Which EFI controller?

[Mater]

will a msII run 8 hei coils?? thinking low budget.. like junkyard low..
hell will it fire 8 old oil filled coils for a ole school look

that would be sweet looking in an old school hot rod. 8 oil filled coils going to indevidual cylanders

[SuperBuickGuy]

ls2 coils are already on the horizon.... just not in the initial fire. Must learn to crawl before I attempt spark and fuel.

[dieselgeek]

will a msII run 8 hei coils?? thinking low budget.. like junkyard low..
hell will it fire 8 old oil filled coils for a ole school look

8 big coils aren't going to be the lowest budget option - not by a long shot. But in case you missed earlier, you can run them wasted spark with the MS1 or MS2, and individual/sequential with an MS3x. You'd need ignitor channels for every coil that doesn't have a built in ignitor.

Want hot spark for cheap/free? rob the Mitsubishi coils and ignitors off of many junkyard cars: Hyundai, Dodge Neon, etc. Those are the hottest OEM coils ever tested, even hotter than LS coils.

[SuperBuickGuy]

will look, thx

[Stich496]

8 big coils aren't going to be the lowest budget option - not by a long shot. But in case you missed earlier, you can run them wasted spark with the MS1 or MS2, and individual/sequential with an MS3x. You'd need ignitor channels for every coil that doesn't have a built in ignitor.

Want hot spark for cheap/free? rob the Mitsubishi coils and ignitors off of many junkyard cars: Hyundai, Dodge Neon, etc. Those are the hottest OEM coils ever tested, even hotter than LS coils.

ok.. for a v8 how many you need, 2 coil packs off(2) 4 bangers, and do you need 2 ignitors, or will one run,fire 8 coils.. or does the # of coils even matter to the ignitor?

[dieselgeek]

ok.. for a v8 how many you need, 2 coil packs off(2) 4 bangers, and do you need 2 ignitors, or will one run,fire 8 coils.. or does the # of coils even matter to the ignitor?

4 cylinder engines have 2 channel ignitors. That's what wasted spark means. So if you are running "dumb" coils (no built in ignitors) on a v8 then you need 4 total ignitior channels, or 2 of the 4-cylinder ignitors.

[SuperBuickGuy]

What is (are) the advantage(s) of wasted spark in performance applications? (taking cost out of the equation)

[dieselgeek]

What is (are) the advantage(s) of wasted spark in performance applications? (taking cost out of the equation)

When compared to a distributor, wasted spark can deliver a lot more energy across the plug gap because there is only one gap to cross! (no rotor-spark tower gap). I've used junkyard Mitsubishi coils on import engines at 40+psi of boost, reliably. That much pressure with a distributor will require hardcore CDI upgrades (MSD 7 or better, and the high dollar coil). Wasted spark coils fire each coil every 360 crank degrees allowing more time to charge than a single coil which has to fire every 90 degrees, 4 times as often. Available charge time (also called dwell) is a lot higher, allowing more energy to be built up before discharge...

What sucks about wasted spark coils? well, compared to Sequentially-fired individual coils (like LS engines), they take almost double the energy to fire - after all, it is "wasting" a spark on each cylinder every engine cycle. But, to step up to sequential you must use a cam position sensor so that the computer knows which TDC event is compression and which is exhaust. And again, sequential allows even more charge time between firing events (firing once every 720 crank degrees).

[SuperBuickGuy]

In my Buick application, would there be any advantage to sequential fire (no higher rpm than 5200)?

Can the cam sensor be located in a hollow HEI housing? would that hurt (I'm almost certain I'm using the wrong term) the 'resolution' that the cam sensor would see because of inherent loose tolerances in the distributor drive?

I'm certain Matt gets there in his book (54% through) - but (in case he doesn't and I forget to ask) when you're firing sequential injectors, does the firing happen just before the valve opens? if so, how long before (I suspect there's a formula)? presuming formula, does the volume of the space between the injector and the valve make any difference?

all the above relates to the Buick motor - so please answer what applies (unless you want to answer more - the theories behind this stuff fascinates me).

[dieselgeek]

I see no advantage for sequential fire in your application.

Wasted Spark will provide simplicity too, not requiring the cam sensor, but you *can* use a distributor's internal sensor (hall or VR) as a cam input easily. It just needs modified to have one "tooth" instead of 8, which is a real simple mod. Use the same sensor and trigger wheel that are already in an HEI or any other distributor, grind off 7 teeth - done.

We've proven (at significant expense and thorough testing) that sequential EFI is usually only worth a few percent average or peak power, UNLESS your engine suffers from air distribution imbalance. On the Megasquirt 2 and 3x, *YOU* pick the time during each engine cycle when the injector opens and closes. At WOT, the injector is open 80% or more of each engine cycle but the intake valve is something like 20% so you have to select between spraying on a closed valve BEFORE it opens or after. OEMs usually spray on the closed valve BEFORE its opened. This is called Injector Phasing and if you have the tools to pick flyshit out of pepper, it can be worth a few percent average power.

I wouldn't recommend going to sequential if you're looking for massive HP gains. You need 8 oxygen sensors to monitor each cylinder's exhaust if you want to tune each cylinder individually - we did that for Engine Master's Challenge and it DID make more power, but not enough to be "worth it" on most applications.

You ask good questions so, keep 'em coming!

[TC]

OEMs usually spray on the closed valve BEFORE its opened.

Not from what I've read............And wouldn't spraying fuel on a closed valve cause puddling of the fuel on the valve??

Also which will give you better fuel economy, batch or sequential??......

[dieselgeek]

Not from what I've read............And wouldn't spraying fuel on a closed valve cause puddling of the fuel on the valve??

Also which will give you better fuel economy, batch or sequential??......

this is Buickguy's thread. We'll let him ask the questions. You can start your own though if you want to argue.

[Bob Holmes]

Not from what I've read............And wouldn't spraying fuel on a closed valve cause puddling of the fuel on the valve??

Also which will give you better fuel economy, batch or sequential??......

Do the math TC, do you really think that all the fuel can get in the chamber if you only spray while the valve is open? Look at OEM cam specs.

And yes, fuel puddles on the valve. Has since the beginning of the ICE. Unless you are using direct injection, fuel will puddle on the valve.

[SuperBuickGuy]

From what I've read, spraying the back of the valve does 2 things 1) cools the valve, 2) maximizes the amount of fill, and 3) changes the liquid to a gas when it strikes the back of the valve.... I'm just wondering at the timing necessary to pull off that feat. Fortunately, it doesn't appear that I have to worry about it. It just appears devilishly hard to get that kind timing right.

since the beginning of ice? I thought fire came first

[Bob Holmes]

Internal Combustion Engine.

One common solution is to spray based on an end time of intake valve closing (IVC).

There are a wealth of papers written about injector timing, spray patterns etc., available from SAE.

Port injection is relatively forgiving. You can waste a bunch of brain cells and the conclusion you'll come to is that you'll have to "fiddle with" your injection timing, if you're keen on optimizing sequential injection, as each engines port, chamber and piston etc., architecture is different. Its only worth it if you're trying to get that last X%.