The RJC boost controller. Questions I have.

Basically the RJC style controller stops any boost from reaching the wastegate until the RJC reaches it's set psi.
 
Nasty Wendy said:
Thanks guys I think I have it now. I had the RJC BIG PUCK installed in my downpipe. So I need to open the wastegate hole up as much as I can still maintaining complete coverage. This will reduce my minimum boost possible to run. Whatever spring is in the actuator will dictate the minimum boost by how much pressure is required to 'open the door' but because the door is bigger (in²) the exhaust pressure against the spring is multiplied by that higher number thus opening the door sooner and bypassing more exhaust and giving a lower minimum boost. It also reduces the maximum boost for the same reasons now you have to shorten the wastegate rod to increase spring tension for higher boost. And if I'm understanding you are also raising your minimum boost by shortening the rod because of increased spring tension and at some point you'll start to restrict the opening by not letting the puck swing far enough open.

Now its starting to make sense the advantages an external gate and controllers that used compress CO2 give.
Click to expand...

Clay this whole thread has been great. However I now wonder about the chip, if you are running with the internal, could a chip be burn that will make the wastegate bleed off at lets say 10-12 psi. If you are not in WOT. Also wonder how the ECM would know if you are only at mid-throttle, maybe the TPS. If so that would sure help the people on this forum with surge. I guess wishful thinking
 
1952ray said:
Clay this whole thread has been great. However I now wonder about the chip, if you are running with the internal, could a chip be burn that will make the wastegate bleed off at lets say 10-12 psi. If you are not in WOT. Also wonder how the ECM would know if you are only at mid-throttle, maybe the TPS. If so that would sure help the people on this forum with surge. I guess wishful thinking
Click to expand...
The ecm controlls boost with the wastegate solenoid. All it does is pulse open the solenoid and bleeds pressure away from the wastegate and lets the wastegate open at higher boost. With the stock actuator and the boost solenoid you make around 10#. I am working on a 2 stage so I can run 12 or so in first and 18+ in second for street tires.
 
Great ideas guys. I'll be in the garage soon enough, measuring my wastegate hole and making witness marks and opening it up. I'll be ordering a boost controller from RJC and giving it a shot. Armed with this info I should be able to accomplish my goal or know what is stopping me from doing so....and making the best compromise....until achievement is possible.
 
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Guys you all deserve a standing ovation for the absolutely awesome input you've given on this thread. My hat is off to all of you. Thanks.
 
Nasty Wendy said:
I'd like a way to lower boost to 10 psi if wanted. This would require an actuator with a 10 psi rated spring I guess.
Click to expand...
Or you could install a spring in place of the clip holding the actuator rod onto the wastegate arm and use it to pull the arm in the opposite direction of the actuator spring. this will have the same effect as a weaker actuator spring and allow the wategate to open farther resulting in lower boost.
 
Ttype6 said:
Or you could install a spring in place of the clip holding the actuator rod onto the wastegate arm and use it to pull the arm in the opposite direction of the actuator spring. this will have the same effect as a weaker actuator spring and allow the wategate to open farther resulting in lower boost.
Click to expand...

Now there is an angle I never thought of...pull the other way with another spring. Jenius.
 
Nasty Wendy said:
Now there is an angle I never thought of...pull the other way with another spring. Jenius.
Click to expand...
This is the reason I've never seen the need for a HD wastegate actuator. If we use a spring to apply pressure in the same direction that the wastegate spring is pulling,the puck is harder to open and the boost rises. This is all you are getting when you buy the HD,a heavier spring. Sooner or later as the power goes up and the exhaust pressure rises and we use a larger wastegate puck and a larger hole,the exhaust pressure will open the puck. The only way to stop this from happening is to apply more force to hold the puck closed.
Try to make as much boost as you want with as little spring pressure as is possible. We do this by allowing more and more boost signal pressure to bleed off into the atmosphere not allowing it to act on the actuator. This is what the factory does electronically with the boost solenoid. This is what electronic and manual boost controllers do. If you want higher boost after that,use some more actuator spring pressure.
 
ITSAV6 said:
The RJC controller helps with spooling some. I built my own years back and i have my wastegate rod adjusted so it only has to be pulled slightly to hook it on the lever. My minimum is 15# and it's normally set to 17/18#. My boost spikes on gear changes went away over the bleeder valve and tight adj wastegate rod.
Click to expand...
This is one of the reasons to hit your targeted boost with as little actuator spring pressure as possible.
 
Nasty Wendy said:
Thanks guys I think I have it now. I had the RJC BIG PUCK installed in my downpipe. So I need to open the wastegate hole up as much as I can still maintaining complete coverage. This will reduce my minimum boost possible to run.
Click to expand...
If you do this,more square inches of puck surface will be exposed to the exhaust pressure. This means that the puck will open sooner at high boost necessitating more wategate spring pressure to achieve it (high boost). Try to accomplish your goals without doing this. Then,if you see a need (boost spike or creep),go ahead.
 
Hanging a helper spring won't do the same thing. It'll still be a linear application rate. The MBC's deprive the wastegate puck of a boost signal until right before it's time to open. That way it stays closed 'till the last second then flys open quickly. Using a helper spring to raise boost will still have the wastegate cracking while spooling.


Sorry about being so scarce Nasty Clay, for some reason I've been on fire with the strange the last couple weeks. :D

PM me your address and I'll stick it in the mail.
 
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