Quote:
Originally posted by vetteKID
ok.....its time for alittle winter money spending. I just sold my other classic car (mopar) and i decided throw half into the vette and half into another car. heres what i got planed..........internally stock L-48 (performer manifold) by the way.
-650cfm holley spread bore carb. (#8055)
-Comp cams 268H .454 lift.
what do you guys think?
the cam right? headers first?
|
Opinion time
Headers and mufflers first definitely. Then put the car on a dyno with a wide band O2 sensor and dial in your Qjet. That should net you a good 20+HP and do it on the relatively cheap too.
I see no advantage to tossing a properly working Qjet out on a stock long block engine. When you install ported heads and a roller cam, then we'll talk, but until then, keep the QJet, it's a fine street friendly carb when dialed in.
Header tip:
Do not buy ceramic coated headers right off the bat. Instead buy uncoated headers and then fit the pipes to the car and the exhaust system first. Once the pipes are all dialed in fitment wise, only then send them out to be coated.
Hooker Super Comp headers are one of the best performing "off the shelf" headers you can buy and can be ordered with the AIR injection tubes for something resembling a smog legal setup.
Walker "Turbo" mufflers are surprisingly good performance mufflers and are a quarter of the cost of a Borla or what have you. Have your exhaust shop pick the largest muffler that will fit properly.
You *really* want a exhaust shop with a mandrel bender to fabricate your 2.5" pipes. Stretch benders are hell for crushing the tubes way down to exhaust choking diameters/cross sections.
Now assuming you have the need for more speed, then get into the engine proper. The cam you've mentioned is a nice not too over the top cam. If your willing to use after market valve covers, I would also add 1.6:1 roller rockers to the shopping list.
Adding the cam and the roller rockers will get you another 25HP or so.
Once you have cam, headers and good mufflers in place, dyno tune the carb on a Dynojet to get the air:fuel ratio dialed in.
One more place to find power is by ditching the stock cooling fan. Replacing it with an electric will free up anywhere from 10-20HP - seriously. I have the time slips buried in my desk somewhere to prove that.
I dumped my fan and picked up .2S and +2MPH. I did that on track experiment after seeing some convincing dyno tests in Hotrod magazin back in '99. It's imperative that you still keep the fan shroud and ensure that all the air seals are in good working order regardless of fan type!
You should be able to net a cool 40-60HP for ~$1800 by doing all the above. If that doesn't put some fire in your shorts, nothing will
CYa!
Allen
Art
trying to get some horsepower.
1974 stingray, 4 speed L-48. Just trying to keep it from falling apart 
2.5 or 3" straight pipe all the way back to a good pair of "turbo" style mufflers. Then you will get full benefit from any other mods you do. After headers, the only criteria you have is, how much do you want to spend? 
Linear Mode
