Saturday, September 08, 2007

Choosing Horsepower and Driveability:
Make Sure Your Ride is Enjoyable

It's all too easy to get caught up in the quest for more horsepower. It's easy to forget that we also want to ENJOY our ride, and to enjoy it, we need it to be driveable.

With the recent rebirth of the muscle car craze, everyone is in search of MORE HORSEPOWER. Go all-out and install a killer big block, 560 cu 800 hp drag racing engine that's built for the strip and you'll have something that'll light up your tires off a stop light, but will probably be a royal pain to drive in city traffic. Most of us want something that will ride nicely on the street, allow you to feel the power, turn a lot of heads, and light things up every now and then! Sometimes easier said than done.

Going overboard is a common mistake. At Motorheads Performance, we ask all of our customers to be honest about your intended use. You should look hard at what you enjoy, and how much time you'll be doing each of the following:

1) Daily driver
2) Short weekend day trips about town (within 100 miles)
3) Occasional cruise to the coast or Hill Country (trips 100-500 miles, a few times a year)
4) Regular cruises and rod runs (trips 100 or more miles, monthly or more per year)
5) Long rod runs (cross country trips and national rod runs)
6) Only for show (car won't be seeing much pavement)
7) Short rides for an afternoon or night out.
8) Occasionally want to "punch it"
9) Like to try the drag strip once to "see what she'll do"
10) Occasional trip to the drag strip "for the thrill" (few times a year at most)
11) Regular trips to the drag strip to "better my time" (6-12 races a year)
12) Serious drag racing (weekly racing but "I want to drive there")
13) Serious drag racing (she'll be trailered)
14) Looks only (won't be driving it much - "I want an investment")
15) ...any other use not mentioned above

There are many things a good performance shop will consider in helping match you with the right engine. For instance, a beautiful, throaty, loping idle usually has a long-duration cam that makes plenty of top end power. It also kills low-end torque and throttle response because it may be putting out a power curve that runs from 4,500 to 9,000 rpm. Great for the drag strip, but not practical or desired for the street. A good street cam will have a power curve that runs from 1,500 to 5,500 so that you get the low-end torque to make street driving enjoyable. There are good street-strip combinations which operate in the mid range of these if you are planning on doing a bit of both.

You should consider reliability of your engine. This can become a concern as your horsepower goes up. Most V8 engines can easily handle an extra 50 to 150 hp without throwing a rod or blowing head gaskets under most driving conditions other than serious racing. Most drivetrains can handle moderate increases without mashing your rear end or grinding up your transmission.

Once you get into the higher horsepower performance engines, you need to start beefing up your drivetrain and other components to handle the torque and keep things from breaking apart.

If you're thinking of serious horsepower, your stock block may have to be upgraded from a two-bolt main to a four-bolt main. Appropriate head gaskets need to be used in order to keep the pressure where it belongs. Performance gaskets are usually used for 400-500 hp engines, while anything above this would require sealing the cylinders with copper O-rings. Stiffer valve springs and pushrods, a larger radiator or supplemental cooling fan, larger high-pressure clutch and U-joints, as well as a stronger rear-end to hold things together. You may need traction bars for control, as well as stiffer rear shocks and/or springs. Even your fuel pump needs to be considered in order to ensure that you get enough fuel to feed your hungry engine.

Speaking of fuel, you'll need to consider the type of gasoline you'll need to use with all your new-found horsepower! The highest common octane is 93. If you have a high compression engine, you may need more than this, and may need to add an octane-booster. If you don't use high enough octane, you may risk damaging your engine from detonation and preignition. With gas prices sky high, your wallet will feel it every time you take her out for a little ride so you'll need to consider this because it may keep you from enjoying your ride as much as you'd like to.

And, something which always needs to be considered is cost. You want to balance your "need for speed" with the fact that SPEED = MONEY. The more horsepower you want, the more money you will need to spend. And, as you've seen above, there are certain hp threasholds that increase your expenses dramatically. Keeping your budget in mind is one way of keeping from going overboard.

What this all means to you is to think carefully about your intended use. Find out what type of engine and horsepower will deliver this and you'll be much happier when the job is all done. Your ride is an expensive project and you want to be able to hit the road with a smile, not a scowl of frustration.

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