Cra$h

Hi all,

I finally got around to tackling my wastegate project and modified my factory WG as Sid (Blown 944) described a couple years ago. I then followed the diagram for the Lindsey dual port (http://www.lindseyracing.com/pics/MBCDUALPORTLLL.jpg), as I assume it should behave the same way given that it's based off the factory WG. The only thing I did differently was just add a line from the top port of the WG directly to the intake instead of T'ing the line from the intercooler pipe, as I have a 5 port vacuum manifold from Laust and had a spare port just capped off.

Additionally I also have a Greddy Profec B boost controller as opposed to an MBC.

So, when hooked up as described, I'm only getting 5psi (WG spring pressure) no matter what setting the EBC is set at. I tried reversing the hoses, and it doesn't seem to be regulated at all, boosting too much.

I'm sure I've overlooked something really dumb, but I'm not seeing it.

Thoughts?

TIA!

951Saga

Where is the boost signal line from the intercooler pipe going?
Changing what you did differently from Sid (Blown 944) may correct your issue.

blown 944

Did you seal up the holes and bottom of the bottom side? If not, it won't hold pressure. The lower side has to be completely sealed. Did you pressure test it?

Tom M'Guinn

Is this the original profec b? If so how did you set the dip switches? Might want to revert to the manual boost controller until you are sure about the wastegate, then work on he controller. None of the dip switch settings in the manual worked for me...but was able to find a setting that worked.

CurtP

I ran the Lindsey Clubgate as a dual port for a couple of years. I had a constant vacuum leak from the secondary side where it leaked past the valve stem. It eventually fouled the EBC's vacuum servo with carbon and I was constantly over-boosting. I replaced the vacuum servo and switched back to single port. I suspect that it will be the same issue trying to run the factory waste gate as a dual port.

Only way I'd run dual port again is to buy a waste gate made specifically for dual port.

Cra$h

One additional bit of info. The system was all working fine before the mod including the EBC connected in stock single port mode.

The boost signal is straight from the vacuum manifold on the intake manifold, instead of using a T from the IC pipe. The line from the IC pipe goes to the in side of the EBC solenoid. The only functional difference from the LR diagram is that one line is pre IC and one is post. If that alone would make the difference, I'll go put a T in so it's identical to the diagram.

Yes, and yes. Both sides were holding pressure. Used two copper washers to seal between the diaphragm housing and the base.

Yes, original version. Dip switches are off on on off (up down down up) set for external wastegate, but not the overboost setting.



On the positive side, it does seem like the dual port mod really did improve spool up, just not sure what else I may have missed.


Thanks for all the suggestions!

toddk911

I have yet to hear or see any benefits to running dual port.

If you search on dual port 90 percent of the posts are all about problems. Just run in single port and eliminate that variable.

blade7

What's your opinion of a shimmed standard wastegate compared to a Tial ?.

Willard Bridgham 3

Sorry to hear about dual port problems, mine has been running fine for a couple of years.

lart951

Don't waste your time with shimmed wastegates, tial wins hands down, there is no comparison.

blade7

I guess you're right, it's just my standard wastegate and MBC has no problem holding reasonable boost so I'm a bit wary spending the $500 or so it would cost to get one shipped to me. I expect the Tial brings the boost on a bit sooner and holds it a bit longer ?.

lart951

Do a search under my name I have comparison, between a shimmed wategate and a tial about 6 or 7 years ago with dyno sheets.

blade7

Will do .

lee101315

Aside from shimming a factory wastegate, I dont have any experience modifying wastegates.

I did eventually run a tial dual port, and I did have problems at the beginning. Mostly from not understanding how to use it, and also not using a true MBC ( you'll need an air regulator, not a ball and spring )

Stock wastegate:
Less boost in control hose, more boost in manifold

Dual port:
Less boost in control hose, less boost in manifold

Running a ball and spring type of MBC allows air to squeak through, which raises boost uncontrollably. I had problems running a dual port until I used a true MBC.

Spool up was much quicker compared to stock, but I never ran the dual port in single line mode.

toddk911

Shimming a stock wastegate only helps a little so the Tial or a rebuilt-modified stock unit is much better than just shimming.