LS3 Cam Only with LG Headers, G3X-4 cam, K&N Air Charger, no tune
07-10-2007, 04:23 PM
#41
Originally Posted by Asmodeus
Um.. what about the engine this thread is about? They are stock L92 castings. I'm sorry you think 484 rwhp from a 376ci engine cam only and untuned is extremely dissapointing.
07-10-2007, 06:34 PM
#43
Originally Posted by Beaflag VonRathburg
How long has the LS3 been out? This is all brand new technology from GM. Things don't always work out the same when you add aftermarket parts. As can be seen by all the dissapointing L92 numbers on this site.
07-10-2007, 08:58 PM
#46
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what would be the normal difference in power M6 vs. and auto? I saw where a bone stock '08 automatic car made in the 360 range in hp and torque. Is 430 hp untuned possible with headers only in a M6 car?
07-10-2007, 10:43 PM
#47
Originally Posted by speed_demon24
This post makes no sense. This car right off the showroom floor not even broken in yet with just headers,intake, and a cam put out 484rwhp UNTUNED yet you think that is disapointing? And thats with "evil" aftermarket parts that you seem to think don't work.
Yes, these results are very impressive. The thing that most people don't think about and has been brought more so to light by PatrickG's 500rwhp 347 is how well a combo needs to be designed. People on here aren't doing that with concern to L92 heads. They just think they're the best bang for the buck. They see all these marvelous flow numbers and think they'll work wonders on their 408. Then they end up with crappy numbers and ask what's wrong.
To quote a something amusingly true I saw a few minutes ago:
Originally Posted by GotStroke?
A sewer pipe will flow 3000cfm, but it won't make **** for power. Flow bench numbers are as useless as a girl w/out a vagina.
07-11-2007, 12:50 AM
#48
That doesn't make the L92 heads worse.
The heads are better. They have higher average flow numbers, as well as higher flow than most heads at any given point of lift. The L92 heads may have a problem with velocity due to having such a large intake port, but that hasn't really been proven one way or another yet. They simply require ridiculously different cam selection and design from what we're used to, and we're still learning. This dyno alone shows that by the time the new Camaro comes out, cathedral port heads will be a thing of the past.
To use PatrickG's car as an example, that car has 10 years of LS1/6 cathedral port knowledge behind it. This car has not even two years of L92 head knowledge to back it up. If you want to see a comparable number, come back in eight years and look at what stock displacement 6.2s are putting out with a combo engineered as well. It's not that people aren't trying to engineer L92 combos as well, it's that we don't know.
This happens to be someone who got it right -- these numbers are more in line with what you ought to be looking for.
The heads are better. They have higher average flow numbers, as well as higher flow than most heads at any given point of lift. The L92 heads may have a problem with velocity due to having such a large intake port, but that hasn't really been proven one way or another yet. They simply require ridiculously different cam selection and design from what we're used to, and we're still learning. This dyno alone shows that by the time the new Camaro comes out, cathedral port heads will be a thing of the past.
To use PatrickG's car as an example, that car has 10 years of LS1/6 cathedral port knowledge behind it. This car has not even two years of L92 head knowledge to back it up. If you want to see a comparable number, come back in eight years and look at what stock displacement 6.2s are putting out with a combo engineered as well. It's not that people aren't trying to engineer L92 combos as well, it's that we don't know.
This happens to be someone who got it right -- these numbers are more in line with what you ought to be looking for.
Last edited by IFRYRCE; 07-11-2007 at 12:56 AM.
07-11-2007, 11:26 AM
#49
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^^completely agree^^ The L92 heads out flow almost everything available aftermarket for the 6.0L and larger, straight out of the box. But with intake ports so huge you start to run into velocity issues.
I'm thinking that these heads are going to work best with huge displacement motor and a cam with enough lift/duration that can draw the huge amounts of air through the massive intake runners. Or on a smaller cube motor with a 4.0" bore and Forced Induction of some sort. Since Forced induction does not utilize velocity to get the air into the cylinder the lack of velocity will have no effect. And with a huge displacement you have to "suck" in more air to make more power.
The reason that cathedral port heads work so well on small cube motors. Especially when ported is because the smaller cube motors don't need as much air to make decent gains in power as big displacement motors do.
I could keep going, but basically these heads are a great design and will make great numbers on the right size motor with a good supporting setup.
-Kevin
I'm thinking that these heads are going to work best with huge displacement motor and a cam with enough lift/duration that can draw the huge amounts of air through the massive intake runners. Or on a smaller cube motor with a 4.0" bore and Forced Induction of some sort. Since Forced induction does not utilize velocity to get the air into the cylinder the lack of velocity will have no effect. And with a huge displacement you have to "suck" in more air to make more power.
The reason that cathedral port heads work so well on small cube motors. Especially when ported is because the smaller cube motors don't need as much air to make decent gains in power as big displacement motors do.
I could keep going, but basically these heads are a great design and will make great numbers on the right size motor with a good supporting setup.
-Kevin
07-11-2007, 12:43 PM
#50
I completely agree with the last two posts.
You have to think out what you are trying to accomplish with the
engine and vehicle usage before you can expect to have any hope
of designing a proper combination of parts to achieve your goals.
L92/LS3 heads are awesome, but they are not for everyone.
My setup is a light car with forced induction and a decent size cam
so port velocity is not much of a concern for me.
I can't wait to get it finished up to see how it runs.
You have to think out what you are trying to accomplish with the
engine and vehicle usage before you can expect to have any hope
of designing a proper combination of parts to achieve your goals.
L92/LS3 heads are awesome, but they are not for everyone.
My setup is a light car with forced induction and a decent size cam
so port velocity is not much of a concern for me.
I can't wait to get it finished up to see how it runs.
07-11-2007, 01:13 PM
#51
Originally Posted by IFRYRCE
That doesn't make the L92 heads worse.
The heads are better. They have higher average flow numbers, as well as higher flow than most heads at any given point of lift. The L92 heads may have a problem with velocity due to having such a large intake port, but that hasn't really been proven one way or another yet. They simply require ridiculously different cam selection and design from what we're used to, and we're still learning. This dyno alone shows that by the time the new Camaro comes out, cathedral port heads will be a thing of the past.
The heads are better. They have higher average flow numbers, as well as higher flow than most heads at any given point of lift. The L92 heads may have a problem with velocity due to having such a large intake port, but that hasn't really been proven one way or another yet. They simply require ridiculously different cam selection and design from what we're used to, and we're still learning. This dyno alone shows that by the time the new Camaro comes out, cathedral port heads will be a thing of the past.
Originally Posted by IFRYRCE
To use PatrickG's car as an example, that car has 10 years of LS1/6 cathedral port knowledge behind it. This car has not even two years of L92 head knowledge to back it up. If you want to see a comparable number, come back in eight years and look at what stock displacement 6.2s are putting out with a combo engineered as well. It's not that people aren't trying to engineer L92 combos as well, it's that we don't know.
Originally Posted by Beaflag VonRathburg
Yeah, there's a cost difference but look at the results. We all see L92 heads putting down great flow numbers, but show me some that are putting down the dyno numbers. All the real world results I've seen from the L92 heads have been extremely dissapointing. The cathedral heads are proven performers with tons of research and development in them. Maybe one day the L92 heads will bypass the cathedrals, but not anytime soon.
Originally Posted by IFRYRCE
This happens to be someone who got it right -- these numbers are more in line with what you ought to be looking for.
Originally Posted by shazow1969
^^completely agree^^ The L92 heads out flow almost everything available aftermarket for the 6.0L and larger, straight out of the box. But with intake ports so huge you start to run into velocity issues.
Originally Posted by shazow1969
I'm thinking that these heads are going to work best with huge displacement motor and a cam with enough lift/duration that can draw the huge amounts of air through the massive intake runners. Or on a smaller cube motor with a 4.0" bore and Forced Induction of some sort. Since Forced induction does not utilize velocity to get the air into the cylinder the lack of velocity will have no effect. And with a huge displacement you have to "suck" in more air to make more power.
Originally Posted by shazow1969
The reason that cathedral port heads work so well on small cube motors. Especially when ported is because the smaller cube motors don't need as much air to make decent gains in power as big displacement motors do.
Originally Posted by GotStroke?
A sewer pipe will flow 3000cfm, but it won't make **** for power. Flow bench numbers are as useless as a girl w/out a vagina.
Originally Posted by MeentSS02
Sooo...with results like these, are cathedral port heads gonna be a thing of the past? Or do they still have their place in this world?
Originally Posted by Asmodeus
They do.. on 3.9 bore engines.
Originally Posted by Beaflag VonRathburg
I think they are still extremely relavent and important. Not everyone can rock a 4.06+ bore. Even things with larger bores they still work. Look at Vengeance's 440 in the dyno section. It made 600+ RWHP with TFS 235cc heads and a ported fast 90 intake manifold.
07-11-2007, 01:15 PM
#52
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Wow, that is just plain sick! I guess we have to hope that this version of the ls3 ends of in the next f boat. Crazy to think a cam/heads/tune car could be pusing the limits of the shortblock(for some).
07-11-2007, 01:39 PM
#53
Originally Posted by Beaflag VonRathburg
Actually it does make sense. Think of all the effort GM put into engineering this engine to exact tolerances and strict guidelines. Your everyday person can't do this in their garage. We can't just make a new engine ourselves. We are limited by what we can get from GM and aftermarket companies.
Yes, these results are very impressive. The thing that most people don't think about and has been brought more so to light by PatrickG's 500rwhp 347 is how well a combo needs to be designed. People on here aren't doing that with concern to L92 heads. They just think they're the best bang for the buck. They see all these marvelous flow numbers and think they'll work wonders on their 408. Then they end up with crappy numbers and ask what's wrong.
To quote a something amusingly true I saw a few minutes ago:
Some people get it and some don't. Which are you?
Yes, these results are very impressive. The thing that most people don't think about and has been brought more so to light by PatrickG's 500rwhp 347 is how well a combo needs to be designed. People on here aren't doing that with concern to L92 heads. They just think they're the best bang for the buck. They see all these marvelous flow numbers and think they'll work wonders on their 408. Then they end up with crappy numbers and ask what's wrong.
To quote a something amusingly true I saw a few minutes ago:
Some people get it and some don't. Which are you?
It takes time to figure out what works and doesn't work on new motors. 
07-11-2007, 01:54 PM
#55
Originally Posted by speed_demon24
I'm one of those people that hasn't drawn judgement on them based on a few bad combos yet. It takes time to figure out what works and doesn't work on new motors.
It takes time to figure out what works and doesn't work on new motors.
07-11-2007, 02:01 PM
#56
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To the naysayers...Precedence has been set every year..to give you a one word answer.
LT1
Look at them now...Hell most aftermarket heads for them don't even stand up to stock 243 heads. I remember when all this stuff was said about Gen III's at look at them now...
Lead, follow or get out of the way
Dave
LT1
Look at them now...Hell most aftermarket heads for them don't even stand up to stock 243 heads. I remember when all this stuff was said about Gen III's at look at them now...
Lead, follow or get out of the way
Dave
