IE: if the wastegate had a large and a small spring and all you had to do was take the large spring out.) In a perfect world, to reach the boost levels that you're seeking, technically you should run a Large Red or Large Green spring, 11.6psi and 13psi respectively.
It is a must to use both pressure ports on the wastegate to have good boost control. You could have some issues by just running one vacuum/pressure line to the side of the gate and nothing on top. Running your lines that way (only one line) is called Open Loop. Using both ports with a manual boost controller is called closed loop. Here is a picture showing how I have always hooked up a manual boost control valve on every external wastegate setup I've ever owned.
If you have done all of these things, tube feeding the wastegate is same ID and at a slight angle, wastegate oriented correctly, checked to see what spring/springs it indeed has inside, and both ports hooked up to the wastegate correctly, then the last resort would be to replace the wastegate spring.
If you already have the 8.7psi Small Blue wastegate spring and the lowest boost you are able to see is 19psi and your goal is 15psi, then I would get two springs as knowing which one will be the solution on your combo will take some testing. I would start out with the 3.6psi Small Yellow spring and see what the lowest boost will be. My guess is it would be around 14-15psi. However, your boost might actually be lower than this. At least in the grand scheme of things it is supposed to be if all of the above items are good to go.
If this is the case and the boost level is now too low and you can't get the high setting where you want it, then I would install the next level spring. This would be the 5.8psi Small Red spring. With what you have said, as far as where your boost is now when running the 8.7psi spring, one of these two should get you going. The problem you might have with running too small a spring is, the wastegate can open up too soon and cause slow spool up, as well as not being able to reach higher race only boost levels. (20-26psi range) This is why it will take some experimenting with the springs.
Here is the link to Tials website that shows the different springs available for the 38mm.
http://www.tialmedia.com/documents/w3_tial_38_sp.pdf
Hope some of this helps.
Patrick
There are a couple of does and don'ts when it comes to mounting it onto the header or crossover pipe.
The tubing that feeds the wastegate needs to have the same ID of the inlet of the wastegate. Discharge needs to be the same ID as well.
Make sure the wastegate is not mounted to the header backwards, (The inlet is on the bottom of the wastegate, not the side)
If you have a short piece of tubing that comes off the header and feeds the wastegate, you don't want it to just be at a hard 90* right angle to the main pipe or header. You want the connector pipe to be at a slight angle (IE: 45-60*) to help facilitate a smooth exhaust flow into the wastegate. What can happen is, if the pipe is at a 90* right angle, the exhaust can bypass the wastegate almost entirely and cause you to have a run away or creeping boost condition and or no boost control.
Make sure that you indeed have the 8.7psi Small Blue spring inside your wastegate and not a doubled up Large and Small spring combo. Check this before you order anymore springs. I have seen in the past where the boxes were mislabeled and the wastegate would have the wrong spring vs what the label on the box said. What would really blow would be to order parts that you don't need because you already had the correct spring but it needed to be modified. (IE: if the wastegate had a large and a small spring and all you had to do was take the large spring out.) In a perfect world, to reach the boost levels that you're seeking, technically you should run a Large Red or Large Green spring, 11.6psi and 13psi respectively.
It is a must to use both pressure ports on the wastegate to have good boost control. You could have some issues by just running one vacuum/pressure line to the side of the gate and nothing on top. Running your lines that way (only one line) is called Open Loop. Using both ports with a manual boost controller is called closed loop. Here is a picture showing how I have always hooked up a manual boost control valve on every external wastegate setup I've ever owned.
If you have done all of these things, tube feeding the wastegate is same ID and at a slight angle, wastegate oriented correctly, checked to see what spring/springs it indeed has inside, and both ports hooked up to the wastegate correctly, then the last resort would be to replace the wastegate spring.
If you already have the 8.7psi Small Blue wastegate spring and the lowest boost you are able to see is 19psi and your goal is 15psi, then I would get two springs as knowing which one will be the solution on your combo will take some testing. I would start out with the 3.6psi Small Yellow spring and see what the lowest boost will be. My guess is it would be around 14-15psi. However, your boost might actually be lower than this. At least in the grand scheme of things it is supposed to be if all of the above items are good to go.
If this is the case and the boost level is now too low and you can't get the high setting where you want it, then I would install the next level spring. This would be the 5.8psi Small Red spring. With what you have said, as far as where your boost is now when running the 8.7psi spring, one of these two should get you going. The problem you might have with running too small a spring is, the wastegate can open up too soon and cause slow spool up, as well as not being able to reach higher race only boost levels. (20-26psi range) This is why it will take some experimenting with the springs.
Here is the link to Tials website that shows the different springs available for the 38mm.
http://www.tialmedia.com/documents/w3_tial_38_sp.pdf
Hope some of this helps.
Patrick
wow thanks for all the info.
I am running a precision pt61 turbo.
ID = internal diameter right? the inlet into the w/g and the outlet are all the same size.
The vacuume lines are hooked up like your schematic also.
I pulled the gate apart and its for sure a single blue spring.
Try a smaller one then?
I am running a precision pt61 turbo.
ID = internal diameter right? the inlet into the w/g and the outlet are all the same size.
The vacuume lines are hooked up like your schematic also.
I pulled the gate apart and its for sure a single blue spring.
Try a smaller one then?
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- Joined
- Feb 8, 2007
try running the vac line from the turbo to the side/bottom port on the wastegate leave the top open to the atmosphere (no air fitting)...take the boost controler entirely out of the situation and see what boost you get..if that is a bleeder boost controler, you really do not need to use the top port
Just wanted to give a big thanks to RUQWKNF for posting that diagram. It worked perfectly with my external Tial 38mm wastegate on the downpipe. For a year it was plumbed all wrong but with a smaller turbo running big boost I never even knew it. Then I changed to a Limit GT70 and found out I had a huge problem when the 30 psi boost guage wrapped around and almost back to zero
I just hope the valve doesnt carbon up and seal shut on me again...which is what I thought the main problem was initially. So I completely took it apart and rebuilt/cleaned it and never seized the plunger valve and seems good to go...time will tell I guess. I have heard others having issues with this.
Ironically the pict you showed was the exact turbo and valve set up I had. I was a little worried with the spring set up I had...(it was a large silver sping with a red stripe on it?) that it wouldnt work right but I took it from 19 to 29 psi with a couple turns of the valve and seems to be great.
I just hope the valve doesnt carbon up and seal shut on me again...which is what I thought the main problem was initially. So I completely took it apart and rebuilt/cleaned it and never seized the plunger valve and seems good to go...time will tell I guess. I have heard others having issues with this.
Ironically the pict you showed was the exact turbo and valve set up I had. I was a little worried with the spring set up I had...(it was a large silver sping with a red stripe on it?) that it wouldnt work right but I took it from 19 to 29 psi with a couple turns of the valve and seems to be great.
You said that you were running C16 with a Tial 38mm and I recently discovered that that is a bad combo. I have a 38mm that had about 600 miles on it when it locked up and caused my car to overboost. I ran about 6-8 gallons of race gas thru it and that was enough to lock it up. You have to buy a different valve to go in the wastegate to make it live with race gas so beware and keep and eye on it. I am selling my Tial and going to a Racegate to avoid this issue.
