BigJim

Hello there. I have a 84 -SE with the stock fuel injection. Ive been wanting to upgrade my intake system for some time to accomidate for my Streetport. This is a list my friend (EddieRotary) helped me create.

Microtech LT4 $550
Microtech Handset $130
2 Injectors(460) $ 50
MSD Box $146
MSD Coils $ 68
S5 Upper Intake
S5 Lower Intake
S5 TPS

Now i was talking to some other RX7 owners and half tell me go Carb, its cheaper and better. The other half say to Efi its not that much more and its much better. In my opinion the EFI setup would be better, but what are your thoughts, do you ahve any of the parts i need for sale, and does that look like all i would need to do this conversion?

lovintha7

EFI is good, it'll deal with mixture (lean/rich) without getting out and adjusting, it's easy to map with a laptop.
It's been proven that carbs add a little more power (1-2) and run more efficiently at WOT, but EFI is where it's at. Easier to add a blower, just remap.

purple82

I've had a little experience with this. I had a street ported 13b in my 82 and originally had a Weber 48IDA on it. The car was strong but there were a miriad of driveablility issues, low rpm stumbling, cold starting problems, tradeoffs between midrange torque and high rpm power. In short, it wasn't my idea of a liveable car. Plus, there was no hope of passing an emissions test.

I then replaced it with all the intake parts from an S5 and controlled it all with a Haltech F10. Now the car feels like a "real" car, not some half finished backyard project. It has a really good power band across the entire RPM range and it even passes emissions. Im my experience EFI is worlds better.

Anex 570

For auto-x EFI, TBI ect is exellent. If your on the drag strip, thats where carbs play their part quite well as you dont worry about float bowls not being full ect. They do now offer a 6 injetor setup for a PP setup, and its for methanol/alc fuel, really awsome thing. You cant beat that hands down. There will be other guys adding into this. Also if your trying to fuel inject a N/A 12A it is still possible. It also sets you up for turbo if you like that direction, or SC as they make a holy throttle body.

Sterling

I'm not dissing EFI, but really, you can't answer the question objectively when you use a carb that NEVER works well with the rotary as an example.
Webers run wonderfully at WOT on a rotary, but suck at low rpm as does ANY two barrel carb that will perform at all beyond 5800 rpm.

BigJim

So S5 parts it is, now anyhting else you can think of i would be needing? Or does my list sum it up. Anythign else i need to do to it fo rit all to work out and anyone have these parts for sale?

purple82

I think I was fair in the assessment. Both systems were set up by the same rotary guru who's got plenty of experience in both types of systems. There may be more appropriate carbs, but that's my experience and I've seen them used on a few of these cars.

purple82

There are plenty of threads on what you need.

https://www.rx7club.com/showthread.p...hreadid=306291

BigJim

Im not doing an engine swap thou, thats why there isnt much information. Not many threads on here about modifying fuel injection system.

YapaKanichi

hhhhmmm.......low RPM stumbling, dude this is really unfair assesment. I have a mikuni 44phh sidedraft carb on my 13B streetport 4-port. My car truhfully drives pretty steady and nicely. The only stumbling I ever have is if I **** up not the car. Dude having a carb is better by all means. EFI is not the best all the time.

purple82

You essentially are doing a swap. The only thing you're keeping is the core engine.

purple82

Good for you.

It's fair because it's my experience. I had a Weber and I reported how it behaved. Everyone knows there are plenty of different carb manufacturers. Why don't you just chime in with your experience to add to the thread instead of trying to undermine someone else's.

Feds

Actually, EFI is best all the time, in any measure.

A similarly sized EFI system will produce more max power than a carb, and more power throughout the RPM range (More AVERAGE POWER). Plus it will be more efficient at part throttle.

Also, with a programmable system, you can have a "Road" map, that maximizes economy while still making good power, and a "Track" map that just makes stinking power!

Not trying to crap on Sterling or Carl, but just look at the HP, Mileage, and emissions gains manufacturers have made by switching to EFI. And that is without the benefit of high octane or SAE GROSS horsepower ratings.

BigJim

In terms of power to money, carb is better, but for with more money u can make a FI system alot better. Im more of the delayed gratification type. I can wait a year to have neough money to modify it again, and when i do itl far surpass a carb setup

FB II

either way you go, just make sure you have someone that knows the product. if it's carb, get a good carb tuner, if it's FI, then find someone who knows your exact model of stand alone. its ALL IN THE TUNING!!!

Sterling

I don't care who set it up. A rotary "guru" wouldn't have used a Weber as a street-car induction choice. Yes. Seems there have been many sold, huh? And the only four bbl choice that's been made available is the over-sized Holley, which also sucks.
Lots of them around, too.

You can put an injector in a 3 inch pipe and get it tuned perfect for WOT!

My only point was that if you're going to compare apples to oranges, don't pick bruised fruit.
There's not a huge difference between fulie systems...either they're the right size, or they're not. The computer does the rest.
But in the world of carbs, there's enormous differences between the most popular "best carb" options.

As for maximum power, the idea that a fulie system always makes more power than a carb is horse ****.

What the fulie will do that a carb can NEVER do, is deliver perfectly consistant mixtures at any given rpm, load, temperature, humidity, etc.

Fuel injection is therefore more efficient, will give you better gas mileage, and can be tuned to deliver perfect exhaust for emission control.
That's why it's used all the time now.

A good carburetor can be tuned just as perfectly as a fuel injection system...for one given set of parameters (rpm, load, temperature, etc), but as soon as one of them changes, something will be comprimised.

nekky

^^
What he said.
If you think about it though, carbs are really just an efficient type of fuel leak :P Dump a little here...dump a little there...
Just kidding.

Zac

Directfreak

iTrader: (2)

Your Stock SE Fuel Injection will work fine for a street-port. It will supply enough fuel with your two injectors.

Save your money.

purple82

Wow, you're pretty combative aren't you? Louie Rivera set up my car. He's been setting up and racing Rx-7s as long as they've been around. I'd trust that he'd choose a setup that matched my wants as I described them to him. If not, no big deal, I love the EFI.

LEZNAY

what kinds of mods am i looking at to tund a carb'ed 12a stock into efi?

BigJim

Yes it will work fine for a streetport, maybe even for my large streetport, but an unported engine will move the car just fine as well, as will a stock exhaust, or a stock carb even. The point of upgrading is for more power, we dont add a new exhaust because the old exhaust doesnt do its job, we add a new exhaust because it doesnt do the job as well as we think it should. Upgrading the FI is just like upgrading your Carbies, the stock carb will make the engine run fine, but you modify it because it isnt to your standards. Im modifying my FI one way or another, i just want to know how to go about it, so please dont tlel me to go carb, or to leave it stock

FB II

we're giving you the opions you asked for. so if you didnt want someone to tell you to go carb; then you shouldn't have asked. thanks,

-zac

oh and P.S. i say you should go carb.

Siraniko

iTrader: (13)

I disagree with the above statement. with the proper mod, it will work fine. All of my IDA's are streetable and I do all of the proper modifications such as adding extra progression hole, reaming the squirters, enlarging the fuel inlet, modifying the fuel bowl and others. No bogging and very responsive. pix below.

d0 Luck

i have all those aforementioned mods to my 51 IDA, and it still sucks ***! bogs too much, and slow at low rpm. sorry, but i like my rx-2 nikki carb! i will boost prep it before 7-stock. wanna race me wackyracer??

Siraniko

iTrader: (13)

your FB with the unmodified RX-2 carb CANT even beat a YUGO. so STFU and learn how to really drive.