03 BlackoutSSS Posted November 8, 2009 Report Share Posted November 8, 2009 (edited) Thinking about changing my cam from this 218*/214* .581"/.581" to this 220*/218* .563"/.590" The intake lobe is Comp Xtreme High Lift and the exhaust lobe is a Comp XER. I think that the still relatively short duration will make it a good setup for a TB converter, and the fast ramp rate of the exhaust lobe will assist in generating vacuum in the cylinder, and help to "suck" in more fuel and air. Can someone tell me if I am on the right track, or if I am out of my mind. I am trying to keep my DCR on the high side, as I am running N/A. My question is what LSA and ICL combination do you guys recommend for a nice broad TQ curve. Edited November 8, 2009 by 03 BlackoutSSS (see edit history) Quote Link to comment Share on other sites More sharing options...
Punisher Posted November 8, 2009 Report Share Posted November 8, 2009 Thats not too much of a change IMO. Generating more vacuum is not going to help "suck" a/f mixture into your cylinders. Air has weight, when you are on intake stroke and your intake valve opens the air is actually being forced into your cylinders due to atmospheric pressure pushing the air into it. The small intake duration and very small lift on intake you probably will not even see a difference. Believe it or not its a strange concept I learned at school, I have thought as well the cylinder was creating a true vacuum and sucking the air in. It is only the pressure differential between atmosphere and low cylinder pressure causing the air to be forced in there. Now in a large cam creating small vacuum is due to pressure equalizing faster or more a/f mix having more time to enter the cylinders and less time the intake valve is closed during intake stroke. It is debatable but most people think 112LSA is the most broad hp/torque curve for general small block applications. Quote Link to comment Share on other sites More sharing options...
Wheatley Posted November 8, 2009 Report Share Posted November 8, 2009 (edited) Are you set on a reverse split on the duration? Just curious? Are you N/A? Edited November 8, 2009 by Wheatley (see edit history) Quote Link to comment Share on other sites More sharing options...
Punisher Posted November 8, 2009 Report Share Posted November 8, 2009 ...I am trying to keep my DCR on the high side, as I am running N/A. Quote Link to comment Share on other sites More sharing options...
8 UR HMI Posted November 9, 2009 Report Share Posted November 9, 2009 N/A with a split lobe like that?? y? ur not getting the most out of ur cam for n/a . thats a good cam for a boost motor but not for n/a Quote Link to comment Share on other sites More sharing options...
03 BlackoutSSS Posted November 9, 2009 Author Report Share Posted November 9, 2009 Just sos you guys aren't guessing, I want to stay below 220 or 222 duration, because I will be running a TB stall (re-tooled by Circle D) that flashes to about 2800. I am trying to figure out a cam that make an AWD SSS do wheelies off the line. Alright, thats an exaggeration, but you get what I mean. I want a TQ curve that peaks around 2500 and stays flat through 5800. Are you set on a reverse split on the duration?Just curious? Are you N/A? Yes, I am N/A. No, not necessarily set on the reverse split, but it makes sense to me why its a good idea for making low end grunt as opposed to top end HP. The truck shifts at 5800, and I like it that way (my tranny has 114,xxx and still going strong), so I don't want to aggravate it by revving it too high. I am also still running full tq mgmt, and so far so good. If you have any ideas as far as duration combos with the supporting LSA and ICL that make mass tq almost from idle, Im all ears. N/A with a split lobe like that?? y? ur not getting the most out of ur cam for n/a . thats a good cam for a boost motor but not for n/a Can you explain that a little more for me? Quote Link to comment Share on other sites More sharing options...
03 BlackoutSSS Posted November 9, 2009 Author Report Share Posted November 9, 2009 (edited) something like this at the wheels would be nice...dont care about the HP, just the TQ. Edited November 9, 2009 by 03 BlackoutSSS (see edit history) Quote Link to comment Share on other sites More sharing options...
8 UR HMI Posted November 9, 2009 Report Share Posted November 9, 2009 (edited) Just sos you guys aren't guessing, I want to stay below 220 or 222 duration, because I will be running a TB stall (re-tooled by Circle D) that flashes to about 2800. I am trying to figure out a cam that make an AWD SSS do wheelies off the line. Alright, thats an exaggeration, but you get what I mean. I want a TQ curve that peaks around 2500 and stays flat through 5800. Yes, I am N/A. No, not necessarily set on the reverse split, but it makes sense to me why its a good idea for making low end grunt as opposed to top end HP. The truck shifts at 5800, and I like it that way (my tranny has 114,xxx and still going strong), so I don't want to aggravate it by revving it too high. I am also still running full tq mgmt, and so far so good. If you have any ideas as far as duration combos with the supporting LSA and ICL that make mass tq almost from idle, Im all ears. Can you explain that a little more for me? the lobe sep is good for boost, spray blower, turbo etc... ur letting a lot of exhaust stay in with the split lobe with a reverse cam. if ur gonna stay n/a with a tb converter flashing at 2800 id do a 228r cam from texas speed. thats got the sound and the torque curve is nice. or u could create ur own making a custom grind and play with it. ur cam is good for spray for sure if u wanna go that route but for n/a i wouldnt recommend that cam. with any high mileage tranny and adding a cam with converter ur gonna add a lot of pressure to the tranny with a very torquey cam. call texas speed and ask them what they would recommend. and btw, ur trying to push out a crap load of tq but if the curve isnt balance with hp ur gonna lose a lot getting off the line and through the 60ft so ur tq really isnt gonna matter. ask mr. p or sprayed99 what they think is best for you. sprayed99 designed my cam and my powerband is awesome!!! Edited November 9, 2009 by 8 UR HMI (see edit history) Quote Link to comment Share on other sites More sharing options...
03 BlackoutSSS Posted November 10, 2009 Author Report Share Posted November 10, 2009 Thanks for all the info man, this is good stuff. Regarding Texas Speed, the customer service I get with them is hit or miss sometimes. I love them, and have bought quite a lot of stuff over the years and will continue to buy from them, but regarding this decision, I think I would prefer to get some tried and true opinions from the guys on the boards, and the other experts. Not trying to imply that they don't know what they are talking about, but I feel like I would get a 'stock answer, go with the 224 or 228, it works good' answer, and thats not what I am looking for. I am looking to get the best info that I can get, then make the decision on my own, this way, if I don't like it, its my fault, no one else's. Whats the deal with your cam, would you mind giving up the specs on it? are you running a converter? where does your power come in? As for what you are saying about the reverse split cams being good to FI, I don't know anything about nitrous. I can see it being a good cam for a turbo (good backpressure to help spool the turbo), but a blower, I am confused about. Being belt driven, I cant see a short duration exhaust lobe being good for airflow. But thats not what I am wondering about. With a shorter or lower lift exhaust duration compared to the intake lobe being good for TQ in a turbo application, why wouldn't it be good for an N/A setup? Quote Link to comment Share on other sites More sharing options...
03 BlackoutSSS Posted November 10, 2009 Author Report Share Posted November 10, 2009 I just re-read that, and it sounds like I am trying to make an argument for a reverse split cam. I am not. I am thinking about something in the range that I originally posted, up to something like your cam. I would consider a 228 if I could get some decisive info on what LSA and ICL I should use to get lots of tq early in the range. Quote Link to comment Share on other sites More sharing options...
03 BlackoutSSS Posted November 11, 2009 Author Report Share Posted November 11, 2009 (edited) Intake Lobe 218* .605" XFI intake lobe Exhaust Lobe 224* .600" XFI exhaust lobe Given the above, what would be a good recommended LSA and ICL for what I am looking for? I know that moving the LSA around changes where the power comes in, and moving the ICL changes DCR (at least I think I remember reading that), I just don't know how the two interact with each other. Oh, and would it jive with 3000 stall? Edited November 11, 2009 by 03 BlackoutSSS (see edit history) Quote Link to comment Share on other sites More sharing options...
Krambo Posted November 11, 2009 Report Share Posted November 11, 2009 Just my opinion however going from what you have now to what you propose will not be noticeable. If you are going to go through the trouble of a cam swap / tuning, make it worthwhile. You can have a much more aggressive cam profile and still idle calm and have good street manners with a 3000 stall converter. Your doing the right thing and getting as many opinions as possible however! Again, this is just my opinion. Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted November 11, 2009 Report Share Posted November 11, 2009 go over the hardcorels1.com and talk to Ed or Brett and they both are probably the to best LS induction guys in the country. Quote Link to comment Share on other sites More sharing options...
zippy Posted November 11, 2009 Report Share Posted November 11, 2009 You're on the right path to getting what you want. You'll want the ICL to be a lower number as this has an effect on how late the intake valve stays open in relation to the compression stroke. The longer the intake valve stays open on the intake stroke, the less your DCR is going to be. There is alot more to it than that, but for quick thinking that is what you want to keep in mind. Read the cam card and look at your valve events. Most of them are listed online. Compare the DCR of the one's you've picked out to something like the Comp Cams 265LR HR12. Quote Link to comment Share on other sites More sharing options...
03 BlackoutSSS Posted November 12, 2009 Author Report Share Posted November 12, 2009 Is there somewhere I can find some real detailed info on the effects of playing with the ICL and LSA? I have been searching for weeks, nothing. If I get this info, I feel that I can make a good solid decision on a good cam. Quote Link to comment Share on other sites More sharing options...
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