NEcivic

Looking for suggestions on troubleshooting why i keep overboosting when I connect my profec b (spec1) up to my car. Tried connecting for both external and internal w/g setups.

My setup: On the current engine: t3/t04e, drag gen 3 mani, ebay tial knockoff wastegate, 2.5 dp. I've ran w/out a boost controller for approximately 3 months with this turbo at a very reliable 9psi. I ran same setup except smaller b turbo for 6months prior using a a turboxs mbc upped to a steady 11psi.

So obviously the egay wastegate has been able to do its job so far. But when i hook the greddy solenoid box into the vacuum lines, boost just keeps climbing past 9psi even when the control unit is turned off. Tried hooking it up per greddy's website instructions for external usage ("out" to top, "in" from vacuum source, side from vacuum source), set dipswitches 2 different times for external w/ overboosting problems and once for regular external, no luck w/ unit turned on or off. Tried their directions for internal usage ("in" from vacuum, "out" to side of wg, top of wg open) and dipswitches for internal w/ overboosting problems, no dice.

Now are the solenoids supposed to remain open until they get current or is it the other way around. Because if they remain open then i should at least be able to hook just the solenoid box up inline on my wastegate signal and not see any manipulation of the wg signal, right? It is obvious they are in an open position right now because i can blow on one port of the box and air will come out of the other side w/ minimal resistance.

Unplug the box and connect vacuum lines like normal and I go right back to a steady 9psi. Anyone have any suggestion or something i haven't though of?

NEcivic

anyone?

Darksyne

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NEcivic &raquo;</TD></TR><TR><TD CLASS="quote">Tried hooking it up per greddy's website instructions...</TD></TR></TABLE>

I thought the instructions on the website were for the new Spec II?

Here's the manual for the original Profec B:
http://www.mkiv.com/techarticl....html

I've never had a problem with mine, didn't even have to touch the Balance ****, just left it straight up.

So it should be:

Compressor outlet -&gt; IN Solenoid
Wastegate -&gt; OUT Solenoid
Pressure reference -&gt; Back of control box.

NEcivic

Yep, that's exactly as its hooked up.

Darksyne

So even with being able to blow through the solenoid, if you put it inline from the compressor outlet to the wastegate it still overboosts?

I don't see how that is possible unless there is a crack in one of your vaccum lines that gets worse when put on the solenoid, or the solenoid isn't sealed.

Maybe try plugging the OUT on the solenoid with a vaccum cap and hook a short length of hose to the IN. Put a few pounds of pressure in the solenoid box and check for leaks.

Logically, if you can hold 9 psi fine with just a vaccum line running from a pressure source to the wastegate, then putting an open solenoid inline shouldn't do anything unless it introduces a boost leak.

ITRpwrdEG

You are probably overboosting since you bought that really expensive Spoon Knockoff SS Autorchrome JDM style Spoon style N1 style Tial wastegate. Some things you can skimp out on if you want, but not when turboing your motor. Your wastegate may not be the problem, but that's my first guess. I wouldn't have to question a Tial if I had one, though I have seen some go bad after a while.

NEcivic

Yes, before with the unit turned off, and the controller inline I was overboosting. In the external gated case, I figure that if the solenoids are staying open (no power to unit) then basically the top of the wastegate is going to see whatever pressure the manifold sees... so theoretically it'll basically continue building until the double the spring rate limit.

And yes I realize that the wastegate is not an official tial and did cost less money. But I bought it because I wanted actually try it for myself and not be like so many other people who will automatically discredit stuff because it costs sligtly less or doesn't have "the name", even though they don't have personal experience with the part. Some stuff out there is crap, but some can serve their purpose. Heck my buddy had problems this spring overboosting and spiking with his .48 exhaust super60 and a real tial... Had to tweak the wg before it would hold. So problems can occur with any part. Not saying the ebay special best wastegate ever, but up until the profec-b experience, it has done just what a wastegate is designed to do... bleed off exhaust pressure to regulate a constant turbo pressure. It's been just as reliable as any of the last 3 setups i've had over the years.

So anywho, after finally getting a chance to play around with it again last night I was able to get it to hold about 12 PSI at full throttle from a 4th gear pull. That was with it hooked up for internal gate, dipswitches on internal overboost, and full sharp. Haven't tried backing off on the full shart yet or tried it with a quick 1st or 2nd gear pull to know if it'll spike. My urbo has no fitting for signal, so I think i'm gonna just weld one onto the first charge pipe to see if I can't drop a couple pounds for low boost setting. I'll just stick with this if it works.