Over boost even with MBC all the way out.
 

I have a hallman boost controller, just the es basic one. Also running one of those ebay mbc valves. It seems that even with my valves loosened all the way out to 2-3 threads im still seeing 13 psi.

Mods are: hi flow cat, modified stock intake, and exhaust.

What else could be the problem.

put your stock main cat back on and see if that fixes the problem. You might have to get your wastegate ported.

Also, make sure you connected your boost controller to the wastegate and not to the turbo precontrol.

And if you continue to have issues, you can always remove the pill from the vac line that goes to the waste gate which should put your boost at 7PSI.

What were your boost levels before the boost controller install? Since even the stock boost control should keep you close to 10 psi with such a lightly modded car, I think I'd look to a problem with the stock components of the control system first.

Disclaimer: I don't know what I'm talking about.

Are you sure that turning the valve out is supposed to decrease boost? I thought those ebay manual boost controllers were bleed off valves aka. the more you turn the valve out the more pressure in the line is vented to atmosphere and less pressure is seen by the wastegate. This would cause high boost.

Try turning the valve all the way in to see what happens. Since you already claim overboost, it couldnt hurt. Or you could post pictures of your setup so we could see how it's connected.

The ebay boost controller (secondaries) is ball and spring type.
shown here:
http://murdaville.com/nxs/Images/nxsmbc.jpg

and here is how I set up my boost controller. (taken from damians thread)
The black parts are where I installed 6mm caps and the orange and green lines are not connected to anything.

http://farm4.static.flickr.com/3286/...534b5d08_m.jpg

here is his original diagram:
https://www.rx7club.com/3rd-gen-archives-73/my-boost-control-setup-perfect-10-8-10-pattern-178136/


as you can see I capped the wastegate actuators' shut and the line that follows that.

Cap off the other nipples on the actuators. If you let it pass through the actuator like Damian's diagram it may not work.

Dave

Dave, are you saying I should cap off the nipples on the opposite side of the boost controllers? (on the wastegates)

If it was unclear that is done and can be seen by the tiny black dots opposite of BC nipples.

The only places I left uncapped are the "spider" lines. but they aren't connected to anything either way.

PINK = it was left open
BLACK = it was plugged



http://farm3.static.flickr.com/2111/...fdf3b80e_o.jpg

OK, yes. One wastegate nipple you have the boost controller going to the compressor tee. The other wastegate nipple is capped. Ditto for the precontrol.

If the boost controller is wide open you should get 7psi. Can you blow air thru the controller?

Dave

Loosened the pre spool MBC further and the damn thing blew off ( screw on cap). Crap loads of smoke and the idle has turned funny. Maybe I blew a rotor.

Anyway are the 2 stock wastegate pills the same size? Lookin to see what i get with one pill on the sec.

So is my diagram and setup correct?

Which turbos do you have?

stock.

Pills? No pills.

Don't mean to sound insulting, (and only asking this as I've done it before!) but double check the vcalves are definitely the right way round :)

What year? The reason I ask is that some of the 94 & 95 FD's turbos have restrictors built into the nipples (no pills). If you have those, you will not be able to create a larger opening in the line, and won't be able to decrease boost with a controller. The nipples will have to be drilled out.

I really only think 99 and up have restrictors built in them. Either way the turbos are a replacement off of a 94 I think.


Valves can only go in one way; they're threaded.


No pills. I thought that everyone who runs MBC does the same setup im running..

He means the boost controllers have a direction. If they're backwards you'll overboost.

There are definitely pre-99 turbos that have built-in restrictors. I think you need to check for this next.

Dave

Thats the next thing I'll check for. BTW the front rotor is at 60 80 89 due to this incident.

(without holding down the throttle)