TTschwing

This was kind of an interesting experiment. Most of you know the N75 controls the boost released to the wastegate which either opens it (high boost release) or allows it to stay closed (little boost released) depending on the duty cycle sent from the ECU. The N75 Race valve just plumbs a different restrictor into the unit therefore allowing less boost to the wastegate hence tailoring the boost curve a bit. The duty cycle is not changed. You can do the exact same thing with a $25 manually adjustable pressure valve. I plumbed this in line ahead of the N75. Just remove the lower hose from the N75, connect to the inlet of the pressure valve, then connect the exit from the valve back to the N75 port you just vacated. Boost line from turbo outlet pipe>>> Pressure valve>>> N75>>>> wastegate. I tried this with the ECS valve and it works, it should work better with the stock valve and let you turn it into a "race valve" for just a few bucks as well as retain control of the boost levels as you choose.. First the schematic:

<img src="http://images.fotki.com/v9/photos/7/7305/149094/turbo_schematic-vi.jpg">

This is a 0-30 PSI regulator. Open it wide open (passing up to 30 psi boost) and the N75 controls the boost exclusively just like stock. As you close it (passing less boost) the wastegate stays shut more and the boost curve is changed. This emulates what the ECS N75 does only is continuously adjustable in case you're scared of BOOST! There are a couple of other variations on this theme including using a relief valve in line (like a Dawes device) that will allow you to completely taylor boost onset and boost curve manually. It's not a true manual boost controller because the ECU based N75 duty cycle change is still in operation. Anyway, just playing around...More info as I play more...

Here's the valve from Dwyer Instruments:

<img src="http://images.fotki.com/v11/photos/7/7305/149094/DSCF0167-vi.jpg">

As always, Don't try this on your own car without understanding the principles involved! Boost and AF gauges are almost necessary to make sure things are OK when you start doing stuff like this....

Steve

AkRascal

Do you ever sleep?

TTschwing

With the car apart for 2 weeks. This is just a flurry of completion activity. I need a life!

So many ideas, so little time....:-)

MOBlueTT

LOL &gt;&gt; Many of us Count on Steve not Sleeping!

TTschwing

Zzzzzzttt.....Wha??

Mike A3T Greece

I have an A3 1.8T 180hp (TT engine). If i plug in boost valve and adjust to 1,1 bar (instead of 0,6 which now) what are the consequnces i may have except more horse power? What about fuel? The car want need more fuel?

TheFriTTz

Impressive