TWEETY's biggest regret

[Subydoug]

Thanks Doug for your trouble taking pics. Great stuff.

My panther trike doesnt have a return line. been using a 2-3 psi electric fuel pump and runs well. the trike has a very large 50 litre tank made of alloy as part of its monocoque chassis so to put another line in there would be a pain.

Just one of the few issues to be conquered in reconfiguring the suck to blow conversion. The work and the fiddling doesnt encourage me. Frankly my wife is fed up with me fiddling so short bursts....while she is asleep lol ! is the go. Cant say I blame her the SC install last year was to take 3 weeks but took altogether 8 months. Surge tanks, rising rate fuel regulators etc seems bit daunting to me.

But to continue with the issues the SC12 is quite large. Even under the spacious Tweety engine bay it wouldnt be easy to remount it to allow for carbie (say 32/36)to bolt in its original location on the manifold. Where my SC12 is now it would need to move 50mm towards the Alt...it has 15mm clearance. The correct mounting of the SC12 took me a long long time.

Doug if your system was more straight forward then I'd be interested. As you described it- its a bit over my little head.

Pity I cant just have a electrical solonoid to shut off on throat of the dellorto. Or a way of - at a switch making the SC12 pulley just turn over without boost to allow for N/A workings. Why mechanical stuff is all so much work is beyond me. T'is why I'm making some cubby houses....wood...is forgivable...

Not too hard tweety, mainly very easy, just more to it then a draw through setup. You can use different carbys then the weber, they just need to have a solid nitrophyl float and seals on all the exits (throttle, choke etc). Holley carbs are pretty easy to get working.

However, maybe there is a way to get your current system better without modifying too much. Biggest use of fuel is your boosting 100% of the time. Solution to this is to run a blow off valve. Issue with that is that there is fuel in the air after the SC, so you'd be venting gas into the atmosphere. Running the vented air back into the carby will mess with your tuning. Just venting the gas into the atmosphere is wasting fuel in the same quantity as just burning it. So what really needs to be done is the vented AF mix needs to be seperated after the blow off valve, so that you can save the petrol. Big question is how to do that without the Wifey noticing......

I suppose the easiest way would be too cool the charge so the fuel condenses. Running a small intercooler after the BOV, then from the intercooler back to the airbox may work. Just need to somehow drain the fuel back into the tank from the intercooler....

Another thought I just had would be to run the blow off valve back in front of the SC, but after the carby so your not blowing fuel into the carby.....but I have to think about that more....not sure if it will mess with the carby.....and you may get fuel condensation or saturating before the motor.....maybe....and heat buildup from putting hot air back into the SC for round 2.....Yep, need to think about that more!

Hmmm, sounds pretty dangerous though.....venting fuel air at good stoic ratios is a pretty bad idea.......you could just plumb the BOV into the exhaust....Afterburners!!

In all seriousness though Tweety, maybe megasquirt is the best answer for you. A single injector into your current manifold, just a little bit of plumbing for an EFI fuel pump, a small computer that you plug a laptop into and can adjust the settings with and a crank angle sensor. I do believe both fuel economy and power would go up. I can have a chat to a mate of mine running Megasquirt on a racing escort. Sure he can give me some pointers for you .

I have been considering going EFI on my wagon for a bit, but I think id build my own ECU. Much cheaper and a pretty cool project .

Crikey I type slow! gotta go to work .

Regards

Doug

[steptoe]

Frankly my wife is fed up with me fiddling so short bursts....while she is asleep lol ! is the go.

Here we are thinking you had an answer to this problem - trade in

[Subydoug]

This is what I think tweety. Id give that a go before anything.

Regards

Doug

[El_Freddo]

Time to bite the bullet Tony and EFI Tweety.

You'll get better economy and if tuneable you should be able to do a fuel map for on boost and off boost via a pressure switch. I'm sure there's a unit out there that can do this.

It sounds like this regret is more of a fuel economy issue rather than a real regret about the conversion as well as the super charger addition. You have a boost addiction and now you're trying to work out how to afford it better!

And with fuel hitting $1.55 per litre for regular unleaded in Shepp I'd be looking at ways to curb the usage too!

Cheers

Bennie

[Subydoug]

I just ordered some stuff, will have a go at making a simple EFI system. If it works Il send you one tweety.

Regards

Doug

[TOONGA]

I just ordered some stuff, will have a go at making a simple EFI system. If it works Il send you one tweety.

Regards

Doug

I would be interested in that as well

otherwise Im looking at a single point system from either a subaru, ford or a holden.

TOONGA

[Subydoug]

I would be interested in that as well

otherwise Im looking at a single point system from either a subaru, ford or a holden.

TOONGA

Dont get to Excited . Been toying with the idea in my head for a while. Its time to take action . Wont be nothing fancy, just Single point. Might hack up my old hitachi for a throttle body to save some time. ECU Will Purely control the injector, just gonna use a pic (18f2550 most likely) if it can sample fast enough. Will also see if I can work out a way of avoiding a crank sensor.........all ideas in the head at the moment.......Probably be prototyped in the next week or two.....Already have the EFI pump in my car .

Probably wont be the best EFI system in the world, but Im hoping I can at least match my Weber, if not better.

Regards

Doug

[pitrack_1]

I would be interested in that as well

otherwise Im looking at a single point system from either a subaru, ford or a holden.

TOONGA

Been following Tweety's progress with much admiration. Much skill shown to get it all set up and working, even more wisdom to be able to say there's possibly a better option and pursue it.

Toonga, my N13 Pulsar has a simple EFI system from Holden- it may be of interest. I believe it uses the same control unit as VN Commodores, jus the Memcal unit programming changed. I will assume it was the same for the Camira too. In the N13 Pulsar/ LD(?) Astra's case there were two options: a 1.6l throttle body injection and a 1.8l multipoint. Both ran without knock sensors or crank angle sensors. They used what I'll call a 'hybrid' ignition system, it was an ECU controlled / advanced distributor where the base idle timing was set in the old fashioned way, by adjusting the distributor body. In the 1.8 MPEFI case, the injectors are fired simultaneously and twice per cycle (ie once per revolution). Unsure regarding the throttle body. It sounds suspiciously like the Bosch Motronic ML4.1 (see wikipedia). Trouble is, they're old now and the early ECUs were known to suffer from Mad Delco Disease. My 1990 version, however, has been robust in spite of several cases of abuse caused by alternator glitches.

[Joel]

I like the whole concept. I never received concrete info about economy prior to the conversion. A beetle owner did a conversion but didnt record his economy before he ripped the engine out for another project. Except he said "the fuel gauge doesnt seem to move faster than previously".

Hi Tony

Bummed to hear about your economy woes.
My Beetle setup was only ever jetted by my seat of the pants so it could have been a touch lean but I did several long trips to brissy and sunshine coast in it and after the 12 months or so it was on it showed no signs of being jetted too lean or rich.

I never took precise mileage records but overall it was only thirsty when I really got on the noise pedal, for the most part it would average anywhere between 8.5L and 9.5L/100 on the stock 1600 VW engine, the worked 1776 engine was obviuosly worse in the brief period I ran the blower on it, but it was never worse than about 11L/100km
I really couldnt see the EA81 being much more thirsty.

I reckon your set up would be far more economical with EFI but where do you draw the line, fuel inject the EA81 or just go EJ both are $$ and would buy alot of fuel.

[TOONGA]

this is a system made by megasquirt called the microsquirt if you do go efi it might be a viable option.

TOONGA

[Subydoug]

That little Micrsquirt is a ripper! Looking over the doco, very basic stuff, but has all the inputs needed for a pretty good efi system. Very cool .

Regards

Doug

[TOONGA]

Yep it is based on the megasquirt but is a compacted version for "sporting" applications.

TOONGA

[Subydoug]

They have all the scematics.....I should build us some .

Doug

[Brumby Kid]

I really don't see why the EA81 is using do much fuel.
They are crazy numbers!
Perhaps a clutched sc?
There has to be some problem with the current setup.

Cheers Cam

[TOONGA]

They have all the scematics.....I should build us some .

Doug

that would be nice how will you flash the eprom chip?

and some of these please

http://www.autosportlabs.net/Megajolt_Lite_Jr.

so we can do away with pesky distributors and run carbied EJ motors

TOONGA

[Subydoug]

that would be nice how will you flash the eprom chip?

and some of these please

http://www.autosportlabs.net/Megajolt_Lite_Jr.

so we can do away with pesky distributors and run carbied EJ motors

TOONGA

I have spent human days programming and flashing chips......Im a PCB Tech .

My Mate with the escort uses megajolt. Very cool system.

One fish at a time but, I really wanna have a go at making my own.

It would be very easy to make a DIS system as well......

Regards

Doug

[Tweety]

Thankyou all for your replies. I'm at best a bolt up guy. Chips - luv them with chicken salt but with ECU's etc I'm lost.

I'm also running 2 part time businesses now so havent got the time to fiddle and the sale of Tweety is several fold. I have come to and end with working on the trike myself. Total burn out!!

Brumby Kid the reason Tweety is thirsty is that the intake is always under some boost. Compressed air means more fuel to keep the ratio close to correct. Thats the reason for the larger jets.

So economy is one reason for the sale, fiddling is another and that makes a new Focus or Peugeot powered trike attractive for a guy that wants clean hands forever. Totally burned out on greasy mechanicals.

Having said that, there is a chance in the next 8 months that I wont be able to sell the trike, or might be forced to sell it without the roof which, isnt a bad idea. Trikes hold their value incredibly. If you paid $25000 for a trike 6-7 years ago you'd get that now. Without the roof I'd get $34000 easily especially because its a rare auto box option.

So, what of a plan B? if I really cant sell Tweety? I've thought a bit about it. Cam suggests a switch on/off type supercharging system. That is one way of getting past the problems of economy. But having admitted, like the topic of this post, that ea81 wasnt the best option in the first place, there would be a better way to go. As has been stated blow thru system isnt so straightforward.

So for conversation reasons I suggest an EJ20 or 22 would be the go. If the 20 is more compact then I'd go that way. Both come under the 20% extra from the Vw 1916 I had in the trike new. So while I'm waiting for the sale of this machine in case I am left with it the option of another engine is highly likely. Then there is other issues- would either engine require engine mounts, mounts that dont exist on this monocoque chassis.? Then there is the diesel option. YIKES!!!! you react. lol its isnt so silly. The weight factor kills it off really but having owned a Hyundai i30 diesel turbo then an engine like that would be attractive. Cam Trikes of Melbourne use VW transaxles and Holden Cruze engines. Cruze also has diesels. it might mean some weighted lead in the front of the trike. Here lies a problem. We have a monocoque chassis made from aluminium...wouldnt surprise me I start getting cracks in the fuel tank or frame sections. VW conversions has a list of some of the 120 adapter plates available for the VW transaxle. I'd want an economical/light/powerful engine mated to the auto.

Then again I could revert to a single carb and take off the SC. Then I'd have my economy but not quite enough power to tow my caravan. Hence the sale.

Your ideas on a new powerplant? EJ, turbo diesel, etc bearing in mind there are no engine mounts.

[Joel]

So for conversation reasons I suggest an EJ20 or 22 would be the go. If the 20 is more compact then I'd go that way.

Gday Tony,
THe EJ20 and 22 are physically identical size, its just the bore that changes.
Even the baby 1.5L EJ15s are the same external size.

Some food for thought for you if you do decide to go that way.

When Custom VW first got into conversions to soak test their stuff they drove a dual cab kombi with a loaded tray from melbourne to brissy also towing a car trailer and on that car trailer was a tractor with a front end loader.
The car trailer on its own weight 650kg so more than your camper and the Kombi weighs 1250kg.

with the empty trailer behind on the way down they were averaging 11L sitting on 100-110.

On the return trip they averaged 15.1L/100km which may sound excessive but he put it on a weigh bridge and it was 5.4tonnes all up......

THe engine was a bog stock unknown mileage EJ22




My beetle now weighs in at 1040kg, with the EJ25 I consistent average 8.5L/100 but with that much power under the hoof its hard to drive it sensibly, especially when it sounds so damn good

[sven '2']

Gday Tony,
THe EJ20 and 22 are physically identical size, its just the bore that changes.
Even the baby 1.5L EJ15s are the same external size.

Some food for thought for you if you do decide to go that way.

When Custom VW first got into conversions to soak test their stuff they drove a dual cab kombi with a loaded tray from melbourne to brissy also towing a car trailer and on that car trailer was a tractor with a front end loader.
The car trailer on its own weight 650kg so more than your camper and the Kombi weighs 1250kg.

with the empty trailer behind on the way down they were averaging 11L sitting on 100-110.

On the return trip they averaged 15.1L/100km which may sound excessive but he put it on a weigh bridge and it was 5.4tonnes all up......

THe engine was a bog stock unknown mileage EJ22




My beetle now weighs in at 1040kg, with the EJ25 I consistent average 8.5L/100 but with that much power under the hoof its hard to drive it sensibly, especially when it sounds so damn good

Love a twin cab...dare I ask about brakes?!

[Tweety]

thanks Joel, nice to hear from you again.

In case I go that way what is the law regarding upping the cc's. I thought it was 20% allowed and any further you werent allowed. the EJ20 would be my choice. I assume it could hang off the transmission like the EA81 is and VW 1916 before that?? eg no engine mounts....but an engineer might have other thoughts on that.

Tweety might be much easier to sell without the roof. but its early days. there is some interest. took him for a spin today and it near broke my heart to think its time to move on.