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Discussion Starter #1 (Edited)
Hey y'all, appreciate all the information that's been flowing on this site over the years. Been on the forums all day trying to make sure I ask an educated question that isn't explicitly stated elsewhere, lol. So, here goes. Total newbie here, btw.

I wanna make around 400 whp in my 04 M6. Only performance mods I'm looking to make are OTR CAI, heads, cam and exhaust (plus suspension, rear end, and valve train to support).

From what I can gather, the LS1 heads when ported and polished push more cfm than LS6? Read somewhere that they can get up to 330 cfm while porting and polishing LS6 heads won't help them out the same. Didn't make sense to me based on how I understand that process, so was hoping someone could shed light on this. Don't want to spend an arm and leg on heads if polishing the ones I've got will get me there.

I've now watched a 1 hour video of a guy on YT explaining how to pick a cam twice.


Around 27 minutes he explains that to choose a duration, you have to know what RPM range you want your cam to perform at. My question here is, if I want low-mid range power, what RPM range am I looking at there? He does calculations for the lift and duration so I'm just trying to work it all out based on the way he explains it. If you don't feel like referring to that video, that's fine too. In that case maybe just a recommendation on range based on said goals.

FWIW, I have really liked how the hot cam and the megadeath cams sound. Want something that's a little raspy.

Thanks in advance for any help, will be sure to share progress when I get around to doing this stuff.

Edit: CFM for the heads was in reference to a .550 lift, I believe.
 

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Looks like you did an impressive amount of homework for a first time owner, good on you for not just posting up "how much does it cost to make 800hp?" Not that there's anything wrong with that...

I gathered you like a chop and have a power goal in mind. I may not have much to contribute yet, but in my experience, most people tend to do the cam before the heads. While you can get more power per dollar with a cam swap, a big cam tends to affect driveability more than a good set of heads. So you'll see a lot of cam only results, not a lot of heads only results. I'm not saying 400whp on a 5.7 is possible with heads only, but you can use a much more drivable cam with a great set of heads to get there, and your driveability will likely be better.

Sure, a great tuner can make any cam drive like stock. But so called great tuners aren't exactly available on every corner. So keep in mind, using common parts makes it easier to find data and examples for a good calibration.

Also, use ls3 injectors when it's time. Factory data, proven consistent, readily available.

Good luck!
 

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Discussion Starter #3
Looks like you did an impressive amount of homework for a first time owner, good on you for not just posting up "how much does it cost to make 800hp?" Not that there's anything wrong with that...

I gathered you like a chop and have a power goal in mind. I may not have much to contribute yet, but in my experience, most people tend to do the cam before the heads. While you can get more power per dollar with a cam swap, a big cam tends to affect driveability more than a good set of heads. So you'll see a lot of cam only results, not a lot of heads only results. I'm not saying 400whp on a 5.7 is possible with heads only, but you can use a much more drivable cam with a great set of heads to get there, and your driveability will likely be better.

Sure, a great tuner can make any cam drive like stock. But so called great tuners aren't exactly available on every corner. So keep in mind, using common parts makes it easier to find data and examples for a good calibration.

Also, use ls3 injectors when it's time. Factory data, proven consistent, readily available.

Good luck!
Thanks for the info. I was unaware that the quality of the tune can kind of "override" the size of the cam...? Or is that not what you mean? My uncle actually has a shop in Mooresville NC and I know they do great tunes. My first ride in a GTO was one he was tuning, back when these cars were new. Been wanting one ever since.

Wouldn't mind making more than 400, that's for sure. Just figured I'd want a cam that can throw my passengers in the back seat stoplight to stoplight over something that produces the best track times. Both is cool, lol!
 

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Hey y'all, appreciate all the information that's been flowing on this site over the years. Been on the forums all day trying to make sure I ask an educated question that isn't explicitly stated elsewhere, lol. So, here goes. Total newbie here, btw.

I wanna make around 400 whp in my 04 M6. Only performance mods I'm looking to make are OTR CAI, heads, cam and exhaust (plus suspension, rear end, and valve train to support).

From what I can gather, the LS1 heads when ported and polished push more cfm than LS6? Read somewhere that they can get up to 330 cfm while porting and polishing LS6 heads won't help them out the same. Didn't make sense to me based on how I understand that process, so was hoping someone could shed light on this. Don't want to spend an arm and leg on heads if polishing the ones I've got will get me there.
a good port on 241 heads can be made to flow close to a ported 243 head. It also depends on the CnC program; not everyone's is the same. Overall, 243 castings are the stock cathedral head to have. but if you have a set of 241's, don't toss them. a good shop can to plenty with them.


Around 27 minutes he explains that to choose a duration, you have to know what RPM range you want your cam to perform at. My question here is, if I want low-mid range power, what RPM range am I looking at there? He does calculations for the lift and duration so I'm just trying to work it all out based on the way he explains it. If you don't feel like referring to that video, that's fine too. In that case maybe just a recommendation on range based on said goals.

FWIW, I have really liked how the hot cam and the megadeath cams sound. Want something that's a little raspy.

Thanks in advance for any help, will be sure to share progress when I get around to doing this stuff.

Edit: CFM for the heads was in reference to a .550 lift, I believe.
you can make more then 400whp with your goals. you can do 400whp cam only, 450-475 is achievable with ported heads. I assume you want drivability foremost with increased power?

There is more to cam selection than selecting duration. Overlap and the specific timing of valve events are all a consideration. I would suggest talking to someone who designs cams for a living.
 

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"Want something that's a little raspy. "
You can achieve that with exhaust. Almost all cat-backs sound "raspy".
 

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That video is so full of misinformation and bad advice...

Just the bovine feces about compounding valve spring loads should tell you how ignorant he is!

Stop listening to YouTube Mechanics.
 

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Discussion Starter #7
As far as the sound, I guess what I meant was what you folks refer to as lope. That's a characteristic of a cam, right? What does that translate to, if anything, performance wise? Intake/exhaust ratios?

Leaning towards sticking with my stock heads based on what I've gotten back so far, just get them CnCd. Will keep an eye out for a deal on the 243s, though.

Also learned today that the hot cam is a sissy cam. Crisis averted! :LOL:
 

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As far as the sound, I guess what I meant was what you folks refer to as lope. That's a characteristic of a cam, right? What does that translate to, if anything, performance wise? Intake/exhaust ratios?

Leaning towards sticking with my stock heads based on what I've gotten back so far, just get them CnCd. Will keep an eye out for a deal on the 243s, though.

Also learned today that the hot cam is a sissy cam. Crisis averted! :LOL:

i may come back and edit this later, coz i gottzta go to work. just an overview, from how i understand it, in terms of increased performance:

intake valve closing affects how much air/fuel charge gets into the cylinder, and at what rpm the engine really makes torque. the later it happens, the more power you make at a higher rpm. At high engine speeds, it takes advantage of the inertia of the air charge flowing in the cylinder to continue to fill the cylinder even while the piston is dwelling at the bottom of it's stroke during the intake cycle. at lower rpms, things aren't moving fast enough to really take advantage of this effect, and it may even become detrimental, where you have reversion. You end up having a drop in performance as well as efficiency and drivability at lower rpm ranges. So, you want an IVC point that reflects how you want the engine to do at every engine speed and load it will see.

intake valve opening is important because of overlap, which is talked about below. the earlier it opens, the more overlap you will have. you also get a head start to higher valve lifts during the intake stroke, which means more flow.

exhaust valve closing effects overlap as well, see below. It also affects the timing of pressure waves in the exhaust system, which coupled with the primary length/diameter of a header system will promote exhaust scavenging during a particular rpm range.

exhaust valve opening helps power production by reducing pumping losses if it is done early. the piston must perform work on the exhaust gas to force it out of the cylinder. You end up with a trade off on loosing work done to the piston and reducing work lost due due to pumping gloss. This will also affect torque vs. rpm, with an earlier opening being better for high RPM torque but detrimental for low rpm. So much like the IVC point, you want it to reflect how you want the engine to perform at every engine speed and load it will see.

now duration and lobe centerlines work together to set these points. when you see cam specs, like 230/230 @.050" .600/.600 112+4 (230 degrees intake/230 degrees exhaust, measured at .050" lift, .600" intake valve lift, .600" exhaust valve lift, 112 lobe seperation angle + 4 degrees of advance), you can use them to figure out at what points during the engine cycles the valve events happen.

as far as your crappy cam sound... i mean, uh, raspiness, when the intake valve is still open when the exhaust valve is closing, you have what is called overlap. overlap actually helps increase cylinder pressure (which means more air/fuel mix "stuff" to smoosh and burn) because it allows the residual exhaust gas in the chamber to be drawn out and replaced with fresh air/fuel mix. exhaust exits, creats a low pressure area, and helps to draw in fresh air/fuel while both the intake and exhaust valves are open. at low engine speeds, too much overlap actually causes reversion (air/fuel in the intake port isn't moving fast enough, and it ends up burping crap back into the intake manifold) which decreases manifold vacuum, and gives you a crappy idle. i mean, er, lope. yeah. because aftermarket cams are all for sound and not for increased performance.
 

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Oh, i'm sure later timed IVC effects effect the poor idle of an aftermarket cam, as well as overlap.

On really big bajonkin cams, you'll get a lot of crap in your intake manifold plenum. Soot, fuel, yuckiness.

Oh, big cams make tuning interesting. Lots of overlap messes with the o2 sensors because oxygen in the exhaust.

Have fun.
 

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I have stage III ported (243) LS6 Heads/cam, Fast 102lsxr, 105mmTB, 100MAF, etc. I at at 437rwhp since last tune, since then have added 1 piece CF driveshaft, forged rims, etc. Here is an idle clip of mine, not sure this sounds crappy.


Engine Mods: Livernois Stage III LS6 heads/cam | Cam - [email protected], Lift .568", LSA 114
Fast LSXr 102mm | LPE 100MM MAF | 105MM Accufab TB
SvedeSpeed OTRCAI | JBA Shorty Headers | JBA Mids w/cats | JBA Split Catback
 

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Discussion Starter #11

i may come back and edit this later, coz i gottzta go to work. just an overview, from how i understand it, in terms of increased performance:

intake valve closing affects how much air/fuel charge gets into the cylinder, and at what rpm the engine really makes torque. the later it happens, the more power you make at a higher rpm. At high engine speeds, it takes advantage of the inertia of the air charge flowing in the cylinder to continue to fill the cylinder even while the piston is dwelling at the bottom of it's stroke during the intake cycle. at lower rpms, things aren't moving fast enough to really take advantage of this effect, and it may even become detrimental, where you have reversion. You end up having a drop in performance as well as efficiency and drivability at lower rpm ranges. So, you want an IVC point that reflects how you want the engine to do at every engine speed and load it will see.

intake valve opening is important because of overlap, which is talked about below. the earlier it opens, the more overlap you will have. you also get a head start to higher valve lifts during the intake stroke, which means more flow.

exhaust valve closing effects overlap as well, see below. It also affects the timing of pressure waves in the exhaust system, which coupled with the primary length/diameter of a header system will promote exhaust scavenging during a particular rpm range.

exhaust valve opening helps power production by reducing pumping losses if it is done early. the piston must perform work on the exhaust gas to force it out of the cylinder. You end up with a trade off on loosing work done to the piston and reducing work lost due due to pumping gloss. This will also affect torque vs. rpm, with an earlier opening being better for high RPM torque but detrimental for low rpm. So much like the IVC point, you want it to reflect how you want the engine to perform at every engine speed and load it will see.

now duration and lobe centerlines work together to set these points. when you see cam specs, like 230/230 @.050" .600/.600 112+4 (230 degrees intake/230 degrees exhaust, measured at .050" lift, .600" intake valve lift, .600" exhaust valve lift, 112 lobe seperation angle + 4 degrees of advance), you can use them to figure out at what points during the engine cycles the valve events happen.

as far as your crappy cam sound... i mean, uh, raspiness, when the intake valve is still open when the exhaust valve is closing, you have what is called overlap. overlap actually helps increase cylinder pressure (which means more air/fuel mix "stuff" to smoosh and burn) because it allows the residual exhaust gas in the chamber to be drawn out and replaced with fresh air/fuel mix. exhaust exits, creats a low pressure area, and helps to draw in fresh air/fuel while both the intake and exhaust valves are open. at low engine speeds, too much overlap actually causes reversion (air/fuel in the intake port isn't moving fast enough, and it ends up burping crap back into the intake manifold) which decreases manifold vacuum, and gives you a crappy idle. i mean, er, lope. yeah. because aftermarket cams are all for sound and not for increased performance.
Thanks for the link and the write-up! Still digesting this, read it last night and looked over it again and took some notes just now.

Looking at Texas Speed's cams right now just as a reference. What are the differences in the 228R, stage 3 LS3 and a torquer going to correlate to when installed? Did hear you when you said to contact someone who makes cams, and I will, just not at that point yet. Going to change a leaky clutch slave this weekend, put some tires on and drive it for a month or so to see if she has any surprises for me first.

The TS cams sound "lopey" to me, especially the clips they have of the torquer v2. Is that a crappy cam? lol I'm sure there's also a difference in a bit of overlap and too much.
 

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When i say crappy, i'm talking about the idle.

OHV engine cams are generally a compromise of performance, efficiency and drivability. Get into DOHC engines, variable valve timing and lift, and you have less compromise. A lot more complexity, though.

I can't say much about what cam grinds work well in a specific app.

Generally, you might want to stick with something in the 22x/22x duration range with low overlap (less than i dunno, 8 degrees) in an LS1 to have good power and decent drivability and tunability. You can definitely go much, much larger, but you start having to make other considerations as you do. Tuning it gets harder, drivability gets worse, and eventually you'll need expensive valvetrain stuff and want to rev it to saturn to make power.
 

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EDC knows a lot more than most of us, and he posts here. Check out ls1tech, too. Lots of bad advice but there are a number of knowledgeable folks there, and a few knowledgable vendors post info, like cammotion.
 

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EDC knows a lot more than most of us, and he posts here. Check out ls1tech, too. Lots of bad advice but there are a number of knowledgeable folks there, and a few knowledgable vendors post info, like cammotion.
The LS1Tech Cam thread is interesting, if you have the time to roam throw it.


Funny thing is a lot of those "internet camshaft experts" are long gone.

:unsure:
 

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Greetings Guys; I'm readin' along as I take in as many perspectives as possible. I'm on a path to do (port & skin cut) my OE 243 heads & 1.8 rockers on a stock cam. Thank you all for postin, Ole' Bob.
 

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Heads, cam, intake manifold and lt headers will get you easily above 400 rwhp, The higher you go on hp corresponds to amount of $$$. TSP, Summit and others have packages.
Cam alone will get you to 400 plus.
Just remember " you have to have traction" to plant it,
 

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I would just call tony Mamo at Mamo motorsports. He use to be a head designer at AFR. He speced heads and cam for me with boost I will be right at 1000 hp don’t get me wrong I did a Darton sleeved 427 and am in deep. But he does smaller stuff too. Heads and cam should be speced by the same guy. You will need a torque coverter with a A4 so it won’t die at lights. You want a person that will give you a complete set up not this from here because it’s cheep then this from here because it’s cheep. It’s like a recipe just the right amount needs to be put in. Not saying it’s not possible to do it. But it’s nice to have it right the first time. Fast cheep and reliable pic two.
 

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Discussion Starter #18
Thanks for all the input. I'm really itching to drive this thing, mods or not. I've got the transmission out right now, remote bleeder for the clutch system was supposed to arrive today but never made it. Had to change the slave cylinder as I was losing hydraulic fluid, observing a leak near the bell housing. Even after I get it back together, waiting on the title to get here and being out of town for work next week is a bummer. First couple things I wanna take care of are intake and exhaust. Should give me time to figure the rest out and keep me happy with little gains here and there. Gonna study that LS1tech cam thread some, see if I can't get learned!
 
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