E. Supercharger Gauge Set Intall

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Gauge Set


We spent a couple hours in the afternoon of 07/21/2016 installing the AEM FIC and harness, running the AEM wideband o2 sensor wiring and a vacuum line for the FIC. See the posting below for Supercharger Gauge Set Installation.

We took this picture of the wideband connector and carefully pulled the wires from it so we could run it through the firewall.

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Both the vacuum line and wire were run into the firewall on the passenger side through an existing hole with a rubber plug.

During the week I welded a bung into the down pipe for the new o2 sensor. Matt had marked it before removal so all I had to do was align and drill the hole.

Then weld the bung.

I made a wiring harness to install from the Westach gauges in the pod to under the dash and out to the engine sensors. The AEM AFR gauge came with the wiring harnesses it needed.

On 07/23/2016 Matt was working on the radiator and fans while I worked on the gauges.

The OEM door pillar cover was removed. I managed to break the plastic off at one of the metal clips.

Then the new pillar cover was test fitted.

I made marks for the screw holes with a drill bit.

I used a flexible extension to get to the lower hole.

Once the holes were drilled, I used a screw to thread the holes.

Then I started fishing the wires and vacuum line from under the dash to exit just be side the dash at the door.

Then the wires and hose were pushed behind the weather stripping.

The plastic connector body was put back on the o2 harness.

The boost gauge will be put in the lower pod, but it will block access to the mounting screw. So, I added some disconnects to allow the gauge to be installed after the pillar cover is fully mounted. It fits tight into the pod so it should be held in place fine without the mounting nuts and bracket on the back.

The other two gauges were mounted and wires extended for the oil pressure/temperature gauge.

The wiring was attached to the gauges.

The wiring harness for the oil pressure/temperature gauge sending units was fished through under the dash to the passenger compartment and spliced to the wires from the engine bay.

Now there was a sea of wires under the dash to connect. Notice the labels I put on some of the wires to be sure they went to the correct attachment.

The boost gauge was attached and made ready for insertion. Notice the zip tie to keep the hose in place under boost.

The screws were too short that I had on hand so, longer screws were purchased a the local hardware store. But, they did not have any stainless screws long enough so zinc coated screws were used.

Now the boost gauge was pushed into place.

The center console and tombstone had to be removed to allow access to the red/black wire to the airbag connector. I found this was the easiest place to get to the dimmer wire even though it also feeds other locations under the dash.

The connector was pulled and the red/black wire was exposed for a vampire tap.

The console was reinstalled.

Now all that remained to finish the supercharger gauge set install was to connect the power and the grounds.

All the grounds were twisted together and connected to one black wire. Then a wire terminal was connected to the ground wire and placed under a screw holding the fuse block in.

The power was taken from a piggyback fuse holder. It plugs into one of the fuse slots and the 10A fuse for that circuit is installed and another 5A fuse for the feed to the gauges.

We will know how well the job was done once the engine is reconnected and the gauges fire up!

Matt will also be changing out the boost gauge at a later date. I use a 15 psi gauge on my car had already bought one like it for this install. But Matt is going to be pegging that gauge so it will be swapped for a higher psi gauge.

I also made a boost pressure warning system. It is outlined on the tuning page:

H. AEM FIC Tuning for M62 Supercharger

Update 08/05/2016

The gauges all worked great!

Matt decided to add a fuel pressure gauge and has one on order. We will install it somewhere but have not yet decided where.

Matt settled on using the center dash where he had a pocket instead of a cassette player. However, the cost of buying the cover plate for this type of mounting is rediculously expensive for what it is.

So, as we do often, we decided to try to make our own. We (I) have plenty of time, but not much money! Also, we gain new skills when we take the time to do new things.

Matt bought a 2-1/8" (54 mm) hole saw at the local hardware store.

I had a piece of 1/8" thick aluminum laying around. First we used an OEM dash pocket insert to determine the size for the plate and trimmed it down to that size.

We were able to cut three nice holes in it since we used the drill press and the new hole saw. It was held carefully in a drill press vise and the holes were cut very slowly while Matt dripped some ATF oil on the drilling. It came out very nice.

Matt cleaned up the edges and the face.

Now the hard part...how could it be mounted?

The weekend was over and Matt had to return to work. During the next week, I was able to remove the radio and cassette player in our Rallycross Miata. I used it to figure out how we could mount the plate in the cassette player slot.


Side Note

Radio and Cassette Removal

Usually, a coathanger wire can be inserted into the holes on the sides of the radio and cassette player to release the clips that hold them into the dash. But, often the tabs that are supposed to allow the clips to release will break off, or the wire does not engage them properly. This can cause you much frustration. This happened to me when I tried to remove the cassette player in the Rallycross Miata.

The radio came out with a little careful encouragement from a small screw driver. Only slight prying can be done without harming the dash, or toombstone surround. So this is not a good way to get the units out.

The cassette player would not come loose on the passenger side. I managed to pull the unit sidways and bent the support bolt on the rear of the unit. I had to work over the top of the cassette player and apply way to much force to get it out. I was lucky to have not damaged the dash.

This is why. Both the small tabs were broken off on this side which meant the clip only grabbed more as pressure was applied.

I was lucky to get the unit out without damaging the dash. This is the worst case of trouble I have had removing radios or cassettes in a Miata.

So, when we worked on Matts car to remove his radio and cassette, we planned ahead. This time we carefully removed the center console and the toombstone. With it removed, there is access beside the units through a rectangular slot.

Sure enough the radio did not want to come out.

We made a tool out of some stiff wire. All that is needed to make a tool is about a 1/2" bend.

With the toombstone removed it can be inserted in the slots beside the radio or cassette and turned to force the clips flat against the radio sides and the radio will slide right out.

Here you can see that one of the tabs is broken on the top and the one on the bottom still in place. When the radio is in the dash, you cannot insert a tool in the small radio hole to get behind the clip. So, the tool has to be inserted beside the unit where it can be used to apply pressure at the arrow.

We had to use the tools we made to get both units loose without damage to the dash or the units.

So, if the coathanger insertion method does not allow the radio to slide out, always stop and carefully remove the console and toombstone. Make a tool to work the clips without damage. It will save your last nerve!


Now back to the gauge panel fabrication. I laid the panel in place to check fitment and to see how it could be mounted.

We wanted to be able to remove it without having to take the dash apart. We could have added some mounts to the edges of the dash frame and used screws, but I came up with a different way to mount it.

I was going to make spring loaded keepers. I bought a couple small springs at the hardware store that would fit over a 4-40 screw. Then I used some small aluminum rod to make sockets for the springs and screws on my mini-lathe. I used some 1/8" x 1/2" aluminum strap to make some small brackets to mount on the ends of the screws. They were drilled and tapped then installed on the screw ends with a lock nut to hold them in place.

I test fitted the first one I made on a piece of scrap aluminum and a block of wood to be sure it was going to work as planned.

Holes were drilled in the corners of the plate to install the keepers. I would move them slightly on the next one I build to allow more clearance top and bottom.

I test fit the plate in the Rallycross Miata and it fit great! I did have to do some filing in the bottom corners to allow the keepers to fit.

Now we could move on to the wiring and sending unit installation. More to come when the new gauge arrives!

Update 08/20/2016

We were able to get back to installing the new fuel pressure gauge on 08/20/2016. We still could not install the sending unit due to problems encountered with the Nitrous Outlet fitting. See I. Engine Start with M62 Supercharger for the problems we encountered with it. However, we could work on the wiring.

We looked over the OEM wiring diagrams to find a continuous 12V source, a switched accessories 12V source, a lighting feed and a ground per the gauge instructions.

The switched accessories source we used was the blue/black wire feeding the radio. It was tapped at the radio connector.

The black ground wire was also tapped at the radio connector.

The lights feed was attached to the red/black wire at the airbag connection we had used for lighting the other gauges. This lead is attached to the dash lights dimmer so the gauge lights dim with the dash lights. Since I had problems with a vampire connector recently, I also soldered all the joints.

The constant power line was attached at the fuse block to a new piggyback fuse holder installed in the Room fuse socket. This fuse is always powered evem when the key is off.

All four wires were tapped then run to the cassette player pocket to be spliced onto the pigtail that came with the gauge.

We then removed the plastic connector from the end of the cable that attaches to the sending unit. This would allow the cable to fit into a small hole the size of the cable jacket.

We removed the small rubber plug on the firewall on the driver's side that is behind the brake booster. A hole was punched in the plug and a coathanger wire was pushed into the firewall cover inside the car.

Matt had to remove the ECU to cut a hole for the cable in the firewall cover at the point where the coathanger poked through. Then the cable was pulled through the firewall and into the cassette player pocket and the plastic piece was reinstalled on the cable end.

Now all we needed was a the fitting to install the fuel pressure sending unit. Since we did not get the improved model that was promised from Nitrous Outlet and the new one they sent would not work either for the same reasons, we made our own retainer for the Nitrous Outlet fitting that had failed. So, after many hours of modification work later, we finally got the fitting to work and the sending unit installed.

We installed the gauge in the new plate, along with two blanks in the other holes.

Once installed installed in the dash, we tested it. It worked and it looks great! Finally we have the new gauge in. It was idling at 40 psi but rose over 60 psi when the engine was revved.

Next we will get back to the tuning. Matt is communicating with Ken Hill to see if he can help us with some of the tuning tasks. More to come in the tuning section later.

Subpages (6): A. BRP M62 Hotside Kit B. Supercharger Parts List C. Supercharger Engine Build D. BRP Intercooler Kit Install F. Supercharger New Engine Start Up G. BRP M62 Supercharger Install H. AEM FIC Tuning for M62 Supercharger I. Engine Start with M62 Supercharger