Finally had injectors balanced... :) also installing a boost gauge - Page 3 - PeachParts Mercedes-Benz Forum

scottmcphee · #31 01-22-2011, 10:26 PM

Here's a link to the actual gauge I bought, with the built in alarm that you can set to any pressure. You can also set the gauge for PSI or bar. I prefer bar.

http://www.auberins.com/index.php?main_page=product_info&cPath=5&products_id=19

I also bought the MAP sensor from the same outfit:
http://www.auberins.com/index.php?main_page=product_info&cPath=5&products_id=122

Notice, this is a MAP sensor (manifold absolute pressure), and not a gauge-style sensor (relative to atmospheric). So instead of reading "zero" at the altitude where I live (about 2000 feet) the gauge often reads about -0.1 bar with the car not running. ...tells the story of why turbos are so useful in airplanes at sky high altitudes where the air thins out, and pressure drops. When I achieve 1 bar on the gauge, I know the turbo actually providing 1.1 bar net boost. BTW, 1 bar is more boost than the car can use, there's not enough fuel coming out of the stock IP to make it matter. It is actually silly to boost more than the 11 or 12 psi as the wastegate is set from the factory.

I screwed a hose barb nipple as a take-off for this sensor into the manifold hole where the overboost switch used to be. From there, a hose to the sensor. FYI, I removed all the overboost protection plumbing and bits from the car. I believe the spec for that switch was to pop at 1.1 to 1.2 bar, for an overboost condition.

bdtsr · #32 01-22-2011, 11:09 PM

About two weeks ago I picked up another engine and trans with about 170k on it. Since it was out of the car and easy to get to, I used my vac/pressure tester to test the waste gate opening pressure and it started at about 14-15 psi. The boost gauge I had used on the engine in my car indicated 14-15 psi steady boost. This is pedal to the floor running through the gears. At 65mph I was showing about 2-4 psi on various road levels. Stomping the pedal to the floor from a dead stop did show some vacuum until the turbo spooled up. While the manifold is wide open, you still have piping and a filter causing some restriction.

Doktor Bert · #33 01-23-2011, 12:45 AM

Quote:

Originally Posted by locry

clock removed

boost gauge innards

gauge mounted

still undecided if I should use the boost gauge face... (i need something to cover up the ugly drill job)

Once this is done it'll be great to see the RPMs and boost work in sync. IF i can get the tach to work that is...demmit

Wow...that is sharp...

How hard is that to do and where could I buy the parts!!!!!

locry · #34 01-23-2011, 08:38 AM

Parts over there i'm not sure of, I did get mine at a local auto parts supply depot...its a pretty common gauge I think. it's not hard at all. Some drilling involved...NO HACKING necessary after all. Mounting of the boost innards to your faceplate requires drilling, as with the metal backplate. Once your there it's pretty straight forward. Just know that it can be done with just minor drilling.

everything will depend on the size of the boost gauge innards.

locry · #35 01-23-2011, 08:46 AM

Installed!!!
Once i get white letter transfer material I'm definitely painting the boost face flat black...with white markings

gatorblue92 · #36 01-23-2011, 09:03 AM

That looks great.

winmutt · #37 01-23-2011, 09:10 AM

I've decided to use my Droid as a systems management interface. Even if you dont have one they are pretty cheap used. Within the next couple weeks I plan on having my arduino be able to measure and report intake boost pressure EGP, rpm and rack position. Perhaps also GPS location/GPS speed etc. The Droid allows for a touch screen interface to communicate with the Arduino as well as being able to set off audible alarms. I also hope that I can get it so that the Droid can play music through the USB to the Arduino and then out to the stereo. Kind of an all in one solution.

Right now its a pipe dream but I've got he skills to make it happen.

locry · #38 01-23-2011, 09:22 AM

what does the interface look like?

winmutt · #39 01-23-2011, 09:42 AM

Quote:

Originally Posted by locry

what does the interface look like?

Ill be happy to let you know when I get it done

jonbobshinigin · #40 01-23-2011, 10:35 AM

Ahhh, the power of open-source! What exactly is the board capable of? In reading, it did not give me direct answers to it's applications.

W124 E300D · #41 01-23-2011, 10:39 AM

Quote:

Originally Posted by winmutt

I've decided to use my Droid as a systems management interface.

Linux and an old merc, must be heaven...

Junkman · #42 01-23-2011, 12:18 PM

Quote:

Originally Posted by locry

Installed!!!
Once i get white letter transfer material I'm definitely painting the boost face flat black...with white markings

I remember people selling gauges faces on fleabay so whatever co;or you want may be available without painting.

bdtsr · #43 01-23-2011, 12:29 PM

Harbor Freight has a 2" vac/boost gauge for $22. Rather accurate with my tester. Yes eBay does have a user selling gauge faces but not with a boost section. Anyone who can do vinyl lettering should be able to make the faces. I already cleaned, sanded and painted one of my spares white so I can get the black nembers done.

winmutt · #44 01-23-2011, 04:32 PM

Quote:

Originally Posted by jonbobshinigin

Ahhh, the power of open-source! What exactly is the board capable of? In reading, it did not give me direct answers to it's applications.

Analog and digital ins and outs with a very easy to use programming language. No complicated programmer board or anything. Just plug the USB and away you go. My plan is to interface with the OEM boost sensor in the 90+ benz. I did pick up an atmospheric sensor today to see if it can do 1 bar. Picked up a map sensor as well. Oddly enough I could not find any MAP sensors on 300z's or volvos (common turbos on the yard). All the rx7s were missing engines. Anyways I am going to measure intake pressure and exhaust pressure, rpm, speed and rack position. Eventually I would like to use these to control a VNT controller.

If nothing else its a fun project.

scottmcphee · #45 01-23-2011, 06:55 PM

Quote:

Originally Posted by winmutt

Got pic? I am making my own system management box. Displaying mostly Intake Pressure/EGP.

Here's a picture of the ceiling mounted digital gauge. I shot upward from chest height to see the mount better, so it's not a true-on eye level shot. From driving position, all you see is the face / digits, just below the mini-me visor. In fact, if I don't want to see the digits, flipping the mini visor down the rest of the way hides it.

Nice thing about velcro is that it's repositionable, altho the industrial grade velcro I used has incredible holding power! You really have to tear it off to move it.. no way a bump in the car would ever shake it down.

I actually put the panel-mount style gauge (as you buy it) into a small Hammond box enclosure, which makes overall width noticeably a bit wider, but overall height barely any taller.

Notice the brown cable... I drilled a 1/4" hole on a forward facing edge of where the ceiling lamp module is mounted. to get into the ceiling.

Mind the mis-matchy-matchy visors... anybody got a couple decent palimino's??

I've put an in/out thermometer and garage door opener mounted on the mini-me visor. None of this obscures outward vision very much. It's a good place to stick things.

I already know what to put on the other side of the mirror on the ceiling: a matching style EGT gauge, from same vendor.

By the way, these gauges can be wired to auto-dim with headlights on, but I found the normal brightness, and being red, is fine at night and not distracting at all when using rear view mirror. But when the blue alarm LED comes on you notice it.

Only downside of this setup is that it looks like radar detector. Either cops or thieves might be interested in that. They're legal where I live. But .. ? do you want that trouble / hassle where you live if the rules are otherwise?