85rotarypower

To everyone that says efi makes better power than carb, I say BS. Both are equally capable. But I just have to raise the question. Why do pro drag racers tend to use carbs? If EFI is so great, why do these guys use "inferior" equipment on their cars? Its because they work great. Also, why does it seem that when a carb is used on a rotary in NA form, the engine makes MORE power? IMO, Mazdas efi system SUCKS. If you wanna make power on a rotary, you either have to pay $1500 or more on aftermarket efi parts, or $600 on a carb, while each is equally capable.

I agree that efi has its advantages, but when it comes to cost, ease of tuning and installation, carb beats the **** out of efi.

tracer

I say in THIS thread, and as it applies to THESE cars, the carbeurator route is COOLER. The induction argument could go on forever, and has gone on forever, in many threads, that started out on various topics. And doesn't this particular engine come with ecu problems or something anyway? Tear that bitch off and throw on the first thing you can find that knows how to breathe a lot of air...

PaulFitzwarryne

85Rotarypower-- I agree that a carb set-up is cheaper and easier to initiall ytune unless you have got a decent map for your ecu. However the rest of your comment does not deserve the epithet BS, more like calf **** its so immature.

Working on a carb gives great personal satisfaction, I think I could still strip and rebuild a Weber with my eyes shut. To tune an efi system is impersonal. However. efi is technically better especially where the ecu is fully programmable.

My experience over 25 years is no carb system can produce more power than an efi system. I have found you can set-up a carb to get within 3% of efi at peak power, but above and below it really suffers as it has a real peaky power curve. However I will leave it to the expertise of Mike Angus in his 'Mazda RX-7 Performance Handbook'.

page 109 " A fully sorted-out aftermarket EFi conversion will add about 5-10% to that of an aftermarket performance carburetor ..... To run an aftermarket EFI system in a Prepared Class will cost a 150lb weight penalty. Most drivers feel that this is too much weight to spot the carbureted cars. Thats why the Holley carb conversion remains the hot set-up for the Prepared classes"

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Elysian

any time i've been to the strip most of the pro street guys etc run fuel injected... one sick setup i saw was a guy with a twin turbo 400 small block.... chevy motor, he was fuel injected... it was stupid fast, like sub 8 sec 1/4...

rotarygod

iTrader: (1)

I've just separated this to make it easier to answer.

1: Let's think about that one. Oh yeah, that's all the rules typically allow! No brainer there. They also use roots superchargers.

2: You nailed that one! The stock efi air flow meter has about 5 sq. in. of total area and this is after the spring loaded flap door that blocks aairflow is moved out of the way. A carb is breathing better. No brainer there too! How much power can an aftermarket efi system make? What do they highest horsepower rotaries use to control fuel?

3: I've got a Megasquirt. Got about $200 total into the system. Works great. Started up the first time I ever cranked it without anyone else's base map. I tune it on the fly. It is very easy and actually kind of fun. You don't need a dyno. Standalones are not hard to use or learn how to use. This is a myth by those who have never used them. A carb is a very simple device that is also not hard to learn how to tune. I used to rebuild those things back in high school. They always ran fine afterwards. The carb is always a restriction though. Efi isn't since it doesn't have a venturi. I agree that carbs can be made to work very well but to say that they make more power than efi is a blanket statement. It is all dependent on what you are comparing it to as you have proven. Let's see who gets their car started easier in the winter!

REVHED

The only advantage of using a carby is cost. Plain and simple. You can't use the ease of tuning and installation argument just because you're ignorant to EFI. The funny thing is, most people who say carbs are easier to tune probably wouldn't have a clue how to dial one in in the first place. Also, please provide proof as to how "both are equally capable." If your simply talking about peak hp then that's impossible seeing as carbs are more restrictive. As for everything else, theres no comparison. How you can expect a crude mechanical device like a carb to provide accurate fuel metering under varying throttle, load, RPM and atmospheric conditions is beyond me. EFI in comparison is almost infinately adjustable. Plus you can't forget the added benefits of ECU controlled ignition especially for boosted applications.

Now that being said, I do like carbs. There's nothing like an oldschool ported rotor with an IDA Weber. It's just that EFI does everything so much better. For example, my friend has an Rx-3 with a very tough 13Bpp. It first had a 51IDA and was quick enough to run 12's in the quarter. But, as you can imagine it was a ***** to drive on the street. It now has a 55mm IDA TB and Microtech and the difference in driveability is like night and day. Whereas before it would buck around like crazy it will now cruise around under light throttle from below 2000rpm.

DJAngelicon

To 9d7gst "Dude all I have to say is make it happen and show us some pictures. I think a Renesis with a carb would rock!"

Alak

iTrader: (9)

I bolt my carb on. Hook up the fuel line. Adjust the pressure to 5PSI. Start it.

Carb is sooooooo much easier to install and initially tune then EFI In My Opinion.

It also takes up less space. Its less prone to failure. AND it SOUNDS WAAAAAAAY Better.

You can get cool beeping sounds on an Engine Managent System. But you can't beat the WAAAAAAAAAAA!


I've had too many bad experiences with EFI that its drove me to never consider it again. Heck, if I could carb my Miata, I would.

GUITARJUNKIE28

sam got a microtech lt12, i built a big streetport cosmo 13b for him, greedy front mount, and some other goodies. i got it fired yesterday and it's coming out really nicely!!

13B4port

Pro racing uses carbs so that they can put the restricer plattes on. NASCAR is the same way. Their are regulations so that the car doesn't blow the **** out of people and the competition is fair so the person with $50million can get beat by the guy with $50 thousand.

it's simple as that. and the fact that less wires = less things to go wrong.

GUITARJUNKIE28

i stand by my preveous statement--the guys that like carbs better do so because they don't know how to install/tune FI systems.

and i bet for most guys, the only reason they don't know how is simply because they've never tried before. people are afraid to learn these days.

Alak

iTrader: (9)

I'll state the obvious.


Guys who stand by EFI stand by EFI. If EFI is the way to go, its the ONLY way to go with no other option for anyother kind of system.

Guys who stand by Carb's stand by Carb's. If Carb's are the way to go, its the ONLY way to go.

Its just like the 2mm versus 3mm apex seal discussion. People stand by what they prefer. And in that sense, what they prefer is always better, regardless.

But going back to the original discussion, how many Carbureted Renesis engines are out there? How many Fuel Injected ones? I'd prefer the carb just to be different. Everyone wants Horsepower these days. Its all numbers. Its just like my 2nd Gen. I left it carb'd because I've never seen one before.

rotarygod

iTrader: (1)

Why do people always quote the lowest form of racing when trying to make a point? Carbs are all that the rules allow! Of course you won't see fuel injection in those classes. NASCAR technology is ancient. They keep everything that way to keep the cars on a level playing field. Yes it is simple but NASCAR is the single least technological form of auto racing out there. There's nothing advanced or modern about it. Top fuel dragsters use roots style blowers. Does that mean they are better too? You are correct in that it is to keep everything fair. Let's go to the opposite end of the racing spectrum, Formula 1. Those cars couldn't do what they do with carbs. Not even close. Yes F1 is an advantage for those with a larger budget but that's because those with better technology and engineering can win and it isn't carbs. If you'll also notice that this season the team with the single biggest budget, Ferrari, has done pathetic. Put your car on the Atkins diet and cut the carbs.

GUITARJUNKIE28

i don't like efi because "pappy" raised me up on it... if carbs did anything as good as a properly tuned efi system, i'd use them. fact of the matter is they don't.

RotaryRevn

Woah! Nice!

GUITARJUNKIE28

it won't go on the dyno for a few weeks though. we're gonna put an fd throttle body and greedy shorty elbow on it so it clears the hood. other than that and a few misc. things, it's pretty close to being done

with the hybrid turbo and race gas, it should do about 340-360 at the wheels. i think he's got plans for a big turbo either later this year or sometime next--then we'll probably go for 450+ whp.

John Senini

Unless your at the track and they just called you to grid and your home brew FI system has a bug in it................I Put forth that for home builders carbs will be more reliable............think being in the backwoods somewhere with a problem!!

Manntis

Ask Matt what he thinks of the carb on his CRX as far as 'easy to tune' goes

MosesX605

That's not a carb, it's a soul sucking contraption made by the devil himself. Honest to ******* God the FD has fewer vacuum lines than this piece of ****.

Actually I'm pretty sure now that I've got an ignition problem AND a carb problem. The carb problem was fixed when I switched to the canadian carb/manifold. The ignition problem is still giving me grief but I have a few ideas yet to try before I start seriously considering rolling the dammed thing into the river.

Nicholas P.

iTrader: (1)

its not garbage. unless you go around powershifting like an idiot on that transmission, but if you drive it, itll do just fine,