[psimitar]

A fun wee project and once you have the fuelling sorted I'd suggest implementing the ignition too for a really smooth drive

Also, check out Mouser for automotive connectors. They stock what Haltech, MAxxECU, Link etc use for their ECU's. Here's a link for a 32 connection panel mount connector from TE Connectivity Mouser Automotive Connectors

 

[dc66]

I've been looking at photos of cut aways of the stock exhaust this morning! I'm trying to decide where to fit the lambda sensor. It needs to be in the gas flow, ideally from all cylinders.
There doesn't appear to be anywhere ideal for this. So I'm thinking I can fit it on one end (side) or how about in a tailpipe? I realise the sensor will only be getting half the story but I think it would work. My only worry with the tailpipe idea is that the internal baffles will get in the way.
I could buy a 4 into 1 manifold and silencer, but I really wanted to stick to stock appearance if I can.
I did fleetingly consider a zoom tube....
The Vintage Speed silencers look a good option And some have the lambda boss already fitted. I just can't bring myself to pay so much!
Or I make an exhaust myself. I've made plenty in the past, but time is an issue here.

So, any bright ideas?

 

[Zebedee]

Is it possible to fit 2 lambda probes like some V6 and V8 engines do?

 

[dc66]

Is it possible to fit 2 lambda probes like some V6 and V8 engines do?

I don't think so

 

[lukej]

Is it possible to fit 2 lambda probes like some V6 and V8 engines do?

You can have 4 lambda sensors if you like. You can tune individual cylinders then if you're fully sequential but due to cost it's more common to use 4 xEGT probes and just the one lambda.

 

[dc66]

You can have 4 lambda sensors if you like. You can tune individual cylinders then if you're fully sequential but due to cost it's more common to use 4 xEGT probes and just the one lambda.

I'm not sure the MS1 v3 will support multiple wideband lambdas. I'm not sure my pocket will support multiple wideband lambdas!
I'll look into it.

 

[psimitar]

If the MS1 supports CANBUS then the Haltech WB2 could be made to talk. Depends on baud rate and a few other things but would give the ECU dual WB O2 sensors. Course Haltech is fecking expensive

 

[dc66]

No canbus on ms1

 

[dc66]

From what I've read, the ms2 and ms3 megasquirt ecu can support multiple o2 sensors, but not the ms1 that I have.
I've also read a lot of people successfully using 1 sensor on one side of a v8.
I think I'll fit it to the end (side) of the exhaust and see what happens. If it doesn't work there, I think I may make a skinny zoom tube and mount it there. I am not a fan of the traditional zoom tube noise, but I think that comes from the larger bore final tube. A skinny tube may do the trick without sounding like a blown exhaust. Dunno.

 

[al_kaholik]

I think you are over thinking it. In the end as you plan will probably get you close enough.

Making an exhaust later if you want to will possibly improve economy, performance and mixture. But I wonder what the real gain will be.

 

[lukej]

I'm not sure the MS1 v3 will support multiple wideband lambdas. I'm not sure my pocket will support multiple wideband lambdas!
I'll look into it.

I really wouldn't worry about dual/quad channel wb. Completely unnecessary. But would be interesting to play with

 

[dc66]

I really wouldn't worry about dual/quad channel wb. Completely unnecessary. But would be interesting to play with

Where would you put the o2 sensor on a stock exhaust?

 

[GlenAnderson]

As a layman when it comes to these kinds of things, my first thought would be to focus on No.3 cylinder, or at least that side of the engine, as that’s generally the one that will melt a piston or drop a valve first when things get out of shape.

 

[dc66]

Good point Glen.

I've been waiting to get an alternator kit before I mount the throttle body on the manifold, just in case there was a fitment issue. Today it arrived (I ordered it while rather inebriated and with a more gung-ho attitude than my normal cautious self!). No problems fitting it to the mock up engine I have, so I won't bore you with the details.
Anyway, this morning I turned my attention to the throttle body. Then I noticed, with a sinking feeling, that the rotation of the throttle spindle was the wrong way round.
So I took it apart to see what could be done. I really don't want to have to go on the search for a different one again!

Hmmmmm it does look like the butterfly can be fitted round the other way....

So I did.

That caused an issue with the throttle position sensor orientation. A quick modification to the spindle and I'm back on track. The only problem now was that the "wide open" position stop was the TPS limit. Not good.
I drilled out the centre of the, well, I don't know what it's called! This thing..

I modified a thick washer to fit the spindle and put both on the body in the orientationi need. I've only tacked the washer on for now just in case.
Then I drilled and tapped the old Wide Open stop to convert it into the new "closed throttle" stop. Now if I can't setup the Idle valve (I have a nagging feeling my ECU won't like the Nissan one) I can adjust the idle with a screw, like on a carb.

The bonus with this set up is that I now have an adjustable wide open stop. Dunno why I'd need to adjust it, but hey-ho!

I fitted a return spring I had so the butterfly snaps shut nicely.
Next I need to fabricate the connection to the cable, but I'll do that once I've finished the manifold. That will be another day now though.

 

[lukej]

Fit the WB02 sensor where ever convenient then just check the plugs when doing the initial tuning. You'll soon see if there's any disparity in the fueling. You're using 1 inj. Per cylinder right? Assuming they flow about the same.
I like that single tb setup, should be quite slick. Adjustable WOT stop, perhaps wire it to a solenoid for when thr Mrs drives it? Mine nearly launched the car through the garage last time she had a go. She underestimated both the throttle response and the lack of forgiveness in the clutch

Is your idle valve a pwm stepper or just a simple on/off?
Does MS1 have cold spark advance? I just add 5° to my base table when cold to keep revs up with no iac valve
Around 1000rpm cold and settles to around 800 when up to temp.

 

[dc66]

It's a 3 wire stepper motor. I've seen I diagram online for the MS1 where it uses a 30 to 40 ohm resister on the earth for the motor. I'm not convinced! Hence my prediction that I will need to provide an alternative idle control. Time will tell I guess.
I did wonder about converting the solenoid one I have from the motorbike throttle body. I'd need to machine up an adaptor plate. Fiddly but possible.

As this is a single port motor I don't have the room for 2 injectors per head. So I'm planning on fitting one injector per head and set it to fire twice per cycle.

I am not initially going to be controlling the spark with the ECU. It does have the coil driver fitted and the Extra code installed. I just wanted to go one step at a time. I may change my mind on this though!

 

[psimitar]

For the O2, if you have a std silencer then do what Vintage Speed do and weld a bung into one end of the silencer.

 

[dc66]

Manifold tacked together.

Not finished with this yet though. I need to weld in a vacuum take off and the injector mountings. Then figure out how to hold the fuel rails in place. Not sure I can call them a rail as each only feeds one injector, but you know what I mean.

 

[dc66]

Obviously this isn't the engine I'm going to be using, just a mockup one I have lying around. The actual engine is still in the car with twin carbs on (twin solex 30 pict 1 actually). It runs fine so I'd rather leave it as it is till I'm finished with all the fabrication for the FI. Then I'll swap it over.

 

[SlowestCoach]

You can get a stepper motor driver for a few £. A very small pcb & a few components. That takes the load off the ECU.