Help and old geezer learn EFI.

I've bought and read the books.  Bought a Megasquirt. Went on line and read everything. 
Watched U tube  3 part series on Jaguar  EFI. 
Ive even plugged in a few meters and "fixed"  EFI 

HELD parts in my hands, got my hands dirty  but I still fall back to carbs.  
 

My last post convinced me to put a pair of Eaton M90's  on my V12. They will fit. The Jaguar XJR uses one for a six cylinder  it adds 115 horsepower. So pumping 2 into a V12  should work. There is room For a pair   Make an adaptor for the manifold  hook up the drive and Bob's your uncle. 
 

Except  I want to cut off the intake and weld on an adapter to use SU carbs.  I know I'm wacko but am I really that stupid?  Just because I can't get my head around EFI?  
Are there professional people who can fix me?  
is it affordable?  Do I need a federal grant or is there enough in my piggy bank?  
 

How does it work?   Do they send me sketches? 
black boxes. Laptop computers with algorithm's explaining things?  
In short, Help! 

In reply to frenchyd :

Congrats on learning new systems! Right now you're in a position of not knowing what you don't know-this makes asking the right questions impossible. 

If I were you I would treat it like a puzzle-start putting pieces together until more of the picture becomes clear. If you keep chugging along you'll run into specific questions that the forum can help you with. 

You'll learn EFI the same way you learned SU carbs-by working on it. 

Can you look at the EFI system from an EFI Jag and see how similar everything is?   Did the V12s ever get EFI?

frenchyd said:

 but I still fall back to carbs.  

My last post convinced me to put a pair of Eaton M90's  on my V12. They will fit. The Jaguar XJR uses one for a six cylinder  it adds 115 horsepower. So pumping 2 into a V12  should work. There is room For a pair   Make an adaptor for the manifold  hook up the drive and Bob's your uncle. 
 

Except  I want to cut off the intake and weld on an adapter to use SU carbs. 

I'm kinda similar. Old guy (some say dinosaur), I'll likely have a EFI car to race in my future, prefer carbs (Webers). But my uncle's name was Leo. I'll be watching this. 

Mr_Asa said:

Can you look at the EFI system from an EFI Jag and see how similar everything is?   Did the V12s ever get EFI?

Yes they were originally designed to be EFI.  the first 3+ years with carbs were an bandaid to sell something. Anything because a Jaguar was a tiny company and a whole new engine cost more than they could afford   
The next 3 years they took VW Rabbit  systems ( 3x4 cylinders =12  cylinders )   And sorta kludged a system to work  Finally by 1978  Lucas came up with  system that didn't infringe   on Bosch's system too much  and shortly after that they went from analog to digital.  
what really killed the V 12 is they couldn't make it meet the newest smog laws and provide OBD2 compliance  

    From 1975- 1984 there were  4 different EFI systems  used when some years barely 1000. V12's were manufactured. 
All this while trying to keep a price point about 1/3 of the other V12's in production.  Ferrari.  

CrustyRedXpress (Forum Supporter) said:

In reply to frenchyd :

Congrats on learning new systems! Right now you're in a position of not knowing what you don't know-this makes asking the right questions impossible. 

If I were you I would treat it like a puzzle-start putting pieces together until more of the picture becomes clear. If you keep chugging along you'll run into specific questions that the forum can help you with. 

You'll learn EFI the same way you learned SU carbs-by working on it. 

Well I do know that Jaguar  used their distributor as a crank position sensor.  One side of the rotor triggered spark the other side located TDC..  That a lot of their sensors are analog and trying to get a Megasquirt to speak British  is like trying to teach a deaf person to sing opera 

Do you have a basic understanding of how a simple factory efi works, and the problem is setting up your own aftermarket system? Or are confounded by all efi? Either way there is an article on diyautotune (I think) about converting from from carb to tbi. It it is the most basic form of efi, work on understanding that, then you can move up.

Found the article

Can megasquirt run sequential injection on 12 cylinders? I'm sure you could run it as batch injection if not. And if anything you should be able to get away with wasted spark ignition if it can't run 12 coils. 
As far as sensors, a 3bar MAP should do all you need for boost, you'll want a good wideband O2 on each bank, and crank and cam sensors are pretty easy. Lots of folks machine their own trigger wheels. The distributor is often turned into a trigger wheel to act as a cam sensor in the acvw world. That and 12 injectors of your choice. It's just wiring and plumbing after that, nothing too complex. You can source and adapt GM sensors as I do know megasquirt does good with them. 
As for making it all work and communicate and synchronize and actually run? Not a clue. 

Start by realizing that the EFI and the Carb do the same thing, They mix fuel and air in the correct proportions based on the load signal from the engine.  That signal can be either vacuum signal MAP or Air entering the engine MAF.

Carb uses a rube-goldberg arrangements of linkages, pumps and jets to cover all operating conditions. EFI reads what the actual conditions are and can be adjusted to deliver the best fueling for that given condition,

If you know how to tune a carb, then you know how to rune EFI since they have the same goals. The thing with efi is that it is going to provide you with a lot of data that tells you how well tuned your are for a given running condition. Up to you to understand that data. 

The various sensors that make EFI so efficient can be a double edged sword; if they are malfunctioning due to install error or damage, they will be lying to the system and suddenly you have nothing you can trust. for example an air leak into the intake can convince the O2 sensor that the mix is lean, so it will ask for more fuel. Or temp sensors can be off for air or water that will then tell the system to do something not good.

EFI will make you walk home. Sooner or later some Chinese electronic sensor or transistor is going to die on your home brew efi. You aint fixing that on the side of the road. Carbs will usually give you both warning and relief since there is most often a way to coax a few miles out of a carb that is having a bad day.

Ask yourself, if forced  to fly in a plane that you built, what would you chose for fuel mixing? Go with that.

Also, I don't care what anyone says, the only benefit of EFI over carbs is the ability to adjust to different running conditions i.e. altitude and temperature changes. 
And I suppose the argument could be made about ease of cold starts. 
 

Anyway. Nothing at all wrong with learning something new, in fact just the opposite. But. If you know carbs, you can tune them, and if you only plan to run local tracks chances are it'll only be during one season and no altitude changes to worry about. A good wideband will let you know how good you are with carb tuning in real time. 
Also keep in mind that with a draw through setup, supercharged or turbocharged, a carb never sees that boost. It only sees air speed/vacuum. Same as it would with an NA setup. 
Again, learn something new. Expand your knowledge base. But don't buy the argument that EFI is always superior. It has advantages, but complexity comes at a cost (both monetary and fragility (and the need for AAA))

In reply to barefootskater :

You and I agree completely. The original carb powered V12 was only 20 horsepower less than the EFI and if you eliminate the dogleg it gave back  30 horsepower so technically EFI cost 10 horsepower.  

 But I cant fit a carb except the SU and there I'm limited to 400 CFM. I measured and tried combinations with some carving of the cowl I could get 450 CFM but there would be 4 " lumps"  just in front of the windshield.  And working on the carbs became something I'd have to do with mirrors  and custom bent needle nose pliers  figuring out how to sync the carbs. 
 

The stock GM fuel injection gives me lots more options. Without the carving in the cowl area  and a simple bell crank to work the throttles. 
All I gotta do is teach the British computer to speak American or the  American throttle to speak British. 

gearheadmb said:

Do you have a basic understanding of how a simple factory efi works, and the problem is setting up your own aftermarket system? Or are confounded by all efi? Either way there is an article on diyautotune (I think) about converting from from carb to tbi. It it is the most basic form of efi, work on understanding that, then you can move up.

Found the article

No I'm reasonably comfortable with EFI.   For example I know that the V12 is batch injected. That works surprisingly well because of the even firing  of a V12.  Adjacent cylinders fire every 60 degrees  where a V8 has adjacent cylinders fire anywhere from 90 degrees  to 270 degrees  that's  a long time for fuel to hang around  and well rules is rules fuel will like to drop out of suspension.  
So batch firing is fine.  
 

I'd like to have a nice chart in front of me to figure the optimum injector sizes. 'Cause I'm really in love with E85. I think there is potentially some magic  with the potential boost of the M90's  and the 7.8-1  compression.  
 Normally the M90 works around 8 pounds of boost.But instead of feeding around 4 liters  it's feeding  a little over 2&1/2 liters.  Allowing for efficiencies I might be working around really wild boost numbers. 
That might be scary  but with all the studs holding the head and so many of them going all the way into the crankcase  the block is remarkably strong. 
 

When  you add the  the strength of the rotating   components   The engine might survive silly boost levels.  If it blows up ?   Oh well,     next? 

In reply to frenchyd :

Don't over think injector size hp/number of cylinders. I know 36lbs ford injectors will feed 230+~- hp on a 4 cylinder 42lbs injectors will feed 330ish (on gasoline). If you want to go E85 which needs bigger injectors you can probably find something that's relatively small and cheap because each cylinder is relatively small. At least compared to a big block , or even to the 60lbs injectors I run in my 4.8. 
 

Edit: gm guys sell white (32-36lbs) injectors super cheap because they don't flow enough for turbo ls stuff but they may be enough for your 12 cylinder. 
 

Edit 2 : Looks like on e85 with 80% duty cycle you could run 42lbs injectors and have a little head room on a 12 cylinder. 36 would be a little light on e85. 

1SlowVW said:

In reply to frenchyd :

Don't over think injector size hp/number of cylinders. I know 36lbs ford injectors will feed 230+~- hp on a 4 cylinder 42lbs injectors will feed 330ish (on gasoline). If you want to go E85 which needs bigger injectors you can probably find something that's relatively small and cheap because each cylinder is relatively small. At least compared to a big block , or even to the 60lbs injectors I run in my 4.8. 
 

Edit: gm guys sell white (32-36lbs) injectors super cheap because they don't flow enough for turbo ls stuff but they may be enough for your 12 cylinder. 
 

Edit 2 : Looks like on e85 with 80% duty cycle you could run 42lbs injectors and have a little head room on a 12 cylinder. 36 would be a little light on e85. 

Wow!!! Thanks for that calculation.  I'm trying to remember the numbers on Lucas injectors. Drawing a blank right now. That sounds near where One set is. I'll check 

barefootskater said:

Can megasquirt run sequential injection on 12 cylinders? I'm sure you could run it as batch injection if not. And if anything I you should be able to get away with wasted spark ignition if it can't run 12 coils. 
As far as sensors, a 3bar MAP should do all you need for boost, you'll want a good wideband O2 on each bank, and crank and cam sensors are pretty easy. Lots of folks machine their own trigger wheels. The distributor is often turned into a trigger wheel to act as a cam sensor in the acvw world. That and 12 injectors of your choice. It's just wiring and plumbing after that, nothing too complex. You can source and adapt GM sensors as I do know megasquirt does good with them. 
As for making it all work and communicate and synchronize and actually run? Not a clue. 

The whole system works on batch firing ( since V12's fire adjacent cylinders every 60 degrees  it works much better than V8's who fire adjacent cylinders between 90  & 270 degrees apart . That causes atomized fuel to drop out and causes all sorts of issues) 

Yes on the V 12 the back side of the rotor is the crank position sender. 
Yes most V12's used a distributor  right up until 1992 and so only the last 5 years of production were distributor less.   actually since the engines were built in batches  only 2 batches were built that way 1993 and late 1994. In 1997 only 2 V12's were sold. 
There doesn't seem to be an O2 sensor that I can see or is shown in the early manual I've  got. I know later ones had them. 
 

Finally you mentioned a 3 bar sensor to detect boost.  Since the Eaton M90 is designed for 4 liters  and typically produces 8+ pounds of boost, a pair of them feeding 5.3 liters might push that 3 bar limit. 
I suppose I can  under drive them but I wonder  what happens to efficiency ?  
If you read everything that people had written about  getting Jaguars to run using the Megasquirt system you'll understand my reluctance.  It's anything but a plug and play system.
Is there a better choice?  something that speaks British but understands Yankees and boost?  
preferably something that doesn't require me to open the case and start soldering? 
 Being semi electronic literate I can speak color code ,  and I don't need to keep it in the trunk like the hired help. 

On a micro and distributor it should be even simpler than other installs. You will want to watch 6 injectors per driver, may need the upgraded ones (I should have  set). Adding an O2 to each bank is easy enough and innovate LC2 or spartans are cheap (<200 ea). 

There is nothing different between yankees and brits, I have gotten lots of these to work, and krauts too which are generally problematic. As long as you can get some sort of rpm signal into it that's workable, the rest is cake. 

It's not *that* hard and I am available to hold your hand at $75/hr and it's amazing how many people jump at that.

In reply to frenchyd :

Not being familiar with British cats, I'm not sure the dizzy is ideal as a crank sensor since it only spins at 1/2 crank speed. That may be different in the 12, idk. 
 

As for Americans speaking to brits and vise-versa, irrelevant. Sensors are sensors. They may have different operating ranges or even different names, but most folks I know that use megasquirt simply adapt common GM sensors anyway. 
Also, someone correct me if I'm wrong, but if you plan to run batch fire injection, you don't need a cam sensor. So that simplifies things a bit. 

In reply to Paul_VR6 (Forum Supporter) :

How much hand holding would it take to get a Megasquirt to like working with a twin supercharged* V12?  I can wire the distributor and figure out the crank triggering wires from it. Welding in a bung for the O2 sensors (4 exhaust manifolds  1 per side?  Just one? ) 
I don't need you to install or connect anything. Just  sort out what goes where and  what connectors are needed plus where do I plug the lap top into?  Yeh and what program to buy so everybody is speaking to each other. This is a race car. I can sort out the tuning issues as I get it up and running. 
 

I don't need a firm quote,  just an idea of how fat my wallet Should be.  I'll assume extra time is at the $75 /hr? 
 

If the mega squirt isn't the right electrons what comes closet to a plug and play?  

* I don't have the superchargers yet. But assume they will be matched GM. M90's  of years are critical etc let me know before I go shopping. 

The microsquirt should work fine the only thing that may end up close is the total injector load, I'd have to calculate that. Matt may know the limit better than I do, I have run up to 5 12ohm per bank on one.

MSextra.com > Documentation > MS2 > Microsquirt manual and Tunerstudio manual

Tunerstudio.com download TS for your OS and the log viewer, laptop plugs right into the Micro with a usb adapter (do you have one?)

1 O2 per side/bank

sc or not doesn't really matter much other then a few setup details, you can do quick napkin math on how much boost they made on the old displacement, then multiply by the ratio of the new to old displacement (taking into account one SC will feed half your total) assuming same sc drive ratio

I generally end up at 4-5hrs support for someone who knows NOTHING to a car that runs pretty well.. assuming they can listen and follow troubleshooting steps, etc. 

In reply to Paul_VR6 (Forum Supporter) :

Thanks that sounds more than fair. And exactly the sort of help needed. 

No problem best bet is just find me at kandpperformance at gmail dot com when you are ready