curly

iTrader: (25)

FTFY.

Feel free to read the real VVT swap thread

Dunning Kruger Affect

This thread has AIDS...



Band Aids

shuiend

iTrader: (24)

Do you have any actual evidence that AFR's won't be more then safe on a stock 94 ecu and a VVT head? Have ever tried running a similar setup and seeing what AFR's are? Amellrotts has a wideband installed on the car, has had it on a dyno, and says that AFR's have been within a safe range during the pulls, what data do you have to counter him with? This is not a boosted motor where AFR's have to be absolutely dead on, nor is it a track car. The 94 ecu already runs rich from the factory so I have no doubt that it will provide enough for a safe street tune. No it won't be perfect, but is the cost of a standalone worth the additional 10hp he may pull out of the motor? In his case most likely not.

I have never ran a stock 94 ecu with VVTuner and a VVT head, I have ran a stock 99 ecu with VVTuner and a VVT head on a 99 lower end. Watching AFR's on a wideband and the car had plenty of fuel. I know my stock 94 runs richer stock then my friends 99 did so I don't there is enough fuel.

Dunning Kruger Affect

I'm not arguing that it won't run, I'm arguing for things being right vs things working. There's a significant difference between the two.

He also has nothing to lose considering that the car doesn't have OBD2 for inspections in NC.

shuiend

iTrader: (24)

He has $750+ to loose to go to an MS3X or some other modern standalone for minimal gains.

emilio700

iTrader: (3)

A bit off topic but this experience might be relevant. We bought this NA6 with a bunch of useful mods off craigslist for parts. PO said the head was shaved. JR header, ceramic cat, 2.25" race exhaust and a Randall snorkel on the airbox. It actually does "run great". So we put it on our dyno to see what it was making. 112whp is strong but one look at those AFR's and I wince. This poor little B6 is begging for an ECU. Anyone who has tuneda B6 on stock cams knows this thing probably has 10 more whp at 7200rpm with a halfway decent tune

Moral is thus: Just because it starts and runs smoothly, makes more power than it did before mods, does not mean it is tuned properly (or at all in this case) or close to optimized. NB engines tend to do the opposite and run dangerously lean on top. Get a WBO2, programmable ECU and have a pro tune it. Or at least let the software autotune for you.

Amellrotts

iTrader: (2)

I am not going to speculate how other cars run with setups I know nothing about. I promise you there are a lot of other people running VVT engines on stock NA ECU's with no isues. I know mine was right on. Since I am using the NA CAS I can easily adjust timing. I know I bought a MSPNP and when I went to a dyno day the shop owner and tuner told me the ECU was controlling the AFR's perfectly. That if I did install the MS I would be paying him a lot of money to make it do what the stock ECU was already doing. He, and several others in attendance were all very surprised. We even did about four extra pulls with my car just to verify things as well as do a side by side comparison of the VVTuner on vs off. After having another tuner ride in my car and tell me the same thing about my AFR's I decided not to mess with it for now. Then I sold the MSPNP because it is kind of nice to have OEM reliability and not have to **** with tuning it from time to time. It starts great, EVERY time. It idles great, every time. It gets great fuel economy, every time. Sure I could get a LITTLE more power by changing my timing curve and removing the MAF, but at what cost? I have lots of power in my boosted miata. Soon I will have a LS1 swapped miata. This is the wife's car and she insisted it not need a laptop hooked up to it, EVER. Since the bitch left it is even more imperative that the car run properly without the need for occasional tune adjustment. I know it isn't normal, I DON"T CARE. I know this car is working RIGHT. Not just working, but doing everything it should, as it should, SAFELY. I have put 50K hard miles on this setup. I would not trust the next one to do the same and would have wide band in it as well. Today however, I have such faith in my setup that I pulled the LC1 WB because I am tired of ******* with the boosted car's MTX WB that won't stay calibrated. I am installing the LC1 in the boosted 10AE and hoping to have a reliable WB. So at this point, even if Reverant gave me a MS3 for the 94, I would not use it.

Thanks to those that actually gave useful information for others to find in the future. To the other clown, I am glad this thread was able to get your post count up you f*cking troll.

Dunning Kruger Affect

Emilio and Savington: known trolls trying to get their post count up.

Between the casual homophobia and misogyny, I don't know why "the bitch" would ever leave you. You seem like a pretty stand-up guy.

harrybeachdog

I'm surprised his factory ecu is running it as well as he reports. Friend swapped an 03 into his 97, factory ecu would NEVER pass emissions again, even with all sensors from NA, vvtuner on or off. We stuck a wideband in just to see what was happening and it was lean up top. 15.5-17 under WOT. I was afraid to put any det cans on it. Sounds like this guy's car got lucky though.
Do you go out of your way to be more of an *** than you believe he is?

Savington

iTrader: (31)

Sounds right. To be blunt, until I see a datalog or a dyno chart with an AFR trace, I call bullshit on the idea of perfect AFRs from a '94 ECU. If it's true, and the AFR trace is actually between 12:1 and 13:1 above 4000rpm, then it's a miracle.

bcrx7

iTrader: (5)

It's funny people make **** up based on nothing and call others with actual experience troll...

harrybeachdog

You know, one thing that could make it safe would be slightly larger injectors. Like a set of 305 greentop supra's I have laying around. Maybe I have a use for those finally!
Or I could do it right and use my ms2...

Amellrotts

iTrader: (2)

I do believe I am the only one here who called someone a troll. Someone who had given no first hand knowledge of any actual experience with the situation being discussed. I however, have that experience. I tried to share my actual first hand experience and knowledge to better the community here. I have no problem with people questioning it, I stated upfront that the empirical data was far different than what I expected. But to be bashed and flamed like this, wow. I am more surprised by this than the engine running properly. I also believe those with lots of experience who have given good info to this discussion admitted their experience was not with a 94. I promise I am the only one who has experience with this 94. There will be a dyno day coming up at 42 Autosports in Concord NC. I will have this car there if anyone has the courage to show up. I am not a **** stirrer and I don't troll. I read to learn and try to add to the knowledge base when I can.

But by all means, please, more people tell me how you know what my car is doing better than I do....

Nagase

iTrader: (6)

So this is where the yikes picture came from. What a disaster.

Ben

iTrader: (33)

I dyno'd a fairly similar combo once. AFRs were surprisingly flat but 13.5-14:1 That car had a big fuel pump and aftermarket adjustable fuel pressure regulator. I was able to increase fuel pressure to keep AFR at a reasonably flat 13:1ish.

Then we installed and tuned the MegaSquirt, and made more power.

I would not call that stock tune good, or even close, but it was "OK". Certainly far from optimal.

EErockMiata

I'm in the process of trying to get an 01+ motor to run on a stock 99 ecu with vvtuner. My MS3 Basic stopped working and this was my stopgap for the miata's @ mazda raceway event.

Anyway. I wired it up to the stock ecu per this. https://www.miataturbo.net/megasquir...nms-ecu-69111/

The only difference being that I seem to have to run 12v switched/fused to pin 5/6 on the vvtuner connector to get it to power up. (found that here) I'm running my 12v from an additional circuit out of the fuse box if that matters.

At any rate I can't get the car to fire like this. I called DIYautotune tech support today and they gave me a handful of resistors to cut out stating issues with the 12v pull ups. Gonna try that tomorrow morning but before I go cutting another perfectly good part up... I just wanted to see what the peanut gallery thought.

TIA

EErockMiata

Hello Chums.

I just thought I'd stop in to say that I ended up getting this working. Was fairly simple on the 99 ecu. I'll do a write up of how it got working but it's "running great"! Most likely dangerously lean but it's going to have to do for a weekend. I'm going to try and throw the car on the dyno to see what it's doing before I convert it back to ms3.

TLR? = Yolo...

hrtworms

So if I start this project using that diagram, I would be on the right track...?


Are these resistors in the VVTuner or the ECU? I'm assuming the VVTuner.

Looking forward to your write up.

Savington

iTrader: (31)

Apples and oranges. The '99 ECU is expecting the BP4W ports and 9.5:1 compression, and it's getting a slightly different cam profile and 10:1 pistons. Probably not all that bad, TBQH. The '94 ECU is expecting a head that flows 30+cfm less and a full point less compression. All bad.

Dunning Kruger Affect

1.2 points less (13.6%). Please don't troll, Sav.