Dial of Death Experts?

[Bucketlist]

This DOD reproduction has been on my car since purchase and even though it is plumbed to the wastgate I have considered it just for looks.
It gets lots of attention at car shows.
Are these usually an adjustable valve with a full range of use?
This seems to be just an on-off type valve.
Do they have a spring and/or diaphragm inside?

[reclino]

I have one, not hooked up yet, and may never be hooked up.
It's an industrial pressure regulator, so it's not on or off, it's adjustable. The problem is that CIS is not very adjustable.
For it to be less sketchy the car needs to be tuned for this adjusted to whatever your max boost is, if it's possible to get the CIS tuned. Then use the knob to adjust down to a lower boost. The problem is it's not likely the CIS tune will be correct at the lower boost if it was working at higher boost. If you have EFI it would be easier to tune, but then you could just get a more appropriate boost controller...
Sometimes the old ways are not better.

[Bucketlist]

Originally Posted by reclino

I have one, not hooked up yet, and may never be hooked up.
It's an industrial pressure regulator, so it's not on or off, it's adjustable. The problem is that CIS is not very adjustable.
For it to be less sketchy the car needs to be tuned for this adjusted to whatever your max boost is, if it's possible to get the CIS tuned. Then use the knob to adjust down to a lower boost. The problem is it's not likely the CIS tune will be correct at the lower boost if it was working at higher boost. If you have EFI it would be easier to tune, but then you could just get a more appropriate boost controller...
Sometimes the old ways are not better.

I agree this may not be the best boost controller for CIS and have always considered it more of a novelty for the car shows.
In some early testing the DOD seemed to go from totally closed to totally open in one turn which made me wonder how useful it would be since most air pressure regulators take several turns to adjust low to high.
If I were to take this apart what is inside and are there parts available?

[reclino]

Sent you a PM, regarding parts. If yours is the reproduction I would doubt that parts would help. All available parts are the same age. If you do open it up, please post some pictures of how it comes apart and what's inside. I believe the diaphragm is made of inconel, so should last forever. Maybe an O-ring or packing is damaged.....

Edit
If I were to use mine, I have a 931 wastegate spring to combine with it. This way lower boost could be 7-8? psi, and then adjust up from there. Maybe making small adjustments from the 930 spring as your lower limit makes it behave like an on off switch ...

[RarlyL8]

The 931 has 0.4bar (5.9psi) wastegate spring.
I really don't see the point of an adjustable boost knob unless it is used to overboost in racing applications where the engine just has to last to the finish line. For a street car just leave it at maximum safe boost and control anything less than that with your right foot. As previously stated, CIS is a mechanical system which functions best at static max boost pressure. Now I can see a use for a hidden on-off switch that pops the waste gate open at 0.1bar for when you have to leave your car at the shop for service.

[Bucketlist]

Originally Posted by reclino

Sent you a PM, regarding parts. If yours is the reproduction I would doubt that parts would help. All available parts are the same age. If you do open it up, please post some pictures of how it comes apart and what's inside. I believe the diaphragm is made of inconel, so should last forever. Maybe an O-ring or packing is damaged.....

Edit
If I were to use mine, I have a 931 wastegate spring to combine with it. This way lower boost could be 7-8? psi, and then adjust up from there. Maybe making small adjustments from the 930 spring as your lower limit makes it behave like an on off switch ...

I took it apart, pretty easy, no sealer or damaged packing to deal with. Everything looks good, no parts needed. Also hooked it up to the compressor and found regulating pressure to be pretty normal thru several turns of the knob.

Here are some pics:

[reclino]

Very nice. Good to know what's inside mine. In the second picture is that the diaphragm on the left? Is it non magnetic metal?

[Bucketlist]

Originally Posted by reclino

Very nice. Good to know what's inside mine. In the second picture is that the diaphragm on the left? Is it non magnetic metal?

It is the diaphragm made of a coated fiber material that feels similar to leather. The maker is Effbe and they have an assortment of diaphragms.
https://www.effbe-diaphragm.com/en/reciflex-%c2%ae-solutions