2 questions on VTCS-->VICS
 

1) In YellowSR's dyno of VTCS v VICS, (http://forum.miata.net/vb/showthread.php?t=491784) 14whp was gained past 6k rpm with the only adjustment being amount of fuel. This is proof that one could swap VTCS for VICS and increase fuel delivery for 10+ extra whp yes? ?

2) The stock NB2 ECU can not handle the increase flow of the VICS manifold and will run lean.YellowSR said the swap to squaretop did not require much adjustment, I am assuming that he is talking about swapping from VICS to Squartop If fuel looks to be the main problem with making a nb2 run with VICS/Squaretop, is a Powercard to increase fuel or perhaps even a JDM ecu (which I assume is tuned differently to run the Square top) not a reliable and cheap alternative to a standalone?

You must add fuel because you cannot make more power without more fuel. The only way a stock ECU is going to be able to handle the increased flow of the different intake manifold is if the stock ECU was designed to be used with that manifold. If you swap in the different ECU, you will also need to swap in the different fueling system, the different sensors, different head....you might as well sell your car and buy the higher performing car if you really want to use that stock ECU. You can successfully swap in a JDM ECU if you also swap in the rest of the JDM Car that it came with. This will require almost no physical labor on your part: Open garage, swap JDM Car for USDM Car, Close garage - you now have a complete, running JDM ECU! You might have to jump through a bureaucratic hoop or two in the process, but I'm sure that's not such a big deal.

Let me explain the benefits of the powercard. That's all I have to say about that.

Hinano, I appreciate the fact that you've at least done a scampering of research, but your expectations of "power mods" are unrealistic. The VTCS to VICS swap worked BECAUSE of the presence of a standalone ECU, not in spite of it. YellowSR may have only incresed the fuel in some cells, but the standalone ECU did a number of other things to compensate for the fact that more air was going into cylinder. One does not simply bolt on an intake manifold and go. You would probably have better luck installing an "electric supercharger".

If you want more power without the effort, you are going to fall flat on your face. Bolting on "go fast" parts to gain power without also adding the compulsory supporting mods is something that children do. Do yourself a favor and be an "adult". Everytime you pull out your debit card to buy something to increase the power of your car on the stock ECU, punch yourself in the face and put the money you were going to spend in a jar on top of your refrigerator. (You could actually burn the money and get a better return on investment compared to power increasing mods on a stock ECU, no sarcasm.) Once you have punched yourself and stored that money between one and three times (that's all it will probably take), take that money and buy a MegaSquirt. Until then, you can add "performance mods" that increase the handling, braking, safety, suspension, etc., but don't even think about touching the drivetrain. You would have to be a fucking retard to do that after I've enlightened you.

Go out to the world now, do great things.



P.S.
In the future, when you hear the phrase "JDM", understand that whomever said the phrase "JDM" is, most likely, a COMPLETE MORON when it comes to cars. Don't be a COMPLETE MORON when it comes to cars. Don't use the phrase "JDM" for a few years. Don't aspire to become or to impress those who throw around the phrase "JDM" like 2 dollar bills in the strip club. Only on the very rare occassions will you talk to someone who says "JDM" AND knows what they're doing. Swapping in a JDM ECU and expecting your car to run well...or even at all...is akin to swapping your wheels and tires for fan blades and trying to win a competitive racing event. They're both round, but it just doesn't work.

Actually, on the stock ecu you would get proper fueling with the VICS or flattop swap. Because the MAF will read the extra airflow. If the stock ecu was speed density it would probably not supply enough fuel, but with the maf it will.

Its still wont make very much more power because the stock tune is pretty meh, and you'd get more power/dollar out of a MS than putting a flattop on a car with a stock ecu.

This is completely opposite of what many people that tried it (Sav, Emilio, etc) have reported.
They reported that the car in fact, does lean out past 5k.
Are you talking out of your ass again or did you actually try/test this?

I didnt try it. I was quoting Sav after I previously said I wouldn't run a flat top on a stock ecu because to flows so much more air up top than a VICS, it would be dangerous. I'm assuming he's right because it is a MAF car, so it should be able to see the extra air and compensate.

^^^ I had thought that at WOT above 4k RPMs, the stock ECU runs an open-loop map, so the MAF isn't doing anything. This is why you get a lean condition above 4k at WOT where it transitions from stoich to preprogrammed map.

I am not 100% certain, but I would imagine you can run slightly larger injectors (say NB2 injectors on an NB1) to enrich the A/F during open loop if you have a lot of modifications that supply more efficient airflow.

Um if the ECU is in open loop, which means the ecu isnt using o2 sensor feedback, but also isnt using the MAF, exactly what magic is the ecu using to determine the fuel load?

maybe throttle position and rpm. either way, it doesn't adjust real time or you have no idea what open loop fueling means

I would hope that the factory ecu open loop fueling table is rpm vs maf.

:facepalm: the bottom line is it leans out up top in open loop, and in typical leafy fashion you're adding a bunch of theoretical gayness to this thread that may lead OP into bolting this thing on and possibly hurting his car. he's too cheap/poor to do it properly and doesn't have a wideband to test this theory of yours.

FWIW, I ran some dyno+A/F logs with totally stock intake exhaust and later with a DDMworks intake + 01 header, and you can definitely see the decreased airflow resistance is not compensated for and the A/Fs are leaner above 4k. I'll try to post the logs later today.


edit: here you go
WOT A/F log, NB1.
Blue is 100% stock, Red has an DDMworks stage 2 intake and 01+ exhaust manifold.

They both see the about the same A/Fs until around 4500 or so and slowly diverge until redline.

https://www.miataturbo.net/attachmen...ine=1387299720

I couldnt find the one with Sav's reply to my post where I said it would lean out to 15:1. Which does happen on a SD tune when you put a flat top on a car that was tuned for a VICS manifold.

This is the exact opposite of what I have come to understand from reading this forum. It would be great if someone with more experience with the stock ECU would chime in.

For example, post number 3 by Sav in this thread.

They're both full retard today. You are completely right scenturion.

Lots of good info ya'll thanks. :)

The reason I am inquiring about this is because I am trying to avoid a standalone for,
1) College budget
2) Not even willing to get exhaust (hurts my ears/expensive/sound pollution)
3) Might move back to Japan in one year
4) No time to tune and retune because I might be leaving real soon
5) I regularly travel from sea level to 14k feet elevation (more to buy/tune)

So in an effort to find some extra power and fun, I have Konisport/GC coil-overs and 8lb flywheel is on my list but I am looking for some extra power on the cheap. If I cannot get that power, it's fine, I don't need it.

I like intake sound and it's not that loud so I though about doing some intake side modifications. I am going to Japan in the summer so I thought it might be fun to look for a square-top(and or other parts) if unable to get a VICS locally.

So now you know where I'm coming from but have a question, please advise.

1) From what I read, for whatever reason, the stock ECU will not compensate for increased air flow when WOT. This would suggest to me that one should have a wide-band before doing any modifications at all no?

2) How would you guys run a cheap intake side modifications set up?

There's no cheap way to get n/a power out of a BP on stock ECU.

If you are broke, don't modify your car. Its as simple as that.

That's the thing.. I'm not really broke. Also, this is a hobby of mine. Let's just call it a $500 budget for power.

I just spoke to Moss and found out that the Powercard does not adjust fuel at WOT so that will not help..

1) What about a AFPR?

2) What about running larger injectors like Scenturion suggested?

3) For timing, what about just throwing on a $30 5xracing timing wheel and calling it a day?

Buddy, i'm pretty sure you don't know what any of those 3 things mean.


Let me help you out again:

What would help me out is supporting my quest to expand my knowledge. I am quite new to 'tuning' but know a lil bit and believe the above questions are relevant to taking advantage of a higher flowing intake manifold. :x: