18psi

iTrader: (76)

Now I'm gonna stay just because you said that.

And to laugh at you.

pakron1122

You know, you sure have a big mouth but I am doubtful of your intelligence. Usually it is the loudest ones too, because they are the most unsure of themselves and need to compensate.

18psi

iTrader: (76)

Yep, that's exactly it.

pakron1122

Does anyone here ever explain anything or is it just a circle jerk of self-superiority. It's funny, because I got a stock welcome PM from Braineack saying how this is a respectful place. I should question someone with nothing better to do in 5 years than to post nearly 18 thousand times.

Anyway, gasoline burns best at a certain ratio, say 14.7:1. Adding more air via a supercharger throws off the ratio, which you must add more fuel to compensate. Now, I can do that mechanically with fuel delivery. The curve may not be exact, as the 1.6 ecu is expecting certain things at certain rpms which are now off. But you can get it close enough. So that is my thinking. Is that not correct?

18psi

iTrader: (76)

This post is a flawless, perfect, supreme example of why we haze n00bs on here.

pakron1122

Anyone care to comment who has hit puberty?

miata2fast

iTrader: (2)

It is very obvious that you lack experience. Every person on this forum will tell you that it is a waste of time without an ECU.

You can forget about getting any help from members here until you ditch the idea of the stock ECU. Even if it takes longer to build it, do what ever it takes to get one. You have no idea how much better your life will be, and how much better the end results will be.

Savington

iTrader: (31)

This is the equivalent of taking the B6 out and putting an SR20DE or a 4AGZE in its place - it's a fundamentally different engine with completely different calibration requirements. You aren't just "adding more air" - you're drastically changing the engine setup, and that means you need to similarly change the engine's calibration. You cannot do this with the hardware you've described so far.

I did not "overestimate" anything in reference to standalone ECUs. In fact, the setup you're talking about building (a hotside roots blower) adds so much throttled volume to the system that the stock ECU seriously struggles to keep control of the idle. Adding an intercooler will make this dramatically worse, and the car will never idle right. If you switched to a standalone, it's fairly easy to compensate for all of this.

At the end of the day, if you don't want a tuner car, you're making a big mistake taking on a DIY project like this. I don't mean to be insulting, but it's pretty clear that you have very, very little understanding of how ECUs and engines interact. I understand that your goal here is to just avoid the ECU part of it, but what I am telling you here is that you don't get to do that just because you don't understand it.

What experience or example has made you think that you can get it close enough?

You're making an assumption because you want it to be true. It's not true. Sorry. You will not be able to fool the stock 1.6 ECU into properly fueling a VVT+JRSC combo, regardless of what mechanical kludgery you use.

pakron1122

Why would I do what someone just tells me without explaining why? I never spend my hard-earned money like that. I'm just looking for some information.

pakron1122

Thank you for the info. The example I can give is achieving a proper a/f mixture under wot at a given rpm I wish to target, which for my daily driving is around 4500rpm.

miata2fast

iTrader: (2)

???

Go to the ECU section on this forum and spend some time reading the stickies and as many threads as you can. If you are a verbal kind of guy, may I suggest you get in touch with vendors here that supply ECUs. I gaurantee you will find that a Megasquirt is the way to go. Megasquirt is the most economical and well supported ECU on the market for Miatas. Most members here have it.

pakron1122

Here's the thing that's bugging me. You can run a JRSC on a stock ecu. In fact, the vast, vast majority of them were done this way for 20+ years. You can also do a vvt swap with a 1.6 ecu. Many people have done this as well. It is no different than any other 1.8 swap that has been done thousands of times on the 1.6 ecu other than adding the vvtuner.

Maybe this is the wrong forum to ask these questions. I knew what I was getting into as I stated in my first post. I know who started this forum and I know the kind of users that are on it and they everyone is very pro-standalone. I've been lurking for a long time. Oh well, just thought I'd give it a shot.

Savington

iTrader: (31)

Cool. What about 2000, 3000, 6000, and 7000rpm? How about at 30kpa, 80kpa, and 140kpa? It's easy to hack a setup together to deliver fuel properly at one particular RPM, but what I'm trying to tell you is that you cannot fool the 1.6 ECU into properly controlling a VVT+JRSC setup at all RPMs and boost levels. You will end up with certain places that are tuned perfectly, and certain places that are either undriveable or unsafe (or both).

That's what I was getting at earlier with the dyno curves. You're changing the shape of the torque curve dramatically, and with that change comes a change in the required fueling that will vary from low RPM to high RPM. RRFPRs only make 2D adjustments - they won't compensate in the low RPM range without making the same compensation in the high RPM range, regardless of whether the compensation needs to happen at both places or not.

A standalone lets you make the adjustments necessary at every RPM and every boost level, and leaves you with a car that drives like it was designed to have a VVT+JRSC setup in it from day one.

Savington

iTrader: (31)

News to me. 1.6>1.8 swaps on 1.6 electronics are pretty common, but the head design and torque curves on 1.6 and early 1.8 motors are fairly similar. Once you talk about swapping to the 99-00 head, the 1.6 electronics aren't held in particularly high regard, and going to the 10:1 pistons and VVT torque curve puts the 1.6 ECU way out of its league.

Again, you're lacking a fundamental understanding of how engine management systems work. What you want to do is not safe or smart, and you shouldn't do it.

miata2fast

iTrader: (2)

You know, maybe it is possible, but the run quality would be so bad, that it would drive most of the members on this forum crazy, and I doubt that a build like that would last very long. Remember, the VVT motor has a lot more compression.

I think that once you really take a hard look at the ECU options, and the fact that going from a stock ECU to a stand alone is not such a horrible expense and learning curve, you will do it and have a much better end result.

I wish you all the luck. Think about it awhile before you get to invloved with it.

miata2fast

iTrader: (2)

By the way, Savington has more experience than anyone on this forum when it comes down to swaping in vvt motors, take what he says very seriously.

Fireindc

iTrader: (13)

I'm pretty sure this is a troll post. I would vote for a ban of this n00b, but I'd rather him stick around so we can see his blown engine thread.

Seriously OP, listen to what others have said. A JRSC setup, even on a 1.6, with a stock ECU sucks. A 1.8 vvt swap with a stock 90 ecu is going to suck. A 1.8 vvt swap with a JRSC thrown on it with band-aids is going to REALLY suck.

2ndGearRubber

OP, let me just make this simple.


1) The 1.6L ECU cannot control the VVT motor properly. COPs, the VVT itself, different sensors, etc. all lead to the 1.6L ECU needing to be hacked together to even TRY to run the motor properly. It's like asking a 4th grader to do trig. Yeah, some of the time it'll work out, they may even be able to make a proof of their answer. But that doesn't mean they can do 100% of trig, 100% of the time. The development of the 1.6L ECU is almost 15 years removed from the OEM 01+ cars. Would you expect a 10 year old computer to run windows 7 flawlessly?


2) The 1.6L ECU can run its' native motor, with piggy-back band-aids, using the JRSC. It's not the best system, but it can be done. The thing is, if the ECU is near the limit of its' abilities running a STOCK motor with a JRSC, why would you expect it to be able to handle a non-native motor while also dealing with the JRSC?

3) 14.7, stoich, whatever, doesn't mean squat. For one, the ECU may try to maintain 14.7 under certain conditions, it doesn't mean 14.7/1 is the be-all, end-all, AFR.

4) With enough effort, you can make ANY ECU control ANY motor in ANY car. It doesn't mean it will do it well, reliably, safely, easily, or consistently.



I recommend you do more reading/learning before you go any further. Listen to these guys, they've done a lot. They know what they're talking about. Let them help you; unless you're just trolling, or just really stupid.

RussellT94

iTrader: (3)

Good luck, keep us informed on your progress. If you do not intend on following the advice in this thread, at least keep us updated on how you attempt to cobble this together.

viperormiata

iTrader: (24)

As someone who ran band-aids for years, I can say that you are in for the worst experience of your life if you keep being stubborn and ignoring all the people on here who actually know what they are talking about.

Good luck.