Twinc Fuel Injection

[john.p.clegg]

Dear All
Had to start this thread as I'm reading the latest Club Lotus magazine with the fuel injection article by Victor Hollnagel (Danish Club Lotus member) and am in the process of doing the same,thinking of Megasquirt,the problem at the moment is wether to go MAF or MAP..

If anyone out there has an interest or any input I would be most interested...

Many Thanks
John

[jayrz]

Just go back from Lotus Owners Gathering #27, LOG27, held in Snowmass, Aspen Colorado.

Anyway one of the nicest fuel injection systems I saw was actually on a ZETEC installed into a Europa. The throttle bodies were Suzuki GSX600 pieces on fabed mounts and run by a megasquirt ECU. Spoke with the owner quite a while,, you want to run the algorythm for/ and use the TPS, throttle position sensor. He said the car ran just beutifully once he changed to a tps driven system. Also,,, gsxr1000 throttle bodies were simply too dang big whereas the 600 size bodies were perfect.

He has a site called 15psi.com , have a look.

Jay

[SimonH]

John,

I would suggest you go with neither. Use alpha-n with the TPS, i.e. using throttle position against engine speed.

The MAP signal you would get from the 4 short runners would be terrible giving bad lumpy idle and poor drivability.
MAF is not easy to set up well. Better with TB's than MAP but there are a lot of things to take into account when mapping it.

Cheers,
Simon

[lotusanglia1965]

I agree,
Map for turbo cars,
Maf for production cars
Tps for throttle bodied cars.
I have used and would recommend omex ecu's
straight forward to map and good people to deal with.
Martin

[elansprint]

John as simon says go with alpha n if you use map as soon as you come off idle with throttle bodies the manifold vacuum disappears & there is not enough variation in map signal to get the engine to run well. Megasquirt should work well but dont pay too much for it. Suzuki 600 TB's will be fine they have a 38mm bore (bigger than the twink chokes in the webers) you need the individual bodies from a K1,K2 or K3 not the latter ones. You can run off the distributor signal then if you want to run mapped ignition it is smple to convert but it is better to get FI running first rather than do both together espacially if you are mapping yourself.
regards
Ian

[john.p.clegg]

Ian
I was thinking of doing it the other way round,keeping the carbs and changing over to wasted spark on the megasquirt and when that is sorted putting the injection on...

John

[john.p.clegg]

Part 2
Am in a quandry re MAF,I have two Mondeo 2.0 maf sensors(with air temp sensors) that fit in line with the air trunking (neat looking)that give a 5v output and would like to use them...rather than the MAP sensors,are you saying that they are not needed,will TPS,air temp and engine revs suffice?

John

[SimonH]

Yes, TPS and revs will do just fine as the primary load signal.

You will need a TPS anyway so why bother carrying around a MAF meter as well? Unless engine calibration is your everyday thing, and you enjoy chasing your tail, I would avoid the MAF meter to keep it simple. Does the megasquirt support it?

Just get either a seperate air temp and put it into the airbox and get a baro sensor from something for altitude compensation. A good sensor is the combined air temp and pressure sensor from any late model K series Rover (EU3). This will then do both of the above. I can get you the characteristic curves for it if you were to use it.

Get the TPS kit from Weber for your carbs and then you map your ignition first if you want. The baro wont come into play untill you go to the TB's but its nice to wire it all in at once.

Simon

[msd1107]

Hmmm,

I am missing something here.

The thrust of Victor's article was getting a closed loop EFI using a wide band lambda sensor to provide real time correction to the fuel mixture. He mentioned a wide range of improvements that could be gained from this.

If any nits are to be made, it is that the lambda sensor used, while wide band, was calibrated to only 15.5 AFR. As a result, he got only a little above 40mpg. Now, Stromberg carburetted cars have returned 45mpg, so 15.5 AFR is not lean enough.

A web search turned up wide band lambda sensors that are calibrated to 18, 19, and 21 AFR. This, with appropriate modification to the ignition and advance curve is what is necessary for maximum gas mileage.

Also, did you notice that he was sort of grousing that he only got 123 HP, compared with the Sprint spec of 126? But that his dyno run was on a rolling road. Giving a 15% increase to take into account driveline and tire losses gives well over 140 HP, quite good for an otherwise stock Sprint engine. Also, the torque band ranged from 2000 to 7000 rpm (same torque figures there) and from 2500 to 6500 for the torque value at 6500. You would love this engine on the road.

By the way, if you email Jane at Club Lotus, she will send you a .PDF of the entire article, which is better than that in the magazine.

David
1968 36/7988

[john.p.clegg]

Dave
Yes,have the full pdf article thanks

Simon
The MAF was part of the Mondeo "idea",ie
Part 1:- 2.0 Zetec swap :-too much engineering
Part 2:- strip all the EFI off the Mondeo and transplant onto the Twinc (including the ECU)
Part 3:- Instead of the EEC-IV (doubts about its ability to "adapt" to the twinc).Programmable Megasquirt ECU using the Zetecs sensors...

John

[SimonH]

John,

The Mondeo parts swap sounds feasible but there is little chance of the EEC-IV running the Twink, I would be amazed if it runs at all.
The cal would be so very far out as its set up for a plenum with single throttle and who knows what parts Mr Ford's ECU will be looking for from the car. It would need the immobiliser at least I would say.

If you did do the Zetec then it would probably sort of work on a plenum but not TB's.

The megasquirt would be the best route obviously. I think they are pre done to work with the Ford coil packs and other sensors. The MAF part is up to you really. It will work with a bit of effort but its not the easiest route to set up by a long way.
You can probably then use the entire Zetec loom with minimal mods, sensors and all.

Any chance of a copy of the pdf of that article??

Simon

[GrUmPyBoDgEr]

John,

I would like to recommend Paul Dunnell of "Dunnell Engineering".
He's done lots of work on Zetecs, Duratecs & can provide variations of his own ECU. to suit all sorts of engines
Paul has his own tame electronics Guru & between them they have a wealth of knowledge.
I've been running one of his older ECU's with my DCOE's with no problems whatsoever. Oh now what have I done ?
It's also very comforting to know that the expertise is only a phone call away.
I'm sure he would be very hapy to help you with your project
(if you buy his bits )
No vested interest, honest.

Cheers
John

[john.p.clegg]

Simon

You have a pm,,,

Shouldn't need the imobiliser,after days pouring over wiring diagrams,the EEC_!V after being powered down for a while goes into learning mode,but wether it would stretch to twinc parameters??

"If you did do the Zetec then it would probably sort of work on a plenum but not TB's."

why?

John

[elansprint]

John go with ignition first if you want i only suggested it rather than try to do both ignition/fuel at the same time. Megasquirt will run MAF but you will gain more with throttle bodies you can scale the zetec air temp with the MS software. The system usually runs with the ford/bosch narrow band lambda & the use of a wide band lambda is good for tuning the engine on the road. If you go FI first you get the throttle pot free with the suzuki bodies for the ignition you will need the ford coil pack.crank sensor & a 36-1 trigger wheel. You can either use an edis 4 module with it or 2 ignition driver outputs on MS & drive the coil direct in wasted spark mode.
regards
Ian

[john.p.clegg]

Ian
Am well on with the project,flywheel machined 36-1,crank sensor fitted in bottom of sandwich plate, ford wasted spark twin coil mounted on bracket that sits in dizzy hole(no longer required),GPZ1100 throttle bodies fitted with Mondeo TPS nearly ready to be mounted on intakes using standard intake housing(fitted with MAF) and standard pipe to front of radiator.
Techedge W/B sensor ordered (bloody postal strike)
Yes I agree it's best to tackle only one at a time and have chosen spark for some reason but can't remember quite why at the moment...
Am sure the MAF is good for something and would hate to throw it down the road after all the work on it....it fits perfectly!

John