Carbs - The Basic
The usual tuning last for the N/A motor includes for the most part, headers, muffler, exhaust, hi-profile cams, high comp pistons... But have you considered carburetors? Here's a look at the classic but effective form of N/A motor induction.
When one thinks of high performance carburetion applications, we tend to imagine funneled intake making that nice classic induction noise...
One of the major advantages in using the carburetors is in it's throttle response. This is more apparent in the racing field where no filters or collectors are used in the intake. Also, compared to the single throttle injection, the Mikuni and Weber style side-draft uses dual, 2 barrel throttles for a total of 4 individual throttle mechanisms to mix the fuel and air with more control and immediacy, resulting in a positive production of gasoline/air mixture, and in turn making potentially more torque than single throttle. As you may know, there are 4 throttle, fuel injection mechanism too. And the resulting principle is similar. The two systems do have very similar, and distinct advantage over the single throttle setup.
So, what's so hot about using carburetors?
Well, here are some characteristics you may find attractive:
First of all, carburetors need no intervention of ECU's which can be both expensive and in most cases limited in adjustability, unless expensive alternatives like those programmable variety is in your budget. Although it takes some practice, setting a carburetor can be as simple as changing the jets and monitoring air/ fuel ratios. The goal is to match the jets within the carburetors to the required spray pattern and volume to desired mixture at a given rpm and vacuum. There are usually main jets and sub jets for various compensation, both of which have to be manually setup.
Second, the carburetors can be adjusted for much wider variety of engine setups using the same unit for the most part. Since the carburetor's adjustment is in the jets alone, it can accommodate almost anything you can imagine...as long as it's normally aspirated. (Well, some forced induction setups exited in the past but all of them are running fuel injection now)
Third and my favorite reason for the carburetors is the esthetics... The setup simply looks really nice!!!! and it sounds mean! Once an addict, you'll never go back.
So why don't you install them right away?
Well, there are some stuff you should be aware before you jump in.
Since carburetors work with very narrow, optimized range, the more you set it for peak performance in one area, the more you will run into substandard operation in other areas. For example, the carburetors cannot compensate for difference in gasoline or effects of climatic temperatures and pressures on it's own. This adjustment is left to the owner to re-adjust each time. Though carburetors do operate very well in most conditions, the fuel delivery under many different conditions is usually much more accurate with modern electronic fuel injection. And usually much more efficient.
For those who likes to tinker or wants optimum mixtures for a narrowly focused field, this can be much fun. Certainly, you will get attention from those not so inclined when you fiddle with carburetors on the spot and get good results. Race mechanics are often admired for such talent and gets gratification from that alone.
But at the same time, it's certainly a chore for those who likes to me free of maintenance tasks or depend on it to commute every day. You must be frequently prepared to re-jet them or make adjustments when weather changes dramatically. For sure, those who live in areas with drastic seasonal climate changes will have to make adjustments all throughout the year, to keep it in top shape, and sometimes even just to start the engine.
Keeping the above precautions in mind, the carburetors are seriously rewarding piece of equipment, and once it is running correctly, it's hard to beat with even the best fuel injection in terms of response and torque output...