Written by “Mike d” @ www.dodge-charger.com


When it comes to fast cars, there are several categories. You will need to decide what you really want to build:
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Racetrack-only car:

It will be an uncomfortable car. It will wear out parts too quickly to drive it on the street. It will have the suspension, gearing, tires, etc all set up for maximum drag-racing ability. This is all at the sacrifice of handling, braking, mileage, etc.
This is a totally uncompromised machine.

10-second quarter miles? Easy. It's not very cheap, but the most effective modifications & parts have all been fairly well-researched by now.

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Street car:
Must handle & brake well, must not wear out tires & parts much more often than a normal car, must be comfortable & reliable. This is a compromised machine.

Doing a 10-second time?
Well, that's not so easy. It's still possible, but it's much harder/more expensive than doing it with a race-only car. Many of the "easy tricks" to speed are off-limits because of the side effects in drivability that you don't want to put up with.

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Something in between the two:

This is the category that a lot of hot rods fall into. It's somewhat less comfortable than a stock car, and it handles & brakes somewhat worse. But it's drivable on a good day for relatively local trips.

A lot depends on where you draw the line, in terms of "race" and "street" modifications. It's all a big grey area.
A lot of people end up building cars that are too close to being race cars to really drive on long trips, but the owners will exaggerate and insist that they still drive the car often. I've met car owners who swear they drive their cars "everywhere, all the time," but they live three blocks away from me and I haven't seen the car in two years.



Every way of making a car faster basically falls into a couple of categories. Understand this, and you can better understand what you want to build:


#1

Making the motor bigger, to burn more gasoline.
This includes stroker motors, swaps to larger motors, etc.

Bigger motors mean more power and torque ALL THE TIME, which is great.
But the downsides are the practical issues. It means worse fuel mileage all the time, too. With the 500-inch motors and beyond, it means bigger fuel pumps and fuel lines. It can also mean heavier transmission & rear axles, if you go high enough. That stuff reduces efficiency and makes the car ride worse.

And a cast-iron big block V-8 is physically heavier than a small block, so the small block will always make a little bit more balanced car for cornering.

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#2

Making the existing motor work at a higher RPM than stock, to be able to burn more gasoline at a higher RPM than stock. This is what the bigger cams, single-plane intake manifolds, carbs, etc, are intended to do.

The factory was building street cars 35 years ago. Most street cars did not get revved up very high, and many of the motors were going into family cars. So the motors were optimized for low-RPM use originally.
The huge manifolds, cams, carbs, etc . . . These parts will help the motor make more power at higher RPMs, at the expense of the power at lower RPMs.
A drag-racing motor like that will operate extremely well at 6500 RPM for a few seconds in a race, but it will run very badly at 2000 RPM during normal street driving most of the time.

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#3

Making the motor/drive train more efficient. This is finding the areas where the factory neglected to make something ideal (usually for cost reasons), and then improving them on your car.
These are things like mild porting of the cylinder heads, better exhaust headers & exhaust systems, ignition improvements, etc. The more advanced changes are switching to fuel-injection over a carburetor, better torque converters & transmission setups, etc.

These issues are generally a very good place to spend money for a street car. They tend to produce good results all-around, and without burning more gasoline all the time.

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#4


Power adders. Superchargers, turbochargers, nitrous oxide.

All three of those methods have strong points and weak points.
Ideally a motor wouldn't need ANY of them. They are all less ideal than just huge-displacement motor, in terms of fun horsepower. But large-displacement motors have their own set of practical problems, as I said above.

Supercharging is good power. The side-effect is that you need either higher-octane fuel or reduced compression.

Turbo charging is like supercharging, but with more efficiency. But it's much more complicated to install, and it has a "lag" of a few moments before you really feel the power when you step on the gas.

Nitrous Oxide is fun, but it's not the best street setup. It only lasts a few bursts in a bottle, and it can "burst" an engine pretty easily too.

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So what do you want to use?

It's a judgment call for each owner, but too much of any one of these changes is usually more trouble than it's worth.
The ideal street car is usually a balanced combination of all of these types of changes. A little of everything adds up to a LOT of power without side-effects.

Cutting the car:

You could tub a car inwards to the frame rails in the rear, and use a narrowed rear axle. You could also push the wheels outward with flared wheel wells. (For some reason, it's considered "professional" to back half a car and cut out the whole rear sub frame, but just cutting out the quarter panel skin & outer wheel wells is considered "butchery." Its leftover thinking from the 1970s, when every idiot was hacking out wheel wells just to look cool.)
Your best solution may be a combination of a little of both. Whatever you do, try not to cut the original rear sheet metal out of a nice surviving Charger body! There are plenty of rust buckets & previously reworked cars over here to use instead.

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Roll cage:

As for chassis bracing, the kind of car you're talking about will need a real roll cage to get that horsepower planted to the ground without destroying the car. You could also use some better crash-protection on a car going literally twice as fast as the factory ever intended.

This is one area where I think people should be spending more money & effort. A well-built roll cage can be the difference between a car that is comfortable enough to drive on the street, and a car that isn't.
The roll cage kits sold in catalogs are decent for a simple 6-point roll bar, but I wouldn't use a pre-bent kit for a real roll cage. Spend the money and get a good builder to custom-make a cage that really fits the car.

I don't know what kind of rules you have, in terms of roll cages. Over here, there are very strict rules about what kind of tubing to use, where the tubes are placed, etc. (That's why all our drag-racing roll cages seem to come out looking the same.) If you're willing to violate the rules a little, then you can build a roll caged car that still has a back seat that you can use. It will take much more planning & thought that a normal cage, but it can be done.

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Suspension:

My feeling is that you need the wide/big/soft tires more than you need the 4-link. It's a fun showoff car, and not something where you are trying to squeeze every last tenth of a second out of it, right?
The 4-link is nice, but you could run a decent, stiff leaf spring setup and get most of the benefit without the major issues involved in changing it over to a 4-link. A leaf spring setup is also more street-oriented.

I know a guy who used leaf springs under his competitive 10-second car for years. It's possible. The car is a '65 Plymouth, and the wheel wells are tabbed inwards to the frame rails. The spring hangers have been moved inwards onto the frame rails themselves, and he fits some decent tires under it.

He'd probably want bigger tires if the racing class gave him a choice. He has recently switched a bunch of things (adding a 4-link was one of them) and he's got the car into the 9's now.

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Gears:

The gear issue depends a lot on the tire size (and the tire size depends a lot on the way you cut the car up).
When you switch to larger rear tires, you need lower (higher number) gears just to break even again.

example: A 4.10 gear set with big Pro-Street tires will not be as low-geared as the same 4.10 gear set in a car with normal rear tires.

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Front suspension:

The Magnum Force aftermarket setup is a little too new for everybody here to have a strong opinion just yet.
But it seems well-done, and it definitely saves a serious amount of weight over the stock setup. (I would not have believed that there was that much weight to be lost, and still have a decent suspension! But they seem to have done it.)

The downsides:
It will probably handle/corner a little worse than a factory setup would have.
It may also be less durable on rough road conditions, partly because it changes where the loads are put on the chassis somewhat. The chassis-loading problems could all be solved with a little extra bracing welded in that area, but it is something to deal with.


Your other all-new suspension option is the "AlterKtion" K-frame setup that just came out. It also saves a bunch of weight, but it is more intended for cornering/handling than straight-line drag racing.
On a positive note, the AlterKtion setup does not change the chassis loading points much at all.

my take.....if you can keep it on the road relatively easy....its a street car!!