Leafy

iTrader: (1)

If this line is actually how it works, you DO NOT WANT. That would mean they are turning off the maf control when in boost. If this reflash worked properly you could tune all the computers for as much boost as the maf sensor is capable of reading, and just change the injector flow between them all. Turning the boost down should keep the same afr (or leaner if its commanded in the tune). I would be terrified to see what part throttle boost afrs looked like.

18psi

iTrader: (76)

The part where she says 9psi on stock injectors and 200whp on stock injectors makes me cringe.

joyrider

iTrader: (8)

9 psi is impossible, my 260CC (NB1 OE) we're maxed at 5 psi on GT2560 AR60....

Leafy

iTrader: (1)

But how rich were you? Corky wants to run at 12.2:1 AFR, which is completely legitimate (but somewhat aggressive) to run at 9psi with a quality tuning solution, I wouldnt try it on bandaids.

triple88a

iTrader: (2)

By redline at 6 psi i was already at 12.3. At 9 psi i'm guessing it would be in the 13.5-14 range. Again for fuel, that is ALL OF IT.. 17.something ms. 100% duty cycle. I have a log somewhere on the forum from that run. About 6k rpm i was at 11.7 and from there it started leaning out.

18psi

iTrader: (76)

Lets say you do run the injectors to the very limit and end up with the 12.2afr by running the system 110%

What happens when you go out on a really cold/humid day and do a high load pull in like 4th gear?

NW Bill

except the NB200 has a reflashed/reprogrammed ECU:

otherwise (from Stephanie):

the stock ECU – by itself – can handle 6 psi.... The stock ECU – unmodified – is not programmed for boost and must have something done for fuel and timing control when under boost.

and as Corky pointed out in one of his postings earlier in this thread, the 9psi, 200whp on stock injectors with an NB200 ECU reflash is "obtainable" if the car is pushed. It is best case, not an all day, every day number.

For 200whp without pushing as much, Stephanie suggests a 2.5" or 3" exhaust, followed by larger injectors. She also notes the maximum injector sizes supported by the reflashed ECU: With the reflash only, 450cc. If used with an Xede, 650cc. , but remember that the reflashed ECU is also tapping into the unused 40% of the injector cycle time, effectively making the injectors act like larger ones.

Bill

triple88a

iTrader: (2)

Bill you do not seem to understand what the problem is... THE INJECTORS CANNOT FLOW ENOUGH FUEL. Imagine trying to fill a pool through a straw in a specific time. He is running a standalone... when you run a standalone you do whatever you want to the engine. You can tune anyhow you want, you can run super rich, you can run super lean, you can add 50 degrees of spark if you wanted to.

"otherwise (from Stephanie):

the stock ECU – by itself – can handle 6 psi.... The stock ECU – unmodified – is not programmed for boost and must have something done for fuel and timing control when under boost."


This is confusing, first she says the stock ecu can handle 6 psi unmodified then says something must be done for fuel and timing control under boost. So whats the deal is she really saying that the stock unmodified ecu will run boost just fine? If so thats a whole bunch of bologna there.


This thread is 4 pages long and you do not seem to understand single **** about the turbo kit.. put down the credit card and read some of the **** posted.

18psi

iTrader: (76)

I'm sure that's meant to say "The stock ecu-by itself-cannot handle 6psi"

richyvrlimited

iTrader: (1)

Irellevant. The injectors are the same. Look on RC Fuel Injection it'll tell you roughly how much power any size injector will support.

Stock MX5 injectors are around 230cc, to make 200bhp you need 330's just to keep the injectors at a safe duty cycle.

triple88a

iTrader: (2)

Because of the confusion in this thread i should mention crank hp =/= whp. Also the stock nb1 injectors are 245 or 250cc and the nb2 injectors are 260cc.

joyrider

iTrader: (8)

In the 13.4 at 5K rpm... Stock fuel pressure. i have a thread somewhere here too regarding this issue. Was running Diypnp and fuel cell were hitting 255 past 5200 rpm.

joyrider

iTrader: (8)

Wrong, nb1 =260cc and nb2 =265cc Both pintle design.http://miataturbo.wikidot.com/fuel-injectors

triple88a

iTrader: (2)

256cc Doesnt change the fact that both are no where near enough to run 9 psi.

FRT_Fun

iTrader: (19)

God this thread is a clusterfuck.

NW Bill

Clearly, there is some disagreement about the capacity of the stock NB fuel injectors; either it is impossible for the stock injectors to support more than 5-6psi or it is not impossible.

However, given that this is hardly a new disagreement, no one seems to be bringing anything new to the discussion, and there is no chance of reaching any resolution , there seems little point to continuing to beat whatever decayed remnants can be found of that long dead horse (unless it is providing some comic relief ). If the naysayers are right, it is not possible for the basic NB200 (and, for that matter, Flyin' Miata's Voodoo kits) to achieve anywhere near the performance levels claimed for them . Equally, if these kits do perform substantially as claimed, then the naysayers are wrong, unless they can provide convincing evidence that some other factor explains the performance.

Since I was leaning towards using larger-than-stock injectors since before this thread began, and decided to use them pretty much at the beginning of this thread, this specific issue is moot for me.

Still, to make this at least as fair and balanced as Fox News, these voices should not be ignored:

from Braineack's DIY FaQ - All your answers in one big post, section 3 on fuel injectors:
The 1.6L (230cc) fuel injectors have enough room to run about 5-6psi.... A very common upgrade is to install the 1.8L injectors. These will should provide you enough room to run about 7-9psi of boost (170-180rwhp).
see: https://www.miataturbo.net/diy-turbo...big-post-4288/

from Corky Bell (BEGi) in an earlier post (#28) in this very thread:
we have made 209 rwhp with stock injectors and zero correction factor. The 12.5 afr was requiring flat out injectors. Nine psi boost, ran smoothly, never a knock, and is a delight to drive. Were we pushing it? Sure, wouldn't you? The suggested Brake specific for NA motors is .45 lbs/hp-hr, supercharged is suggested as .55. That says the afr ought to be 12/1 under boost. The .55 number goes back to pre-MIller Indy cars. The Miata does not.

from BEGi, check the dyno charts of the MSM (with various upgrades) running 8-10psi with the same stock injectors shared with other NBs
see: BEGi

from Keith Tanner (Flyin' Miata guru), on the FM Voodoo kits (which are spec'd with stock injectors):
There's no need to tweak anything [on the Voodoo box] if you're playing with boost settings. I wouldn't recommend going past the 8 psi level because that's where you start to hit the limits of the stock injectors.
see: Voodoo Box vs. Powercard - Head to head compairison? [Archive] - MX-5 Miata Forum

Bill (but not O'Reilly )

NW Bill

And moving on ....

Here is another reply from Stephanie at BEGi to some further questions I had about the NB200. As before, Stephanie's responses are in bold italic.

From: Bill
Sent: Tuesday, July 23, 2013 5:47 PM
To: stephanie@bellengineering.net
Subject: RE: BEGi NB200 kit questions

Thanks for the quick and informative response, Stephanie! After I sent the email to you, I discovered the FAQ section and found some of the answers there. I thought I’d been all through the BEGi website, but somehow never noticed that despite repeated visits. Getting old, I guess.

You are welcome. No worries on the FAQ, there is a whole lot of stuff on the site no one sees.

I posted your response in the NB200 discussion on Miata Turbo, and it has provoked some heated responses, as could be expected. While I find this ability to reprogram the ECU exciting (and really the most attractive thing about the NB200 kit, although not the only good thing), a lot of folks seem to find it too good to be true, or at least a challenge to the conventional wisdom.

I get that a lot. Especially from the MSM crowd. Now if I told you that we tuned cars remotely half way around the world, you might really questions my judgment. But, it works! Modern technology lets you be just about anywhere. And we can tune remotely, the only bad thing about it is that you are not physically sitting in the car so you have to rely on someone who knows what it should feel like.

ECU reflashing is nothing new. It has been done for years and years, it is just new to the miata. And sometimes is almost too good to be true. The bottom line is that it works. And there is a whole lot more we could do with it that we don’t… LOL. But we’ve been doing them on the MazdaSpeed Miatas for just as long now and done over 75 ECU’s. I can’t say much other than it works. Pretty darn good. More answers below!


Anyway, I have a few follow-up questions.

I live in Oregon, so don’t need to worry about compliance with the CARB, although I do have to pass an OBD2 emissions check every other year. From what I’ve read, the Shanghai turbo/wastegate should not generate ECU error codes, so there should be no problem with using them.

Correct

As much as I would like to go with the Garrett and TiAL options, they really kick up the initial cost of this kit. OTOH, I consider the Chinese parts the weakest links in the kit, at least in terms of reliability, so maybe I should reconsider my budget.

When it is all said and done the Chinese turbo has been significantly more reliable than we ever expected it to be. I would not hesitate to use one on my own car. The whole premise behind using it is that if it breaks it is cheap to replace. You could buy 3 or 4 Chinese turbos to one Garrett turbo. Short of the turbo being assembled wrong by the manufacturer, what will fail a Chinese turbo will fail a Garrett turbo.

In any case, if I go with the standard Chinese turbo and later replace it with a Garrett GT2554 or a GT2560 (the two NB200 optional turbos), will either of these require a new ECU reflash?

Maybe is my best answer. I would tend to lean towards most likely though. It would all depend on boost level and if the overall power output were to change.

My goal is to reach a reliable +/- 200whp with a stock engine on a Miata used for the ever-popular “spirited driving,” especially on twisty mountain roads. I have no plans to track it, and auto-x will be limited and only for fun (I have just finished getting the parts to upgrade the suspension and had to face those decisions already). Since I have no plans to build-up the engine, even if I want more power it will be limited to about 250 max (or whatever whp 250 lbs of torque equals). Even if I don’t go over 200whp, I think it would be good to have some headroom left as a margin of safety.

All completely do able. MSM guys have auto x’ed with our reflash for years now. Just remember though, safety and reliability is just as much the attention paid to detail when it is installed.

I am already planning to replace the stock exhaust with a 2.5” exhaust, probably from Flyin’ Miata. While I respect Flyin’ Miata’s quality, this is really about value for money, so if I find another reputable 2.5” exhaust system for less I may use that instead. Is there any reason to go to a 3” system at the relatively low boost level I will be using?

We sell and use the Enthuza Exhaust Systems. So much better quality and performance benefit from it than a FM exhaust! Just the exhaust pipe alone, ours is $28.00 cheaper plus we allow for customizing of the muffler and tip. They don’t. Our Midpipe is more expensive, but it is a case of you get what you pay for. They use a ceramic core catalytic converter. We use a metallic core convertor. Just the difference in converters is 5-7 hp! Plus the metallic core cat is significantly more resistant to fuel and spark conditions. Should the cat ever fail, it will not cause harm to the engine or car like a melted ceramic core convertor. A ceramic core cat is a ceramic core cat. Magnaflow will tell you that it is called high flow because the inlet and outlet are larger than stock. But when the internals are the same, that inlet and outlet size being bigger won’t get you much. If you place the convertors side by side, you can physically see the difference in flow between the two converters. Ours costs a little bit more because the converter costs about $100 more. Is it worth it? You bet! Is there a reason to go to a 3” exhaust? Yeah, it will get you a few more horsepower. It is louder. Do you really need it? No. If you were trying to get every last hp out of this system, then yes, use it.

I’m sorry, I was not clear in my earlier question about what boost levels are supported by the ECU – I meant to write the reflashed/reprogrammed ECU. Since the choices are 8psi and 10psi, in order to be able to go to 9psi reliably (with 91 octane gas and a 2.5” exhaust) would it be better to have the ECU reprogrammed for 8psi or 10psi?

10psi. Just to be on the safe side. You can always run less boost, but not more boost with a re-chipped ECU.

Again, this is based on a goal of about 200whp reliably, but with some headroom. From what you wrote, it seems it would be better to run 9psi with the ECU programmed at 10psi (so, a bit rich) rather than at 8psi (so, a bit lean).

Yup!

On the fuel injector options – would it be better to have the ECU reprogrammed for 330cc or 450cc to use injectors sized between those? I guess I am asking is how much leeway there is for the size of the actual injectors used, since there are a lot of different injectors that will fit the Miata. So, for example, if I get 400cc injectors, would it be better to have the ECU set for 330 or 450? Or should I really try to limit my options to +/-330cc and 450cc Bosch-type injectors?

I’d go with 450cc injectors. Mostly because we have mapped those the most. It gives you a little room to grow also, should you ever decide you want more power.

The injector size seems related to the boost level – so, if I use 330cc injectors, would it be best to stick with the 8psi boost, and opt for 10psi only if I am planning on 450cc injectors?

No necessarily, no. You can do 8 psi with 450cc if you want. I don’t see the point to it, but you could do it. If you ever decide to upgrade starting with the larger injectors is just one less part to replace. And when it is $4-$8 more in price now, just go bigger injector. Drivability will not suffer either.

Since my goal is reliable rather than maximum power, my desire is not to push the parts to their performance limits (that can also be fun, but can get expensive fast when those limits are exceeded).

True, but this is nowhere near pushing the engine to its limits. And reliable is how well you install it too. Oil changes and making sure the car does not over heat. I have kept my engine stock for this very reason. I have run 11-12 psi for 7 years now. One failed turbo, because it swallowed something, no idea what though. And just routine maintenance. I have kept it that way intentionally to show people it can be done. And still run 240 whp+ for many years. Safely and reliably. I have a 2002, btw.

Things that are not necessary but may be helpful with a turbo: I have a BEGi Air Scooper I plan to install with the turbo, to help cool the stock radiator & intercooler. Ought I also add a radiator cover to direct even more air to the radiator & intercooler?

Yes. The scooper is not the most beautiful piece. But it works. And it does its job pretty darn good. LOL.

Is an oil/air separator useful, or really only of value in higher power turbo systems?

I don’t have one, FWIW. I would not use it unless you were getting a lot of blow by. Even then, I probably still would not use it. It is one of those parts – like a turbo timer – that is a marketing genius part. But not really necessary. I’ve put 80K miles on my turbo. Still going strong!

Thanks,
Bill

You are welcome!
Stephanie
BEGi / Bell Engineering
Phone: 830.438.2890
Bell Experimental Group - BEGi

triple88a

iTrader: (2)

That is on a 1.6L motor.. Therefore you can run higher psi because overall the motor flows less than the 1.8L motor. Thats what AFR means... AIR to FUEL ratio....

Anyways dude buy your turbo kit, install a wideband and record a video at 9 psi on stock injectors so we can have a laugh at the 14afr in boost.

18psi

iTrader: (76)

LOL relax dude....He's already mentioned that he doesn't plan to stay on stock injectors.

So he's obviously seeing our problem with what begi/fm say about stock injectors.

And aside from the fueling arguments, I really don't have much against these systems otherwise. I don't LOVE them, but I definitely can't knock em. They're okay imo

FRT_Fun

iTrader: (19)

Fueling is.. kind of a big thing.