How can stock heads make 425 rwhp & ported only go 450 rwhp?
04-08-2003, 01:38 PM
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How can stock heads make 425 rwhp & ported only go 450 rwhp? The G5X2 cam in LG's car is doing 425 rhwp with stock heads.
when you goto a stage 2 300 cfm ported head you only pickup to 440-450 rwhp.
Does that mean heads on a ls1 is one of the worst bang for the buck mods???
I dynoed a customers car that had all the boltons and a 220 cam on a c5, made 340 rwhp.
went to MMS stage 2 heads 5.3 (higher compression) and we got 360 rwhp after tuning.
seems pretty crappy the numbers im seeing for 1500-2000 spent.
<small>[ April 09, 2003, 01:15 PM: Message edited by: C4VetteLS1 ]</small>
when you goto a stage 2 300 cfm ported head you only pickup to 440-450 rwhp.
Does that mean heads on a ls1 is one of the worst bang for the buck mods???
I dynoed a customers car that had all the boltons and a 220 cam on a c5, made 340 rwhp.
went to MMS stage 2 heads 5.3 (higher compression) and we got 360 rwhp after tuning.
seems pretty crappy the numbers im seeing for 1500-2000 spent.
<small>[ April 09, 2003, 01:15 PM: Message edited by: C4VetteLS1 ]</small>
04-08-2003, 01:52 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? If you lost 80HP that can't be good for the money. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
04-08-2003, 02:50 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? I think he means 360 rwhp, but both the before and after head numbers suck. Several people on these boards have hit 390+ rwhp with stock heads.
04-08-2003, 02:53 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? well for the stock cubes, the stock ls1 heads aren't the best but they are probably some of the best stock heads on a car in our price range. You should look at one compared to like some 5.0 heads. Ported heads add a little, but they mainly shine on bigger cubes.
04-08-2003, 03:11 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? Mustang dyno or not, thoes numbers are still pretty shitty <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> It has to be something wrong with that car <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
04-08-2003, 04:21 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? bad tuning? Bad o2? could be 1000 things...what's the timing like? should be in the 30ish range at WOT...
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04-08-2003, 06:10 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? The answer in my opinion is b/c the stock LS1 heads are great flowing heads and the aftermarket heads are usually only good for another 25 rwhp. Upgrading to an awesome cam like the G52 is the way to really open wake up our LS1 cars. I think many have proven that you can had a solid mid 11 second LS1 with the right cam, converter, gear, bolts ons and stock heads.
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04-08-2003, 06:31 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? It depends.
A lot of folks run smaller cam out of necessity, they have to pass emissions or it's their daily driver... A friend of mine just dynoed 420rwhp with stage II heads and a C2, and the car barely lopes... Sure he could add that new LG cam but I don't think that's his goal.
A lot of folks run smaller cam out of necessity, they have to pass emissions or it's their daily driver... A friend of mine just dynoed 420rwhp with stage II heads and a C2, and the car barely lopes... Sure he could add that new LG cam but I don't think that's his goal.
04-08-2003, 07:53 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? I would say in one word, INTAKE. There is no intake on the market currently that surpases the ls6 intake and doesn't cost 1500 bucks and doesen't crush the low end of a 346 for the gen III small block. The ls6 intake only flows 280 cfm and the stock ls1 heads are between 240-250cfm. Most ported heads flow 300+ but not with a 280 cfm intake. I believe a new intake is on the horizon and we will see some interesting numbers after that. That is also the same reason we are not seeing giant increases out of the superstrokers. I believe it was on this board that a 427 c5-r motor made 750 horse power on an engine dyno but this motor was equiped with an after market sheet metal intake manifold.
04-08-2003, 08:38 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> But to take that and see a 422 or 409 makeing 475-490 the money that it takes to go big cubes is outrageous. 430 on a stock bottom end then pay $12,000 to get another 50-60 hp for a more displacement doesnt make sense. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You are correct about diminishing returns on adding cubes. However enjoyment is more than just peak RWHP. You got to look at the torque produced in the 422's. A 490 RWHP 422" motor is a lot tamer to drive than your average 430 RWHP 346" motor. Those guys go faster and enjoy excellent drivability.
04-08-2003, 10:36 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by DailyAluminumBlock:
<strong> I would say in one word, INTAKE. There is no intake on the market currently that surpases the ls6 intake and doesn't cost 1500 bucks and doesen't crush the low end of a 346 for the gen III small block. The ls6 intake only flows 280 cfm and the stock ls1 heads are between 240-250cfm. Most ported heads flow 300+ but not with a 280 cfm intake. I believe a new intake is on the horizon and we will see some interesting numbers after that. That is also the same reason we are not seeing giant increases out of the superstrokers. I believe it was on this board that a 427 c5-r motor made 750 horse power on an engine dyno but this motor was equiped with an after market sheet metal intake manifold. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Bingo! Give this man the Cupie doll! One day somebody is going to design a GOOD long runner intake for an LS1 and then you'll see a bunch more power.IMHO
<strong> I would say in one word, INTAKE. There is no intake on the market currently that surpases the ls6 intake and doesn't cost 1500 bucks and doesen't crush the low end of a 346 for the gen III small block. The ls6 intake only flows 280 cfm and the stock ls1 heads are between 240-250cfm. Most ported heads flow 300+ but not with a 280 cfm intake. I believe a new intake is on the horizon and we will see some interesting numbers after that. That is also the same reason we are not seeing giant increases out of the superstrokers. I believe it was on this board that a 427 c5-r motor made 750 horse power on an engine dyno but this motor was equiped with an after market sheet metal intake manifold. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Bingo! Give this man the Cupie doll! One day somebody is going to design a GOOD long runner intake for an LS1 and then you'll see a bunch more power.IMHO
04-09-2003, 12:52 AM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? Also - I am not sure that 425RWHP is "par" for this setup - just because someone else has hit this # doesnt mean that you will..
Before you guys jump on me - I am not saying that LG didnt do 425 (as I have only "read about" 1 car so far - but I AM SAYING that I have too many times seen people expect the same #s and not get near the #s they have read about on the net. There can be many differences between your setup and the car that achieved these #s..
Having said this - please keep your expectations within reason.. and dont always accept the highest # you have read about as going par for that paticular cam or setup..
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by C4VetteLS1:
<strong> The G5X2 cam in LG's car is doing 425 rhwp with stock heads.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">
Before you guys jump on me - I am not saying that LG didnt do 425 (as I have only "read about" 1 car so far - but I AM SAYING that I have too many times seen people expect the same #s and not get near the #s they have read about on the net. There can be many differences between your setup and the car that achieved these #s..
Having said this - please keep your expectations within reason.. and dont always accept the highest # you have read about as going par for that paticular cam or setup..
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by C4VetteLS1:
<strong> The G5X2 cam in LG's car is doing 425 rhwp with stock heads.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">
04-09-2003, 04:37 AM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by C4VetteLS1:
<strong>I dynoed a customers car that had all the boltons and a 220 cam on a c5, made 340 rwhp.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">My car dyno'd 348rwhp 363rwtq with only LID, LM, and headers. Imagine what this car will make with ASP pulley's, TB, G5X2 cam!!
<strong>I dynoed a customers car that had all the boltons and a 220 cam on a c5, made 340 rwhp.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">My car dyno'd 348rwhp 363rwtq with only LID, LM, and headers. Imagine what this car will make with ASP pulley's, TB, G5X2 cam!!
04-09-2003, 07:08 AM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ragtop 99:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> But to take that and see a 422 or 409 makeing 475-490 the money that it takes to go big cubes is outrageous. 430 on a stock bottom end then pay $12,000 to get another 50-60 hp for a more displacement doesnt make sense. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You are correct about diminishing returns on adding cubes. However enjoyment is more than just peak RWHP. You got to look at the torque produced in the 422's. A 490 RWHP 422" motor is a lot tamer to drive than your average 430 RWHP 346" motor. Those guys go faster and enjoy excellent drivability. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">What Ragtop said is right on!!
Bigger cubes means a huge area under the curve!! Big torque everywhere in the rpm range. Very very fun to drive!
If only I had the cash <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> But to take that and see a 422 or 409 makeing 475-490 the money that it takes to go big cubes is outrageous. 430 on a stock bottom end then pay $12,000 to get another 50-60 hp for a more displacement doesnt make sense. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You are correct about diminishing returns on adding cubes. However enjoyment is more than just peak RWHP. You got to look at the torque produced in the 422's. A 490 RWHP 422" motor is a lot tamer to drive than your average 430 RWHP 346" motor. Those guys go faster and enjoy excellent drivability. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">What Ragtop said is right on!!
Bigger cubes means a huge area under the curve!! Big torque everywhere in the rpm range. Very very fun to drive!
If only I had the cash <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
04-09-2003, 04:34 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? It's all in the package as a whole. It would be nice if it was as easy as saying, "Well, Joe Blow's car made XXX hp w/ the YYY cam on stock heads, and Jim Blow's car w/ the ZZZ heads made an additional AA hp over his stock heads; so if I run the YYY cam and the ZZZ heads, I should make XXX + AA. CRAZY POWER!!!" However, it's just not that simple.
We see all these posts about "what is the most powerful cam", "what are the best heads", "what are the best headers", "what's the best exhaust set up", etc... But just because you take the "best" heads, the "best" cam, the "best" headers, the "best" cat-back/exhaust config, the "best" air lid, the "best" MAF, etc... doesn't mean that you will end up with the "best" package as a whole. Look at the recent big-number 346" packages we have seen in the last couple of months... they are just that: packages. The heads work with the cam, works with the headers, work with the... well, you get the idea.
That being said, since it was brought up at the beginning of this thread, while the G5X2 made 425/411 on a stock-headed car, it makes 460+/420+ when used with LG's heads. If you take that cam and slide it into a motor with GTP/TEA, etc... (just using the GTP and TEA heads as examples; not bashing them at all) heads, all bets are off.
<small>[ April 09, 2003, 11:53 PM: Message edited by: BurnOut ]</small>
We see all these posts about "what is the most powerful cam", "what are the best heads", "what are the best headers", "what's the best exhaust set up", etc... But just because you take the "best" heads, the "best" cam, the "best" headers, the "best" cat-back/exhaust config, the "best" air lid, the "best" MAF, etc... doesn't mean that you will end up with the "best" package as a whole. Look at the recent big-number 346" packages we have seen in the last couple of months... they are just that: packages. The heads work with the cam, works with the headers, work with the... well, you get the idea.
That being said, since it was brought up at the beginning of this thread, while the G5X2 made 425/411 on a stock-headed car, it makes 460+/420+ when used with LG's heads. If you take that cam and slide it into a motor with GTP/TEA, etc... (just using the GTP and TEA heads as examples; not bashing them at all) heads, all bets are off.
<small>[ April 09, 2003, 11:53 PM: Message edited by: BurnOut ]</small>
04-09-2003, 06:53 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? I agree with burn out, the correct combination of parts is the answer to the riddle. Bottom line is this..... a 420 hp cam only car gets raped by a 420 hp heads and cam car every time. AREA UNDER THE CURVE is what makes car A out accelerate car B.
04-09-2003, 07:04 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by KECHME:
<strong> I agree with burn out, the correct combination of parts is the answer to the riddle. Bottom line is this..... a 420 hp cam only car gets raped by a 420 hp heads and cam car every time. AREA UNDER THE CURVE is what makes car A out accelerate car B. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">We'll there is a blanket statement. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
I've raped PLENTY of H/C cars...stock internal.
There a TONS of variables....
But I fully understand what you are saying
(all things being exactly equal) <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
<strong> I agree with burn out, the correct combination of parts is the answer to the riddle. Bottom line is this..... a 420 hp cam only car gets raped by a 420 hp heads and cam car every time. AREA UNDER THE CURVE is what makes car A out accelerate car B. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">We'll there is a blanket statement. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
I've raped PLENTY of H/C cars...stock internal.
There a TONS of variables....
But I fully understand what you are saying
(all things being exactly equal) <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
04-09-2003, 07:42 PM
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Re: How can stock heads make 425 rwhp & ported only go 450 rwhp? I guess I should have said all other things being equal <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> .
