Dunning Kruger Affect

Savington

iTrader: (31)

http://www.flyinmiata.com/projects/c...ts.php?UID=594

John-5X Racing

None taken, and thanks for your input. I appreciate feedback on why what I am trying to do will not work, rather than being told that it just cannot be done without helping to educate me on the reasons behind the dangers.

Of all the research I did on this swap, 90% from this forum, somewhere along the lines I must have not realized that a standalone ECU was the default ECU being used in the swaps, which is why I proceeded with the stock ECU. Naive as it is of me, I went forth with the stock ECU. So, with that said, I know (as I've been scorned already) that the standalone is the best route. 100% crystal clear. If it were my car, I'd have a standalone in it, and I plan to do this with my personal 99 soon to get the experience. But in this particular case, being a customers car, who was on a budget and has been waiting for this car for a LONG time, I'd really hate to tell him we gotta plunk down another $1K and the time involved for me to install, learn, and tune a standalone. And I also understand that a blown engine is not desirable either, and can be avoided by the addition of a standalone. So this is where I lie, in a tough spot and is why I am now asking for further advice in the form of an alternative way to control the AFR being that an over lean condition is a possibility with a 2001vvt engine being controlled by a stock 94 ecu.

I do understand AFR's and their relation to a stock based engine at certain RPM's from Spec Miata racing, and what's "good or bad" AFR's in racing conditions. So, with that in mind, what AFR do you consider being too lean? What AFR do you consider being in the right range for a bone stock 2001 engine? I know what's good for our SM's, and if I could get it there on the vvt engine, wouldn't that suffice? We have an adjustable fuel pressure regulator on the engine that we can use to control the AFR, I know it's not as good as a standalone, but it still works and is how we control the AFR on the stock ECU in racing. It may not be the ideal solution, like a standalone, and may be a work around, but in stock class racing we cannot use a standalone, and considering the circumstances above for my swap, would adding fuel pressure work to help control a possible lean situation? Possibly going with a bigger injector also? Still an added cost, but way easier to me than having to install/learn/tune a standalone.

John-5X Racing

Thank you for taking the time out of your day to find this and share this with me. I'm sure it would have been very enlightening had I watched it.

Dunning Kruger Affect

AFPR is a terrible idea. So is doing a science project on a customer's car without knowing the full scope of the project.

If you want to make it right and actually learn something from this, I'm going to suggest eating the cost of a standalone and being 100% truthful with said customer. Melting a piston through ignorance is a bad way to have repeat customers, I won't argue that it isn't a good gambit; however, there are much better ways to go about this.

Dunning Kruger Affect

No problem. I see that you're within spitting distance of Disney World. Good to know that there's something else near Orlando that's all sorts of Mickey Mouse.

A great way to win over the community and expand your customer base is by being petty and ignoring the fact that people are actually helping you out.

Savington

iTrader: (31)

The hard truth is that your customer's budget and your lack of experience don't change the laws of physics. That package needs its original stock ECU or a standalone, whether or not your customer can afford it, and whether or not you know how to tune it. I think you understand this, but don't want to admit it.

Safe AFRs are ~12.8:1 through the torque peak, leaning out to 13.0-13.1:1 at redline. You can try playing with base fuel pressure, but what you'll likely realize is that the fuel pressure that gives you safe AFRs at 4500rpm will produce extremely rich AFRs at 6500rpm+, and what gives you acceptable AFRs at redline will be dangerously lean through the midrange. Anyone who has built a turbo setup using old-school piggybacks (i.e. an RRFPR and a Bipes) will tell you all about this in profanity-laced detail.

Even if you were to get it running perfectly, you're looking at a car that might cough out 120whp and 105tq on the stock '94 ECU and intake. Open up the intake, delete the MAF, and add the standalone, and those numbers jump to 135whp and 117-120wtq, with even more torque gained under 4000rpm.

MX5RACER

You have a VVTuner, you can make some adjustments to the VVT map to help the motor stay happy. It will not make full HP potential, but NOT going to full retard in the high RPM's and not advancing the cam so much in the mid-range should help you keep the AFR in the safer range.

John-5X Racing

So Savington, now that I have your attention, do you mind sharing some more knowledge and feedback with me? I pretty much based the swap on your information shared in the mega post here called "how to wire a vvt engine", and I have a few more questions based on one of your posts on that thread. This is probably where I misled myself in thinking the stock ECU would suffice, as I was reading heavily into the "stuff that will stay the same" and "stuff that you'll add", and didn't see a standalone. Didn't think about it being the default ECU and not needing to be pointed out.

Original text from Savington's post in "how to wire a vvt engine" thread circa 2012:

The easiest way to swap a VVT motor into an early chassis is to use as much of the original engine wiring as possible, and then add the incorrect bits last. I've done 3 or 4 of them now, and this is the method that involves the least amount of wiring alterations.

The stuff that will remain the same:
-All of the starter and alternator wiring, as well as the OPG wiring (use a 94-97 1.8 alternator and the OPG sender that corresponds with your gauges)
done
-The injector and coolant temp sensor wiring. You should pull the +12v for the VVT solenoid from this harness - it's the easiest, closest +12v. Your old CLT sensors (for the ECU and gauges) will carry over to the new engine.
done, however I am running the VVTuner and it's supplying the 12v to the VVT solenoid.
-The wiring for the TPS and IAC (the connectors are different, but the wiring itself is the same) (Note for 1.6 guys, you'll either not use the variable TPS or you'll need to move some stuff at your ECU connector to use the factory TPS wiring)
I used the throttle body from the 94, so the TPS and IAC were carried over.

The stuff you'll add:
-The cam/crank wiring. The OEM CAS has a 4-wire connector - you have a +12v, a ground, a cam sensor wire, and a crank sensor wire. Feed +12v and Ground to both of the NB sensors, hook up the cam signal to the cam sensor, and the crank signal to the crank sensor. Easy-peasy.
I am still kind of confused by this. Are you saying that the cam and crank sensors and their signals from the 2001 engine will interface with those of the 94? The 94 CAS has a black wire (Ground), a White/Red wire (12v), a white wire and a yellow/blue wire which are the signals. So if I connect the white wire to the cam sensor signal output, and the yellow/blue wire to the crank sensor signal output of the 2001 engine it will be a straight substitute to the CAS? I am using the original CAS for now, but would love to get rid of it if possible. For reference of what I am talking about on the CAS wiring: Our Friend CAS
-The VVT signal wire. Grab +12v from the injector harness and then run your own wire for the signal to the control solenoid. There is no polarity, so hook up the +12v to either pin.
I am using the VVTuner to control the solenoid.
-TPS and IAC pigtails. The IAC is easy, since there's no polarity, but you'll need to pay attention to which wire goes where on the TPS connector. Each car has slightly different wire colors so there's no color-by-numbers for this one. I will usually hook it up temporarily, confirm the TPS function, and then make the connections permanent.
I used the original 94 throttle body, so it's functioning the same as if on the original 94 engine
-Coil wiring. If you have a 94-97 NA, this is pretty easy - just hook up the wires as you otherwise would, and then use your ECU to drive the tachometer. If you have a 90-93 NA, it's slightly more complicated, as you'll need to bypass the OEM ignitor before you hook up to the OEM wires. This assumes you're using the 2001+ coils - if you're doing LS coils or keeping your factory NA coils, then you don't have to touch the wiring here.
Got majorly crossed up on this and it was the cause of my swap not wanting to stay running. I converted to the 01 coils using the "one for one" method (ground to ground, 12V to 12V, trigger to trigger) but was left with a tach signal wire that had no home. Come to find out that this was the cause of the engine failing to stay running after starting. How do you use the ECU to drive the tach? I wanna use the 01 coils, but will definitely need the tach signal to send to the ECU to do so. 01 coils don't have a tach output.

I'd appreciate your feedback again. Also, I want to be able to help future people trying to do that same thing to make sure they're getting the facts about their swap, whether it's "use a standalone before you even think about it", or "you're gonna need to use the 4-wire coils if originally equipped because of the tach signal".

concealer404

iTrader: (3)

John, i think at this point you need to have a talk with the customer and tell him that he has two choices:

1) Spend the money on a standalone

2) Have drastically decreased power and dangerous running conditions.


If he can't afford a standalone, he also can't afford a new motor. This really has no sort of negative bearing on you, besides the fact that you were conned into attempting this in the first place. If he gets mad about it, you didn't want him as a customer in the first place.

Good luck!

John-5X Racing

Nice. Well I have no interest in carrying on an argument, but for some reason, I feel that you were not here to help me out from the beginning, rather just troll and embarrass someone looking for some advice. Everyone else on here, yes. They offered their advice and help in a friendly manner, and most certainly try to help me understand which direction I might go and why. I might sound ignorant because I am ignorant on this subject and am trying to learn from you all. I'm sorry if I sound petty because I might be faced with the fact of having to spend a lot more than I planned to on this build because of an oversight. It's not sitting with me well at the moment as I have to make this decision with the customer.

As far as winning over the community and expanding my customer base, I would hope that anyone interested in my companies products or services would base their shopping decisions on our customer service, our prices and offerings, and how we conduct business rather than basing it on my reaction after getting provoked by you on this thread. I'm not used to the tough world of forums and usually am reading rather than writing.

Dunning Kruger Affect

This is me trolling and embarrassing someone.

Savington

iTrader: (31)

The signals won't interface with the stock ECU, obviously, but what you can do is use the stock wiring to correctly input the NB signals into your standalone. That's what I was referring to (that entire post assumes you have a standalone, specifically our AEM EMS-4 PnP)

The AEM drives the tach itself, without any help from the coils.

In other words:

This, basically.

John-5X Racing

I am afraid that looks like the only two options. I am gonna look into the Megasquirt options tonight and do some research on what I would need to do and spend.

I wouldnt say I was conned into the swap, it was our idea instead of rebuilding the original engine vs. the cost of a swap in terms of power/reliability. Customer wanted a Spec Miata type engine build, which get expensive. Knowing this we proposed a vvt swap instead. I would say I misunderstood the aftermarket ecu need after researching it and went ahead with the swap with the notion that the stock ecu would work. We would still come in less than the cost of a race rebuild on the original engine if we added the standalone. We'll figure that part out!

MX5RACER

PSST...

You should be able to get the VVT motor to run safely by de-tuning the cam advance/retard using the VVTuner. It won't be ideal for performance, but it should let you get it safe.

Remember that the VVT is changing the intake cam advance/retard to get the max performance with the hotter VVT cam than the '99-'00. The intake cam is retarded at idle to give good idle quality and low-end torque. It starts to get into full advance by the mid-range and then goes full retard in the high RPM's to make power. By limiting the advance in the mid-range and the retard in the upper range, you should be able to get it to run safely.

Savington

iTrader: (31)

And then it will make even less power than his stock motor did in the first place. Not a good plan at all.

MX5RACER

A running car without having to spend more money might get the customer down the road until they can save up enough for a real ECU.

albumleaf

iTrader: (7)

The fact that you're doing this swap with little to no knowledge of AFRs would be enough to get me to run screaming from your shop. I'm sure you're very capable mechanically, but this thread :fp:.

John-5X Racing

Not a public shop, personal. We only work on our race cars and focus on parts development. Someone just couldnt walk in and order this swap up, I would quickly send them away. This car is for a family friend, he wanted us to build the car for him. If someone I didnt know were to request this build, I would run screaming as well as I have never done a 94>01vvt swap. Customer fully understood the challenge and challenged us to it. I am just trying to save him money on an already expensive build.

This thread = me reading other threads on this forum, beginning a project, and now trying to get the facts straight.

I wouldn't hand someone a time bomb, which is why I am bouncing this info off of people who are knowledgable about the subject here to get it right. If I need to get a standalone I will, but I needed to at least get it clear on what my options are and if I could make what I am working with work. I think everyone has got me all wrong in thinking that I am on your level with this knowledge, which I am not. I started this to get info on one issue I was having and it turned into a mess.

segore

Thank you John and Andrew, you have both answered a lot of questions for me. I am currently doing a 03 VVT into my 95 swap. I was trying to start up using the 95 ECU and having the same problem you are John and now I know why! Andrew, I do have a MSPNP and VVTuner kit that I need to finish, most of my wiring is very close to what you posted before. I, like John, did not understand about having to have a standalone to make things work. This is also my first try at this and it is my car. I have been doing this for years but I'm from the age of carburetors and setting the dwell on the points. Thank all of you for some very lively conversations and other comments.