SLK 32 Boost Gauge
The following shows how to hook up a boost gauge in the SLK 32 AMG.
Parts and Tool List:
"Y" pipe MB part # A 112 090 00 31 - $41.00
Hose nipple 4D AN840 - $1.98 Click here for more info
Gasket sealer - $3.00 approx for tube
5/16" drill bit
3/8" 28 tpi tap - $17 (yeah I know)
Air compressor
Silver touch up paint
Dremel
Hole punch
HKS 46mm silver boost gauge kit - $123
HKS 46mm pod - $35
The only way to get a boost measurement is to tap into the intake system after the intercooler.
The solution is to tap the pipe that comes directly out of the intercooler.
This pipe is a "Y" pipe that can be removed from the engine.
The first step is to remove the airfilters and intake to the throttle body.
Remove the front cover of the engine. It has three point where it secures to the engine.
It will lift off. Be firm but careful.
Next remove the airfilter assembly. It lifts up like the front cover did. Disconnect the flexible pipe from the intakes
that are on either side of the radiator.
Disconnect the wire to electronic throttle. Then lift the retaining clip for the air filter assembly where it connects to the throttle.
There is a similar clip underneath.
Disconnet the PCV hose. Remove the air filter assembly.
Here the intake is removed so you can see the two retaining clips.
Once the air filter assembly is removed, the rear of the engine will look like the picture above.
The red arrow is where the vacuum line to the brake booster hooks to the engine. That line has been removed here.
The blue arrow is the "Y" pipe that will be modified. The green arrow point to the intake air temperature sensor (hard to see in this photo).
The "Y" pipe is outlined in blue. The arrow points to the intake air temperature sensor which is
under the fuel rail.
A closer view of the "Y" pipe.
Loosen the clamps that hold the black hoses.
Loosen the rear most clamp on the hose just off the intercooler.
A total of 5 clamps should be loose.
Slide the side hoses upward off of the "Y" pipe.
Disconnect the wire to the intake air temperature sensor.
Remove the "Y" pipe.
The blue arrow points to the intake air temperature sensor. Note that this is not the "Y" pipe from the car.
I purchased a new pipe "just in case".
The "Y" pipe removed from the car will not have the black couplings (hoses) attached.
A close up of the sensor. Remove it from the "Y" pipe.
"Y" pipe, aluminum fitting, tap.
Mark the pipe in preparation for drilling.
The aluminum fitting and the tap.
Drill and tap the hole.
Test fit the fitting.
Here the fitting is inserted in to the "Y" pipe. Gasket sealer is used to ensure and airtight seal.
You can see it in brown. The fitting is then cut to shorten it. The surface was then roughed.
The inside of the "Y" pipe. The fitting is flush with the surface so as not to disturb the airflow.
The above connection came with the boost gauge. The custom fitting would normally negate the need
for this fitting but the line must have the brass restrictor for proper gauge operation.
As a result, I cut the "T" fitting as shown.
Here the plastic piece with the brass restrictor is being inserted.
Note that the base of the aluminum fitting is now painted.
Fully inserted.
The boost gauge hose is then installed and a wire strap is tightened around the hose.
Before installing the pipe on the car, blow off and clean any foreign particles to be sure
nothing will get inside the engine.
The "Y" pipe is then installed back on the engine. The blue arrow is to the "Y" pipe and the
red arrow is the new boost line.
The boost line is then run under the brake booster and through the firewall at the area shown.
There is a plug for the hole in the firewall. Punch a hole in it to allow the boost line hose to pass through.
Reassemble the engine.