I've recently aquired a '90 AWD Turbo DSM as a daily driver. Yeah I know it's a DSM but I had the boost bug when I was shopping for a replacement for my 91 CRX Si. Anyways, I've been trolling DSMtalk.com researching info on DSM's, mods, and other stuff...Amoung my browsing I found a few places that depict DIY EBC's. Now it's not a "real" EBC, more like electrically controlled MBC's. I found the pictures/specs on http://www.taboospeedshop.com so all credit goes to them. Anyways, here are 2 different setups enjoy.

-- This is the basic Cheap-man Profec design. The boost signal goes straight to the WGA through the MBC with both solenoids closed (Low boost) or is bled off through only one (Mid boost) or both (High boost) solenoids to the atmosphere. The Mid and High boost levels can be fine tuned by restricting the outlets of the solenoids by bleeders with different-sized holes or adjustable needle valves.



--A 3-way valve is being used to switch between two MBCs set at different boost levels (Low and High). A similar 3-stage unit can be easily built with 4-way valve and 3 MBCs or bleed solenoid incorporated to the WGA line.



[Modified by Speed PHreak, 2:30 PM 2/3/2003]


[Modified by Speed PHreak, 2:30 PM 2/3/2003]

 

nice, finnaly not having to stop, open the hood and raise it right chris ?

also, I know some ppl who haas run the MBC to the interior, making it possible to adjust boost level from the comfort of your driver seat hehehe

stan

 

There are also map switch controlled solenoids. The adjustable hobbs map switch is popular. It's what quite a few of the diy alky kits use to trigger the jetting.

 

now where can we find these solenoids?

 

hey stan If I remember wouldn't running the line into the cabin effect either the accuracy or performance of the MBC since it has to travel that far before it regulates boost. In other words closer is better.

 

^bump for the day people.

The 3-way ARO version of the valve needed for 2nd setup, can be found here

 

Now, can you make the setup use just one MBC, and the other just go straight to the WG?

All I am looking for is a low boost (WG spring) and a high boost (MBC).l

Thanks

EDIT: Looking closer at the pic's you provided, it looks like you could just remove one of the MBC's and run just a peice of vaccume tubing.

Sweet!


[Modified by Bryson, 5:54 PM 1/20/2003]

 

nothing wrong with dsm's!
did you mod your intake? take the nipple out of the..i forget what its called..the little sensor thing ontop of the intake.

 

why not just run the vacuum line into your interior and mount a ****

cool. i gotta re read this topic cause it made no sense..

why am i posting :D

 

That's exactly what i'm planning on doing. A high boost(14~15psi)on the MBC, and my 8psi wastegate spring as the low boost option

 

The 4-way ARO version of the valve needed for 2nd setup, can be found here. This will give you the option of running 3 possible boost settings, low, med, high. All at the flip of a switch.


[Modified by Speed PHreak, 1:55 AM 1/21/2003]

 

Thread hijackage underway!



You see the Saab APC prewired to plug into generic power/rpm/sensor feeds I have installed in my existing wiring harness. Expect to pay $50-75 from a private party, $75-125 from a yard.

WTF? It has a knock sensor? It doesn't need to be attached to a Saab? What exactly does it do?

Here.

Here.

And Here.

Hint: they say not to adjust the knock sensor sensitivity, but if you run your car around NA for a while with the APC wired as a knock detector (grounds pin 19 under knock) you can adjust sensitivity - finding a setting where it doesn't go off due to high rpms but does go off due to spark knock (pinging) isn't too hard.

Speed PHreak can tell you I have some very strange notions on how to modify a car. The above might just be some interesting at work reading for some of you and nothing more... installing and trusting your car's engine to some ~15 year old equipment (that's a reflection on it's expected longevity, not it's concept/application) is not something a lot of people would care to do.

 

thats pretty neat but bleeding boost off the actuator signal line is nothing like what a profec does.

that saab thing looks cool though!

 

Wow J. Davis......thats a neat little POS. How hard was it to install? And yes you do have some wierd ideas. Might have to go junkyard hoping later this week. I dunno.....it's another damn thing to have to tune.

Oh yeah thanx for highjacking my thread


[Modified by Speed PHreak, 11:03 AM 1/22/2003]

 

where do you get the solenoids for the first setup?
sounds like the turboxs dual stage mbc

 

I did something close to that....just used one line with no mbc so it was stock boost....other line for mbc...daily driven talon....didnt put it on yet though.

 

You can prolly get the from grainger.com Just did around a little. Honeslty If you want 3 levels of boost I'd go with THIS 4-way valve, 2 MBC's, and a 3 way switch. That will give something that looks like this....




[Modified by Speed PHreak, 12:06 PM 1/22/2003]

 

Holy ****, i guess i'm not the only one who knows about the saab apc
I still have one in my engine bay, but i was having problems with the thing detecting knock when there wasnt any. after troubleshooting, i came to the conclusion it must be the actual box, but never got a chance to switch it. I'm gonna have pics posted up one of these days once i do.

 

so technically, you could get the 3 way valve and 1 mbc.
you could still switch between 2 boost levels like the turboxs dual stage mbc.
assuming this is possible, would u use the 3 way valve connecting one side to the mbc for high boost, and the other side to the wastegate for low boost settings?
that way you could just run your high boost controlled by the mbc, and the low boost controlled by the wastegate spring.

 

can u get that 3 way valve from somewhere local?
grainger says they don't sell to consumers
only to businesses?
anyway around this?


[Modified by TurbothisLS, 11:16 AM 1/22/2003]

 

*edited* looking for more sites that sell these valves



[Modified by Speed PHreak, 12:26 PM 1/22/2003]

 

hey, on the website you can look for local branch stores.
call them up and maybe they can hook u up if you don't have a business account.
they are not supposed to, but i called the guy in austin and he said he could sell it to me over the counter.
1 left, going to pick it up today

 

It's not hard to install - power, ground, and tach feed, then run the knock sensor, solenoid, and transducer that you took off the Saab. The only hard part is if you have to remove the APC from the Saab itself - the knock sensor line CANNOT be cut and you have to thread it back thru the firewall which is a real PITA.

Using one of the two step systems like Speed PHreak's talking about isn't a bad idea... I usually have my APC switched off and just run on the stock Saab 5.5 psi wastegate - I see 4 psi due to altitude. Traction is a bitch at higher boost. I can see myself going with a two-step boost system on top of the APC - driveability setting, fun setting, and the APC for when I'm worried about popping the stock engine.


In re to the other APC guy's knock problem, have you adjusted the K potentiometer much? It's pretty arduous getting it tuned in right 1/16th of a turn at a time. If that doesn't do anything for you, then suspecting a bad APC is the correct assumption in my book.

 

picked up the 3 way valve from grainger today
they gave me a discount because i'm in college
what a deal!
i'm going to pick up the 1/8" fittings today and the switch

on the pneumatic valve itself, there are 3 ports. 1 in, 1 out, 1 exhaust. which vacuum lines go to what?

 

TurbothisLS this http://www.machinedesign2.com/specthis/clippard/d1.html might help.