Jake the Snake

Has anyone ever seen or thought about building a sbc with a dual-plane, dual-quad (not tunnel-ram) intake (EDL-7525) with two 220 throttle bodies on it? It would give 800 cfm of induction with stock TB's, just about right for a high rpm or stroker setup (even a 406 with modded TB's). No more messing around with small gains from TBI mods. I realize what I'm talking about will require a chip that is radically different than stock and major tuning effort. Think the stock injector drivers could run two extra low-impedance injectors or would it require an aftermarket ECM (think MegaSquirt)?

Fast355

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Actually go to Dynamicefi.com and look at the EBL. It can be modified to run 4 injectors at a small charge. RBob's product is superb.

Jake the Snake

Now we're talking MegaSquirt prices. Of course MS requires considerable rewiring and the EBL doesn't. And using the original ECM would make it more reliable. Looks like a good way to go.

Fast355

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I know some will argue, BUT the EBL is worlds above the MegaSquirt. With Motorola assembly code knowledge just about every stock GM ECM is better than the MegaSquirt.

pizza_guy

Okay...hmm...now that you talked trash on the Megasquirt I gotta represent.
Are you up to date on the latest MS releases?? The MSII is a huge leap from the original, and it's still getting better as you read this. Could you be more specific on the "better". Better at what?

With my WB02, I can set my MS to 'autotune' to a specific AFR at each load/rpm cell. Bet the OEM can't do that. I don't know if the OEM will even support WB?

I happen to be rewiring the entire car anyway, front to back. Redoing all the heavy crap the oem used. Driving your car is the funnest part, but assembling it is a very close second to me. The MS can piggyback onto your OEM ecm to skip a lot of those headaches if you prefer.

Does anybody still remeber the original pentium computers?? Years AFTER these cars were designed, huh. Now look at computers today. I just don't understand why a 20+ year old design/hardware could be more reliable/capable than a modern interpertation of the same. My MS is due to be fired up after thanksgiving, and I will have actual evidence to support my hypothosis.

And with C language(more friendly than "assembly" languages IMO), I can imitate ANYTHING(and I mean anything) an OEM ecm can accomplish. Without knowing the limitations of the OEM units, I can't give a specific example, but I'm sure it could do things the OEM can't.

Oh, and my MS weighs less than the OEM computer. That makes me just that little bit faster. So take that

Jake the Snake

And I wouldn't have buy a chip burner or an emulator (with MS) and still have the same or better tuning capabilities, right? Because if I can keep down the cost of the engine management system I can spend more money on mechanical parts (stroker crank, vortec or fastburn heads).

pizza_guy

The MS has the advantage of being able to be scaled to your budget. Naturally, the nicer accesories make it much easier to put together and tune, but they are not absolutly nessecary. Here is my parts list for my carb to stockish TBI setup.

MegaSquirt II with the V3.0 Board: $250
MS Stimulator: $45
Relay board(not required): $65
WideBand 02(not required, but very nice): $200 and up
Harness(being creative can lower the price here): about $50
Extra time to learn/assemble your equipment: $depends$
A recycled laptop($150-250) and a serial cable will finish off the neseccary componets to install and tune your MS.

That however doesn't include the tools to assemble the MS componets.

Soldering Iron and solder: $30
Lead snips: $5
Digital Volt-Ohm-Meter: $20 and up
Provision to ground yourself and work surface: $0 and up
Tidbits that add up: $20-$40, it depends on what you might already have.

If you want to just piggy-back your original ecm, you can retain the factory timing control and still be in control of the fuel. Your costs will decrease with this option, and it will be simpler to tune. Later, you could upgrade to staight MS control to spread the cost of the conversion. You would need to make another harness, but your first one would be cheap and simple.

Your fuel system is not method dependant so I didn't include it's costs. They will be very similar no matter what controls the injectors.

BMmonteSS

Ok I'm changing my old saying, there are now 3 things in the world you can't tell a guy .

1. how to have sex
2. how to drive a car
3. that MS isn't the holy grail of ECM's


How can you be so certain that MS is so much better than the EBL or even the stock ECM if you haven't even tried to tune either system? I can tell you for a fact that GM spent millions on developing the code and hardware that went into the stock ECM, and then Rbob made some very substantial modifications that tailor that code to the performance oriented crowd.

Fast355

iTrader: (2)

The later model TBI PCMs are definately far supperior to the earlier ones and even the Mega Squirt, yes the newer version. I have tuned one of the newer version and it couldn't do anything the newer PCM couldn't. With the PCM, I am running an 85mm MAF sensor to control the fueling.

dimented24x7

iTrader: (2)

One inherent drawback to the C3 ECMs is that theyre real turds hardware wise. The processor has only the most basic capabilities and lacks alot of the later features, like the F/IDIV instructions, capabilities to really work off of the stack, enough memory to support a large stack, timed/event driven interrupts, speed, etc. You can teach the old ecms some neat new tricks, and theyre cake to use, but I always found them too confining hardware wise.

pizza_guy

Yea, I'm a fanatic. I absolutly love the product and the idea behind it. You can't tell a guy what football team to root for either. And some guys you just can't convince to not buy a ford, either.

BMmonteSS, companies can spend billions on a product and it could still be inferior. I don't see the sum of money put into it as a good measure of how good it is. It's true I haven't started to tune it yet, but I'm not out here touting tuning superiority, yet. I'm still learning what things like "X-tau" and whatnot do. But once I'm into it, if I can't get the results I need with the provided features and controls, I can just write them in the code.

Okay Fast355, I know you think the OEM is better/superior. Why? Any specific feature(s) that convice you. What time resolution does the OEM ecm have when controlling injectors? Can you wire up 16 injectors with no issues? Can your ECM support sequential fire? That is only a few features to look at, but that's the kind of info we need to make a comparison. Ya'll keep pushing the OEM like I do my MS, but you're not telling me why it serves you better.

Nobody has confirmed my WB02 compatability question. If the OEM can't use one, I think it's tuning capabilities fall far short. It also makes tuning world's easier for a newbie like me to get a grasp on.

The MS suits my purposes and future plans sooo well, it is my holy grail. My future plans include building my own digital dash, as well as many other automated features the factory didn't think of. It'll all be running off the MS in time.

Currently under development at the MS site is an expansion card that will allow all sorts of custom circuitry to run all sorts of neat things.
All those seperately purchased devices(WOT switch, N20 solenoids, water injection, boost control, timing boxes, rev limit, low fuel pressure cut-off, etc.) could be built into the ecm for dirt cheap compared to buying purpose built products. You could even include climate control, headlight control etc. Oh, and you won't need to find all that space to mount those boxes. And all that wiring and weight...ugh. I trade harness building for circuit board building. Wire is more expensive and heavy than a few diodes and resistors.

MS isn't for everybody. If you don't want to learn about electronics or the hardware basics, then yeah, MS isn't good for you.

Sure it's not the end-all, but nothing at this point is. Unless there is a product I can buy, assemble, tune and run my engine perfectly with no cognitive thought for under $1000, there isn't an end-all. Just options.

dimented24x7

iTrader: (2)

the later OBII stuff is way ahead of the megasquirt. The hardware and 32 bit MCU's are really over the top compared to what we're collectivly using. Theyre real computers with really advanced instruction sets.

The TBI PCMs are fairly good, and can control an e-trans and feature full PID control of just about everything, so they're nothing to sneeze at. With the above addition of the MAF Fast is using (+/- .05% airflow accuracy on the computers side with 16 to 32-bit code), I was able to tune with nothing more then a vacuum gauge and an LM1 in just a few passes. Its easier then tuning a carb and all the control (timing, fuel, etc) is integral to the PCM itself.

I think the point to be made here is that there is no perfect system. If there was, we would all be using it. Each system has its advantages, and disadvantages.

dimented24x7

iTrader: (2)

Tuning is what makes or breaks a setup. You can have all the functionality in the world, but if its too hard to tune, then its about as useful as a life vest in the middle of death valley. Itll turn your project into a nightmare. BTDT with my first setup that I did. Thats one reason I put so much effort into the software development is that I wanted to make an intuative system that could be tuned as quickly and easily as possible and only had the functionality that I needed.

This alone probably gives the EBL a leg up over the other systems for the original poster, as lots of people are using it, so there is a very large knowledge base.

dimented24x7

iTrader: (2)

I took a look at the megasquirt, and the base unit works in a similar, but slightly simpiler fashion as the stock 7730 ECMs (no sequential injection with the ECM, obviously). It looks like a great unit for something like an SAE car or project car. But... theres not enough resolution to really make a motor run good at the leaner AFRs required for using a cat. Its hard to get a stable idle at 14.5-15:1 and leaner because of the steep changes in power there. This requires ALOT of resolution.

As I said, there is no one perfect system...

pizza_guy

Exactly.

Thanks, dimented, for the information. Perhaps the OEM isn't as 'anemic' as I previously thought.

I've yet to get an answer to the WideBand. Hard to hit ANY ratio other than stoich with a NarrowBand.(Mathmatically it's possible, but not convienant, and with no real-time correction).

Jake...are you still there?? I hope this is helping you decide.

One last point and I'll wait till I start tuning to further push my position:

The MS is expandable. As new ideas become available, they can be easily implemented in a system that you built and know. My experience in learning how to accomplish an install has also taught me many other useful skills. These include creating my own sensors, building displays from scratch, and others that are useful outside the automotive world.

dimented24x7

iTrader: (2)

Some of the OEM stuff is pretty advanced, and it has to be to meet emissions/drivability/fuel economy/performance standards. Although the early ECMs where pretty bad in stock form, some of the later ones are pretty flexible, and alot of the input/outputs can do things other then what they where originally intended for.

As far as the WB, both the megasquirt and ECMs would basically be handled the same way. Plumb in your controller to an input, set the target AFR and gains, and drive off. From what I can tell, the only issue is that your limited in that you can only really target one AFR with the megasquirt. Some of the late model PCMs today have full wideband control across the whole operating range.

BMmonteSS

I guess it should also be mentioned that the EBL has WB inputs and a self learn feature that will tune itself based off the WB readings.

pizza_guy

The MSII has it's own AFR table for WB. You can setup ratio targets just like a VE table. Includes the same "autotune" feature as well.

dimented24x7

iTrader: (2)

Thats pretty cool. Is it full closed loop at all times? I was on the verge of using a full WB setup, but I decided to go to a predictive rather then adaptive system. The closed loop fueling can correct for alot of stuff. Tuning the PID action can be really tricky, but if its set up right, itll correct for all sorts of tuning shortcomings. I know with my engine when it was first started with the new computer, it would idle and run at 20:1 and less. Once it hit closed loop, youd never know there was a problem. WB was tight to 14.7:1 while driving.

pizza_guy

There are some parameters you can set to switch it on and off at certain times(e.g. above coolant temp, below TPS), but 30 seconds is the default switch to closed loop. If you dove into the code you could change that as well, but I'm leaving it like that to make sure my sensor warms up.

The speed density programming is predictive using the VE table and sensor input, but it uses the WB to adjust the pulsewidth real-time.
(I might have misunderstood what you were saying, which is why the above remark may not make sense)

I'm not familier with PID. I'll search around and edit this when I find out.