I bought a PT6776E turbo used that came with the "628 actuator upgrade for Buick turbos" but I don't know what the minimum psi it will run is. I want to run about 5 psi initially but if the actuator's min is above that am I going to have to go to an external wastegate? I do not know much about turbos; up until an hour ago I thought the actuator was the wastegate, although I had been wondering what the rod coming out of it was for.
GT6776E for Corvette: want to run ~5psi; can I do so with actuator?
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turbo buicks
ESADAH!!!
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get a manual boost controller and run the WG rod on its lowest tension that still hold the WG puck shut. should work
A little screw in a box boost controller came with it. Is the wastegate rod the rod coming out of the actuator? If not, what is the rod coming out of the actuator that ends near the mating surface of the turbine housing called?
Is the setup on the stock Buick turbo like this? What is the min pressure the stock wastegate and actuator can provide?
Is the setup on the stock Buick turbo like this? What is the min pressure the stock wastegate and actuator can provide?
Sh----. The little things tack on and on. You can save money building a turbo kit yourself, but if you made six dollars an hour at work, the number of hours you spend web surfing, thinking, buying, and working on it make it cease to be "saving" money. If you just bought the kit for 5 or 6 grand and put those, oh, about three hundred hours of D.I.Y.ing into a job at Hardees, you would have made more money than you saved doing it yourself.
It doesn't seem promising to me to be able to get a custom actuator; and to do it myself I would have to cut this thing open and pop some kind of spring in there, hoping I didn't break something and that the result was somewhere close to what it should be. So I'll probably go with an external wastegate. What are the chances that I could still use the boost controller right where it is and just pop the tube off the actuator and onto the external wastegate?
It doesn't seem promising to me to be able to get a custom actuator; and to do it myself I would have to cut this thing open and pop some kind of spring in there, hoping I didn't break something and that the result was somewhere close to what it should be. So I'll probably go with an external wastegate. What are the chances that I could still use the boost controller right where it is and just pop the tube off the actuator and onto the external wastegate?
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Bob is correct, the lowest boost you would be able to run with a standard spring actuator that was designed for a Buick would be around 12psi. If you cracked open the actuator to the point that the puck was opened with the rod adjustment, you would have severe turbo lag, and if you ran a smaller actuator with a lower boost level (such as an actuator for a GT25 series turbo), you would possibly not have enough wastegate and the boost would run away. The answer to this debacle would be an external wastegate such as a Tial 38mm with the smallest spring you can get, which I believe is a 7psi spring. Another thing, the 67mm wheel, really doesn't like to be run at such low boost levels, although it will, as there are many fwd turbo 4 cylinders out there running around on the street running high compression ratio safe boost levels with this turbo. I would suggest running an alcohol injection kit on the Vette and running the boost a little bit higher, say 8-10psi, which the wheel would like better.
HTH
Patrick
HTH
Patrick
Gracias RUQWKNF. The consensus for the LT1 and the LS1 is that 7 or 8 psi is the max you can run (with methanol) on the stock internals before blowing something up. (The rods or rings on the LT1 are the weak link and the rings on the LS1 I think.)
Will I be able to use the same boost controller and just pull the hose off the acuator, put it right onto the wastegate, and drive happily away?
How does the external wastegate work? I've searched around the web but haven't found anything that describes it.
The pressure through the boost controller assists the valve in staying closed? So to achieve minimum boost, you completely close off the pressure to the wastegate, and to up the boost you open the boost controller so more pressure is sitting on top of the valve helping to keep it closed? So the min boost you can achieve is determined by the spring? If that's true, could anyone just go with a spring that will hold only 4 psi unassisted, and then up the boost as desired to the max achievable by the turbo just by increasing the pressure on top of the valve?
Will I be able to use the same boost controller and just pull the hose off the acuator, put it right onto the wastegate, and drive happily away?
How does the external wastegate work? I've searched around the web but haven't found anything that describes it.
The pressure through the boost controller assists the valve in staying closed? So to achieve minimum boost, you completely close off the pressure to the wastegate, and to up the boost you open the boost controller so more pressure is sitting on top of the valve helping to keep it closed? So the min boost you can achieve is determined by the spring? If that's true, could anyone just go with a spring that will hold only 4 psi unassisted, and then up the boost as desired to the max achievable by the turbo just by increasing the pressure on top of the valve?
I ran 10 psi on 93 octane in my 96 Impala for 6 years with no issues.
Detonation is your enemy, you must reprogram the spark advance or you will break the pistons.
Those others in the Impala club that didn't fix their spark advance all bought new motors........
8 psi is no problem in my opinion (intercooled, with proper spark advance).
Give us more details on the car, engine, and controller.
Bob
Detonation is your enemy, you must reprogram the spark advance or you will break the pistons.
Those others in the Impala club that didn't fix their spark advance all bought new motors........
8 psi is no problem in my opinion (intercooled, with proper spark advance).
Give us more details on the car, engine, and controller.
Bob
turbo buicks
ESADAH!!!
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i would think the increased displacement of 2 xtra cyls would bring the needed boost range down do a lower boost. kinda like ported heads make same power on less boost b/c of a lower restriction
It's a stock automatic 99 Vette. I'm going to keep the engine stock since I plan on selling the car before long. I bought EFI Live, which is very popular tuning software for the LS1s. If you're curious, here's a great thread on FI LS1s with stock bottom ends. LS1TECH - Poll: My Stock Bottom End Lives With ## RWHP
But I need to figure out now what I'm going to do with the wastegate. Oiling will be next after that.
But I need to figure out now what I'm going to do with the wastegate. Oiling will be next after that.
GNVYUS 1
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TurboBob is right on again, timing is going to be your worst enemy. Don't worry if it gets down to 14 or 15 degrees, the boost will make mad power still.
External wastegate is the only way to go on this. Like many have said the GN actuator is not going to get you down that low. And if it did, it would probably creep like mad causing major problems.
IMO, a Tial 38mm is to small for the low amount of boost you want to run with that larger turbo. Get a 44mm and never look back. With a big cube/big turbo combo you do not want any creeping, and at 5-8psi the smaller 38mm might not be able to handle the job. A couple extra bucks will save you a motor if you creep 2lbs on a hammer down.
External wastegate is the only way to go on this. Like many have said the GN actuator is not going to get you down that low. And if it did, it would probably creep like mad causing major problems.
IMO, a Tial 38mm is to small for the low amount of boost you want to run with that larger turbo. Get a 44mm and never look back. With a big cube/big turbo combo you do not want any creeping, and at 5-8psi the smaller 38mm might not be able to handle the job. A couple extra bucks will save you a motor if you creep 2lbs on a hammer down.
turbo buicks
ESADAH!!!
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an ext wg functions the same as a GN style wg just looks different and uses a valve vs a puck. it will work. just remember the less boost u want to run the bigger the wastegate needs to be
Where are you located?
Find someone who has done it and get some real-world advice.
Be sure your fuel supply will keep up. As the boost goes up, your injectors will get 'smaller' since your fuel pressure does not track the manifold pressure.
The guys on LS1tech are great, if y2khawk says something, listen........
Start small, work your way up.
Bob
Find someone who has done it and get some real-world advice.
Be sure your fuel supply will keep up. As the boost goes up, your injectors will get 'smaller' since your fuel pressure does not track the manifold pressure.
The guys on LS1tech are great, if y2khawk says something, listen........
Start small, work your way up.
Bob
I'm in Dahlgren, Virginia.
I got 65 lbers and a Walbro. The injectors should be good for 670 hp but I'm not going that high, the pump should be good for 550 which is about what my goal is. I'm a member at LS1Tech but I wanted to ask the Buick owners about this since it's a Buick turbo. A pal of mine in Virginia Beach who owns a GN had been helping me out. He's a member here but I don't know what his screen name is.
I got 65 lbers and a Walbro. The injectors should be good for 670 hp but I'm not going that high, the pump should be good for 550 which is about what my goal is. I'm a member at LS1Tech but I wanted to ask the Buick owners about this since it's a Buick turbo. A pal of mine in Virginia Beach who owns a GN had been helping me out. He's a member here but I don't know what his screen name is.
But remember, these GN guys aren't used to the fixed rail pressure of your LS1.
If your rail pressure is 50 lbs, and you run 10 lbs of boost, your injector only has 40 lbs of pressure across it.
That turns your 60lb injectors into 53's........ Should still be plenty, just FYI.
Get the injectors in and running properly. Then get your trans tweaked up to handle the power. Then install the turbo and run 5 psi or so until it runs right, then go up from there.
Go slowly, one step at a time, making sure everything is right and it will make excellent, reliable power.
Bob
If your rail pressure is 50 lbs, and you run 10 lbs of boost, your injector only has 40 lbs of pressure across it.
That turns your 60lb injectors into 53's........ Should still be plenty, just FYI.
Get the injectors in and running properly. Then get your trans tweaked up to handle the power. Then install the turbo and run 5 psi or so until it runs right, then go up from there.
Go slowly, one step at a time, making sure everything is right and it will make excellent, reliable power.
Bob
I heard about the effective pressure at the injectors changing under boost. Apparently it makes tuning harder, but it looks like the only alternative is a boost sensitive fuel pressure regulator, and since the LS1 is a returnless system (only one fuel line from the tank to the rail, no line going back), to install one, you have to put in a fuel return line and make it fit into whatever setup is in the tank. Or, although I've never read of anyone doing this, you should be able to just put the pressure regulator at the tank and run the boost reference line all the way back to it from the manifold, or I could run it from after the turbo since it'll be in the back. But still a major PITA so I plan on skipping that.
What you said is the order of events I had planned on following. I got a laptop off ebay a few days ago to tune the injectors in.
What you said is the order of events I had planned on following. I got a laptop off ebay a few days ago to tune the injectors in.
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