Consider your whole package before you throw parts at it....

I talk to a lot of people who unfortunately-spend big dollars on speed parts for their car and then are severely disappointed in the car's performance. Often, the car doesn't even run as good as it did in stock trim. The reason is these people buy stuff that they read about in a magazine, or they listen to a friend, and they don't have all the information needed. Part of the problem is they read the buff magazines, but they either don't read the whole article, or they don't assimilate the information properly. A perfect case in point-Car Craft recently ran an article comparing various single-plane intake manifolds. They said the one that offered the most "Bang for the Buck" was the Edelbrock Torker II. That it would work equally well on a stock engine or a wild one. The hp and torque champ was a Holley / Keith Dorton unit. They said that while this intake worked well on their test mule, it wasn't really a streetable intake. The reason is the test mule was an 11.4:1 compression 406 inch smal-block chevy with 215cc intake port aluminum heads and a cam with 242 duration ( @.050 ) and .600 lift!!  Now 99% of the people reading that article aren't going to have an engine anywhere near that radical. But-he races off to Summitt Racing or Jeg's and orders up a Keith Dorton intake and an 750 Double-pumper Holley, because the article said that was the hp and torque champ. He puts it on his 8.2:1 compression L48 350 in his '78 Camaro that's an automatic with 2.73:1 gears and has stock 153cc heads and a cam with .390 / 410 lift.  It bogs off the line, doesn't begin to do anything until 4,000 rpm, and because of the lazy stock cam, is all done in by 5,000 or so. He's pissed. He should have read the article and the box the manifold came in. The Dorton intake is basically a NASCAR manifold-much like the Edelbrock Victor Jr-it's designed to make power from 3,500-8,000 rpm!!  This guy would have been much happier with an Edelbrock Performer and a 600 cfm vacuum-secondary carb. The car would have showed a noticeable improvement in power and torque from idle on up. If he "had" to have a single-plane-he could have got by with the Torker II and a vacuum-secondary carb. It would have had a little less bottom-end torque than the Performer, but it would "hit" like "gangbusters" at 2,500 rpm and pull hard to 5,500 or whenever his valvesprings gave up. Not Ideal-but the car would have been faster than stock and the guy would have been happy for the most part. Now the guys sells the Dorton intake and double-pumper to his buddy who has a '79 Corvette. The buddy's 'Vette really rocks with this setup. How is that possible? The buddy's 'Vette is an L82 that has 9:1 compression, "2.02" heads, and a cam with 224 duration (@.050 ) and .450 / .460 lift. It's a 4-speed with 3.70:1 gears. He drops the clutch at 3,500-4,000 rpm, it rockets out of the hole and pulls hard to 6,500 rpm. The T10 4-speed has about 1,500 rpm drop between gears-so he hits 2nd and subsequent gears at 5,000 rpm in the thick of the manifold's torque band. It works because the L82 has the cam and the heads and the gearing to take advantage of the manifold's power band. And with a stick-the driver can launch at whatever rpm he wants by manipulating the clutch, and he can rev the motor up at the line to "clean out" the carb. You can't do that with an automatic. Ironically-if the 'Vette was an automatic-it would still work ok. Not as good as with the 4-speed-but the L82 package would have 3.55:1 gears with the TH350-close enough to 3.70-and they came from the factory with a 2,500 rpm converter. Enough to get the car moving and up on it's torque curve. Much better than the guy's Camaro that had 2.73;1s and a converter that stalled about 1,600 rpm. See what I'm saying?  Here's another example. Guy has a 389 Tri-Power, 4-speed '65 GTO with 3.90:1 gears. He slaps a Ram Air IV cam into it that has 308 / 320 duration ( 231 / 240 @.050 ) and .470 lift with his 1.5 rockers. It has a badass lope but idles at 900 rpm. He pops the clutch at 3,200 rpm and shifts at 5,800. The M21 rock-crusher has a 1,400 rpm drop between gears so he's hitting 2nd at 4,400 right where the power and torque are the strongest. The car is way quicker in the 1/4, launches fine on the center 2bbl, really rips on the street. His buddy puts the same cam into his '77 T/A with an automatic and 2.56:1 gears and it absolutely kills what performance the car did have. It won't idle, you have to kick it into neutral at a stoplight to not creep into the car in front of you,and it's actually slower than stock. Here's why. The 389 in the GTO had 10.75:1 compression, a stick, and 3.90:1 gears. The huge cam-even if it lowered static compression by a full point-the car still had 9.5-9.75:1 compression. The 3.90:1 gears covered the lack of bottom end torque and got the motor into it's powerband quickly. ( There's a reason RAIV's were only available with 3.90 or 4.33 gears! ). Idle quality didn't matter-because again the driver can launch at whatever rpm he wants by manipulating the clutch. Now in the '77 T/A-the 400 had 8.0:1 compression. If the big cam cost it a point-now your static compression ratio is 7:1. Your going to lose what little power you had. Further-the choppy idle won't work with a stock converter, and the salt-flats 2.56:1 gears can't cover the off-the-line bog. The T/A driver would be much better off with the Edelbrock Performer Cam, or the factory "068" cam-both of which build massive low-end and mid-range torque. The only way the T/A driver could use the RAIV cam would be if he got some 72cc chamber Edelbrock or factory heads ( or milled his .060 to raise the compression over 9:1 ) and installed a 2,500 rpm converter and some 3.42:1 or 3.73:1 gears. It still wouldn't be as strong as the high-compression, 4-speed, stiffly geared GTO-but it would be pretty damn quick and definitely wouldn't bog. I know another guy who had a 390 hp 427 Stingray that nearly ruined it-he was going to install a Lunati "L88" spec cam. Thankfully-I talked him out of it. I pointed out-Lunati's catalog said the cam worked best with open exhausts and 4.56:1 gears!!!  Didn't that throw up a red flag?  Regardless of the 427's massive torque-this cam would have made his car-which had Q-jet on an iron intake, stock iron exhaust manifolds and a 4-speed with 3.36:1 gears-run like shit. It wouldn't have been as quick as it was stock. The spec sheet for the cam showed it idled about 1,500 rpm and made power from 4,000-8,000 rpm. "Bigger" isn't always better. Sometimes,it's better to err on the side of caution. Especially with cams and carbs and intakes. Comp Cams has their "Thumper" line which gives you the sound-but still has acceptable low and mid-range torque if you have to have everyone hear your car going "pocketa-pocketa-pocketa" at idle. And think of this-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?  I'm all for "Restification" and more speed-but be reasonable and do some research before you start throwing parts at your car. Mastermind