max psi on stock actuator
- Thread starter terryjh6
- Start date
Welcome!
By registering with us, you'll be able to discuss, share and private message with other members of our community.
Gary Wells
White turbo Buick trailer park trash
- Joined
- Mar 2, 2002
- Messages
- 9,778
------------------------------------------terryjh6 said:right now i seem to stop at 21 psi on my turbo is this the max on my stock actuator? do i need a hd actuator to go higher? and what psi will my stock turbo stop making boost? 25,30,35? anybody know? thanks terry
From what I have read on the boards 20/21 lbs. boost is about what the standard adjustable wastegate actuator unit will go, and the efficient amount of horsepower & torque available from a stock turbo is questionable above this too. Mine seems to max at 22 lbs. with a TA-49 & a few other mods.
terryjh6 said:right now i seem to stop at 21 psi on my turbo is this the max on my stock actuator? do i need a hd actuator to go higher? and what psi will my stock turbo stop making boost? 25,30,35? anybody know? thanks terry
Your doing a bit better than me, mine stopped at 20..
The HD actuators start at about 18.
I believe from reading the stock turbo starts get really innefficient past 22-23.
Im shooting for 22 with mine. Bought a manual boost controller to see if i can get there with it..
Gary Wells
White turbo Buick trailer park trash
- Joined
- Mar 2, 2002
- Messages
- 9,778
---------------------bdeliman said:
Lack of wastegate actuator adjustment is not causing the problem, using a standard wastegate actuator in leiu of a heavy duty actuator is.
i'm using a rjc boost control and have not needed to use the adj. rod on my accuator. I can dial in anything from zero to 21 psi w/ my controller. I was under impression that the stock accuator is only good to around 20ish psi, and anything over that would require an HD accuator. I thought that the adjustable rod was used on boost control solienoids like the stock set up. Therefore, I need to know is 21 psi, like I'm running now, is that the limit of my stock accuator? Thanks, Terry
Rasing boost by shortening the actuator rod is not a good way to reach your goal. If you choose to use this method with the stock actuator,you'll probably reach 20-22 lbs. There are two problems this method will create. The first one is that since there is more force trying to keep the wastegate closed,it will not be able to open as far. The second problem is that it will not be able to open as fast.There are two situations that will call for the wastegate needing to open farther. The first is during a shift,when the motor suddenly slows down. When this happens,your motor has an instant need for less air to maintain any given amount of boost. If the wastegate can't open farther during this time, the boost will spike. The secound situation that will call for the wastegate opening farther happens at the upper end of third gear. In this situation,the motor will be producing more exhaust energy.If the wastegate isn't allowed to open farther during this event,the turbine will spin faster causing the boost to climb.The situation that calls for the wastegate to open faster is,the above,situation one. Since the event that happens during a shift happens so suddenly,the wastegate needs to open just as suddenly to to keep the boost from spiking. When you increace boost by shortening the actuator rod,you inhibit the wastegates ability to open farther and faster when it needs to. The way you control your boost solves both problems. Since your boost controller is only letting pressure act on the actuator when needed,You don't need to adjust the actuator to increase boost and,in fact you'll want to lossen it up as much as possible. This will allow the wastegate to open farther and faster when it needs to. Your boost won't spike or creep. With your controller,you don't need to adjust the rod for more boost, You simply adjust the controller if you want to produce more than 20 lb. of boost.terryjh6 said:
- Joined
- Nov 24, 2001
- Messages
- 11,267
Stretch the spring on your RJC controller to get more boost out of it
BW
BW
Before doing this,disconnect the hose from the actuator and plug it. With your eye on the boost guage,gradually open the throttle and see if it will easily make boost beond 21lbs. If it does,do as Quick6'n'-K.C. advises. If it doesn't make any more boost than it does now,you have other problems.Quick6'n'-K.C. said:
Kevin87TurboT
How many can I own??
- Joined
- Jul 29, 2005
- Messages
- 376
I've seen 23 psi several times with my stock wastegate. I have shortened the rod to get there. It does spike up to 24-25 on the initial hit, then settles at 23. So far I've gone 12.43 @ 107. That's on pump gas w/ Alky, stock turbo, injectors, valve springs, and torque converter.
I used to be able to hit 23psi with hardly any tension on the wastegate spring at all. If you can delay filling of the wastegate, it will automatically raise boost...thats what the little orifice in the Y fitting is for. Without it, pressure would hit the wastegate with so much force that it would swing open so fast that it will overshoot...and once it overshoots and is open too far, it will stay open too far cause there is so much exhaust flow...and then you have low boost. I used to have a normal air pressure regulator in place of the wastegate solenoid, (old school boost control) and this bled off enough air that it allowed the wastegate to fill slowly, bringing my boost up without having to tighten the wategate arm. I ended up making my own quick spool boost controller out of a pressure regulator, I tear it apart, change springs, modify some things and plumb it up backward. After dialing it in on a pressure jig I made, it works pretty awesome. The controllers out there dont bleed off all pressure and then just slam shut like alot of them say. Given the spring, ball and seat design, thats impossible. I even made my own and saw that it is really just a flow control. It limits the flow rate to the wastegate, which delays filling, which controls what psi the puck will open. The thing I made actually does exactly what others claim theirs does. It bleeds off all pressure very fast and then instantly slams shut at X psi, pressurizing the system and easing the puck open, for a precise boost limit...no boost creep. Drilling out the puck hole is a serious bandaid that treats a symptom and not the cause...which is the wastegate not filling as fast as boost is rising. Anyway, long story made longer, I reversed the Y fitting to limit the flow rate to the wastegate. The orifice now aims at the wastegate, not the compressor. Pre-orifice, (section of line from the compressor to the controller) the controller blows off all pressure until it hits the set pressure, boost controller slams shut, Pre-orifice line pressurizes instantly (because there is nothing limiting flow to the controller...the line goes straight and unimpeded from the compressor to the controller) and then the wastegate side of the Y fitting orifice plays catch up. Pre-orifice, it pressurizes fast, but because I have the orifice now aimed at the wastegate, that Y fitting to wastegate diaphragm section of line pressurizes slowly and eases the puck open....not slamming it open. If you have the orifice between the compressor and the controller like in stock fashion, you limit the flow rate to the controller, and the controller wont be able to react as fast as the boost is rising. I dont know if Ive made any sense, but it works really well. This controller doesnt control peak boost pressure. It pretty much just acts like an on off switch for line pressure. I have to use the wastegate arm to adjust peak boost. And because of where I have the orifice aimed, the puck is eased open in a controlled stable way, and doesnt overshoot. And no Im not selling anything so Im not making **** up. Thats how it works in theory, and the end result seems to prove it.
Similar threads
- Sticky
