Should I change to ECU & TB, who has done it ?

[crypto]

Couldn't find a lot in the forum regarding this conversion. My Sprint is currently not running extremely well. And before investing more time and money in the old carburettor and ignition system I would like to learn from other members who have already done a conversion.

I intend to use an omex kit with the 600 ECU and their TB's. I know it's expensive and complicated and involves a lot of changes etc. but I would like to hear more from a personal point of view what has improved most. E.g. cold / warm start, fuel economy, change of torque / power and maybe an owners already using an omex 600 ?

Thanks, Peter

[john.p.clegg]

Peter
I run a Megasquirt ( DIY build,tune,home made TBs )

" cold / warm start, fuel economy " all improved

John

[Spyder fan]

Peter,
All the people I know who have done this to a Twincam seem very happy with it. Really hands on people like John have engineered their own solutions with good results, others like me have bought an off the shelf system from Jenvey and Emerald or similar such as the system you are considering. I think it best to go with the system that gives you the most support in getting it all set up and running properly.

There is an old topic that briefly discusses the merits here lotus-carbs-f40/fuel-injection-t19597.html

Brian Clarke who doesn't post too often these days runs throttle bodies in his Sprint (BCMC33) and gets 40mpg plus better running characteristics.

[crypto]

Peter
I run a Megasquirt ( DIY build,tune,home made TBs ). ...

John, can you get into details, e.g. what type of Megasquirt you are using, which kit did you buy ? How good/satisfied are you with the PC application to adjust/control it ? Are you running fully sequential ? Are your TBs the same length and diameter as the original Weber/Dellorto ? Where did you get the swirl pot and pump ?

Cheers Peter

[john.p.clegg]

Peter
Long story ( steeeep learning curve ),but I bought rather than build a Ms1 V3,and am well pleased with the controlability of it from a cheepo HP NC6220, ( need a serial port ) as a matter of fact both SWMBO and myself use them as day to day laptops , the only thing lacking at the moment is someone who has PC and Tuning skills to sit with myself for a hour or so as I drive to sort out the AFR table...saying that my MPG has increased from 28 to 38 (target..over 40 ).
The Ms1 is not capable of full sequential . but when you do the math you don't need it, the injection pulses are longer than the valve opening times at high rpm,the atomised fuel just sits in the venturi and on the back of the valves cooling them.
The TBs ( GPZ1100s ) are the same length as the dellortos but am experimenting on a plenum and single throttle body,last year nearly got it to work,loads of low down torque ( which is what I was after ) but it back fired ( literally ) and blew up the plenum ( have a plan to re-fit the dizzy to prevent the wasted spark igniting the plenum...).
The swirl pot was home made from a triton shower capsule ( good old Blue Peter ) and the fuel pump a Bosch item ( beware of Bosch types- they are cheaper but don't last as long ).


John

[gherlt]

Just a thought: I would give Keith Frank a try, read his papers and use his Hypojets/Etubes.
He tries them on an Elan. There are a lot of people who's engine got a lot better.
You will find him in Yahoo groups and http://Webstore.com/~DCOE_Tuner

[gav]

Peter
I gave up with unreliable electrics - whatever I replaced, I couldn't get my engine to run reliably and I drew the conclusion that modern replacement parts aren't as good as the originals.
I wanted a car that would start on the turn of a key and gave no grief thereafter and was going to fit an ignition only system but allowed myself to be talked into a full fuel injection system. Truth is that I haven't looked back but there are some buts that go with the conversion:-
1) It was expensive and I am only running Jenveys and an Emerald system which I suspect is the lesser end of the market but I think very good (if you are into tinkering, the emerald programme can be downloaded for free and you can re programme elements of the system at home)
2) you do need the system setting up on a rolling road.
3) I ended up with a lifter pump and swirl pot which along with the fuel pump and filter took up a fair amount of the boot. Next time I might have a new fuel tank made with a pump within.
4) you need high pressure flow and return pipes running from the tank/ swirl pot to the Jenveys and back again so this needs planning
5) There is a mass of electrics to wire in (I'm not electrically bent but I quite enjoyed that bit - it is pure logic)

So a fair amount of planning, work and money. Would I go back to carbs and dodgy electrics - no I love it. I have a pretty smooth power curve for the cams I'm running and a reliable engine that starts on the button every time.

I hope this adds a balanced opinion that is of use.

Good luck
Gavin

[pauljones]

Guys,

I run mine on Emerald and Jenvey TBs.

Reason was reliability and economy as well as a few others.

Basically I started with a new fuel tank from Axminster Panels, it was designed with built in swirl pot and a return pipe.
This gravity feeds the 044 spec Bosch fuel pump via a pre filter. Used -8 fixings. The fuel pump is ECU controlled and must run via a relay for this.

This goes direct to fuelrail with the fuel regulator at other and and the return direct to tank.

Other than that it's actually a simple swap from carbs to TBs. Bolt off,bolt on with gaskets. The linkage needed a bit of fidleing to fit properly and id honestly think about a propper Webber twin spring return instead. My filters are Webber but thin and I'd also want to fit a deeper setup so I can fit trumpets in, don't have any at moment.

The inducton side is easy really,I will say I worked with a profesional to fit it all but they did all the electronics themselfs.

A blanking plate takes care of the now removed dizzy and a trigger wheel from qed supplies the pickup. Be carefull when this is fitted as there's a much needed air gap, get it wrong and it will not work.

Spark is picked up as above and the emerald in mine runs a standard zetec cool block and Leeds. The Leeds are actually two new sets from halfords,and I used the appropriate size Leeds to make it look nicer. If I could id have Leeds made to suit but it's the price.

Altho not fitted yet I have a wideband 02 senser recently supplied via emerald. This is because the coolant senser is only read when the stat opens, so on warm up it's very rich. I hope the extra fuel control will help with this.

As stated the electronics were done professionally and it was rewired at same time,

Jkm in Portsmouth not only were closest rolling road to me but we're also recommended by Dave from emerald. They picked up the issues with the air gap and set it up.

The pics were out up years ago on here, and off top off my head is 105 but, I'm still unsure if this is wheels or crank but I think the torque was 88, and almost flat from just over idle to a little over 6k rpms.

It wasn't the cheapest but I saved up my money from being in a desert for 9 months and got the best package from emerald I could. It's the best mod I'd done and meant fuel was now excellent, started better when warm altho the over fueling at start up hinders it when cold. I still need this sorting. It's also alot smoother to drive round towns but still has that intoxiating induction roar. It's not lightning fast but it's a plus two with a 3.54 diff so I don't think it ever will but it's fine for me.

Hope it helps

Paul

[gav]

Paul

I run a pre heater which is permanently plumbed into the heating circuit making starting very easy.

Whilst I agree that it is not adding lightness, it really helps starting and I think will preseve the engine. Might this assist with your starting problem?

Regards
Gavin

[pauljones]

Gavin

I never really considered that as an option.
To be honest it actually started fine on the carbs so it's just the richness that needs adjusting. Jim at JKM set it up this way because he said the coolant senser was the wrong side of the stat and it was safer, but when it's cold cold it fouls the plugs before starting. I had to heat the plugs up to get it to start.
I should adjust the cold start table really.
Slark racing in Amesbury, SRE, are 10miles from me and are emerald rolling road specialists. They will be installing the wideband senser and rolling road tuning her. Strange because as soon as the electronics are working fine and the twinks running as it should then I'm taking the twink out and replacing with a zetec.

Thanks for the recommendation tho, appreciated.

Paul

[memnon]

I've done it,

I am on Jenvey's and an MBE ECU,

Most people have covered the steps. But I can give a back to back comparison standard sprint vs My Sprint

Jenvey's need starting with a little throttle, but when you have learnt the position, its a doddle.

I have no flat spots anywhere in the rev range, whereas on std chokes the sprint could be lumpy and not pull around 2000rpm (we fixed it by taking the choke diameter down 1mm)

I have way more low down torque.But at every point on the curve I have more urgency & power
I do run a hotter cam profile than std (Can't remember what off the top of my head though)
The car will keep on revving all the way to 6800, where I have the limit set, as I am std rods & crank.

It still sounds like a twin cam, but even on a standard size exhaust its got a slightly deeper tone.

I can't comment on fuel economy - as my right foot may have become heavier since the changes.

I love a standard car, but I'd take my 5 spd, more modern equivalent most days.....

Hope it helps, if you are anywhere near Coventry and fancy having a look, just let me know.

Jason

[crypto]

Hi Jason, thanks for the offer to have a look, unfortunately I'm not that close to you (Switzerland)
In the meantime I bought new TBs from Omex (they look nice I must admit) and also the ECU from them.

I intend to do the conversion in 2 steps, first the ignition only (but with throttle position, coolant temp, air temp and barometric sensor) and if that runs properly I will add the injectors.

Have you any experience with return less fuel systems ?
What kind of injectors are you using ?

Thanks Peter

[greg40green]

I have been following this thread with some interest as I plan to add fuel injection to my next build project .

Gavin mentions a petrol tank with a swirl pot and pump built in does anyone know who supply's this type of petrol tank ?
Thanks , Greg,

[gav]

Greg

It was Paul not me - but I think it is a great idea.

I get my alluminium fabrication done at AH Fabrications so they may be able to asist but sadly the swirl pot in the fuel tank wasnt my idea (wish it was)

All the best
Gavin

[stevebroad]

Is there a sound difference between carbs and TBs? Difficult to beat the sound of twin 40s (or 45s for that matter) on full chat