cam question for those in the know
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cam question for those in the know
ok i have the car in my sig, i am putting my ported 243 heads on in about a week, but i have been thinking about getting a different cam. with these heads that flow nice up top, and the headers and ls6 intake, and the 918 springs i could run it higher so would i benefit from a bigger cam? or should i just keep this cam and take it higher in rpms. i do have hardened pushrods.
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Answer depends on what you are doing with the car. If a daily, I'd keep what you have. It'll still run well at the top end. If drag race, go with something bigger. If you do, you'll have to plan on new valve springs most likely.
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its def. not a daily driver, it might see street once or twice a week. and when i do bring it out its mostly to look for a street race. i saw somewhere that the 918's were good to a little over .600 lift.
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What LSA & ICL are you running the TR224 on? Depending on how it's installed, you could make quite a bit more power upstairs without swapping the cam. If you haven't already, mill the heads for more compression, that cam won't get you into any PTV clearance issues. Extra compression will help make the most of the cam.
#6
Don't be scared of a big CAM. Many people daily drive big cams. Its all about the tune. I would definally go bigger though with those heads and you will get some nice power. Good luck.
-Trevor
-Trevor
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#8
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Theres nothing wrong with the new 26918s that are grey in color. They are a great spring that I run on many engine combinations. They are rated to handle .625" lift.
I just got done running an LS1 with heads, intake, and Comp LSR cam 219/227 .600ish lift with 918s and it made 495hp on the engine dyno. I also am running them on my engine and will be adding that same cam most likely very soon!
I just got done running an LS1 with heads, intake, and Comp LSR cam 219/227 .600ish lift with 918s and it made 495hp on the engine dyno. I also am running them on my engine and will be adding that same cam most likely very soon!
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its a m6, the cam is a tr224 on a 114, because i was planning on going FI. my springs are def. gray with a blue line down the side. i could ask they shop to mill the heads while they still have them, but when you start going up in CR don't you start getting problems with detonation, especially running nitrous like i am? I'm not stating fact I'm asking.
#11
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Those are the old 26918s, they are good to .600" lift not .625" like the new versions. I guess I should have said the new ones were "Silver" not Grey...haha...
Anyways, as long as you have been running them already they probably are a good set and shouldn't have the issues seen with some other 918s.
The .600" rating is a safe margin and is not the "limit" of the spring. If your willing to spend more time you can find the actual limitation of spring by finding coil bind heights and seeing how much lift it can physically take. Now, Valvetrain stability is an entirely different and issue that needs thought separately when your changing your cam.
Assuming you have typical heavy 100g valves, steel retainers, and such.... If your new cam is going into the mid 230s+ @ .050 I would look into a new set of springs, just to be safe.
I personally decided to run the new LSR cams from Comp. They have the newest lobes(LSL) avaliable and are agressive that will really help ported heads shine, without having to use a large cam.
Im a proponet of great heads and small cams, see my sig. If you have the heads, you dont have to overcompensate with a large cam to make a exciting ride! People get way to caught up with sound and forget everything else IMO..
Anyways, as long as you have been running them already they probably are a good set and shouldn't have the issues seen with some other 918s.
The .600" rating is a safe margin and is not the "limit" of the spring. If your willing to spend more time you can find the actual limitation of spring by finding coil bind heights and seeing how much lift it can physically take. Now, Valvetrain stability is an entirely different and issue that needs thought separately when your changing your cam.
Assuming you have typical heavy 100g valves, steel retainers, and such.... If your new cam is going into the mid 230s+ @ .050 I would look into a new set of springs, just to be safe.
I personally decided to run the new LSR cams from Comp. They have the newest lobes(LSL) avaliable and are agressive that will really help ported heads shine, without having to use a large cam.
Im a proponet of great heads and small cams, see my sig. If you have the heads, you dont have to overcompensate with a large cam to make a exciting ride! People get way to caught up with sound and forget everything else IMO..
#12
Since EFI-Live and HP-T (plus some other companies with similarly sophisticated tuning software)..... became available for use.
With their ability in the right hands, to almost defy the laws of physics by making race-level cams street-able and acceptable to a pretty reasonable level.
Though that's relative!
#13
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I understand your point, and am not disagreeing. Larger cams have more potential in the right combinations but can be harmful in some of the combinations I see. I look at it differently though, people are willing to give up almost anything for sound which I don't understand, from a performance maximization mind set.
That being said, there is a large "IF" someone has and can use the EFILive or HPTuners software. Then not only has time and money for the software, paying the tuner, but dyno time also. Its always relative....to how much time and/or money you have
But for most 11sec-12sec cars, which is realistically 90% of the people, don't need 240+ cams.
That being said, there is a large "IF" someone has and can use the EFILive or HPTuners software. Then not only has time and money for the software, paying the tuner, but dyno time also. Its always relative....to how much time and/or money you have
But for most 11sec-12sec cars, which is realistically 90% of the people, don't need 240+ cams.
#14
I didn't intend to make a point though, it was just an observation.
Small duration and good lift is the way to go as I see it, too.
The statement was concerning the "bigger must be better" line of thinking.
It's not just here.
It probably started down-under (LS1.com.au) a while back, when they seemed to have a fair idea on how to be able to tune out the worst of the idle and low-speed issues with what are basically race cams and making them pretty drive-able.
Anything under 220 intake duration now, is seen as a baby cam.
#15
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Yup, thats why I like the new LSL lobes, to get to .600+ lift and back in such small durations (215/219/223) is moving the valve in a hurry, yet keeping the advantages of small duration. Its about area under the curve, plus the smaller cams like this can be controlled with beehives without issue, I like simplicity..
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so actually my 224 duration wouldnt be a baby cam, i geuss i'll just stay with it, i dont think i have even seen the full potential of this cam, once i get the heads on and tuned for the nitrous maybe bring the limiter up a little with some nicer springs, im sure i'll be happy with it, oh and it does sounds pretty damn nice. real mean, and its 114 lsa
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Jester, what intake are you running with the ported 243's and TR224 on a 114?
If it is a LS6 intake, your TQ and HP peaks will be likewise be determined by its flow characteristics. Patrick G, did a huge post a few years ago on the LS6 intake TQ peak being ~4800 rpm's, and a cam duration (IVC) exceeding ~46 degrees did not gain much additional power, and could cost you down low.
Whether you go 224-228, it is probably only a difference of about 10-15 HP (peak).
Now if you started adding compression, no doubt some additional power gains would be gained from a larger cam. While some light milling with those heads are not going to cause detonation problems, the power gain vs PTV, flow issues, etc., is always something to consider.
Personally, with some light milling, a cam duration from 224-228 on a 112 or 114 LSA sounds like a good choice for a LS6 intake.
Good luck..
..WeathermanShawn..
If it is a LS6 intake, your TQ and HP peaks will be likewise be determined by its flow characteristics. Patrick G, did a huge post a few years ago on the LS6 intake TQ peak being ~4800 rpm's, and a cam duration (IVC) exceeding ~46 degrees did not gain much additional power, and could cost you down low.
Whether you go 224-228, it is probably only a difference of about 10-15 HP (peak).
Now if you started adding compression, no doubt some additional power gains would be gained from a larger cam. While some light milling with those heads are not going to cause detonation problems, the power gain vs PTV, flow issues, etc., is always something to consider.
Personally, with some light milling, a cam duration from 224-228 on a 112 or 114 LSA sounds like a good choice for a LS6 intake.
Good luck..
..WeathermanShawn..