Controlling Overboost on a AHU w/VNT-17/22

I'm installing a VNT17/22 on a AHU, that I was told should have a boostvalve.com to control spikes. If so, where do I locate it?
And can somebody explain boost spikes? I'm assuming it's the turbo getting out of control.
I'm swapping this 17/22 with a K14. The K14 is putting out to many EGT's.

The MAP sensor inside the AHU ECU can only measure up to 21psi (2.5bar absolute) I was told so I need to stay below that. From the pictures it looks like the boost valve can be adjusted to select a desired PSI.
I'm wondering if this TORBO BOOST TEE I have lying around will work.
It's the blue one.

Thanks
http://boostvalve.com/


http://www.turbosmartdirect.com/Product-Categories/Manual-Boost-Controllers/GBCV-Boost-Tee-Blue.html

I'd be upgrading that sensor on the ECU, isn't there a GM part that can be retrofitted?

As for boost spikes, it's not really the turbo getting out of control, more like overshooting the requested PSI then settling back down. Very common for VNT turbos and nothing to lose much sleep over as long as your tune is in check (ie not spiking 15psi above requested, etc)

Vac pump to n75, from n75 goes to turbo actuator.
Put a T from the n75 to turbo line.
Tap boost from intake manifold or intercooler pipes.
Take that boost, goes to boostvalve inlet.
The output goes to that T you put between turbo actuator and n75.

Remember that setting the boost valve to crack at 21 psi for example, will not give you 21 psi, but less. Why? Because vacuum is pulling on the other side of the boost valve. (example: vac one side is -2 psi... boost side 20 psi... differential is 20 - (-2)= 22 psi..opens valve , and you arent even at 21 psi boost for example.

So you have to tweak it after that for the response you want.
Higher gears, lower rpm will be different than higher rpm.

Best to upgrade the map, and have the ecu remapped with the right n75 values and PID controls. The boostvalve is not as good as a proper ecu setup.

Set up and tuned properly a 17/22 won't spike. I had a boostvalve in my wagon for the VNT-15 and when I switched to the 17/22 I removed it. Not necessary.

Thanks for he help. I have a Malone 2 with DLS1019 injectors. At the moment I'm running the K14 with this setup. I believe the guys at Malone are setting me up with the correct tune to keep the PSI below 21 with the 17/22.
I will see after testing if I need the boost valve.
robnitro I thought that the N18 was the correct valve to run the turbo.
Here is a schematic of how I was told to setup the vacuum to make this work. Does this look correct? Ignore the blue waste gate controller.
Thanks for the help.
Tony

http://tinypic.com/m/ibamow/1

http://www.boostvalve.com/vw.html

If you haven't gotten a proper VNT tune and using a VNT N75, you should start there.

Excellent display JFettig. This makes it easy to understand. I have more detailed info on the Malone tune. I was told that it's recommended that I use a boost valve to control the spikes because they can't quickly tweak this tune with something like a FlashZilla. I'm not sure what this means.

IndigoBlueWagon who did the tune for you? And what is the psi set to peak with your tune?
Thanks again for the effort.
Tony

What that means is that every time you need to make a change, new chips need to be made and mailed out with an older ECU. To tackle the issue best, you will need to get logs and very good descriptions of whats going on so the tune can be updated. A boost valve does help bandaid the issue and could cover it all together.

It looks like I need to get the N75 valve. I was told the N18 EGR frequency valve would work. Do you have the P/N for this N75? And where can I find one?
Thanks