0001tmn

iTrader: (2)

i was looking around and i seen this, i thought it would be awesome for a 12a, and i am thinking of buying it, just wanna see if any one here has ever used it, or heard of it,

http://www.compperformancegroupstore...Category_Code=

rwatson5651

iTrader: (5)

I have not heard of it, but I will be watching this thread closely as I have been toying with the idea of going to fuel injection is spite of being a FI- Idiot!!!!

Good Luck!!!

0001tmn

iTrader: (2)

yeah i really want this kit, i emailed the company to see if it works with a rotary, so i'll let you know what they say about it

j9fd3s

iTrader: (3)

its fuel only so it'll work just fine with the rotary. just remember a 12A is a 2.2L 4 cylinder, and a 13B is 2.6L 4 cylinder, and the 3 rotor is a v6, and you'll be all set...

i think once you price out a throttle body + ecu+ injectors+ pump + etc etc, the $2200 is going to look like a very fair price.

edit: 5. Can I use a turbo or supercharger with the EZ-EFI®?

No. The MAP sensor and tables in the firmware are only rated and scaled to 1 bar for normally aspirated applications.

http://www.cpgnation.com/forum/ez-ef...ions-2896.html

0001tmn

iTrader: (2)

yeah thats the only part i dont like but i planned to stay NA for awhile if i go EFI

rwatson5651

iTrader: (5)

Could you explain why this is significant?

j9fd3s

iTrader: (3)

sure. to be simple it is because of the trialing ignition. the 2 rotor engine fires a spark plug every 180degrees of output shaft rotation just like a 4 cylinder reciprocating engine. however there is no reciprocating engine equivalent to the trailing ignition, the trailing spark plugs are in a place where you cannot run them in a waste spark, and the timing of the trailing does change relative to the leading ignition.

so an ECU that does rotary engines needs to fire the leading ignition, which is simple, and SEPARATELY fire the trailing plugs.

OR

you can run the leading and trailing together (fire at the same time), and use any ECU you want. the timing curve will be slightly different.

this ecu we are talking about being fuel only will just get the tach signal, just like the um tach, and work just fine. you will have to double the rotary displacement to get the fuel right, as a piston engine takes 2 rotations of the output shaft to fire its rated displacement, and the rotary takes one.

the rotary and a piston share a lot of things, but the ignition scheme, and the displacement/vs output shaft rotations, are just two places where its apples and oranges

Verneuil

I saw that setup on Horsepower TV. That **** was awsome. They did one dyno run and had like 300 HP and next runs just kept increasing as it tuned itself. I think they ended up with close to 400 HP. Id love the get that with the camden supercharger.

flight_of_pain

Megasquirt seems like a more viable alternative to me. It is also capable of autotuning, but has a lot of rotary support and runs rotary ignition correctly.

arghx

iTrader: (3)

While it is better than a carb (doesn't take much to beat a controlled fuel leak) This is an EXTREMELY crude fuel injection system that is clearly modeled off early 80s GM technology. Don't be fooled by marketing hype.

1. It's throttle body injected and batch fired just like old 80s GM motors... that's a very primitive design (but I guess still better than a carb in ways) which doesn't allow for many of the fuel economy benefits of true EFI.

2. On the subject of "Self tuning" : lots of EFI products claim they can do that. If you believe it's "set it and forget it" then I've got a bridge I'd like to sell you. If set properly it will get you into the ballpark which is fine, but "no tuning required" is a stretch if you care about consistent driveability under all conditions. Even with an IAT sensor it's hard enough to get the engine to run right on an aftermarket computer as the seasons change. That's why modern Hondas and other speed density computers have dynamic self learning capability (fuel trims etc).

3. There's no air temperature sensor. That's a huge limitation on a speed density system like this. There is no direct way for it to adjust to changing weather and engine conditions besides relying on the O2 sensor feedback. Just in case any of you considered it, I would never run a turbo engine without air temperature correction. That's a quick way to lean your engine up when it gets cold out and air gets more dense.

4. Since it's throttlebody injected you don't have the flexibility to use a more optimized intake manifold with a real plenum

5. There's no idle air control system at all, or integrated computer controlled spark advance of any kind

All those limitations doesn't mean you shouldn't buy it, but make no mistakes--this is an aftermarket imitation of 30 year old GM technology. It's simple because it's crude. While this is better than a carb in a lot of ways, a "real" fuel injection system has so much more capability to make it drive more consistently and control more systems.

Rx-7Doctor

iTrader: (13)

Better off getting a SE engine or S4 or S5 if you want FI.

snwyvern

I've (almost) got all the parts to put together my GM TBI setup, I have less than $600 invested, including what I paid for the MS2. I really want to get the bugs worked out of the ignition system before it goes in, however...

---

I've seen the same SBC engine go from being poorly carb'ed, to well-carb'ed, to being (Factory) TBI, to a high-end (holly) TBI and finally to TPI...

When it was FINALLY dialed in, the difference in HP and fuel economy between the last three in that list were almost zero. A lot of guys talk about the horrors of a wet intake, but even a 'modern' car with staged injectors still have spray duration that exceeds the intake-open lobe on the cam.

All of that being said: in the end it'll be easier to just get a fuel injection intake. I'm leaning that way right now, despite having just about everything ready to bolt on.

0001tmn

iTrader: (2)

Like i said i just wanted to get some info on this setup, cause from afar it looks great, i still might get it, inless some one can show me another setup thats just as good for cheaper

j9fd3s

iTrader: (3)

its nice that its a kit. the con's are basically that the injectors end up far away from the engine, mazda has proven that is not ideal. mazda has published a couple of SAE papers, the 787B on is the most direct, about injector placement.

2. there is no air temp sensor, so its going to run like a carb, as like a carb, it has no way to compensate for changes in air temp. i don't think i've ever seen an aftermarket ecu without, so its kind of weird.

3. no boost! every other ecu can be configured to run boost, not a deal breaker at all

better would be an ecu that has more function, and maybe control of the ignition too, and better injection placement

weather this matters is another thing. it IS simple, i'd recommend it to one of my friends, just because its simple enough for him to figure out.

i don't know how it works when you factor in price though, seems like once you factor in ALL the stuff in the kit, it might not be too bad

0001tmn

iTrader: (2)

How much would a setup cost putting all the peices together yourself? could you show me some parts that would be okay for that? i just wanna go to EFI cause my carb has been having problem after problem and going to an aftermarket carb would be the thing to do just if i can get EFI for about the same price then yeah lol

patmac6075

iTrader: (26)

INMO, if you're going to stick with the 12a you're better off sticking with the carb and learning how to get it set up properly. I'm not a purist or anything, but all the engineering has already been done by Mazda. Why try to re-invent the wheel? If you're bent on FI, look into a 13b....tons of options and thousands of "been there...done that's" to help guide you. You'll probably save a ton of money too and get a higher performance to dollar spent ratio...
Then again....it's your money/time.

0001tmn

iTrader: (2)

Thats true, i guess i should start looking towards a 13b,

snwyvern

<soniamdissapoint.jpg>


In short:
There are a handfull of things you need to go from Carb'ed to FI:
1) An intake that will allow it.*2) Fuel delivery thing.3) Air measuring things.4) ECU (Electronic Control Unit, Computer, CPU, whatever you want to call it.)5) O2 Sensor------

After all that is done you'll have to tune the car. With a MS system, it takes about 10 minutes to type in tables, check the apropriate boxes and turn the key and have the car idle... Poorly. After you can achieve idle, you should be running in what is called "Closed loop" mode, which means that the computer is using the input from the O2 sensor in order to lean out, or richen the mixture based on what you specify... Which is where the major differences between a piston engine and our rotaries begin. (As far as tuning the tables, etc.)

Once you're comfy with the way the car is behaving (Exhaust gas mix, idle speed, the exhaust note, timing if you're using an ECU that controls that too...) then you (and a friend, durr...) take the car out on the road and watch how everything goes through the powerband, stopping to look at your data and change what's neccesary and so on-- Until you're happy with the entire powerband through the first few gears.*

*I HAVE NOT TUNED A ROTARY, THIS HAS BEEN MY EXPERIENCE WITH BOINGERS.

---

As far as price goes, MS2 ECU + Wideband: $500(ish,) intake + TBI (Had one, if you got a used RB intake and a reman GM TBI: $150(ish,) + Fuel pump (forgot that in the above, didn't I?) ($30, new if you're using the GM TBI, depends on your application, blah, blah, blah.)

So, on my setup... I have about $500 invested, and I'm looking for a GM Flex-Fuel sensor FOR LESS THAN $300.... so that I can run E85 and cheap-gas if I so elect without having to press a button to change the O2 sensor target.

Hope that helps.

0001tmn

iTrader: (2)

Awesome info just what i was looking for, is the wiring harness hard to make for the MS?

Edit: cause i'm horrible at wiring **** up lol

flight_of_pain

Go spend some time in the megasquirt section here. Piece of cake.

C. Ludwig

iTrader: (27)

We've done fully terminated, plug-in kit's for 1st gens using the Haltech ECU. On the 12A you could run something like a TWM throttle body setup, a 2nd gen CAS and coils, and our harness. Installation would be very simple. At a later date if you wanted to go 13B or forced induction, everything would be capable of accommodating the changes. And you could do it all for a LOT less than the $2k+ for the FAST system.

https://www.rx7club.com/showthread.p...ghlight=sprint

Directfreak

iTrader: (2)

Nice Option with the terminated harness!

Jeff20B

iTrader: (13)

So this is a learning ECU? It must only use the O2 sensor and a temp sensor as external engine feedback sources (well tach and TPS etc but you know what I mean). That's why it won't do boost or much else. Makes sense as a basic step up from a carb if you've got lots of cash to spend and not enough brain to do a MegaSquirt instead. No offense to anyone here as this was a general comment.

rotaryboy23

iTrader: (1)

lol. You're in rotary town, son. We don't do that around these parts...

If you're going to go this TBI-style injection route, I believe the Holley Pro-jection kits can be turboed and are cheaper. Don't quote me on that. It's been a while.

Dcashdollar

iTrader: (8)

You could just buy an adapter plate from tweakit to mount TII intake manifolds on the 12a, then just get a stock ecu. It would be a lot cheaper than $2200, but it might not look as clean as this product. Its what i am doing on my 12a turbo currently.