Robbie said:
In reply to frenchyd :
I'll help you figure out the mega squirt! I've never done it either but you won't have to pay me to learn.
I'm in IT professionally so I'm confident I can do the computer side. You handle the mechanicals.
If you want SEFI, then doing two independent I6's with a 6 injector driver MS would be the way to go (I'm not aware of a 12 driver MS, but there could be one...)
But if batch fire is ok, which it would be for just two injectors, you can set up a batch fire 6 cyl set up with one MS and waste spark. That would be the simplest way of doing it. Just have to know what cylinders are 180 out of each other, and what's the order of how they should be set up.
Both ways, you need to lay out on a piece of paper the basic events- all 720 deg for each stroke, and the rough area where the valves actuate. That way you can put the correct order of the system.
For the two I6's, one bank will have the easy set up for which is cyl 1. The other bank is more complicated, as it will depend on where you can put the second crank sensor. On the V12 I worked on, the engine designers were lazy, and put the sensors 180deg out from each other, and that meant #1 was #1 for the right bank, but #11 was #1 on the left bank.
Stefan
MegaDork
6/15/19 8:26 p.m.
3 JB Performance Boards connected to an MS2 or better, an MS3 could allow you to drive 12 cylinders of fuel in sequential form:
http://forum.jbperf.com/viewtopic.php?f=4&t=1174
In reply to Stefan :
While there might be some trivial fuel savings with sequential firing of injectors I haven’t seen any real examples of significant power output. At least not at the grass roots level. Where the budget is critical
Too often I see people focus on the latest technology and miss the obvious. Regrinding a camshaft to more correctly reflect it’s intended use ( racing ) is a better use of money.
In reply to alfadriver :
Most Jaguars are batch fired but because they still use a distributor there is no wasted spark. There are rare exceptions. But none at an affordable price.
The 1971-1992 V12’s used a distributor only the 6.0 V12’s had a crank sensor
Dusterbd13-michael said:
In reply to bruceman :
My bet would be megasquirt an old jag with straight pipes. Cheapish and simpleish.
The early EFI was totally analog and decently reliable ( although the sensors, vacuum hoses, and connections weren’t ) the nice thing about that system was the mixture strength was easily adjusted from lean to rich. Since the injectors were also the biggest used in production the potential for power enhancement merely required an adjustment back in the trunk.
Stefan
MegaDork
6/16/19 1:10 a.m.
frenchyd said:
In reply to Stefan :
While there might be some trivial fuel savings with sequential firing of injectors I haven’t seen any real examples of significant power output. At least not at the grass roots level. Where the budget is critical
Too often I see people focus on the latest technology and miss the obvious. Regrinding a camshaft to more correctly reflect it’s intended use ( racing ) is a better use of money.
Better idle characteristics and the ability to fine tune each cylinder for maximum power, especially if you have a compromised intake solution or forced induction. So while you won’t see it in peak numbers on a dyno, you’d likely see it in “power under the curve”. Similar to wasted spark or CNP ignition solutions. Better idle and the potential to fine tune timing per cylinder.
the challenge is collecting the necessary data to know which cylinders need adjustment and which adjustment is needed.
Those boards can also be used to control the cylinders in batch fire with a single MegaSquirt, instead of having to tune 2 of them. Just a thought and certainly not the only way to do it.
In reply to Stefan :
While I haven’t spent any time sorting out BMW or Benz V12’s they look very similar to Jaguars in the intakes and exhausts don’t have the compromises you’ll see on V8’s
A V8 can have adjacent cylinders fire anywhere between 90 /180 / 270 degrees while a V12 will fire 120 degrees from the adjacent cylinder.
That even pulsing of exhaust/intake strokes produces the smooth running V12’s are known for. Thus batch firing isn’t an issue.
On the other hand every V12 produces a very high torque compared to a similar sized V8. ( since it has one more cylinder on the power stroke per crankshaft revolution) That higher Torque means they are excellent at moving off briskly with a heavy load.
The downside of all that means the lift and duration of the camshafts is extremely modest only .375 or 3/8ths of an inch on both intake and exhaust. ( for all Jaguars)
increase lift and duration and the engine begins to come alive. While still maintaining a smooth idle. Full out racing cams seldom exceed 1/2 inch of lift. ( and maintain a smooth idle with stock 600 rpm idle speed.
Since a second megasqirt is more than the cost of regrinding a pair of camshafts while producing as much as 80 extra peak horsepower with no other modification clearly for racing purposes the choice is simple.
Cam’s, E85 and timing advanced should bring a V12 to near 500 horsepower.
The most GRM way to drive something that sounds like a vintage Italian V12 race motor is to mount a trombone player on the back of a Miata.
https://youtu.be/kwaXjtRybhI
frenchyd said:
In reply to Stefan :
While I haven’t spent any time sorting out BMW or Benz V12’s they look very similar to Jaguars in the intakes and exhausts don’t have the compromises you’ll see on V8’s
A V8 can have adjacent cylinders fire anywhere between 90 /180 / 270 degrees while a V12 will fire 120 degrees from the adjacent cylinder.
That even pulsing of exhaust/intake strokes produces the smooth running V12’s are known for. Thus batch firing isn’t an issue.
On the other hand every V12 produces a very high torque compared to a similar sized V8. ( since it has one more cylinder on the power stroke per crankshaft revolution) That higher Torque means they are excellent at moving off briskly with a heavy load.
The downside of all that means the lift and duration of the camshafts is extremely modest only .375 or 3/8ths of an inch on both intake and exhaust. ( for all Jaguars)
increase lift and duration and the engine begins to come alive. While still maintaining a smooth idle. Full out racing cams seldom exceed 1/2 inch of lift. ( and maintain a smooth idle with stock 600 rpm idle speed.
Since a second megasqirt is more than the cost of regrinding a pair of camshafts while producing as much as 80 extra peak horsepower with no other modification clearly for racing purposes the choice is simple.
Cam’s, E85 and timing advanced should bring a V12 to near 500 horsepower.
1 megasquirt system can run a v12.
NickD
PowerDork
6/17/19 8:32 a.m.
Cotton has owned a couple of cheap twin-turbo V12 Mercs, and it seems like if you're willing to do the work and know what you can and can't live without, they aren't too spendy. Not sure if a twin-turbo V12 makes the sounds you are looking for, but I bet the thrust would overcome the sound deficit.
Stefan said:
frenchyd said:
In reply to Stefan :
While there might be some trivial fuel savings with sequential firing of injectors I haven’t seen any real examples of significant power output. At least not at the grass roots level. Where the budget is critical
Too often I see people focus on the latest technology and miss the obvious. Regrinding a camshaft to more correctly reflect it’s intended use ( racing ) is a better use of money.
Better idle characteristics and the ability to fine tune each cylinder for maximum power, especially if you have a compromised intake solution or forced induction. So while you won’t see it in peak numbers on a dyno, you’d likely see it in “power under the curve”. Similar to wasted spark or CNP ignition solutions. Better idle and the potential to fine tune timing per cylinder.
the challenge is collecting the necessary data to know which cylinders need adjustment and which adjustment is needed.
Those boards can also be used to control the cylinders in batch fire with a single MegaSquirt, instead of having to tune 2 of them. Just a thought and certainly not the only way to do it.
That takes a lot of tweaking that most people wont or can't do. Especially the individual cylinder ignition timing- we don't even do that for production. Heck, doing individual cylinder fuel trim is a major PITA, that only works for OEM's if it's specific design problem that is universal to all engines.
If someone wants to do a full SEFI V12 on one computer, nothing wrong with that. But it is very computation intensive, so you have to spend the money on the fastest computer available- at 6000 rpm. 6 events per engine rotation, it's 600 events per second to run the full calculations. I don't know what processor the MS systems use, but I know that OEM systems struggle at that speed, given the computations.
In reply to alfadriver :
Good point! I’ve learned not to obsess about tiny changes. Right after I bought my distributor machine I spent a month getting each lobe of my distributor exactly on time and with the same amount of lift
Obsessed about leak down variations until I got them as close to identical as I could. Then indexed my spark plugs, and carefully set the fuel mixture in each carb exactly the same.
After 5 months of real nit picky, painstaking obsession a tiny change in air density was still a bigger change in horsepower than all that work.
yupididit said:
frenchyd said:
In reply to Stefan :
While I haven’t spent any time sorting out BMW or Benz V12’s they look very similar to Jaguars in the intakes and exhausts don’t have the compromises you’ll see on V8’s
A V8 can have adjacent cylinders fire anywhere between 90 /180 / 270 degrees while a V12 will fire 120 degrees from the adjacent cylinder.
That even pulsing of exhaust/intake strokes produces the smooth running V12’s are known for. Thus batch firing isn’t an issue.
On the other hand every V12 produces a very high torque compared to a similar sized V8. ( since it has one more cylinder on the power stroke per crankshaft revolution) That higher Torque means they are excellent at moving off briskly with a heavy load.
The downside of all that means the lift and duration of the camshafts is extremely modest only .375 or 3/8ths of an inch on both intake and exhaust. ( for all Jaguars)
increase lift and duration and the engine begins to come alive. While still maintaining a smooth idle. Full out racing cams seldom exceed 1/2 inch of lift. ( and maintain a smooth idle with stock 600 rpm idle speed.
Since a second megasqirt is more than the cost of regrinding a pair of camshafts while producing as much as 80 extra peak horsepower with no other modification clearly for racing purposes the choice is simple.
Cam’s, E85 and timing advanced should bring a V12 to near 500 horsepower.
1 megasquirt system can run a v12.
That’s pretty much What I’ve been told. It would be nice if someone had a how to for luddites. Connect the green and red striped wire to here. The brown and yellow wire goes there
Etc.
All that would be left is make sure the various sensors are working and the vacuum lines aren’t leaking. Then crank it over until I have oil pressure and turn it on.
Stefan
MegaDork
6/17/19 2:26 p.m.
In reply to frenchyd :
Read the Megamanual.com
Understand that YOU need to configure it to YOUR engine parameters, but the basic settings and wiring is pretty much the same for all of the implementations.
To get used to the software side and generally ensure it works, etc. buy/borrow a Stimulator to connect to the MegaSquirt and connect the MegaSquirt to your computer or laptop (yes you can use smart phones and tablets with appropriate hardware, but lets try to keep it simple)
Plan out how you want to configure the wiring for the injectors, etc. It only needs a single vacuum line to the MAP sensor, so ditch any other vacuum lines you don't need to simplify the engine bay. Once you have a plan/layout, figure out what parts from the factory EFI that you can re-use, then order the labeled wiring, connectors and MS2 from DIYAutoTune.com to finish out the installation.
There are also some great online Videos on YouTube to help explain things visually, plus DIYAutoTune.com has some good tech articles that explain how they converted a carb'd SBC to Megasquirt using first a TBI unit and then MPI. While it isn't a direct correlation to your V12, there are a lot of similarities.
Stefan
MegaDork
6/17/19 2:34 p.m.
Robbie
UltimaDork
6/17/19 2:50 p.m.
In reply to frenchyd :
How to for luddites... Just say the word and we can start working on it!
frenchyd said:
yupididit said:
frenchyd said:
In reply to Stefan :
While I haven’t spent any time sorting out BMW or Benz V12’s they look very similar to Jaguars in the intakes and exhausts don’t have the compromises you’ll see on V8’s
A V8 can have adjacent cylinders fire anywhere between 90 /180 / 270 degrees while a V12 will fire 120 degrees from the adjacent cylinder.
That even pulsing of exhaust/intake strokes produces the smooth running V12’s are known for. Thus batch firing isn’t an issue.
On the other hand every V12 produces a very high torque compared to a similar sized V8. ( since it has one more cylinder on the power stroke per crankshaft revolution) That higher Torque means they are excellent at moving off briskly with a heavy load.
The downside of all that means the lift and duration of the camshafts is extremely modest only .375 or 3/8ths of an inch on both intake and exhaust. ( for all Jaguars)
increase lift and duration and the engine begins to come alive. While still maintaining a smooth idle. Full out racing cams seldom exceed 1/2 inch of lift. ( and maintain a smooth idle with stock 600 rpm idle speed.
Since a second megasqirt is more than the cost of regrinding a pair of camshafts while producing as much as 80 extra peak horsepower with no other modification clearly for racing purposes the choice is simple.
Cam’s, E85 and timing advanced should bring a V12 to near 500 horsepower.
1 megasquirt system can run a v12.
That’s pretty much What I’ve been told. It would be nice if someone had a how to for luddites. Connect the green and red striped wire to here. The brown and yellow wire goes there
Etc.
All that would be left is make sure the various sensors are working and the vacuum lines aren’t leaking. Then crank it over until I have oil pressure and turn it on.
It really is that easy. Scary as heck the first time out, but once you do it, it's a lot less intimidating, My personal analogy is like welding- I got a welder for a birthday, but it took me two years to drum up the courage to actually use it. Now it's easy.
And while I am a professional at EFI tuning, what is available to most out there in terms of system, they are actually very easy. Just go through what Stefan has posted (and I've not seen them, I'm trusting him), take a lot of notes, and go from there.
Instead of guessing on leak rates to deliver the right amounts of fuel, you can specify a specific amount based on a pretty strong physics model of what's going on. And instead of points and hoping that they line up right, you specify exactly when you want spark, and it will do it, every single time, without points bounce. Getting an EFI to run better than a carb is pretty straight forward and easy. Getting it to run to get really great emissions is a lot more work, but from what I can see, is reasonably capable with MS. Doing what we do for production cars isn't required.
alfadriver said:
Robbie said:
In reply to frenchyd :
I'll help you figure out the mega squirt! I've never done it either but you won't have to pay me to learn.
I'm in IT professionally so I'm confident I can do the computer side. You handle the mechanicals.
If you want SEFI, then doing two independent I6's with a 6 injector driver MS would be the way to go (I'm not aware of a 12 driver MS, but there could be one...)
There is - either an MS3 Pro EVO for a ready to run option, or a heavily modified MS3 V3.0 will do this too. Even an MS2 can do dual distributor operation with a single crank sensor; that's been around for quite a while. The MS3 uses a NXP MC9S12XEP microcontroller - it helps that a lot of the timing functions can be offloaded to hardware timers and the X-gate coprocessor, and that it's not keeping track of a lot of smog control functions.
In reply to MadScientistMatt :
the hard part wasn't any emissions hardware or functions- as at 6000rpm, all of that's being ignored or skipped, It was the culmination of all the normal stuff that needs calculated and sent out to the various drivers. But it sounds like a lot of that super high speed things on the MS is offloaded to other processors- which is good.
It's funny this thread popped up, I was also wondering how to get cheap V12 power on a relative budget.
I've seen a couple of videos showing stock V12 XJS accelerating and they don't seem really fast... of course that's stock and this is GRM...
Let's say one gets a 5.3 HE Jaguar, puts a T5 behind it using one of the available bellhousings, re-gears to something like 3.73, makes a custom exhaust and makes it run on a standalone... Does that turn a lazy engine into something more entertaining? Is the 6.0 the way to go?
So on a v12 three cylinders should be on intake at the same time, and since the injectors should be firing only part of the intake stroke it seems like you should be able to run a 6 cylinder injection system with a pair of injectors off each output that will both be firing on cylinders in their intake stroke. Kind of a pair batched sequential injection.
In reply to oldopelguy :
Batch firing will put injection pulses 360 crank angle degrees out. So for pairing up cylinders, you want opposite ones. On the Jag- that would be 1-6, 8-9, 4-3, 11-8, 2-6, & 7-12. And I'd set the WB up from one bank to the other, and hope that each I6 has even a/f distribution.
MadScientistMatt said:
alfadriver said:
Robbie said:
In reply to frenchyd :
I'll help you figure out the mega squirt! I've never done it either but you won't have to pay me to learn.
I'm in IT professionally so I'm confident I can do the computer side. You handle the mechanicals.
If you want SEFI, then doing two independent I6's with a 6 injector driver MS would be the way to go (I'm not aware of a 12 driver MS, but there could be one...)
There is - either an MS3 Pro EVO for a ready to run option, or a heavily modified MS3 V3.0 will do this too. Even an MS2 can do dual distributor operation with a single crank sensor; that's been around for quite a while. The MS3 uses a NXP MC9S12XEP microcontroller - it helps that a lot of the timing functions can be offloaded to hardware timers and the X-gate coprocessor, and that it's not keeping track of a lot of smog control functions.
So posting my last reply made me wonder- for that V12 set up, how many O2 sensor inputs does that have? 2 or 4?
alfadriver said:
In reply to oldopelguy :
Batch firing will put injection pulses 360 crank angle degrees out. So for pairing up cylinders, you want opposite ones. On the Jag- that would be 1-6, 8-9, 4-3, 11-8, 2-6, & 7-12. And I'd set the WB up from one bank to the other, and hope that each I6 has even a/f distribution.
When I ran the Weber’s all the cylinders showed similar patterns on any given set of jets. Running mainly alcohol ( E85 ) makes it much more tolerant than gasoline. So it shouldn’t be an issue.
I’m beat tonight but I’ll take some pictures as soon as work eases off and I can have a few minutes to run down and take them.
Mind you I was able to get the early Bosch based system rich enough to handle about 6 pounds of boost just by richening the adjustment , triggering the enrichment injectors at 3 PSI and using a FMU to trick the whole system into thinking it was going leaner as boost increased.
Very inelegant, Rube Goldberg ish, but it’s still around doing smoky burnouts at the local drive-in at least once a summer.
ps: that whole system is analog. Not a single chip in it! In fact it wasn’t until the late 80’s the analog system was replaced. And then only for fuel. It didn’t start controlling the spark until 1993. By then the V12 was on its last legs and there weren’t that many made. The last 3 were made in 1997.
