pushinfreight

Say you are just doing a cam swap on a stock ls1 motor and 6m trans. How do you maximize the area under the hp/tq curve? Would you be loking at specifics on the cam? I have seen the pictures of the dyno sheets and some people have great peak numbers but things fall off quickly.

jyeager

Got to do your homework and pick the cam that does this. You can maximize the area under the curve by gaining tq in the lower rpm at the expense of the upper, or by gaining in the upper rpms at the expense of the lower...You decide. If you gain tq in the higher rpms, you have more horsepower and that means faster from point A to point B. But I understand what you mean. You can pick a cam that gives you equal performance (to stock) at lower rpms and gains at higher rpms.
Basically ask around for cam recommendations for stock heads that don't require reprogramming. (you'll want reprogramming to maximize the benefit, but by putting that caveat on you won't get aggressive cam recommendations that will hurt lower-end tq very much).
Basically staying fairly close to the stock grind but adding lift is what you'll want if you don't want the lower-end tq to suffer. keeping a wide LSA will help keep the tq band fairly flat. Take a look at the MTI Stealth cam.

98SS Blackattack

What Tranny do you have is a big factor. An a4 with a high stall will spend 85% of its time 5k and above.An m6 with stock gears will see lower rpms longer, with gears not as long.What size cam are you considering?

98SS Blackattack

Well i see you have an m6. The ls6 cam would not be good for you, No power under the curve. Any small cam will help. Comp216/220--G2-3--B1--T1--C1--TR220 are all good small all around cams-The next step would be TR224--C2 and so on. These cams will give you more power on the top end.

CAT3

iTrader: (9)

I am curious how you figure an A4 with high stall will spend 85% of its time over 5,000rpms? I only have a 3,000 stall but I would say your exactly opposite of what reality is. An A4 will only see 5k 15% of its life. Unless you have some badass gearing. And then not so sure. BTW my friends with 3500 stall, 4000 stall and one with a 4400 all agree, that 5k is limited to track use. Daily its under 3k.

pushinfreight

Basically I am trying to understand what cam specs allow for the greater area under the hp/tq curve for cams. I see such a wide varriance of choices in people who choose cams for street use. I was under the impression that torque is more important in light to light and HP was more important if you are wanting top end. I guess I should have asked the question this way, is the amount of area under the curve more important than peak numbers? If area is more important what part of the specs maximizes the area under the curve?

Vents

iTrader: (9)

thats a big ol nasty question to contemplate. here's some variables:

gear
tire size
vehicle weight
max useable RPM
trans seletion,
et goal,
mph goal.

you need to know all of these. each variable can make or break a combo, start by getting a baseline at the track, and go from there.

pushinfreight

Also, I am not real sure on what "ramp up" means. How do you tell if your cam has a fast "ramp up"?

pushinfreight

As far a my car goes, rear end and tires are currently stock. As far as the current goal is to have more around town 2-3 gear power and if possible a little better pickup when doing highway speeds (65-75) and I put my foot in it From what I understand the real limiting factor is the rear end and the injectors on my 2001 WS6. Now back to the cam thing, so there is not a single thing that gives more area it is the combination of LSA, lift, ect...?

BadBadZ

As far as area under the curve goes I did a comparison of the stock '00 cam, the LS6 cam, MTI C1 cam and LG G5X2 cam. The stock & C1 numbers are from my car. But all of the cars used had similar mods, such as LTs, LS6 intake.....

The comparison can be found here:

www.afbforums.com/area

pushinfreight

Why the C1 cam, it did not have the most area?

98SS Blackattack

I ment at WOT. After 15mph in 1st gear my rpms Never drop below 4900rpm in any gear because of shift extension. So my main concern was at 5000rpm and around there. Thats why i picked a B1 grind.Plus its very streetable untuned in an A4

BadBadZ

The C1 cam is what I have in my car right now. What I was trying to do is provide a way to compare the increases in going from one cam to another. Comparing peak HP/TQ numbers is not a good comparison for how a cam will compare real world, area under the curve seems to be that. So by looking at the comparison you can use it to help you make a decision on a cam. For example an LS6 cam and springs can be purchased more cheaply than a C1 cam and its appropriate springs. Does the difference in the 2, based on area under the curve, make it worthwhile to upgrade? That is the idea behind the comparison.

I chose the C1 cam over a year ago, before the G5X2 was available. Plus, the C1 has less lift, therefore it is easier on springs and my car is my daily driver.

Chicago Crew UnderBoss

iTrader: (1)

GREAT graph and info. I take it then if you were to install a new cam now you would go with the G5X2 cam, correct?

Also, I take it that your graphs pertain to those cams being used with stock LS1 heads. Am this correct?

Thanks!

jrp

iTrader: (16)

98's and 01+ have 28.6# injectors, there good for 450rwhp. your rear becomes more of a factor when going to the track; around town and daily driving it should be fine.

ramp rate means the aggressiveness of the lobes; most cames use XE or XE-R lobes. the later be the more aggressive. you can compare ramp rates by looking at the duration @.006 i believe. FWIW i down graded from a tr230 to an mti T1 for a more streetable setup and more low end tq.

jyeager

To answer the last question (ie. what gives a cam more area under the curve) I see 2 things that gain tq across the board (as opposed to just within a certain rpm window). These are LSA and lift. If you use a wide LSA (for our LS1 this is 114-117) and increase lift over stock (must consider springs and piston reliefs) then you should pick up power throughout the range. That's why I suggested you consider the MTI stealth cam. Take a look at that cam's specs. My guess is that this might be what you're looking for.

ps. You would really be happy with the results if you'll add matching heads to the equation rather than just swapping the cam with stock heads.

pushinfreight

Thanks for the information. The wish list is heads, cam and headers. I am justtring to better understand what is going to work for a street car that will not just see weekend use. I have had some great suggestions in the past from some others on the board for the cam and head combos. my question came from seeing so many people take sides on what is better peak numbers or area under the curve. What it seems to me is that area is what I am going to be looking for and not peak numbers. This should give more of in town driving when not over the 4000rpm range.

BadBadZ

Yes the graphs are all with stock heads. And if I do get a new cam I may go even bigger than the G5X2. I come from a circle track background. So the harder it lopes the more it is music to my ears... If the funds were available I would go the 427 root as you have.

BadBadZ

You are correct, more torque down low makes the car more driveable around town. The stealth cam, as previously mentioned, would be a great cam. Or the C1 or T1 would be great as well. The only trouble I have is trying to not spin the tires all the time because of all of the torque down low....

BigTex

iTrader: (16)

I agree with this. With a more lift, you are allowing more air in without really changing up the powerband. By making the LSA wider, you will be giving up some of the very peak HP, but you'd gain a longer flatter power curve. Compare some dyno graphs of wide LSA cams to narrow LSA cams. The narrow ones usually have a higher peak number, but the powerband is shaped like a large hill with power coming on late. On the wide LSA dynos, they typically have a longer flatter power curve, less peak HP, but larger range of usable power.