TurboGibbs

iTrader: (6)

Another thing. We typically lean torward the wide lsa's on this board for our applications for 4 reasons.
1- 110 lsa and less, computers don't like them. They can and have been tuned and ran but it is a battle to get them tuned just right. The idle and off idle transitions change constantly and the powerband is much more noticable rather than a smooth transition of more equal combustion efficiency across the rpm range.
2- In a lot of cases, people on this board run some form of FI or Nitrous. Neither of them like anything less than 112* lsa on a street engine.
3- Our trucks are heavy and, in most cases, have small cubic inches. Those two together are going to need all the help they can get to help get a heavier vehicle rolling.
4- Most of us still use our trucks for a daily driver and still use them as a truck to haul and tow. Putting a cam in that will increase higher rpm power, although will make it faster, will sacrifice the low end tq for everyday usability.

JimS

Next week we'll be putting in my Dart 225's and Comp Cam. The cam #'s are 224/230, 581-588, 114. My thinking was that with these heads and cam I might lose a little on the bottom end but with the Radix and 4.56 gears it probably wouldn't make a huge difference in narrowing the range and with these heads and the 114 the upper range should be improved significantly. Is my thinking correct?

TurboGibbs

iTrader: (6)

You will not suffer in the low end with the radix and 4.56's by any means. With the 4.56's you will be wondering where first gear went it is going to go by so fast with those mods. The duration is the main thing that will improve your upper end over a stock cam. The stock cam has 114lsa. But as stated before, when you change the duration the effects of lsa will change a little as well. Basically a 210* 114lsa cam will not have the same power band as a 230* 114lsa.
Your truck is going to be a beast with that combo .

Sport Side

iTrader: (6)

Bringin' out some results... Just to show where I'm coming from.

My Pop's '03 Z06 - Bone stock w/ the 204/218-118.5LSA cam
Notice the 'lack' of torque below 3800 RPM.

Single Pattern 221 cam? One of the MTI grinds. 112LSA vs. 114LSA
112 takes the victury throughout the midrange.

224/224-110LSA/106ICL... Comp X-E grind. Check out the torque.

Shaun Perry profile... Put in a 347ci Mustang. Same EFI intake restrictions as us, applying the same rules. 246/240 110LSA/111.5ICL... Retarded the cam. Broad and Flat torque curve.

Just some results that I have saved up... I have some dynos I may host that shows the negative effects of advancing a cam in one of these motors.
... But I may save it before I get called a dyno racer.

JimS

That's kinda what I figured and CERTAINLY what I want Goin to see the Zipster next Tuesday. Pretty exciting.... even for an old fart.

Sorry to interrupt the dialouge with my personal stuff. Thanks for your interpretation of my combination. Now back to your regularly scheduled programming.......

TurboGibbs

iTrader: (6)

I don't really see where you are coming from with what you are posting with those combos. I totally agree and would expect the same results with what you are showing with those cam dynos. Each one has different amounts of duration for one thing. When I have refered to "low end tq" I am mainly talking about off idle. Or up to 2500 which is the area people with trucks are usually concerned about loosing. You can't compare the lack of torque @ 3800 and consider that the low end of the power band. The way I see it we are both on the same page with cams just we are thinking in 2 different spectrums. I personally consider anything less than 240* duration and more than 112lsa a ***** cam. I am forced to run one in order to have a nice smooth DD. You get big increases in power with cams less than 240* duration by tightening the LSA and increasing duration because most engines are restricted severely by the cam in that area, especially the LSx,LQx engines that have excellent flowing heads.
As I stated before, there are too many variables to make a general statement like "the tighter the LSA the lower the cam comes in". My sole purpose of this thread is to keep people from saying that when it isn't true.

Sport Side

iTrader: (6)

Yeah, we are on the same track... This whole time when you described "bringing in the power sooner" I had assumed you were hinting towards the midrange torque and how 'soon' the torque curve, really just KICKS in.

The wide LSA is great for drivability in the Z. Idles like stock... Easy idle tuning exc. But, as you can see from the dyno, the midrange torque takes its toll in how quickly it builds up.

But anyways... Cool! Good talkin.