Stock Turbo PSI

[GNONYX]

Hi All, I know every engine is different, but what is the average PSI coming out of the stock turbo before entering the wastegate solenoid or an manual boost controller?

 

[turbo nasty]

Huh...before entering ??? Stock is about 13-15 psi of boost.
Posted from the TurboBuick.Com mobile app

 

[pacecarta]

stock boost was 15-12psi
thats controlled by the wastegate actuator and the wastegate solenoid

the wastegate actuator rod moves the puck inside the turbo exhaust elbow
closed it builds and the more its open the less boost you will see

that said ifyou have a wastegate issue where the puck stays closed and you could see 30psi in 1st-2nd , less in third gear because the turbo just cant supply the air
pump gas 93 octane intercoolled with a modern chip (like turbotweak) can support a few psi past the stock boost but every car is different
if you see 20-30psi on pump gas without alky injection you'll see damage

 

[GNONYX]

Thanks for the reply, but the reason why I'm asking this is I would like to remove the hose coming from the 90* brass fitting on the turbo, apply house air with approximately 40psi so I can adjust the manual boost control to obtain 17psi (boost gauge) Is this request possible?

 

[pacecarta]

easier to dial it low and test drive it , slowly adjust as needed


the reason is the air applied will be to open the puck , a partially opened puck can still build boost
and the air that the actuator sees from the turbo will be higher than the pressure you see on your boost gauge because we monitor manifold pressure and the wastegate sees pressure before the intercooler and on a stock intercooler that could be 3-5 psi more than manifold pressure

 

[GNONYX]

easier to dial it low and test drive it , slowly adjust as needed


the reason is the air applied will be to open the puck , a partially opened puck can still build boost
and the air that the actuator sees from the turbo will be higher than the pressure you see on your boost gauge because we monitor manifold pressure and the wastegate sees pressure before the intercooler and on a stock intercooler that could be 3-5 psi more than manifold pressure

Thanks pacecarta for the info, I guess I'm going to have to wait until I'm finish with the major maintenance I have been doing.
I though I could be ahead of the game and make the majority adjustment before finalize when I do drive the car.

 

[mgmshar]

You said you're running a manual boost controller, do you mean a check-valve type boost controller? If so, I have the same thing. On mine, I have a vacuum line tee'd into the very same line on the vacuum block that feeds my boost gauge. The line runs from the tee, through the check valve, and to the wastegate actuator. By doing this, there is no difference between the boost pressure in the intake manifold and the check-valve opening pressure. The 90-deg. elbow on my turbo is capped-off.

With this set-up, if I wanted the boost pressure in the intake (as measured by my boost gauge) to be 17 psi, I would hook-up the shop air to the inlet side of the check-valve and rotate the knob so that the check-valve opened and allowed air to flow through it at 17 psi.

If you are using the 90-deg. elbow on the compressor cover to feed the check valve, then the check valve must be set to open at a higher pressure than want you want in your intake manifold (on your boost gauge). This is because there is a large pressure drop across the intercooler, so the pressure the turbo is delivering at its outlet is higher than what is in your intake manifold. I agree with the above that if you are running the stock intercooler, you should set the check-valve to open about 3 to 5 psi higher than your desired intake boost pressure. So, if you're shooting for 17 psi, then set the check valve for 20 psi - that should get you pretty close.

Honestly, whenever I take my car apart, I just turn the wheel on the boost controller way loose to ensure my first run has very low boost (maybe 10 psi), and the slowly turn the knob tighter on back-to-back runs until I get to my desired boost level. It doesn't take too long.

If you're not running a check-valve type boost control, then ignore everything I said above.

 

[GNONYX]

You said you're running a manual boost controller, do you mean a check-valve type boost controller? If so, I have the same thing. On mine, I have a vacuum line tee'd into the very same line on the vacuum block that feeds my boost gauge. The line runs from the tee, through the check valve, and to the wastegate actuator. By doing this, there is no difference between the boost pressure in the intake manifold and the check-valve opening pressure. The 90-deg. elbow on my turbo is capped-off.

With this set-up, if I wanted the boost pressure in the intake (as measured by my boost gauge) to be 17 psi, I would hook-up the shop air to the inlet side of the check-valve and rotate the knob so that the check-valve opened and allowed air to flow through it at 17 psi.

If you are using the 90-deg. elbow on the compressor cover to feed the check valve, then the check valve must be set to open at a higher pressure than want you want in your intake manifold (on your boost gauge). This is because there is a large pressure drop across the intercooler, so the pressure the turbo is delivering at its outlet is higher than what is in your intake manifold. I agree with the above that if you are running the stock intercooler, you should set the check-valve to open about 3 to 5 psi higher than your desired intake boost pressure. So, if you're shooting for 17 psi, then set the check valve for 20 psi - that should get you pretty close.

Honestly, whenever I take my car apart, I just turn the wheel on the boost controller way loose to ensure my first run has very low boost (maybe 10 psi), and the slowly turn the knob tighter on back-to-back runs until I get to my desired boost level. It doesn't take too long.

If you're not running a check-valve type boost control, then ignore everything I said above.

I removed the factory wastegate solenoid since I do believe it's still work, and after troubleshooting my problem was with my boost gauge was showing more then want a stock psi should show of boost level. I got this manual boost controller as an secondly backup measure in case the factory wastegate fails and I would have something ready to put in as replacement.
Right now my setup is the first picture, and according to you, your setup is the 2nd picture of the inserted photo I attached.
http://www.circuitse7en.net/page27.php
You can purchase this manual boost control at EBay or through their web site.
http://www.ebay.com/itm/Manual-Boos...pt=Race_Car_Parts&hash=item4cfbba4863&vxp=mtr

 

[pacecarta]

thats a looks like check ball style similar to the rjc in operation
it should be hooked up end port to turbo , other port to wastegate actuator (check your instructions)

if you loosen nut and turn the shaft in (putting more pressure on the spring inside) the boost is increased, back out the shaft and boost will decrease

cant see what type of hoses you used with those rubber 90s but if one of those hoses pops off at WOT you will get maximum boost the turbo can make instantly
if you connect reversed you will also get maximum boost the turbo can make because the check valve will block the air signal to release the wastegate , your right foot will be your boost control

that said take it slow when playing with the boost , dont just take it out and drop the pedal to floor , ease in and if it passes your desired boost stop and readjust and try again

 

[GNONYX]

thats a looks like check ball style similar to the rjc in operation
it should be hooked up end port to turbo , other port to wastegate actuator (check your instructions)

if you loosen nut and turn the shaft in (putting more pressure on the spring inside) the boost is increased, back out the shaft and boost will decrease

cant see what type of hoses you used with those rubber 90s but if one of those hoses pops off at WOT you will get maximum boost the turbo can make instantly
if you connect reversed you will also get maximum boost the turbo can make because the check valve will block the air signal to release the wastegate , your right foot will be your boost control

that said take it slow when playing with the boost , dont just take it out and drop the pedal to floor , ease in and if it passes your desired boost stop and readjust and try again

Hi pacecarta, Yes the first picture of the C7 web site is how I presently have the manual boost controller setup (Minimize Spike plumbing)
All of the rubber hose including the 90* connection have tie-wrap on them. I put the black flexible wire cover for cosmetic look.
Once I have this setup figure out then I want to replace back the factory wastegate solenoid and make my adjustment on the wastegate rod just to make sure that part is still working.