Fabrik8

$30k for an engine is nothing in the racing world, I think you're lowballing the amount of money that's wrapped up in those engines. It costs more than that to rebuild each of the two 4-cyl Cosworths we have in the lab here. But that's not the issue here.

Like I said, why aren't the top end racing classes not using carbs?
I'd only accept your argument if carbs were more widespread.

To address the emissions issue, I believe it's illegal to downgrade to a carb if the vehicle came equipped with EFI.

kawgomoo

an efi car will NOT pass emissions with a carb. becuase you tampered with and removed half the emissions equip in the conversion.

reguardless of how it runs on the sniffer.

drag cars only have to tune for WOT. they use carbs because of simplicity and WEIGHT. efi systems have lots of pieces, miles of wire, require a big burly electrical system and usually an alternator to keep them happy. if voltage drops ur carb still works. they dont give a shit on part throttle drivability, emissions, reliability or fuel consumption.

also nhra makes the rules, and they do so for reasons you cant even comprehend. you think mandating carbs to keep the sponsors happy is out of the question? it is a business after all.

we race trophy trucks out here, and guess what they use efi. its all about what your after.

carbs on drag cars are by no means cheap, a dominator thats been split and spread isnt something you get for 300 bucks from summit. however nostalgia has alot to do with the rules in drag racing... why do top fuelers have to run roots blowers? because the cars have to look a certain way to keep the crowds comin back. why do they make nascar run carbs? it surely isnt beneficial for them to do so. but its what they feel people want to see.

heres a nice little write up for anyone that cares.

http://www.stockcarracing.com/techar...uel_injection/

Fabrik8

Good article, it's been a while since I've heard anything on that topic. I might think about trying to work in NASCAR one day if they go EFI. Right now that series holds no interest to me at all as a career.

Nic

And because they're faster. It's been proven, time and again.

Do you understand what a carbeurator really does? A carbeurator can be tuned to provide you whatever air/fuel ratio you desire. Think of it as an analog fuel injection system. My part-throttle driveability is as good as any EFI car I've ever driven, factory or modified. I still get in my car and drive it every day anywhere I want to go, usually 500 - 600 miles per week. I still get 18 mpg in a 10 second car with a cam with a 108 degree lobe seperation and more duration at .050" than most people can comprehend. Like I said, I couldn't be happier with my switch to a carb. I used to sing the same tune you guys did about EFI being so much superior to carbs until I actually got in and tried the other side.

You're right about this. Warren Johnson has been quoted as saying they have over $50,000 worth of custom built carbuerators in their shop for their pro stock operation. For your average enthusiasts who's looking for bang for the buck, on the other hand, they're not going to build an EFI Mustang anywhere near as quick for the same price and if you know what you're doing, drivability is NOT going to suffer.

Either of you two are more than welcome to come take a ride in my car anytime you're in the area or anytime I'm down in yalls area and then tell me again whether or not you think a carb'd car can't offer the same drivability as en EFI car

Fabrik8

I have driven and worked on carb'd cars, and I'll still stick to EFI. I still like the total control over fuel and ignition, and the ability to fix and tweak even the smallest glitch in whatever parameter I want. Maybe I'm a control freak, I dunno. I really do agree that carbs are simple, etc., but I believe in flexibility and tuning for almost all conditions. You just can't do that with a carb, especially over a wide range of temp and altitude. There is no "set it and forget it" carb setup, that's not the way they work, and you don't have the easy ignition adjustment either, or the ability to detect knock, adjust for octane, rev limit, etc. To be fair, many basic EFI setups can't do that either though, except for the igntion. I'm not even going to bring turbo setups into this argument, because this thread has to do with a Mustang which I'm assuming will be N/A.
This is a really good debate, no one (myself included) has brought anything new or novel out in the open though.

Nic

That's where your ignition box comes into play. The msd digital 7 series ignitions give you control over all that and more. That along with the carb is the best of both worlds IMO. Laptop control over your timing curve with the air/fuel delivery capabilities of the carb setup If the DFI systems ever come down in price or I somehow manage to win the lottery, I plan on building a boosted car around one of those.

John L.

So what do the maps look like on that ignition box tuning? Oh, and how much does one of those ignition boxes run you? I'm guessing 500 dollars or so. I have 12x12 maps (144 points obviously) for both fuel and ignition. With a carb can you pull a 15-16:1 AFR on the highway and around town and 48 degrees of torque building part throttle timing? And at the same time will the carb pull down to a 12:1 AFR at WOT? And pull the timing down to 20 degrees or so.

Sure, if all you do is WOT racing then go for a carb if you want, but what you're saying is that the multiple people running over 1000 HP and going a lot faster than you in street cars are doing it all wrong because they are running a FAST system or Megasquirt? Sorry, I just can't go for that.

You said you've tuned EFI systems using the EEC Tuner and the Tweecer, I know a little about those systems, I know people that have used them and then gone to standalones and the difference in tuning is night and day. It sounds to me like you've never worked with a real standalone EFI system. Ford's EEC series is decent and will make power, but the driveability really isn't all that great. I can't even begin to explain how much better my car runs on Megasquirt than on the factory computer system. Power delivery is perfectly smooth, I can tune AFR at any RPM and MAP point I want to get it just like I want.

And at 400 dollars for a wideband and Megasquirt kit combined, it costs about the same as a new carb and it's all inclusive. No ignition boxes to buy, no two step boxes, it does it all.

If you can't make more power on EFI then you don't know what you're doing with the EFI system. I've seen back to back tests just like you, except the results showed about the same power, but quite a bit more torque, it's been a while so I can't tell you exact numbers. The fact that a carb turbo setup is such a hassle to setup and tune tells me that carbs are inferior to fuel injection, maybe they work, but by their very nature they cannot flow as much air as a fuel injection system without massive driveability reduction. Like I said, in order for a carb to operate it must introduce a restriction (the venturi) to pull fuel in.

I'd rather spend my time under the hood putting on hot new parts, not playing with the carb.

P.S.: Let's not forget the difference between peak HP and torque and average HP and torque. Just because someone makes 20 more HP or more torque or something like that, means nothing because it's the peak of the curve. What you have to look at is the area under the whole curve.

P.P.S: No I was wrong! http://store.summitracing.com/partde...5&autoview=sku
600 dollars! With the rebate! Wow, IGBT technology, that's the same thing that's in my Megasquirt ECU, and this isn't even an ECU, they make it sound so crazy high-tech.
My MS does pretty much all of that stuff...plus fuel control and table switching blah blah blah.

And the individual timing feature, I'll admit that's pretty cool, if you actually have a way of determining which cylinder needs timing pulled, which is nearly impossible to figure out, plus you'll need a crank trigger for that feature, your distributor's just not gonna give the information needed to do individual cylinder timing control.

DOHC crx VTEC

All I have to say is "To each is to own." Honestly, In small engine's class, We've learned quite a few about carburated engines. Do I like them, you may ask? No, not really. I'm a Fuel Injected Guy. I've never really like carburated car's. Honestly, I think as technology is advancing, so is fuel injection. I don't see carburator's getting anymore advanced than they already are. I mean look at this video...You may have seen it but what he talk's about is some goood stuff. http://videos.streetfire.net/search/...2C936F472C.htm and the TOPIC about the NHRA rules are mentioned in the video.

Fabrik8

Argh!!!!! Time to rant about stupid crap. This has nothing to do with you, I'm mad at advertising departments and the people who eat it up with a spoon.

"IGBT technology" means it has flashy high power transistors in it. IGBTs are a type of high power transistor (insulated gate bipolar...), there is nothing magical about that. They are used because they are cheaper and easier work with, and more forgiving in design than big MOSFETs for that type of application. They work really well for that type of stuff. They're kind of a cross between a BJT (bipolar junction..) and a FET. I hate when marketing departments put that kind of bullshit spin on something really simple like that. It's like advertising an electric kitchen stove as having "ceramic reactive burner technology". It sounds flashy, but it's bullshit!!!!

As a sidenote, if you can make a megaquirt system run an engine very well, just think about what a sophisticated ECU can do.. That's the fun of EFI, it's all about the hardware, the better it is, the more performance is possible depending on the sophistication of the system. That's why I think the "technology policing" argument in NASCAR is moot. You can't pull power out of your ass in an already optimized system on any given type of engine. Basically, if a megasquirt system gets almost optimal power under all conditions, throwing a Motec, Bosch, DTA, etc., engine computer at it isn't going to give anyone a big advantage. Limiting the sensor type and quantity is much more important than how much processing power the ECU has. You can't generate information you don't have. Obviously if you put (on every cylinder for example) a knock sensor, intake temp sensor, EGT sensor, O2 sensor, etc., you can do crazy amounts of optimization if you can process and utilize all that data. If you have about the level of sophistication of a OBB0 setup, you can't do that.

kawgomoo

ok this topic is getting just plain fucking ridiculous.

carbs suck. the end.

an engine with more than one cylinder is really several engines connected together by a common shaft... ie the crank. due to machining tolerances and everything no 2 cylinders are going to be EXACTLY the same. there for EFI can be used to trim each individual cylinder to its optimum output. if carbs were so fucking great why did the OEM switch to much more costly efi?.

the simple answer, long and short is that efi is better. carbs are antiquated. you need to be able to adjust fueling and spark based on many different inputs while the engine is running. carbs simply cannot deliver that kind of performance. believe what you want, spout whatever bullshit you want.

however, this is what it all comes down to. an EFI is a computer based system. junk in, junk out. the EFI will only work as well as it is programmed. if you lack so does the engines performance. carbs are easier to get in the ballpark so alot of people like them. ALL oem engines are going to injection. both high and low performance alike.

to say an efi runner has to be long is ridiculous, you can run injection on any manifold designed for a carb. just add some injector bungs and a carb body with no float bowls... ie a throttle body. to say carbs atomize the fuel better is crap. if you can suck fuel out of an emulsion tube you can do the same through an injector.

im so tired of this argument. if you want a powerful street car that you can drive every day, hot or cold, something you can let your wife or mom take to the store with NO SPECIAL KNOWLEDGE of how to operate it go EFI, and buck up and let someone tune it thats knows wtf there doing.

if you want a 1970 chevelle ss and all its inherent problems then by all means get a holley 750, mechanical secondaries and drown your poor little 302 in fuel.

ultimately will a carb make more power? maybe maybe not... whats the chance your street engine will be built to its ultimate potential.. not real likely.

im sorry but technology moves forward for a reason. the engineers take what they learned last year and improve on it this year. as this happens refinements will happen, things will change. hard headed purists will resist. but the ball keeps on rollin. why do you think it took harley 100 years to build a better engine... not because they couldnt do it {even though porsche designed the vrod engine} but because people resist change.

once again. carbs suck. efi is the way of today and tomorrow. if you dont like it run a carb, and trailer ur heap to the track. because not only do i race my car, but i have to drive it to work everyday.

last but not least engines with carbs dont last as long. because they overfuel when there cold and wash cylinders down which kills ring life. when the motor is cold they cant add more fuel {except for choke} and when there hot they cant lean out. same with ambient air temp etc. thats why you have to tune a carb car for track conditions as where efi does it automatically {assuming your correction tables are correct} why do you think engines today go 100,200 even 300 thousand miles and more without a rebuild, but 20 30 years ago youd be lucky to get 50k before tearing it down. and no metallurgy is not all there is to it. refinement is the key.