External weaste gate install ?

[SVORay]

My car is having issues staying on or around the preset boost limit. I'm using one of those RJC controllers instead of the stock set up. It seems to work but I still get an extra 5 lbs of boost with some detonation every once an a while. I'm guessing the detontion is from to much timming since my car is only tuned for 15pi instead of 20psi. Anyhow, I hauled off and bought a Down pipe and Turbonetics Evolution ex-gate from Cotton. I'm looking to double check installing this in my Regal.

Now I'm guessing but I think I simply pull the aculator rod completely off the car along with the old DP? The aculator has a vaccum hose running from it to my controller...is this the line I used to plug into my external gate? The other end off the controler connects to my compressor side of the turbo.


Also, I've heard it's best to have the external gate close to the boost level that you have the car tuned for? ATM my setting is going to be 15lbs but my gate is set at 9lbs. My question, is this enough or should I shim the spring to gain a few lbs of boost? In the ner futur I plan on installing an Alky kit and pumping the boost up around 18-20psi. Will the same 9lb spring or shimed set up work for the extra boost or should I see if they make a high boost spring?


Thanks for all the help and opinions.
Ray

 

[SVORay]

Anyone?

 

[RUQWKNF]

Yes, the line that ran to the stock style wastegate is what hooks to the external wastegate.
Here is a picture showing how to hook it up if you want to run the RJC manual boost controller. It should work.

I know it's not a New Gen wastegate, but it should have similar ports. The 9psi spring will work fine. Just make sure that the port on the bottom of the RJC valves line is the line that goes to the compressor covers hose barb. The port on the RJC valve that comes out of the adjustment side will go to the top of the wastegate. Make sure you install the plastic Tee as shown in the picture as well. With the RJC valve closed all the way (not tightened but barely together) and running the 9psi spring, the boost should go to around 12-13psi and hold steady. Take the adjustable wastegate completely off the turbo, reuse the bolts and use washers in place of the clamp that was on the actuator, to hold the comp cover to the backing plate.
Hope this helps.

Patrick

 

[unix_punk]

I could be wrong, but I thought that it's best to take a boost reference from somewhere else because the surge ports on the turbo aren't as reliable or as of a steady rate because their so close to the source.

 

[RUQWKNF]

With wastegate control source signals, I have always plumbed off of the compressor housing and here's why. If you plumb the source line off of the intake, the signal is less that what is really being put out by the turbo. There is a pressure drop that comes from the intercooler. Most of the time it's not more than 1 or 2psi. When it comes to sourcing a signal line to a MAP sensor or to a fuel pressure regulator, by all means, source it from the intake. I want my wastegate to see the exact signal pressure that the turbo is putting out. A boost gauge source is best from the intake as well.

I've found that the wastegate also responds faster when it's source signal comes directly from the compressor cover. There is one exception to this rule, placement of the hose barb is critical on some turbos compressor covers. Some covers have the barb placed in the scroll and some have it placed in the discharge. I have seen some that plug the spot in the scroll and retap a spot in the discharge, mainly on larger race series turbos. You will notice that almost all OEM Garrett turbos typically have the hose barb on the compressor covers discharge and that line almost always routes directly down to the wastegate.
HTH

Patrick

 

[unix_punk]

Makes sense, I just figure that regardless of what reference the wastegate gets, its still going to be adjusted by the controller to be where you want it anyway. The only thing is it will need to be re-adjusted if the reference were to be moved.

 

[SVORay]

Hey thanks Guys


Now I'm currently not running any kind of T fiting. There is a single hose running from the bottom of the RJC to the compressor and a single hose running from the adjustment side to the actuator. I'm going to install the external gate anyways, but do you think not having a T is the cause of my spikes?

Thanks again
Ray

 

[RUQWKNF]

On the internal wastegate setup, you don't run any Tee. Only time we run the Tee is when you switch over to an external setup.
There are two ways of plumbing an external wastegate.

Open Loop

This is when you simply run a source line to the side of the wastegate and let the spring pressure control the boost level. Some external wastegates do not have an adjustment screw. On those types of wastegates, boost level is set by spring rate only. Not the best way to do it, but in some cases it's the only way.

Closed Loop

This is when you run a line from the turbo, to the bottom of a plastic Tee and split the signal evenly. One side of the Tee goes into and out of an adjustable regulator valve into the top of the wastegate. The other side of the Tee goes into the side of the wastegate. Essentially you have a closed loop system. With a standard regulator valve, when it is completely closed and no air can get past it, the boost is controlled by the spring rate and or the adjustment screw. When you start to crack open the regulator valve, you are putting more pressure on top of the wastegate, this increases the spring rate on the valve which takes more exhaust pressure in order to open the valve. IE more boost is made.
With the RJC in place of a standard regulator valve, you will see more pressure on top of the wastegate, which means the boost level will be higher than the spring rate.
Here is a picture showing how I would plumb an external wastegate with a standard regulator valve.

The problem with running a standard regulator valve on an internally wastegated style actuator is that when you crack open the valve, a lot of air is put to the actuator all of a sudden. This can cause a boost spike because you really can't regulate the air in small increments like you can with the check ball style regulators such as the RJC. The other problem is that the actuator does not have a second signal port. At one time you could purchase a dual port internal style wastegate actuator and make it work. But those style actuators are very hard to find today. By plumging it up with a standard regulator valve, you would have good boost control. Effectively making it a closed loop setup. Spikes can also be caused by the wastegate hole being too small and needing to be ported just smaller than the actual puck size. When you go to the external dp setup, I would recommend you port the wastegate hole to the same ID of the wastegate tubing, making sure that you get the alignment right before you port it.

I have been very happy with my RJC controller on my current turbo. It has been very easy for me to be able to run steady boost levels from as low as 16psi, all the way up to 29psi. I still have more turns on the actuator and could probably see as high as 32psi, but what's the point, the turbo is done at 29. I would really like to hear some results about people putting the RJC controller inside the car and posting if their spool up times were drastically changed or if it were the same. I think I might just do it myself and see what the results are.
Hope some of this helps.

Patrick

 

[DR BOOST]

patrick...i think the diagram for the rjc controller may be wrong. according to that, the gate would open at spring pressure and close when the rjc controller opens????

 

[GNguy]

the top port on the WG should be left alone, only the bottom one should be used. Leave the spring inside the gate alone , thats why u have the RJC BC, control the boost from there, I have the 9lb. spring and I can hit 25psi+ with the RJC BC.

 

[SVORay]

Cool


I'll check out that ID of the waste gate hole & DP waste gate tube. As for the in car RJC controller, that would be cool for sure if it works. You could do all your tuning inside the car like an electric boost controler but minus 450.00 bux :biggrin: