how to make stock wastegate adjustable

[fredmeister]

ANyone know how to make the stock wastegate adjustable for boost pressure.
I know that the central air tube from the wastegate housing goes to atmosphere. There should be a way of installing a pressure relief valve of some sort to this line to control the pressure to something below atmospheric.
This would have the effect of creating a smaller differential pressure inside the wastegate and thus alowing more engine boost before it opens.
I know the theary but need to know the hardware to make this work.
Anyone have tried this that could show the install to do this? I was hoping to do this with mechanical valves or something inexpensive. Do not want to start springing big bucks for electronic boost controllers and such.

Fred

[equality72521]

What about a manual boost controller then? They are much less expensive than an EBC.

[930gt-40r]

Fred its easy, Just put a knot in the line going to the bottom port, you didnt know?

Just kidding- I used to have a GFB (Go fast bits) mechanical boost controler and it worked great. I used a Tial 46 with a 12 lb spring. This controler used only the bottom port. I also have a Turbonetics manual in my garage that utalizes both the top and bottom ports.
But the first one I mentioned was a lot simpler and worked great.

[9dreizig]

My roller had one of those when I bought it.. Don't they call them "dial a grenades" for a reason ?

[dewolf]

Get a manual boost controller and leave the over boost switch connected. Mine has faultless for over a year.

[beepbeep]

It's easiest to leave the vent as it is and just reduce the pressure going to the bottom of the wastegate bell by ways of fitting controllable "vent" valve on a hose going to it.

It can be easy as simple plastic T-orifice or as complicated as electronically PWD-operated electro-magnetic valve.

Just remember one thing: You cannot reduce the boost below basic spring setting, you can only raise it. That's why I'm a strong opponent to practice of fitting harder wastegate springs.

[930gt-40r]

Originally Posted by 9dreizig

My roller had one of those when I bought it.. Don't they call them "dial a grenades" for a reason ?

If your talking about the turbonetics unit where you have to pull the knob up and turn to adjust; thats the exact same thing I was thinking. It felt like some kind of weapon of war that you set before tossing over enemy lines.

[NathanUK]

You guys mean "Dial a Death"

[930gt-40r]

or "Dial a Boom"

[9dreizig]

Oh by the way, I have one from the PO.. I'll be happy to sell it to you, make me an offer..
T

[fredmeister]

Interested.....this is exactly what I had in mind but did not know where to find one and who made them.
Can you send photos of what this looks like, both installed and not if you have them?
Does it mount in the engine compartment then and you just set it and leave it alone? The factory 935 used a dial that was adjustable in the cockpit.....but this may be too tempting.

thanks,
Fred

[9dreizig]

It was mounted next to the emergency brake. I'll try to take a pic today and post it.
T

[NathanUK]

I'm sure RUF did this as well and they were pressure regulators. They tee'd into the control line, the regulator went from the tee & then from the reg to the vent on the WG.

[9dreizig]

Here's a couple of pics,, Make me an offer , or guys let me know what it's worth I have no idea..

[spuggy]

Originally Posted by fredmeister

Interested.....this is exactly what I had in mind but did not know where to find one and who made them.
Can you send photos of what this looks like, both installed and not if you have them?
Does it mount in the engine compartment then and you just set it and leave it alone? The factory 935 used a dial that was adjustable in the cockpit.....but this may be too tempting.

thanks,
Fred

A search for "manual boost controller" on Ebay or Google will get 100's of hits for various types that mount in the engine bay, most of which are about $50-80 bucks, tops. Although there's cheaper too.

They're typically just a piece of billet or bar stock with a couple of pipe fittings, the total mechanism in the simpler types consisting of a ball bearing, a spring, an adjusting knob to tighten the spring and maybe a locking nut...

No way I'd put one in the cockpit myself, with a CIS car.

[fredmeister]

Thanks guys for the info.......how many of you have done this mod?
Any issues with it going out of adjustment......do not wanna hear about the blown engines from deliberatley dialing in 1.2bar boost.

[9dreizig]

Actually, that little red ring that you see under the adjustment ring goes down and locks the adjustment ring in place. You have to pull it up to make any adjustments, I can't imagine that it would ever come out of adjustment once it's been set, it's pretty rock solid.

[RarlyL8]

I'm getting ready to experiment with a boost signal controller like the one pictured above.
What I plan to do is put an adjustable unit in the cockpit and a non-adjustable unit in the engine bay. The non-adjustable unit will be plumbed in parallel with the adjustable unit and will be locked down at a pre-tested 1.0bar. That way the adjustable unit can never exceed 1.0bar.
The factory cutoff switch adds a double redundance of protection.

[78P930]

Can someone post a picture of the ones that Porsche supplied?
Pat

[RarlyL8]