Adding a second set of injectors to handle boost?

Paul_VR6 (Forum Supporter) said:

frenchyd said:

    But I never see them go under the hood and change  anything.  It's always in the laptop.   


      
       

What the heck is changed under the hood other than the plugs?  It's a bit true, other than doing a preflight check and verifying nothing mechanically or electrically stupid is going on there is little to do to the actual engine itself unless something breaks. Even then, it's not like you put a rod and piston back in if something goes wrong. 

I tuned a car in Australia a few weeks ago from my basement in Pennsylvania. The hardest part was the time zones.

 I was thinking they were removing and replacing springs in the boost controller.  And dialing the fuel bypass around.          
      Please remember who you're talking to.  Mr. Card  carrying Luddite. ;-)  with his two buddies Mr. 1970's designed EFI, no, no actual tubes.  It uses those modern transistors ;-) and lots of vacuum tubes. 
      And his buddy, pocket change!!  
   Sure I know the factory changed things for race cars. And probably had to steal a few pieces from the Queens jewelry box to do so back in the day.  ( Sir William  did look awfully  chummy showing the Queen around);-). 

    So I stick my Megasquirt in, wire it up, connect the unit to the lap top and all that stuff turns into typing instead of wrench's?   Sorcery, witchcraft,  I say!  The club will burn me at the stake.  

frenchyd said:

   What my mind fails to grasp though is the variation from warm idle to full tilt boogie making 5-6-700+ horsepower.   Or a little partial chirp of fuel to a full throated fire hose of alcohol and fuel.   All done with a little injector?    I mean the feed hose is 5/16's ?  That's enough?         

Fuel injection runs higher pressures than carbs typically do, that means you can get more fuel through the same size hose.  5/16"s hose is good for something like 400-500 hp if you're running normal gas (somewhat less on E85).

Injectors have a range of on-times over which they work effectively -- just as 80-90% is your maximum useful on-time, there is a minimum time below which they don't function predictably.  One problem with running lots of boost on a small engine is that injectors big enough to make the max hp numbers may not be stable when operating at very short on-times and often have trouble idling smoothly.  This was particularly a problem in the 90s, which is why fuel injected rotaries often have factory staged injection.  Newer injector technology has largely fixed it by now though (plus direct injection, of course).

In reply to codrus (Forum Supporter) :

I need to remember times 12.  Injectors for 700 hp need to make 58 horsepower per cylinder which if it's a V8 that's not even 500 hp. 
      The fuel line from the gas tank  is I think 3/8's  and the  hose from the injector  manifold is 5/16's. 
     If I need to fabricate something bigger  I can always grab a couple of fuel manifolds from 2 Trail Blazers  and if I'm using Chevy injectors that will click right on.  
   Are injectors all the same physical size?   Down at the base where it goes into the intake manifold?   I think there is a little extra beef in that pocket.   Should be able to enlarge it easily enough.  
   Can I use a Chevy injector on my Jaguar? I realize I may need to change hold downs and connectors etc around. But hey!  That's just mechanical stuff. Even a card carrying Luddite understands that.  ;-)

frenchyd said:

In reply to codrus (Forum Supporter) :

I need to remember times 12.  Injectors for 700 hp need to make 58 horsepower per cylinder which if it's a V8 that's not even 500 hp. 
 

You will only need something like a 42lb injector to meet your needs on gas.
      The fuel line from the gas tank  is I think 3/8's  and the  hose from the injector  manifold is 5/16's. 
     If I need to fabricate something bigger  I can always grab a couple of fuel manifolds from 2 Trail Blazers  and if I'm using Chevy injectors that will click right on.  

Be sure to check the spacing between the cylinders. Sometimes it's easier to make your own fuel rail.
   Are injectors all the same physical size?   Down at the base where it goes into the intake manifold?   I think there is a little extra beef in that pocket.   Should be able to enlarge it easily enough.  

There are several common body styles, then some styles come on various lengths.
   Can I use a Chevy injector on my Jaguar? I realize I may need to change hold downs and connectors etc around. But hey!  That's just mechanical stuff. Even a card carrying Luddite understands that.  ;-)

Your jaaaag won't know it has gm parts in it. A fuel injector is nothing more than a relay that opens and lets fuel in. 
 

Stop overthinking and just put it together. Walbro 450 in tank pump. 42lbs gm injectors. Gm 3 bar map , use your stock coolant sensor if you want or use a gm one. Run a new fuel line from your big Walbro to the fuel rails then use your existing line as a return. 

For the op,

we ran a tercel to 98mph in the quarter with a 100$ used aem piggy back bought off someone who never used it. 
 

More basic than that I'd just go with an fmu. Like others have said though, used microsquirts can be pretty cheap. 

In reply to Honsch :

I recall several Saab Turbo owners using SDS units, with good results, about 20 years ago.

Tangentially related, there was one guy who did a lot with water injection (he was an Aquamist dealer) and extra fuel injectors back then. Two pieces of advice he gave, with potential relevance to this thread, FWIW: if mounting a single injector, put it as far upstream of the throttle as possible, eg, at the intercooler outlet; for multiple injectors, mount them as far back on the runners as possible. 

frenchyd said:

   Are injectors all the same physical size?   Down at the base where it goes into the intake manifold?  

There are three common sizes of port injectors, EV1, EV6, and EV14, from oldest to newest.  The 1s and 6s are the same length and have the same size O-rings at the top and bottom, but the 1s are fatter in the middle.  The EV14s are shorter, but you can get adapters to put them into engines designed for the earlier ones.

You may also run into high vs low impedance, which is an electrical difference.  Low impedance (aka "peak and hold") require more complex circuitry to drive, but are better for short duration times.  Modern high impedance (aka "saturated") injectors have pretty much made that irrelevant though, so almost all EV6 and EV14s are high impedance.  Even in the old style s the low impedance ones were fairly rare.

frenchyd said:

 I was thinking they were removing and replacing springs in the boost controller.  And dialing the fuel bypass around.      

The wastegate spring is usually set in the build, there are some limits to how high you can go on a fairly low spring, but this is known at the outset. The controller itself is totally electronic, off they let the wastegate spring work as intended, a 10psi spring gets you 10psi. If you start cycling the valve, it will raise boost (not linearly usually) but 2-2.5 the wg spring is typical for most setups and this is plenty. Fuel pressure usually you set and leave alone but there are some fancier things you can do with pwm controlled fuel pumps now.

For OP:

I think extra injectors would have been a challenge-solution 15 years ago. 

MS EFI systems and decapped LS injectors have gotten so cheap it's just not worth it anymore.

Some OE ECUs from the 80s/90s also have full fuel and spark control at this point as well.

1SlowVW said:

frenchyd said:

In reply to codrus (Forum Supporter) :

I need to remember times 12.  Injectors for 700 hp need to make 58 horsepower per cylinder which if it's a V8 that's not even 500 hp. 
 

You will only need something like a 42lb injector to meet your needs on gas.
      The fuel line from the gas tank  is I think 3/8's  and the  hose from the injector  manifold is 5/16's. 
     If I need to fabricate something bigger  I can always grab a couple of fuel manifolds from 2 Trail Blazers  and if I'm using Chevy injectors that will click right on.  

Be sure to check the spacing between the cylinders. Sometimes it's easier to make your own fuel rail.
   Are injectors all the same physical size?   Down at the base where it goes into the intake manifold?   I think there is a little extra beef in that pocket.   Should be able to enlarge it easily enough.  

There are several common body styles, then some styles come on various lengths.
   Can I use a Chevy injector on my Jaguar? I realize I may need to change hold downs and connectors etc around. But hey!  That's just mechanical stuff. Even a card carrying Luddite understands that.  ;-)

Your jaaaag won't know it has gm parts in it. A fuel injector is nothing more than a relay that opens and lets fuel in. 
 

Stop overthinking and just put it together. Walbro 450 in tank pump. 42lbs gm injectors. Gm 3 bar map , use your stock coolant sensor if you want or use a gm one. Run a new fuel line from your big Walbro to the fuel rails then use your existing line as a return. 

 

I'm lucky,  the cylinder centers are the same on the Trailblazer as on the Jaguar 6 cylinder which was made from 1/2 a V12. I like the idea  of the GM connectors  because they just click together.  Where the Jaguar  has this fiddly assembly process  that is easy to mess up.  
     Jaguar has an external fuel pump but it only puts out about 30 PSI  Is there an external version  of the big Walbro  450 pump?  
I might even grab the throttle bodies off them since replacing GM sensors should be much easier than Jaguar sensors.  
I might even go with an aftermarket crank sensor.  Then I can get rid of the distributor.  
  I'm tempted while I grab the Trailblazer fuel rail to also grab  the flex fuel injectors.  My calculations are they will work since the trailblazer  is feeding 700 cc's per cylinder and I'm at 442 cc's  per cylinder.  Or horsepower stock 48.8 per cylinder to estimated 58 per cylinder horsepower goal.  

codrus (Forum Supporter) said:

frenchyd said:

   Are injectors all the same physical size?   Down at the base where it goes into the intake manifold?  

There are three common sizes of port injectors, EV1, EV6, and EV14, from oldest to newest.  The 1s and 6s are the same length and have the same size O-rings at the top and bottom, but the 1s are fatter in the middle.  The EV14s are shorter, but you can get adapters to put them into engines designed for the earlier ones.

You may also run into high vs low impedance, which is an electrical difference.  Low impedance (aka "peak and hold") require more complex circuitry to drive, but are better for short duration times.  Modern high impedance (aka "saturated") injectors have pretty much made that irrelevant though, so almost all EV6 and EV14s are high impedance.  Even in the old style s the low impedance ones were fairly rare.

 

 That's very helpful. Thank you.   If I replace injectors with GM. And sensors with GM the Megasquirt should be content and let it  run.   My Luddite question is, how does the Megasquirt "learn" that the firing order is a V12?   

1SlowVW said:

For the op,

we ran a tercel to 98mph in the quarter with a 100$ used aem piggy back bought off someone who never used it. 
 

More basic than that I'd just go with an fmu. Like others have said though, used microsquirts can be pretty cheap. 

That is how we we able to get enough fuel into a twin turbo'd V12 where it didn't have any memory in the EFM.  Everything was vacuum hose and transistors. We used a FMU  to trick it into thinking it was lean.  

An MS2 won't care about the firing order - injectors fire in groups and are not timed to valve events. Early injected Jaguars were the same way. MS3 gives the injectors letter codes and fires them in alphabetical order. Trivia: one of the first MS3pro prototype installations was on a speedboat with a Jaguar V12, by Ed Senf.

In reply to MadScientistMatt :

That I understand.  But something has to trigger the spark plugs if you no longer have a distributor.  

I seem to recall one of the nutters in my old Lincoln Mark VII forum had a blower on his car (all Mark VIIs were speed density) and had an injector hooked up to a boost pressure sensor that would fire off the injector at X psi. He flogged it pretty hard and kept it speed density.

frenchyd said:

In reply to MadScientistMatt :

That I understand.  But something has to trigger the spark plugs if you no longer have a distributor.  

You run a crank mounted trigger wheel (36-1 off the Fords is a common retrofit) and that deals with the triggering activities. It's enough for waste spark (fires alternate firing order plugs simultaneously) or add a cam sensor for full coil on plug sequential ignition. Your microsquirt can do none of this (on a v12), it will just trigger off the distributor.

In reply to Paul_VR6 (Forum Supporter) :

 When  Jaguar went to EFI in 1975 they put a Hall effect crank trigger on the back of the distributor rotor  ( oops)   They stopped that in 1992 and went to a proper crank trigger  when Ford disposed of the Whirlygig ( distributor ) using coil on plug arrangement.    Using 6 coils and dry firing on the opposite off stroke. However not many V12's came to America under Ford.  Maybe 5000? By the time they ended V12 production in 1997.  Rare and reliable  so you don't find any in junkyards.  
   
    I say hurray!    Setting timing on the V12 is a night mare.   You have to take the distributor apart and then using a ball end socket loosen 3 set screws. And rotate it the 3 degrees allowed. 
 Then reassemble the distributor and go check the timing.   The  mark is on the bottom of the engine.  So you need about 50 feet of extension  for the timing light to get underneath  and see where you moved the timing to.  If you went too far or not far enough you need to start all over again.  
Nobody  checks the timing on a V12 Jaguar.  
      
     I'd like to use a crank trigger.  So I can fire the ignition and adjust timing with the lap top computer. I think that's going to be rather important using boost and E85.  

   I just don't understand how it "knows" the firing order?    Is there a program in the memory that tells it "hey!  this is a V12".   Does it have an algorithm that divides the crank pulses and say's Hmmm it's every 60 degrees instead of 90?    
   If I suddenly start using all these accessible and affordable GM sensors  will it treat it as a V8?   I really don't care even if it's magic, I just don't want to sit there and not have it run. 

There is a ton of useful info and discuss in here, thanks everyone! 

@codrus- thanks for that injector info. I didn't realize that injectors were generally the same size. 

frenchyd said:

   I just don't understand how it "knows" the firing order?    Is there a program in the memory that tells it "hey!  this is a V12". 

There is are configuration options in TunerStudio (the laptop software that you use to set up a megasquirt) that tell it the number of cylinders and how many degrees apart they are.  You also configure what kind of cam and/or crank angle sensors it has, and how to convert the electrical signals it receives from the sensors into an angle.  Once it's got that info it has everything it needs to compute the TDC for each cylinder in the 720 degree crank rotation cycle as well as the current engine position, and thus how many milliseconds in the future it needs to fire each injector and coil.

AIUI, sequential fuel injection is pretty important for getting it to idle smoothly and doesn't matter much at higher RPMs.  When you're getting close to that 80% duty cycle the injector is open most of the time anyway.  Running sequential spark is only a fairly minor improvement anywhere unless you need the longer dwell times that it allows at higher RPMs.

At least, the idle benefits of sequential fuel is true on a 4 cylinder Miata.  Maybe with a V12 it doesn't matter.

Absolutely Brilliant. That explains the missing piece.  I get to tell it what it's working with.   
 
     Now I nderstand enough to start ordering parts and bundling wires.  
 With regard to idle quality. Stock it uses wasted spark and batch injection letting the camshaft sort out which cylinders get it next.  
   In spite of that the engine is so smooth you can balance coins on it at idle.   Rumor has it there is some potential power to be gained with sequential injection.   I guess I'm going to crawl before I walk here because I'm just not going to Pursue  that.

   With the coil on plug arrangement Ford used  I should be able to keep a strong spark  in the 7-8500 rpm range  I believe the engine is capable of. The tiny short stroke will keep piston speed down well under 3000 fpm I think at 6500 it's under 2000 fpm  even if I go to the 6000 cc version  of it that stroke is only 3 inches   

       I can realistically hope to achieve 700 horsepower without opening the engine. Especially if I can find some of the billet cams used by me  back in  the late 90's or by some of the pro teams. 

  Thank you everyone who has been so helpful.  

One big hole in the plan is you don't have enough spark outputs on a microsquirt to do waste spark on a v12 (you need 6 and only have 4). You can still use a crank trigger and a distributor. If you are modifying a ms2, it's possible to have 6 spark outs.

In reply to Paul_VR6 (Forum Supporter) :

I thought that Ford had a 2 plug wire per coil on their V6?    So two sets of those coils should get me there?   
 

 Oops I get it.   I guess my MS still won't be used.  Should I step up to something like a MS 3pro. Or even Gold?  I guess I better start doing some research on the MS site.  Wonder if my unused old MS is worth anything.  

Yea the ford coil can fire two plugs per coil, but it requires 6 spark channels. For your hp a distributor with good cdi ignition should be fine. The micro can easily be resold, if you want a pro we can do an exchange if its all new.