New guy in Mojave

[NVP66S]

Hello all:
I guess some introduction is in order. This forum seems to have some Lotus interest, so I can admit I owned a '72 Elan for several years. (OK, I admit it was a Plus 2S ). I had that car apart many more times than it asked for, but I was having fun. The real reason I am here is that I just bought a Westfield kit through the US dealer, Flyin' Miata. It's scheduled to ship from the factory in November. I bought a donor car a week ago and it's already in bits. Dang that wiring loom looks complicated. I traveled to Grand Junction to test drive their Westie, but it had lost oil pressure that morning. Heck. That's my second failure to drive one. I visited the factory in Kingswinford in February, but there was snow and ice all over the roads. I didn't even ask that time. So I'm wondering, are there any Westie owners in So Cal or Central Cal? Any possibility of getting a ride?
Thanks,
Dan

[Doug Liedblad]

I believe there are one or two in So. Cal but don't think they are active on the list.

There is one in N. Cal who has been posting.

Welcome to the group anyhow and come down and drive a Caterham or Birkin some weekend. See the AROSC driving school at the Streets of Willow in November. A couple of us will be there.



Doug

[Mondo]

Welcome neighbor

[rzempel]

Welcome. Don't let that stock harness intimidate you--there;s all sorts of pointless junk attached to it. You should only need a small fraction of the wires and fittings.

[NVP66S]

Welcome neighbor

Is that radial engined motorbike yours? Or more to the point, do you have an interesting car in Bakersfield? I'm gonna hafta get an avatar and I might as well as use my bike until the Westie is more along.

[NVP66S]

Welcome. Don't let that stock harness intimidate you--there;s all sorts of pointless junk attached to it. You should only need a small fraction of the wires and fittings.

The easy part (I think) will be identifying the useless junk such as window lifts, door locks, etc. The Chilton's book has excellent schematics.

To me the hard part is figuring out which are reused and which to discard. Flyin' Miata's build diary mentions not to discard the clutch switch or the engine won't idle properly. OK, I understand the clutch full-out switch is to disconnect the cruise control and the full-in switch is to enable the starter, and neither function gets transferred to the Westfield. But which switch is used by the computer for engine control, and why the heck should the engine idle be affected by clutch position?

[Mondo]

Yeah, that's a radial engine bike, sadly not mine. Got rid of my crotch rocket as I felt my days were numbered on that thing (made it 5 years and a few track days). You can click on "Mondo" and see my photo album of the S2K

[rzempel]

The easy part (I think) will be identifying the useless junk such as window lifts, door locks, etc. The Chilton's book has excellent schematics.

To me the hard part is figuring out which are reused and which to discard. Flyin' Miata's build diary mentions not to discard the clutch switch or the engine won't idle properly. OK, I understand the clutch full-out switch is to disconnect the cruise control and the full-in switch is to enable the starter, and neither function gets transferred to the Westfield. But which switch is used by the computer for engine control, and why the heck should the engine idle be affected by clutch position?

When my daughter gets to that point (she has an old CMC7 Miata kit), I'll counsel her to use an aftermarket ECU such as the Emerald and use new wires.

I would guess that the Miata ECU 'expects' to see the clutch disengaged at low speed, low load. When it doesn't, it tries to compensate for what it perceives as an idiot driver about to stall the engine.

[escondidoron]

OK, I understand the clutch full-out switch is to disconnect the cruise control and the full-in switch is to enable the starter, and neither function gets transferred to the Westfield. But which switch is used by the computer for engine control, and why the heck should the engine idle be affected by clutch position?

I would guess that the Miata ECU 'expects' to see the clutch disengaged at low speed, low load. When it doesn't, it tries to compensate for what it perceives as an idiot driver about to stall the engine.

Very interesting.

That does seem a possible scenario. But then wouldn't the ECU also want to know what gear (or at least if any gear) is engaged so that the situation for idle in neutral with with clutch pedal out is covered. Is there also an input to the ECU from the gearbox for transmission gear/neutral? Or maybe wheel speed?

Another possiblity is that it is somehow related to a/c; For increasing idle fuel to compensate for the a/c compressor switching on/off. But you would think that the ECU would just monitor the a/c clutch compressor switch for that function. But then maybe it monitors both?

Other scenarios? Hmmm.

This is an interesting bit of ECU trivia to me. Please do let us know what you find out if you decide to pursue this further.

[NVP66S]

Very interesting.

That does seem a possible scenario. But then wouldn't the ECU also want to know what gear (or at least if any gear) is engaged so that the situation for idle in neutral with with clutch pedal out is covered. Is there also an input to the ECU from the gearbox for transmission gear/neutral? Or maybe wheel speed?

Another possiblity is that it is somehow related to a/c; For increasing idle fuel to compensate for the a/c compressor switching on/off. But you would think that the ECU would just monitor the a/c clutch compressor switch for that function. But then maybe it monitors both?

Other scenarios? Hmmm. This is an interesting bit of ECU trivia to me. Please do let us know what you find out if you decide to pursue this further.

There is a sensor sticking out of the trans, but I haven't dived into it yet to see what it does. Could be just backup light. While we're speculating, I would guess that the clutch switch tells the ECU to maintain idle regardless of AC or other variable loads because the road is not determining engine RPM if the clutch is in. That would not require inputs from the AC or transmission. But that's just me guessing.

BTW, escondidoron, I changed jobs many years ago because of an Esprit. I saw the Bond movie and decided to work for the company that turned an Esprit body shell into a submarine. The guys who designed and piloted the sub became a good friends of mine.

[magnusfeuer]

I warmly recommend buying an aftermarket ECU since you will save so much time trying to coax the stock unit to behave.

I see stock ECUs pretty much as high-maintenance girlfriends. Everything must be just right for them to be happy. If something is not to their liking, they will just sit in a corner and sulk and not tell you what is wrong.

/Magnus F.
PS. Since I've been married to a non-high-maintenance wife for 15 years, I am drawing on old sexist and misogynist memories here.

[NVP66S]

I warmly recommend buying an aftermarket ECU since you will save so much time trying to coax the stock unit to behave.

I see stock ECUs pretty much as high-maintenance girlfriends. Everything must be just right for them to be happy. If something is not to their liking, they will just sit in a corner and sulk and not tell you what is wrong.

/Magnus F.

Magnus: I like your analogy. :) I have been considering an aftermarket ECU and I have a lot of questions. For example, are they street legal? I'm building a street car and would be really unhappy if I couldn't register it. On the plus side, the Miata reused loom has the ECU behind the passenger seat and the Westfield puts it forward of the IP in the scuttle. Just shortening the wires is probably 20 hours. On the minus side, how many of the retained sensors will still talk to the new ECU? Will it drive the Miata instrument cluster, or a set of VDO gauges? The fuel level sensor? etc, etc.
Thanks,
Dan

[rzempel]

I see stock ECUs pretty much as high-maintenance girlfriends. Everything must be just right for them to be happy. If something is not to their liking, they will just sit in a corner and sulk and not tell you what is wrong.

Wheb I bought my Birkin, it had a wholelload of junk attached to the loom just to fool the stock Ford ECU into running in "limp-home mode." The original owner thought it was running fine. :-)

Dan, yes aftermarket ECUs are fine on the street. You will be SB100-ing your car to be smog-check exempt, anyway, won't you?

[NVP66S]

Wheb I bought my Birkin, it had a wholelload of junk attached to the loom just to fool the stock Ford ECU into running in "limp-home mode." The original owner thought it was running fine. :-)

Dan, yes aftermarket ECUs are fine on the street. You will be SB100-ing your car to be smog-check exempt, anyway, won't you?

I plan to move to West Texas next year, so most likely I will be registering & titling it there. They have safety inspection but no smog checks. Kinda the opposite of Cali.
Dan

[magnusfeuer]

The street legality should not be an issue, although I can only speak for CA cars.

As for the sensor setup, I would buy something that somebody else has already tested on a Miata setup. With the grassroots racing culture around that car, there must surely be an (almost) plug-and-play replacement programmable ECU package that will have the CAN protocol to drive the instrument cluster and hook up with all the sensors.

If you decide to go VDO, you just need to worry about tacho output, which all ECUs have programmable pulse setup for.

Speedo is usually driven from the gear box (or a wheel). Fuel level is connected directly from the sensor to the gauge.
As for engine coolant, people (and sometimes OEMs) usually have two sensors; one for the ECU and one for the dash.

Oil pressure is another direct route from sensor to gauge, with no ECU connection necessary (unless you want the engine to stop firing on low oil pressure).

You can get an engine up and running with only a few sensors (crank and one of TPS/MAF/MAP) and correctly driven injectors and ignition. The more sensors you add on top of that, the better the engine will run. Again, get something that is proven to work on the same engine/sensor setup as you have.

/Magnus F.