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Previous Next Up Topic Engines / Subbug - Subaru Power / Jay - Megasquirt Question (19917 hits)
By @Jeff GS Date 2009-09-30 00:48
Hey Jay,
Are you running the relay board with your MS controller?  If so where did you mount it?  Use any kind of "conformal" coating on the boards - if so what did you (or Paul?) use?  How did the MS system handle all the "water" ingestion from your shake down trip?

I'm at the point where I need to start planning exactly where I'm going to mount and wire up the MS controller.  I have the relay board, which I'd like to position somewhere in the engine compartment.  I've got a spot on the frame near the engine that looks to be about perfect, and I'd like to mount the EDIS module adjacent to it, kind of as an integral unit.  Thinking along the lines of a flat aluminum plate to mount the electronics to, with small rubber standoffs attaching the plate to brackets on the frame.  I'm a bit concerned about any water getting into it, as it'll likely be mounted face-up - though under the engine cover so it'll have at least some protection from the elements.  Like any buggy though, the engine compartment is still fairly "exposed".
I just ordered a full case for the relay board, but believe I'll still have to make a cut-out in the top for the relays to poke through.  Not sure if I should seal this up with some other "cover" on top, or not worry about it?

Going to mount the main controller in the cockpit, probably on the firewall behind the driver seat.  It'll only be a few feet from the relay board and pretty easy to access for computer plug-in, etc.  Also contemplating some kind of "rain guard" cover - just in case......

By Sandsurfer Date 2009-09-30 00:55
Why wouldn't you mount it above the fuel tank. The top of the fuel tank never gets wet.
By @Jeff GS Date 2009-09-30 01:03
The tank's at the opposite end of the car Sandsurfer.  The relay board takes in all the sensor and injector wiring from the engine.  It is generally mounted somewhere close by the engine.
But you're right - above the fuel tank is a pretty much guaranteed dry spot!

By Jay H (X-20) (ManxVair CC) Date 2009-09-30 07:06
Hey Jeff,
I followed Paul's advice on what he had experience with working in the past, which was to mount everything in an ammo box, which is completely waterproof. Obviously, you need to make provisions for wire entry into the box, but I think overall it works well. Sand, dirt, moisture, and water are kept out of it. I have all the electronics mounted in the .50 cal box. The ECU is mounted to the latched top of the ammo box, which allows the ecu to pivot out of the box. I can easily leave the box top cracked open so I can connect the laptop cable for tuning, or close the whole thing up as long as the laptop cable is not connected.

There is plenty of room for the fuses, breakers, and associated electronics to stay out of the elements. I've driven through rain that would have made any sane person run for cover. You know you're testing out your system when you are still on the road, but you can make out cars on the shoulder of the road who pulled to the side because they couldn't see where they were going with all the rain! :-)

If you have the room for something of this size, I would recommend it. There are also smaller ammo boxes that I have personally seen, but not that are readily available for sale.

By Tom & Kathleen I 639 Date 2009-09-30 10:49
Per the suggestion of Outfront Motorsports, we mounted the ECU in a small aluminum box and then sealed the openings with plumbers putty.  Boxes like these are availble from electronic stores.  You can see it here - .  It is the square box in the upper left corner of the firewall we made, behind the engine.  Tom
Tom & Kathleen Manxter #16, Kick-Out SS #16 & FiberFab Buggy
Manx Club #1030, CVA, RBC, SCCA
By @Jeff GS Date 2009-09-30 11:18
Thanks Jay, Tom,
Seems like the full enclosure idea is probably the way to go.  Seeing how the relay unit has fuses and the relays, I want to have easy access for servicing.  I'll see what I can find for a suitable enclosure, ideally something with a hinged cover and rubber seal for full sealing, but simple latch-type opening - without looking too "industrial".

By @Jeff GS Date 2009-10-03 12:52
Whew - after lots of research, measuring, mock-up and eye-balling - I "think" Ive got a solution to the relay board problem.  I found a small aluminum chassis box with removable lid I think will work to seal up the relay board/assembly.  The biggest problem was I wanted to keep the D-Sub 25 connector (and cable end) inside the housing due to it not really being weather compatible.  But this caused problems with the overall box size and couldn't find one with a good fit, without being way too big.  The other thing I realized is I "barely" have enough room to locate the relay board in the engine compartment, even as small is it is!  My prime planned location is between upper frame rail and engine cover, and found out there is barely 2.5" of vertical clearance.  But no other location makes sense - either down low and even more exposed to the elements, or near the hot exhaust, etc.  I considered moving it to the cockpit, but very tight there too and not readily accessible for maintenance or servicing.  The exo-skeleton limits access to the side pods, though I'm still thinking that location for the main ECU.  Maybe stick it in there with some velcro for easy in and out access.

Back to the relay board - if I locate the board about as low as it will go in the extruded chassis, it gets the overall height down to about 2-1/8".  The electrical chassis box is 6"x4"x3" high, and I can cut this down to 2-3/8" so that should work.  The other item that will make this work is one end of the new box will become the "end plate" for the relay board chassis and D-sub connector will stick through.  The trick here is a waterproof cable end from L-com with seals that should do a good job of keeping any liquids and dirt out!  It should seal right up to the end of the case.  The other box end will use standard grommets and some silicone to seal any wiring going out.

I still want to rubber mount this box to the car chassis to minimize vibration, but will have to figure this out later once I assemble the relay unit and new chassis.  Probably have to still mount the whole thing onto another flat plate of some sort.  That could provide the mounting location for the EDIS controller too.

That's my plan anyway.... updates to follow.

BTW - these waterproof D-sub connectors look to be the real trick for hooking up the MS controller and/or relay board.  IMO, these should be incorporated into the build from the get-go!  Only questionable "detail" I can see is the pins are solder connect, apposed to crimping.  But since the while ECU board is assembled with solder I don't see a problem with this?  From the looks of the connector, it appears the cable is well supported and eliminates any movement between wire and terminal.

By @Jeff GS Date 2009-10-14 11:31
Small update.  I'm extremely space limited in the GS for electronics back around the engine and cockpit - so compact-ness is the order of the day.  I just picked up a new full enclosure for the relay board, it's just the complete case assembly instead of the 1/2 case provided in the RB kit.  It won't fit 100% over the relays, but I can clearance the case and position another top piece over the hole to seal it back up.
Bigger problem is the waterproof D-sub connector.  Everybody has 25 pin versions available, but only found 2 manufacturers who make a 37-pin version needed for the RB - and no one carries these in regular stock!  Waiting to hear from one company who might be able to get me one, otherwise I'll have to make do with the standard connector.  The problem is these electronic outfits require a "minimum order" for non-stocking items, usually over $100 or more.  Much more than I want to spend on a connector!
Using this case will provide the most compact layout I can do (no room for large cases or ammo boxes!) and I'll have to try and seal it up best I can.
Good "project" for this weekend, as some nasty weather coming in and it'll definitely be an "indoor" weekend!

By Jay H (X-20) (ManxVair CC) Date 2009-10-14 11:38
Jeff, sounds like you've got your work cut out for you this weekend. Judging from the rest of the build, this is just a small stumbling block for you to tackle, and I'm sure your craftsmanship will show in your box modifications! Don't forget to snap a picture every now and then for the rest of us.

By Sandsurfer Date 2009-10-14 21:41
We have a buggy in our group that has 30,000 miles on a MS ECU. The ECU is mounted in the LH sidepod and the relay board is over the fuel tank. The buggy has been driven in torrential rains and the water has never infiltrated the electronics. The ECU is in the standard aluminum box as well as the relay board.

By @Jeff GS Date 2009-10-14 23:07
Good looking buggy Jerry!  Seems odd the relay board would be mounted up by the fuel tank, since all the control wiring has to be run from it all the way back to the engine?  But sure sounds like it stays dry!

Have any close-ups of the electronics?

By Sandsurfer Date 2009-10-15 01:22
The only wires running to the back from the relay board is the injector wiring, the fuel pump is under the tank in the front of the buggy.
There really is no visible wiring.
By @Jeff GS Date 2009-10-19 21:32
Got to thinking about your idea Jerry, as my fuel pump will also be up front under the tank.  I'm still going to mount the relay board back by the engine, but decided to use the fuel pump relay output mostly as a signal wire to another relay under the dash.  Fuel pump will get power from the front mounted battery, through this extra relay.
I'll be using the RB FP relay also as power for the O2 sensor heater, as shown in the MS wiring diagrams.

Anyhoo - my limited space requirements led me to installing the RB inside a fully enclosed case, just a full version of the 1/2 case provided with the kit.  Had to clearance the top for the relays, but it all fits in pretty nicely once done.  I epoxied a piece of .062" aluminum on top to seal the case back up.  Next up is to get some wiring details figured out and fit up a relay board "harness" with quick disconnect plugs for the sensors and injectors.  Once I determine the exact wire bundles out of the case, I'll put in holes and grommets to help seal the wiring coming out of the case.

Couple of pics:
New case with top opening and fitted for D-sub connector:

Internals and top with new cover plate glued in place:

And fully assembled:

Got to figure out some wiring specifics pertaining to the EDIS ignition control wiring, using quick disconnect plugs and figure out exactly how the wiring is going to be routed.  Need to have (2) 12V main feed wires, one for ignition and one for relay board, plus ground wires to the engine, then I can flesh out the sensor wiring.

Still trying to decide where I'll locate the EDIS module?  It's a little tighter than I though around the relay board, and not sure if I direct chassis mount it if it can take the vibrations?  Bolting it directly to the chassis provide a bit more flexibility for mounting locations.

By Sandsurfer Date 2009-10-19 21:59
Nice job on the box!!
By Jay H (X-20) (ManxVair CC) Date 2009-10-20 01:23
Sorry Jeff, I can't give you any real world info on mounting the board directly to anything rigid. My board is rubber mounted within the ammo box.

Just as Jerry said, Beautiful job on the box itself. I knew it would be nothing short of high quality... just like the rest of your build. :-)

By @Jeff GS Date 2009-12-04 14:08
Hey Jay,
Got another MS related question for you.

Can you provide details on how you installed the boost controller on your system?  Kit(s) used?  Any difficulties or pointers for setting up boost control?
Also, did you incorporate any knock monitoring or control?

I've finally figured out where I'm going to mount the relay box, now out of the engine compartment.  I just couldn't fit it in there and still be able to easily access it for maintenance.  I've decided instead to fit it into the side pod, near where I was planning to put the main ECU.  Now time to make some mounting parts and get it situated in there to begin the wiring process.

But I got to thinking about later fitting boost control, I'd like to pre-install any mounting points (and wiring) for whatever is needed for this so it would be a simpler plug-n-play when the time comes.  This would likely be a Winter time retrofit, at some point after I get the thing actually running and driving.

By Jay H (X-20) (ManxVair CC) Date 2009-12-05 13:49
Hey Jeff,
I'm using a General Motors boost control solenoid, which was available through the MS web site. I see they don't offer the GM boost controller although they still offer two different styles of connectors?

The cost for the GM version was $24.00 and the pigtail I got was $14.50

I see they now have a $38.00 option for boost control which looks like something generic. Ran the numbers in the photo through google. Top three results were Honda discussion forums. a quick "find" search got me to a discussion that the valve is made by humphrey's and it's a 410.

I imagine DIY has a markup on the valve.

I'm not near UWISH right now or I would go out and see if there are any markings on the GM valve.

Hope this helps.
By Jay H (X-20) (ManxVair CC) Date 2009-12-05 13:53
Just re-read your post. I don't have anything for knock control. I was on the fence with knock control, and may at some point add a LED on the dash, but I thought with the Devil's own methanol/water injection I was running, I was pretty safe.

By @Jeff GS Date 2009-12-05 16:05
Sure does help Jay!
Interesting and I agree it looks like they (DIY) are using a generic Humphrey solenoid valve - with "markup".
I guess it would work OK for this application?  We use these same valves to actuate larger pneumatic vacuum valves on our vacuum chambers at work (except in 120V versions and @ ~80psi).  Unfortunately they seem to have a limited life-span in my work applications.  After about 3-4 years they start leaking through the valve mechanism and have to be replaced.  They are under operation 24-7 though and only actuated ~once daily, so not sure how this reliability experience would translate to a lower pressure, but much higher temperature swing and higher use frequency "under-hood" application.  It is a nice and compact valve, I'll have to look into what else is available for options.

So talk to me about the function and "electronics" side of the boost controller.  I'm running a V3 board - is the BC kit a mod to the board itself?  Or is it a separate mini-board added inside the MS ECU case?  Any problems or tricks installing it?  What about the extra wiring and getting it from the ECU to the solenoid?  This doesn't sound like something that would run through the relay board box, or does it?
Functionally, I guess the solenoid interrupts the signal between turbo and WG.  What exactly does it "do" with the pressure signal?

By @Jeff GS Date 2009-12-05 16:30
A quick Google myself and found where Humphrey has "improved" this valve for better reliability.  Seems the going rate at a couple of vendors is around $24, a few bucks less than DIY, but doesn't include fittings.

Still interested in what "function" the valve performs relative to the boost signal.

By Jay H (X-20) (ManxVair CC) Date 2009-12-06 01:41
Ahhh. That valve powers closed, spring open. It is installed between the compressor housing and wastegate. When power is applied through the MS board, the valve is held closed stopping any pressure from reaching the wastegate until the map sensor senses whatever pressure your MS has been programmed to. The power signal is cut, and the valve springs open instantly increasing pressure to your wastegate.

Thus, you have an electronic means of controlling the boost your turbo can achieve electronically through the MS computer, as opposed to mechanically.

In the event your MAP sensor fails or the wiring fails, the valve will fail open, so you don't shell out a perfectly good turbo. For this reason, it is still important to set your mechanical wastegate at a conservative level and allow the boost control valve to do the work of raising the pressure.

That should clear up the function of the thing. :-)

By Jay H (X-20) (ManxVair CC) Date 2009-12-06 01:52
As far as the board goes, I didn't do any of the mods. The company that Paul knew about put it all together. External wiring consisted of either 2 or 3 wires to the map sensor and the ecu and one wire from the ecu to the solenoid valve. The ground wire from the solenoid valve just went to engine ground and did not go to the ECU.

By @Jeff GS Date 2009-12-06 13:07
Thanks again Jay.  Sounds like a straightforward hook-up for the valve, not so sure about the electronics.  I looked at the DIY kit page, and read through the assembly of the electronics.  Not as plainly spelled out as the MS main assembly instructions (like solder pin A into hole A kind'a thing).  I'll have to do some searching on the MS forums and see if I can pick up any more details.  I want to fully understand exactly how and where the components are installed before cranking up the soldering iron!
I'm not planning to install it this Winter though, mostly wanted to see how the hardware/valve needed to be installed and provide mounting points for it during my final chassis work.  Easy enough to do that now that I know what valve is used.

Thanks again,
By Jay H (X-20) (ManxVair CC) Date 2009-12-07 03:32
No problem, glad to help out.

Previous Next Up Topic Engines / Subbug - Subaru Power / Jay - Megasquirt Question (19917 hits)

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