russ67chevelle

im looking to find dyno'd engine combos with near 572 cu.in with near 10.2:1 compression-if you guys have,please list parts including exact cam manufacturer and specs to find best cam to give most torque and horsepower in the 3800-7000 range.thanks in advance russ-oh by the way 572 will be seeing 250 shot of nitrous also

russ67chevelle

Posted: 29 Oct 2007 23:40 Post subject:

--------------------------------------------------------------------------------

i ran my chevelle this past labor day-ran [email protected] at 90 degrees heat.my current cam is comp 7/4 swap .748 lift 286/296 at .050 112 degree lobe ctr.dart 355 1150 three circuit dominator dart intake jesel belt.the scales said car and me is 2950 lbs.2 1/4primaries to 4"collector. 9" 4400 rated stahl-turbo 400.4.11 rear gear 33"tall m/t et street.car doesnt flash much at all past 2000 rpm(i atribute to cam and vehicle weight combo)my rpm at 142 is 6000 so with the right cam profile and on spray i want to have car peak rpm to be approx. 7000.currently, car is very doggy under 5000 rpm.(5000-8500 rating)
it seams like newest trend to get best results in pump gas motors is high lift cams and short duration=most power at 6500.so basically i want to get cam correct for 3800-7000 with peak horsepower to be around 6500 rpm cause i heard you want to have peak horsepower 500 rpm less than highest rpm motor will spin.i want to footbrake the car to about 3000 rpm then stomp on it to activate nitrous(cheap mans transbrake).i am very anxious to hear what you guys think.im thinking of leaving current cam specs alone but take out duration.............what would you do???thx!

jmarksdragster

Your converter is killing you. That much duration wants at least 5500, probably up to 6000 to get it to launch. There is at least a half second in a converter change.

blue66

I work with Chris Straub for cams.
I can ge his contact info if you would like.
I have a 10.5:1 496 running on pump gas in my 3600# chevelle.
Times in sig.

Tod74

More converter and more gear. ..if you are only @ 6000 through the lights you can run a 4.56..at least I think you could,but there are calculators online to figure all that. Definately a looser converter.

just my .01 cent

russ67chevelle

the whole thing im missing is the 4000-7000 rpm driveability and using the big arm of the stroke for shorter duration to fit more torque in this rpm range.sofar im most apt to take out cam and grind off close to 20 degrees but leave lift and lobe alone............so i guess im saying what duration would i be best at with 4000-7000 rpm range for my 572?

jmarksdragster

Is this a street driven car? You will probably lose power going much smaller, but to work with that converter you will need to go in the low 260 range @ .050 intake. Might not lose much ET but will lose some MPH. And it will give your suspension a bit more work with the cam and converter better matched. If you are looking to go faster, change the converter.

russ67chevelle

ultimately i dont want to loose mph-actually i was thinkin by shortening the duration itll build more torque(and as equally important-at a lower reving range)because if valves are open longer cylinder pressure will be less.if thats the case then would i be correct in saying peak power(and fastest quarter times)has a certain trade off between more duration which will bleed off cylinder pressure and less duration which will increase cylinder pressure with a 10:1 compression motor?bottom line...with the current combo of the car,what would be optimum duration number if i was to taylor converter to cam(because i get one free adjustment on converter)but not to rev beyond 7000 rpm.keep in mind i have a plate system,so i know activation will instantaniously jump rpm of motor but honestly im not sure how much it will on a 250 shot............

r8ceredy

this is an example of why "street" cars can never be defined. "doggy below 5000 rpm"...seems as if you have to make a choice of looser convertor to be quicker at the track, or lower duration cam to work with your gear/convertor and pick up some street driveablility.
JMO

jmarksdragster

Ditto!!!