The biggest baddest, isn't always the best...

Sometimes the thing that makes the most horsepower is not always the best. If your building a race car then the sky's the limit-you don't care about idle quality, or fuel economy or drivability. All that matters is speed. Back in the '60's when Trans-Am racing was popular-a lot of their races were run on road courses like Lime Rock. When Ford was developing the "Boss 302" the feedback they got from racers, both factory backed and privateer-that had been previously running 289s-( The displacement limit was 5 liters or 305 inches ) was they needed peak power between 5,000 and 8,000 rpm. So that's how they designed the engine. They didn't care about anything below 5 or above 8. That's why production examples were disappointing performers. They had very little low-end torque-especially below 3,000 rpm. If you had 3.90:1 or 4.30:1 gears that helped keep the engine on boil-but if you had 3.50:1 gears they were a little sluggish. Further-to cut down on warranty claims- unbeknownst to the public Ford put rev limiters on them that killed the ignition at 5,800 rpm. That's just when it was starting to really roll. Now race examples with out rev limiters and proper gearing would totally rock from about 4,000-8,000 rpm. But the street versions felt sluggish because of the lack of low-end torque and and the rev limiter kicking in just when it was starting to really rock. In fact the 351W that was standard in the Mach 1 was actually quicker in the 1/4 mile and had great drivability. The reason being-the 2bbl 351W had 355 lbs of torque at 2,600 rpm. ( 4bbl versions had 385 lbs @ 3,200 ) This made the 351W a much better STREET engine, while the "Boss" 302 was undoubtedly the better RACING engine. The same thing with the Chrysler 426 Hemi. It was designed to do one thing-go 200 mph at Daytona. It dominated NASCAR and some people like Dick Landy or Sox&Martin had great success drag racing them. If you had headers, and a 4-speed and 4.30:1 gears, or a Torqueflite with a 2,500+ rpm converter and 4.10:1 or stiffer gears-yes your Hemi-powered street car could rock-n-roll with the best of them. But most of them had stock exhausts and 3.23:1 or 3.54:1 gearing. Popular Hot Rodding tested a 1969 Charger with a Hemi and a Torqueflite and 3.23:1 gears. They were very disappointed. They said it was like running with one flat tire. It couldn't break out of the 14s and went through the traps in 2nd gear. The PHR writers said it needed a stall converter and 4.10:1 gears. The 440 GTX and the 383 Super Bee they tested were both quicker in the 1/4 mile. The '69 GTO they tested in the same issue was quicker in the 1/4 mile. Does that mean that a 383 Mopar or a 400 Pontiac is a better race engine than a Hemi?  No!! The Hemi's superiority in any kind of competition is legendary. But the 383 Mopar and 400 Pontiac are much better STREET engines! Their massive low-end torque gives them great drivability. When you've got 400+ lbs ft of torque from idle on up- you don't need to rev to 7 or 8 grand. What I'm saying is-if your going to drive the car on the street at all-it's better to err on the side of caution. Sure you can write a check for 15 grand and put a mega-inch 600+ hp 12:1 compression, solid-roller beast in your car. It's choppy 1,500 rpm idle will sound badass, and if you've got a stick or an auto with the proper converter and gearing, it'll certainly rip ass on the strip. And off the strip-if it's only driven on and off the trailer or a few blocks to "Cruise Night" once a week you may not give a shit how nasty it is.  But again-if your going to drive the car on the street or the freeway at all-9.5:1 compression, ( to run on pump gas ) and a cam that idles at 800 rpm  makes a lot more sense. Like I said once before when discussing induction systems-"If a Super Stock Firebird can run 11.30s with a Quadrajet on an iron manifold, why do you need a Tunnel-Ram and dual 660 Holleys?"  Here's a perfect example. A guy I know was looking for a '68-'70 Olds 442. He ran across a 1970 W31 Cutlass. If you don't know-the "W31" was a factory-built high-performance 350 V8. They had special heads, an aluminum high-rise intake, special exhaust manifolds and a hot 308 degree cam. They were so nasty that they were only available with a 4-speed-no automatic was offered-and 3.90:1 or 4.33:1 gears, and you couldn't get power brakes, because the engine didn't make enough vacuum at idle to operate them! To fool the insurance Nazis they were rated at a ridiculously low 325 hp. The standard "station wagon" 350 in the Cutlass was rated at 310 hp!!  GM wants you to believe that all those go-fast goodies-intake, exhaust, heads and cam-are only worth 15 hp?  Puhleeze.  They were blisteringly fast, as was the one my friend test drove. He didn't like it. He said with the 4.33:1 gears he was always shifting it around town, and the motor was buzzing at 3,800 rpm on the freeway. He passed it up and later bought a 400 inch '69 442. He loved it. The 400 inch motor had so much torque that around town if he was in any gear but 4th-acceleration was just step on the gas, and the 3.36:1 gearing was a good compromise between jackrabbit starts and easy cruising rpm on the freeway. He told me he thought the W31 was quicker in a drag race, but the 442 was much more fun to drive all-around. Here's a couple more good illustrations. Edelbrock claims 387 hp and 439 lbs of torque for the "Performer" Package on a 400 Pontiac with 15 inches of vacuum at idle. The "Performer RPM" Package claims 422 hp and 441 lbs of torque, with 10 inches of vacuum at idle. You know what those specs tell me? That by using the "RPM" package your giving up quite a bit of low-end and mid-range torque for top-end rush. And that's if you have optimum gearing,traction, etc. In a typical street / strip machine is a car with 422 hp going to be THAT much faster than a car with 387 hp?  Probably not. Another example-when Edelbrock introduced the "Air Gap" line of manifolds-they raised the plenum so air could flow under it- cooling the fuel charge substantially-the buff magazines raved because they made 15-20 more hp on the dyno than the "regular" Performer / Performer RPM / Torker II / Victor manifolds. In sunny California this worked great. However many people in the mid-west and Rocky mountain states who ran out and bought these manifolds were furious-writing to the buff magazines and Edelbrock and demanding refunds because now their cars wouldn't start in cold weather!! Or even if they'd start-they'd experience carburator icing-or have to idle for 15 minutes or more to not die and cough and spit when trying to drive!!  That extra 15-20 hp wasn't so wonderful now!!  Many of them angrily said they were going to re-install their old intake so they could drive the car!!  So be careful-yes swapping your 2.73:1 gears for some 3.42:1s will give you a stunning improvement in acceleration without hurting drivability or freeway cruising rpm too much. If 3.42:1s are great-wouldn't 4.56:1s be totally badass?  No-because chances are you don't have the motor or the valvetrain and would run out of rpm before the end of the 1/4, and you definitely don't want the motor buzzing at 4,000 rpm on the freeway! So err on the side of caution. The biggest and baddest thing isn't always the best. Mastermind