Always something

[Shimy87]

This dam car leads a pampered life and still punishes me constantly. Nice day so I descide to take it to work and set my new RJC boost controller on the way. let things warm up and make first pull, only 15 LBS so I pop hood to make adjustment.... ...coolant sprayed around and pooled in intake valley     cant see obvious leak so continue on. Get to office and look further, after much wiggling stuff and burning of fingers I find the rubber cap I put on the steel nipple that used to feed the throttle body has a split on the under side.
 
I think I'll get a short piece of hose and just run it between the 2 outlets, afraid the rubber caps will continue to fail.
 
Side note, have RJC controller almost maxed out ( have about a turn and a half left) to get to 23 LBS. Sound right? I read where guys run close to 30 lbs. and I would run out of adjustment way before that?

[motorhead]

Depending on the turbo 23psi may be plenty.  Don't get hung up on the boost number, as boost is really just a function of a restriction - not performance.

[Steve Wood]

Are you running a hd actuator?

[Shimy87]

Are you running a hd actuator?

standard actuator

[Steve Wood]

That is the reason why...the standard has a 12 psi spring whereas the hd has an 18 psi spring...

try shimming the spring a little

[Shimy87]

confused..... are you talking about shimming the spring in the boost controller or adjusting the arm on the actuator a bit tighter?

[Steve Wood]

I was speaking on increasing the tension in the controller...y ou can try tightening the wastegate arm as well but watch out for boost creep if you shorten it too much

[Shimy87]

Just came in from a test spin, 21 LBS with controller maxed out. Stupid question time. I think the controller just has a spring with a ball in one end inside. How do I shim the spring?

[Steve Wood]

Maybe, if I try to explain how it works, it will help.

The manual controller is nothing but a a check valve and a spring.  Boost from the compressor port pushes against the check ball which is held in place by the spring tension.  Because the check ball  is closing off the boost until the boost is high enough to overcome the spring tension, no boost is getting to the wastegate actuator.

The more tension you put on the spring against the ball, the more boost it takes to lift the ball off its seat so boost can go onward to the actuator.  This tends to make the boost control somewhat binary by design and by purpose.  Maximum boost is thereby dependent upon this spring tension  if we ignore the actuator.

If we look at the wastegate itself, it comes with about a 12 psi spring that operates against a diaphragm.  When we adjust the arm length on the adjustment rod to about 1/8" inch of tension to get it on the wastegate puck arm.  this gives us about 12 psi of boost.  If we shorten the rod, it creates more tension on the diaphragm and it takes more boost to push the rod out to open the wastegate puck.  The problem is that when we get the rod as short as possible to increase the boost while still being able to connect it to the wastegate puck arm, there is not much movement possible in the arm and the puck cannot open as far as possible.  The opening may not be large enuf to control a larger turbo and the boost creeps upward as the flow is not being bypassed.   Seems like this was around 20-22 psi as I recall.

Now, if the maximum boost that the manual controller can withstand before opening is about 22-23 psi, then it pops open and immediately overwhelms the actuator which also opens.  We get fast spool up because the wastegate actuator is not seeing any boost, but, we don't get much more boost.

So, if we increase the tension inside the manual controller so we can get say 25 psi before it pops open then we should see 25 even if the stock actuator cannot hold that...but, it may be erratic in nature because the manual controller was not made to be a primary control

If we increase the tension on the factory actuator too much, we may not have good boost control because the flow volume is more than the puck can control because it is not opening.

The best solution is to use a hd actuator that has the 18 psi spring so that we can get close to 30 psi before it limits the flow.

Or, a more expensive and more elegant solution, which can also be more problematic,  is to throw it all away and install and external wastegate that bypasses the factory arrangement and which in theory, anyway, should be better.

I will leave this to someone more experienced than me since the last time I used something like that was two Deltagates on the cross over pipe and that was a long time ago

[Steve Wood]

Just came in from a test spin, 21 LBS with controller maxed out. Stupid question time. I think the controller just has a spring with a ball in one end inside. How do I shim the spring?

This is what you are dealing with  http://www.gusmahon.org/html/boostcontrol.htm

take it apart and put a washer on the end of the spring to increase the tension when assembled. Remember that boost has to flow thru it so make sure the shim has a hole in the middle (washer)

[Shimy87]

Thanks Steve, made a shim out of a thick paperclip, will report back. Also, I dont notice any difference in spool up or boost delivery with this installed. I expected a noticable change after reading the "sales pitch" but not seeing it    Anyway I'll be happy if I can just get it to stick 23-24 LBS and hold it 

[Steve Wood]

you could probably see it better on PL and particularly from a standing start.

If you have boost set at 20 with the factory system, the wastegate may start moving at 14 or so and be fully open at 20.  Therefore the leakage would slow it down a bit.

If you are going from a roll, I don't think you will see a difference.

If you are using the factory wastegate solenoid, it is an electronic bleeder so it diverts boost from the wastegate by bleeding some portion the atmosphere which delays the wastegate opening.

You will see the biggest difference when the turbo has been set up "tuner" style with a hose straight from the actuator to the compressor port.

If you understand how stuff works, then you can read the "ads" better

[Shimy87]

Worked like a charm!!

[Steve Wood]

that was a cheap fix

[Shimy87]

Just saw what you posted. Yes, it does make quite a difference, from a stop now I cant just floor it or tires just blow away. Going to the track next weekend and launching is going to be a challenge.