Zetec conversion Ecu and throttle bodies or webbers plus ignition ecu

[S2Zetec54]

I think there maybe a few here with Zetec conversions.

She is currently running an early megasquirt with 45 jenveys. Quite hard to tune to smooth transition…ie quite a digital throttle which is fine ragging it but tiring tootling around. Tuners say they can get the map to operate on TPS.

So choices

New ecu and new loom…plus rolling road session
Keep ms1 just for ignition map and pop a pair of 5 progression hole Webber 45’s on

Those who have Zetec what do you run?

[TurboFource]

Roddymac on here is running 38mm Keihin bike carbs and I think he is happy with them.

[S2Zetec54]

Thanks Turbo….I wonder what ecu he uses for the ignition map.

This is one of the issues for not running standard of course but there we have it and this is what I have ….bought with eyes wide open. Back in my really ignorant days I remember how easy it was to buy an old 16TX strip the engine out and pop it into my first S2 and just bolted on a Weber doce the s2 came with no adjustments and she ran beautifully! I had absolutely no idea what I was doing….

[BDA]

A buddy of mine has a Zetec in his S2. He uses Webers, 45s I suppose, and an ECU that I believe he got Dunnell Engines in the UK. I think he’s happy with it. He just recently got it on the road and then he was hit by hurricane Helene, and then he discovered his polyurethane bushings had degraded…

[SwiftDB4]

I have had 45 DCOE Webers on my Zetec for 20 years now. They were pretty close on jetting out of the box. I have an Electromotive ignition system, but that is not available anymore. The 5 hole Webers are pretty good on transitions, but injection could probably be better. I'm not a computer guy so went with Webers. I think there is a UK company Motorsport Electronics that sell just the ignition for Zetec at reasonable prices.

[S2Zetec54]

Dear BDA and Swift DB4 thanks you very much for replying.

Good info. Great you have had experience of the 5 progression webbers….very interesting to hear your experience with them.

[berni29]

Hi

This reply is probably not going to be of much use to you but here it is anyways. I have a Zetec 2.0 Blacktop in my Elan+2 and it is running a turbo type plenum with the standard Zetec throttle body on the end of it and standard Ford ECU. I have had the engine running, but only for a very short while as proof of concept. I am plumbing in the cooling and fuel system at the moment.

My plan with this was to just have a nice running car with minimal grief. Ford spent a lot of money developing the ECU so why not take advantage of it? If I was running ITB's (and I still might at some point or on a Twin Cam) then I would probably use a modified standard airbox with the MAF on the end. The ECU is adaptive so no tuning to do.

I will know fairly soon if it all works as expected. I certainly don't see why it shouldn't.

All the best

Berni

[jbcollier]

45mm throttle bodies flow a lot more than a 45mm DCOE carb.  There are no venturis, no aux venturis, no accel pump nozzles, etc.  Fit 40s or smaller and it will be easier to tame.

[S2Zetec54]

Thank you, I didn't know 45’s meant a different effective size in terms of flow…makes sense.

Berni, it has crossed my mind to go back to absolute standard, as you say Ford knew what they were doing….useful that their ecu is adaptive…amazing actually….would be good to find an adaptive stand alone ecu….Emu Black has an ethanol sensor which might be useful

Anyway thanks everyone for their thoughts.

[HealeyBN7]

This is a Zetec with the OMEX ITBs and OMEX 600 ECU.  Omex says it is perfect right out of the box, but light throttle transition is a difficult tuning space to get just right and if you can't help but fiddle, you can improve it just a bit.  There are also 1,000,000 possible combinations to make it worse.

Dean

[Clifton]

I have a similar issue of too much throttle area and touchy at small openings. I went from a single 70mm throttle body down to a 65mm and lengthened my accelerator pedal to give more travel. Adding more pedal travel helped the most. I run a DBW pedal and don't remember how the stock pedal works but with a cable, it should be easy to change the attachment point and get more travel.

[RoddyMac]

Sorry, a little late to reply to this thread.  I am indeed running Keihin carbs, ignition is handled by a Megajolt.  The carbs needed larger idle jets and larger mains, which made it very easy to drive.  It's never been on a rolling road, so can't comment on power (or if it could be improved).  Unfortunately, the laptop that had the ignition tune is longer working, and I have no idea if I can connect a surface tablet to the MJ.

I am also running a Zetec in my BGT with the same carbs, but ignition is controlled by a Speeduino as I might swap to TB's in the future (if I keep the car). 

[S2Zetec54]

Dear Roddy, Clifton and Dean, thank you all for your thoughts passing on your experiences. Dean a cam cover like yours is on my wish list….very DFV…love it.

All very good stuff, interesting to hear of the pedal travel adjustment. I think if I were starting afresh I would probably go carbs with the links here and elsewhere for ignition maps ….it seems a well trodden path but I have these expensive throttle bodies and I am quite keen on the efficiencies fuel injection can bring.

My local tuner who has come very highly recommended has directed me down a path he is familiar with and I think there is value to use a system the tuner is skilled with.

So I think I’ve come to a decision and will use an Emu Classic with a new loom which he'll build for me (I have no time)  using a sequential set up……this new system also uses more inputs including water temp and the oem cam position sensor along with a wide band lambda sensor.

I'll let you know how I get on…thanks again for all your help

[Clifton]

My local tuner who has come very highly recommended has directed me down a path he is familiar with and I think there is value to use a system the tuner is skilled with.

FWIW, there's no way to just tune out the part throttle sensitivity. I and every MR2 that runs the same motor I run, have the same problem between 15% (idle) and 25% and we can tune the stock ecu. I just don't want you to get misled that another ecu is going to be better at idle to 25% throttle even if running a TPS or MAF instead of MAP.

[S2Zetec54]

Thanks Clifton, yes it does worry me and this will be my last bash at this and it is a real risk. This hesitation is worse after a few hours of driving so this gives me hope that the maybe some tunability potential with at least some aspects of this idiosyncrasy. We're adding water temp and cam sensors into the mix.....We shall see. It's only money! 😳