Ecu position

[chris.richard]

I was planning on putting the Ecus and its relays behind one of the seats (flat bulkhead), but after a trial fitting, I'm not sure if the loom is long enough - on the 164 the cabin is on the other side of the engine. Does anybody have theirs in the engine compartment? Heat and wet doesn't sound a great environment.

[rutthenut]

Originally posted by chris.richard
Does anybody have theirs in the engine compartment?

I mounted my ecu on the rear of the bulkhead, on the passenger side. This is a sloping bulkhead, so is a bit further forward than it would be on a flat bulkhead and also gets some (minimal) protection from being below the chassis rail.

It's not an ideal position, but there's plenty of space around it. The exhaust isn't too near either, and the fuel tank and splash guards seem to prevent water getting at it.

On my new car, I'm considering putting it in a similar position, but within a box of it's own to keep it clean and protected (and dry). This would mean a bit more work on the sloping bulkhead, to put an inset stepped section into it, with a cover over it. That's only an idea so far though, but it seems pretty good to me (at least my thoughts on it are good, but implementing it is another thing).

Hopefully not tempting fate, but I've not had any water-induced problems with the existing ecu setup - it seems to stay dry, but does get dirty over time. I suppose WD40 could have something to do with both of those points though, keeping water out but attracting dirt and dust. Silicone grease is also used around these areas.

I do recall near-waterproofing my old CJ7 for off-road work, which made use of rubber gloves on the distributor and plenty of silicone grease, WD40 and re-routed air induction paths. But that's for mud-plugging and wading, not Stratos activities!

[roger001]

I ues a standard loom (12v) and this is plenty long enough to reach into the passenger compartment - mu ECU sits happily behind the space where once upon a time there was a passenger seat. the excess harness of which there is plenty can be folded upon it'self and hidden between the inner and outer bulkheads, which makes for a much neater engine bay.

[Stratos]

Before I changed to the Omex mappable ECU, I used to have my ECU mounted on a bracket at corner of the upper chassis and bulkhead.

Never had any problems with it. I don't have any rear inner arches, so it's got dirty at times.

Gary Lomas has his mounted in a similar position.

Both cars have been through numerous watersplashes, rallies in torrential rain, etc, etc without a problem.

[chris.richard]

Originally posted by roger001
between the inner and outer bulkheads, which makes for a much neater engine bay.

Mine was built originally with only an "inner" bulkhead (:confused: ) Are two recommended?

[lynden]

I have been using a V6 for some 7 years , my brain! is located on the upper chassis rail , on the near side.
Believe me its been through a lot of rain and water splashes, in Rallies.
The only thing it does not like is the power washer at 1500psi!!!
I fitted it hear for two reasons.
Accesability,and so I could use the standard engine loom without mods.
It worked without problems.
Provided you dont power wash!
You can even connect straight to the standard loom for rev counter, and feeds, still retaining the Alfa plugs for fault finding.

For the best satisfaction using the Alfa engine lower the final drive a tad, you wont be dissapointed, as the standard for a kit is overgeared.

[chris.richard]

Originally posted by lynden


For the best satisfaction using the Alfa engine lower the final drive a tad, you wont be dissapointed, as the standard for a kit is overgeared.

I.E. use a 24v gearbox / diff ?
Thanks for the inf, guys.:)

[mogul_x]

Originally posted by chris.richard
Mine was built originally with only an "inner" bulkhead (:confused: ) Are two recommended?

A double layer bulkead does provide the benefit of better insulation from noise and heat from the engine bay. Whether it's needed, or even recommended, I can't say.

I gather that some owners have both vertical and sloping bulkheads installed in their cars, and packed the void in between with sound deadening. The space might also be used for a convenient hiding place for ECU, stereo equipment (if so inclined), or illicit commodities transportation as a means to supplement your income.;)

I had considered installing a double bulkead in my car for the sake of noise & heat abatement, but never got so far as to look into the details. Since mine has only a sloping bulkhead, I was thinking about attaching a panel to the back side of the chassis members that mount the bulkhead already installed. The result would probably amount to an inch or two of space to pack with insulation.

I won't know for sure until I trial fit the engine. Once I get an idea of how much room there is to work with, I'll decide whether or not I can fit a second bulkhead.

[guy mayers]

On the assumption that we are talking mainly Transformer or Hawk cars mine originally had 3 bulkheads. The vertical chassis members were enclosed both sides with the cavity filled with "rockwool" insulation - basically a solid fibrous material used in the building industry for sound and heat insulation. There was also a sloping bulkhead on the interior for authenticity. All this was in the days of Twin Cam engines. Once converted to Alfa it was found that the front exhaust manifold was too close to the bulkhead to allow ease of maintenance. So this bulkhead was done away with and a dished version fitted in its place. There is a reason for this that relates to the floorpans on earlier Transformers. These usually extend to the vertical chassis members and if there isn't a bulkhead sealing the engine bay off this would accumulate water/petrol/oil which could then seep into the cockpit and ruin carpets/seats/your whole day! Later Hawk chassis have a crossmember behind the seat to which the sloping bulkhead is fitted and the floor behind this is open to allow more air to flow in from under the car.
On the earlier chassis this can create a useful void space behind the seats that can be used for hiding electronics. Mine houses the fusebox and relays plus cut out switch, Motronic ECU, alarm and central locking controls, ABS control box, stereo head unit plus speakers!
Guy

[Steve Strain]

My impression from reading the above is that no matter how or where the ECU is mounted vibration is also not an issue.

Can anyone confirm this? I have never had the ECU apart to see what is inside.

I was considering mounting the ECU and the 2 relays in the gap between the inner and outer faces of bulk head so no that wiring is visible in the car and to make the engine side tidier.
I have and earlier chassis 075 built August 1989 with the verticle type bulk head. It should fit in the 50mm gap as the ECU is approx 45mm thick.

For the bulk head, I have made a double skinned triangular section that can be removed from the inside of the car. (After removing the drivers seat, speedo cable, hydraulic clutch, gear lever link and unscrewing the wiring loom plug, a 23 pin CPC etc.etc..,).

regards

Steve

[rutthenut]

Originally posted by Steve Strain
My impression from reading the above is that no matter how or where the ECU is mounted vibration is also not an issue.

This is always a *potential* issue, but the chassis and bulkhead panels shouldn't be too bad for vibration. Mounting it to the engine would be a different matter! (even then, it's a smooth V6)

But I would recommend using some of the rubber bobbin-type mounting bolts rather than a solid mounting. I think that standard installations use these things, but they are available from many suppliers. Essentially they are like a small engine mount, consisting of a rubber centre with two threaded sections coming out of it. That should isolate the majority of high frequency vibrations, which could possibly lead to ecu failure.

[David May]

A typical 1990s Bosch ECU was designed to withstand engine-compartment conditions (water spray but not immersion, 125°C peak temperatures and nasty vibrations.) There are however many good reasons not to push these to the limits and a good circulation of cooling air is always welcome. They are normally mounted away from chassis rails and other load-bearing members (where vibrations can be transmitted). The connectors are nominally waterproof (if assembled correctly!) but the tin lids only have a nominal gasket and should be shielded from direct water sprays (especially if opened for chipping.)

Dave May

[Jerry B]

Chris, the ecu from my 24v is mounted inside the car on the bulkhead behind the passenger seat. The loom seemed plenty long enough.
Get it inside if you can.

[Andrew Way]

This thread is perfect timing for me guys….. I was thinking about how to fit a second bulkhead to my sloping bulkhead but I’ve got a few “issues”. Ideally I’d like to fit a second bulkhead without having to fit the engine to measure up (lazy, I know!). I was thinking of running an almost vertical bulkhead up from the chassis cross member to just under the rear window. Does anyone know how much of the engine compartment space I can afford to use? It’s hard to picture at the moment but I’m guessing I’ve got a good few inches between the sloping bulkhead and the alternator. Although fitting a second bulkhead will make driving the car more comfortable I guess engine access is compromised…..


Cheers,

Andrew.

[chris.richard]

Andrew, 12 or 24v?

[Andrew Way]

Sorry, 12v.

[chris.richard]

The 12 &24v exhaust manifolds are different, but I don't know if one is bigger than the other.