bleeder valve and billet turbo

[bad V6]

I have a billet 6765 journal bearing w/.85 exhaust housing turbo and am getting an initial boost spike when going WOT. Boost is being controlled by a heavy duty actuator on a 3" Terry Houston DP (internal wastegate) and a RJC bleeder valve. The turbo's exhaust housing has been ported to 1.28", radiused and polished. Upon going WOT, the boost goes to 25# and settles back to 20# and holds steady at that pressure. When checking the pressures to open with the engine off and compressed air and a known good pressure gauge, the wastegate actuator opens at 22#, going through the RJC valve and the actuator begins opening at roughly 33#.

I am wanting to get a handle on what needs to be done before cranking it up to the mid-upper 20's. Should I leave the RJC valve in place and tighten the wastegate actuator rod? Remove the RJC and use only the wastegate actuator? Adjust the RJC to increase boost? Something else? Anyone have any insight on what to do would be greatly appreciated.

Pat

 

[3.8L V-8 eater]

Curious on this myself..Have to take mine out for test drive after porting the housing..I eliminated the manual boost controller for now..

 

[DoubleD]

I would imagine backing out the rod as much as you can and increasing boost pressure to your desired amount using the controller would be the most effective way of mitigating the spike.

to me that theoretically makes sense... I could probably explain my thoughts with a little more time.

 

[jasjamz]

i would imagine backing out the rod as much as you can and increasing boost pressure to your desired amount using the controller would be the most effective way of mitigating the spike.

To me that theoretically makes sense... I could probably explain my thoughts with a little more time.

x2!
I did the same thing with mine. I had the spikes when I had the wastegate rod tight.

 

[*BuickBoy*]

I have a T61 with internal wastegate, and I bought a 6765. Would you know if the stock blowoff valve and wastegate would work on the new 6765 from the 61?

 

[BEATAV8]

Do you still have the Y fitting with the orifice in it installed?

If the boost controller is in line by itself, it's probably dampening the signal pressure too much and making the actuator react too slowly. Restricting the signal to the controller with the orifice would quicken the wastegate response.

 

[jasjamz]

I have a T61 with internal wastegate, and I bought a 6765. Would you know if the stock blowoff valve and wastegate would work on the new 6765 from the 61?

Start a new thread to get an answer. Also the vendor you purchased the unit from should be able to tell you that. You need to supply all the information about the 6765. Compressor cover style?

 

[bison]

going through the RJC valve and the actuator begins opening at roughly 33#.

Knowing this you should realize that this is a major problem. If the actuator doesnt move until 33psi then its not going to move till it has 33psi at the compressor cover. There fore the only thing you have opening the actuator is the back pressure from the exhaust. You will not be able to get a handle on the boost with your configuration with the HD actuator and valve letting pressure past it until 33psi. If you want to run under 25psi you need a standard actuator and no restriction between the compressor and actuator. You are already way to big for an external style actuator on the wastegate hole. The first thing id do is disconnect the actuator and do a 3rd gear pull and rev the engine as high as you ever would. However much boost it makes under this condition is the least it can make. From there any spring pressure you add to the actuator/swing valve will increase the boost. You shouldnt need anything in between the compressor cover and the actuator. Just run a line directly to the actuator or run the RJC valve on a very loose setting and use the actuator rod tension to dial in the initial hit. Chances are when you want to run 25+psi/700+hp you will need to get a plate to resize the oversize wastegae hole or you will have boost drop off from the extra surface area the backpressure is pushing against. Tightening the rod will aggravate a boost spike situation if its spiking.

 

[JP112_89]

Yes, get the standard actuator instead of your hd actuator. Do not use the "Y" fitting either like noted.

 

[3.8L V-8 eater]

My boost seems to have stabilized going tuner style...I have the rod on where it barely needs pulled onto the puck..I had an old style manual controller with only one port which required me to use the stock orifice...I do have HD actuator...

 

[bad V6]

Knowing this you should realize that this is a major problem. If the actuator doesnt move until 33psi then its not going to move till it has 33psi at the compressor cover. There fore the only thing you have opening the actuator is the back pressure from the exhaust. You will not be able to get a handle on the boost with your configuration with the HD actuator and valve letting pressure past it until 33psi. If you want to run under 25psi you need a standard actuator and no restriction between the compressor and actuator. You are already way to big for an external style actuator on the wastegate hole. The first thing id do is disconnect the actuator and do a 3rd gear pull and rev the engine as high as you ever would. However much boost it makes under this condition is the least it can make. From there any spring pressure you add to the actuator/swing valve will increase the boost. You shouldnt need anything in between the compressor cover and the actuator. Just run a line directly to the actuator or run the RJC valve on a very loose setting and use the actuator rod tension to dial in the initial hit. Chances are when you want to run 25+psi/700+hp you will need to get a plate to resize the oversize wastegae hole or you will have boost drop off from the extra surface area the backpressure is pushing against. Tightening the rod will aggravate a boost spike situation if its spiking.

I am looking to run somewhere around 28# when dialed in. I just want to be cautious about getting there, we've made a lot of changes to the car since last year. With the RJC valve out of the picture and the actuator with very little tension the car makes a solid 16#. Approximately what size should the wastegate hole have been ported to for this turbo? I still have about an 1/8" or so of the puck contacting the housing.

 

[bad V6]

My boost seems to have stabilized going tuner style...I have the rod on where it barely needs pulled onto the puck..I had an old style manual controller with only one port which required me to use the stock orifice...I do have HD actuator...

What boost # are you running the combo at?

 

[bison]

I am looking to run somewhere around 28# when dialed in. I just want to be cautious about getting there, we've made a lot of changes to the car since last year. With the RJC valve out of the picture and the actuator with very little tension the car makes a solid 16#. Approximately what size should the wastegate hole have been ported to for this turbo? I still have about an 1/8" or so of the puck contacting the housing.

The more horsepower you want to run the smaller the hole needs to be to prevent boost drop off when you are trying to maintain boost across the entire usable rpm range