whys everyone use big carbs on there track cars???

 

More fuel + more air = more HP...........go fast.

 

because fuel economy isn't at the top of the list of priorities

 

People that run big carbs thinking they'll get more power are stupid. The engine will only pump as much air as it will pump, putting a bigger carb on won't change that. A GOOD carb that's not restrictive is what makes power, many people claim the car is faster with a larger carb, but it's often because they bought a large cfm HIGH QUALITY carb that shears fuel better. A lot of people run too large a carb on everything ranging from street cars to track cars, and if they ran a good carb that was just the right size the shear/atomisation would be even better than it is, and they'd make more power. Most engines aren't moving NEAR the cfm at peak rpm that people think they are. And this isn't even getting into the rating sdtandard of carbs dealing with the flow tested pressure differential as it relates to your intake vacuum.

 

but why not just upgrade injectors and rails and fuel lines? why go through the trouble of getting new heads and everything is it really worth it?

 

Some of us have been working with carbs for 35+ and know how to work with them.
Another point is, why spend money on EFI when carbs are cheaper...........

 

exactlly!!! except the 35 year experience part 15+ for me...anyway, I'm only running a classic holley 650 double pumper on my 347 with good results based on track times.....some told me to go with a 750....but since In had the 650 from the 306..I thought I'd try it first and it's worked well so far

 

Carbs are by far a lot cheaper than EFI. Those of us who do run them like them for their simplicity and reliability, as well as their ability to make excellent top end power. You don't need a big carb per se, only the right carb. NASCAR Nextel guys are running meager 830cfm carbs on their 348's that are turning upwards of 8,500+rpm with something like 110-115% VE(perhaps more). Even with a carb that's about 20-30% too SMALL(ideally they should be running 1,000cfm carbs at least) they still manage high volumetric efficiency and produce 800+hp naturally aspirated. Despite what some people may say, carburetors work, and they work well.

 

yup^^^you can't argue the cost vs simplicity vs power they help a combo produce

 

wtf? do you even know what you are talking about? carbs dont have injectors and fuel rails. And who said anything about getting new heads?