Low Numbers?
09-17-2012, 07:42 AM
#22
It will boost your DCR and your torque production which will only help make more horsepower.
09-17-2012, 08:23 PM
#23
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There is some of your problem, you need to advance that cam at least 2-3 degrees. Put it on a 110 ICL and I bet it gains 15rwtq and at least 25rwhp. Verify PTV though when and if you do this.
It will boost your DCR and your torque production which will only help make more horsepower.
It will boost your DCR and your torque production which will only help make more horsepower.
but i will defiantly do that this winter
09-17-2012, 08:59 PM
#24
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There is some of your problem, you need to advance that cam at least 2-3 degrees. Put it on a 110 ICL and I bet it gains 15rwtq and at least 25rwhp. Verify PTV though when and if you do this.
It will boost your DCR and your torque production which will only help make more horsepower.
It will boost your DCR and your torque production which will only help make more horsepower.
Nothing against LS3 heads but they are really better on a short runner intake or Big bore... Keep that intake valve open as long as you can!!!
09-18-2012, 04:53 AM
#25
Without going into great detail....
He is using a 4.0" bore, those heads were designed for a 4.065" bore. I know there will be people that argue that it is minute, but it's a big difference maker in flow at low to mid lifts. Up top in the higher lifts there is more available air mass so you don't see as much of a drop in peak air flow, but torque production suffers. Torque=HP...the more torque you can make and then shift to your advantage where you want it the more hp you will make as a result.
The large intake valve of the LS3 heads along with the large intake runner on a smaller bore with diminished low-mid lift flow numbers will not carry enough port velocity to make efficient torque production. This is why the cathedral port TFS heads make so much overall power and can make huge power up top when the torque curve is taken advantage of and shifted where the power wants to be made, intake manifold design will limit rpm that peak power is made though so the combo as a whole needs to be taken into consideration.
The large runner also does not help and needs the added air flow that a larger bore will offer.
In a nutshell this is the dilemma. Camshaft can only do so much when the short block isn't optimized to the cylinder head. You could try and throw some more intake duration at it to make the IVC event later for more peak hp, keep the ICL tight to not lose a lot of torque it has and then throw 4-6 more degrees on the exhaust duration to try and bump the mid-range and peak numbers some by helping carry the torque out further past peak torque.
Again though there is only so much a camshaft can do.
He is using a 4.0" bore, those heads were designed for a 4.065" bore. I know there will be people that argue that it is minute, but it's a big difference maker in flow at low to mid lifts. Up top in the higher lifts there is more available air mass so you don't see as much of a drop in peak air flow, but torque production suffers. Torque=HP...the more torque you can make and then shift to your advantage where you want it the more hp you will make as a result.
The large intake valve of the LS3 heads along with the large intake runner on a smaller bore with diminished low-mid lift flow numbers will not carry enough port velocity to make efficient torque production. This is why the cathedral port TFS heads make so much overall power and can make huge power up top when the torque curve is taken advantage of and shifted where the power wants to be made, intake manifold design will limit rpm that peak power is made though so the combo as a whole needs to be taken into consideration.
The large runner also does not help and needs the added air flow that a larger bore will offer.
In a nutshell this is the dilemma. Camshaft can only do so much when the short block isn't optimized to the cylinder head. You could try and throw some more intake duration at it to make the IVC event later for more peak hp, keep the ICL tight to not lose a lot of torque it has and then throw 4-6 more degrees on the exhaust duration to try and bump the mid-range and peak numbers some by helping carry the torque out further past peak torque.
Again though there is only so much a camshaft can do.
