Efficiency potential of the L28 (MegaSquirt)

[FastWoman]

I understand what you're saying, Leon, but I think some of the old stuff if kinda cool. The engine is the soul of the car, and I hate to go overboard with modernizations. If MS had a way to incorporate the AFM, I'd probably be all over that! I may still bite on the MS, though. I think I would want to keep the distributor and not go EDIS, but it would be cool to be able to disable the advance mechanism and make it a hybrid CAS/distributor sort of device, with the MS handling all the spark advance.

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Rob, I suspect your mixture is way off!

[LeonV]

It would be more modern (good thing), but that doesn't mean it will look it. The ECU will go somewhere hidden, perhaps in the location of the current ECU (you can probably even make it look like a stock ECU! I think TonyD has done some sneaky stuff like that). You'll have to integrate a couple of sensors but those can be made pretty inconspicuous as well. No need for that bulky flow-restriction called the AFM!

I completely understand the allure of old tech, I have triple Webers and enjoy understanding and working on them. The sound is awesome and the look on people's faces is even better!

Still, the draw to go ITBs, standalone ECU and adjustable coil-overs is almost too great to resist!

Edited July 19, 2011 by LeonV
Wording

[cygnusx1]

MS can run an AFM. At least I know MSII can. I have it turned off in my tune since I am using the MAP sensor built into the brain box. MS can run better and probably more efficient than the factory system...having said that, you will NEVER be done tweaking the tune, if you are like me. Seems like every little bump or burp I hear, I whip out the laptop and tune some more. It never ends. Sometimes I wish I had the stock system back and just drove it. It can be made to look totally stealthy installed in the car. You could probably use the factory EFI harness for most of the install if you wished to. I mounted my box under the drivers seat but it will mount in the stock location. Heck, it would probably fit into the original ECU case. My boost gauge is double taped on top center of the column clamshell. An AFR gauge could go there nicely as well.

Edited July 19, 2011 by cygnusx1

[madkaw]

Isn't tweeking part of the fun! Can't do that with the stock stuff.

Sarah, you might venture on to the DIY Tune site and and look at the FAQs they have. The site is geared for first timers to the the stand alone world and is pretty user friendly. It was a matter of getting used to the terminology in the EFI world and it's components.

MS can run an AFM. At least I know MSII can. I have it turned off in my tune since I am using the MAP sensor built into the brain box. MS can run better and probably more efficient than the factory system...having said that, you will NEVER be done tweaking the tune, if you are like me. Seems like every little bump or burp I hear, I whip out the laptop and tune some more. It never ends. Sometimes I wish I had the stock system back and just drove it. It can be made to look totally stealthy installed in the car. You could probably use the factory EFI harness for most of the install if you wished to. I mounted my box under the drivers seat but it will mount in the stock location. Heck, it would probably fit into the original ECU case. My boost gauge is double taped on top center of the column clamshell. An AFR gauge could go there nicely as well.

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[FastWoman]

Thanks, guys! Dave, if MSII can be used with the cursed AFM, I'm definitely interested! I'll check out the FAQ, Steve.

Oh, and I was thinking about the distributor. I don't really need a CAS except for sequential injection, which y'all say isn't a big deal anyway. Otherwise I presume the distributor's reluctor signal could be used trigger the MS, which would handle the spark advance and drive the coil. I would need to disable the vacuum (and also mechanical?) advance. Do I have that right?

Anyway I'll check out the FAQ. This all sounds much more do-able now. The only part of my EFI that I really WANT to replace is the ECU, as I don't really care about the originality of some box hiding under the kick panel.

[cygnusx1]

MSII can work with a stock dizzy. It has a coil driver built into the board that you can use. I am NOT an electronics guy so I can't give you too much more than that, but I know it has those capabilities and more. DIY Autotune is a great place. Also check out MSEFI.com. Don't be afraid to give DIY a call or an email. They are very helpful.

PS, I am sure you can use the vacuum advance OR block the mechanical functions and use the onboard MAP sensor to build a timing advance map based on RPM vs vacuum. The AFM becomes a restriction, but if you like it, you can keep it and use it. The MS system is totally flexible and the software is all open source so you can find a firmware version with the features you like and use it...or write your own.

Go download the tuning software from DIY and play with it offline.

Edited July 20, 2011 by cygnusx1

[Z train]

Sarah,the stock system will NEVER come close to a"O2 sensor driven system" in terms of economy and all other aspects,for that matter.

[aarc240]

Sounds like you're talking yourself into a second rate pile of trouble there.

Forget the factory AFM, it's ancient c**p. If you really want AFM (and it does have some advantages) then think about disguising something from a late 90's BMW or Porsche. They did at least work.

The comments re sequential injection obviously come from sources who have yet to use it. It does make a significant difference, particularly to idle and low throttle angles like light foot cruise. The engine is both smoother and more economical with sequential. Funny that OEM has all gone that way.

The stock distributor based electronic ignition is likewise outdated technology. A good hot spark around 60mA at 50kV is easily achievable with MS3/MS3X driving the coils, that will fire an unbelievably lean mixture just like a modern car does.

A feature in MS2extra and MS3 that few seem to use is fuel cut on over-run. Why have the injectors dumping fuel in when no power is required? Don't let anyone tell you the engine won't respond quickly when you get back on it 'cause it will if the rest of the tune is right (just like any very late model does!!).

You need engine position sensing but why cripple that by using a known inaccurate source like the distributor?

You don't need 440cc injectors unless you are planning on a 400hp+ engine. That sort of size in a road car will just make it hard to get good control at idle because the pulse width is so small with a relatively small engine capacity. Good for bragging rights though!

The 250cc turbo injectors will supply a 280hp NA just fine.

You do need a larger throttle body, 60mm works fine for road use, 65mm is nicer when you stand on it. Naturally, you might as well not waste the money or effort to go to a larger throttle body if you keep the restrictive AFM.

Do your research, spend some time looking for sites that give solid data on stuff like injector sizing etc.

It doesn't have to be exotic, it doesn't even have to look very non-standard, but it sure will work really well.

Art

[sblake01]

Merely for curiousity's sake, what would be the cost of a complete 'properly' set up MS system with crank trigger ignition, coil packs, the appropriate injectors, etc.?

[Z train]

1)The comments re sequential injection obviously come from sources who have yet to use it.2) It does make a significant difference, particularly to idle and low throttle angles like light foot cruise. The engine is both smoother and more economical with sequential.3) Funny that OEM has all gone that way.

Art

1)Wrong.

2)Correct.But not without serious engineering to retro fit.ANd the benefits gained do NOT warrant the expense.

3)Last i checked,L-motors are 37+ years old.

[cygnusx1]

Lots of good info in this thread. I happen to make somewhere North of 350 crank hp so I need 440cc injectors. Stock injectors will work with MS just fine. MS2 is batch injection, there are two banks. They don't need to both fire at the same time. You can break up the banks and alternate them. I do. Just do it based on the firing order. It's not sequential but it works with almost zero practical pitfalls compared to sequential. I have zero issues idling with 440cc injectors. Although it might be better and snappier off idle with smaller ones. MS hardware can run from about $300 to about $1000 depending on how much DIY you do, and what bells and whistles you want to add. A decent wideband O2 system will run you around $200. It is an absolute must have. You can solder the entire thing from ziplock baggies of electronic parts if you want to save some cash. I bought the finished brain, the terminated cable, an LC1 wideband system, and a few temp senders. I think it was around $500 or so. I fabricated my own power and relay board.

Edited July 22, 2011 by cygnusx1

[doradox]

2)ANd the benefits gained do NOT warrant the expense.

3)Last i checked,L-motors are 37+ years old.

2) Purely your opinion. Beauty is in the eye of the beholder and all, you know.

3) Really. Why bother upgrading at all. They are like, so old.