rough hp estimates-before/after
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Joined: Sep 2007
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From: woodbine, md
rough hp estimates-before/after i was hoping to dyno my car before swapping parts, but it didnt happen, so
what would have been a decent rwhp out of the ex setup, and the new
EX comb.-lq4(6.0 block), with a z06 cam, stock 317 heads w/springs, d1sc procharger, vic jr intake, 750 blow thru carb, 12 lbs boost, intercooler
NEW comb.-same as above, but with Patriot stage 2 lq9 heads, and their cam, 224/229, 580, 590
when i built the engine, i installed forged rods/pistons, 9.2 comp
i realize there are a lot of varibles, with the afr's, tuning-
the engine is in my 69 chevelle-i have a lot of experience with prochargers, but on s/b's, b/b's-this is my first gen 3 engine
the car runs beautiful right now, just want to turn up the wick a little, get an idea where i might be-i am starting on the switch today
i realize most guys are running FI, (and i might this winter)but i should be in the neighborhood power wise-thanks
what would have been a decent rwhp out of the ex setup, and the new
EX comb.-lq4(6.0 block), with a z06 cam, stock 317 heads w/springs, d1sc procharger, vic jr intake, 750 blow thru carb, 12 lbs boost, intercooler
NEW comb.-same as above, but with Patriot stage 2 lq9 heads, and their cam, 224/229, 580, 590
when i built the engine, i installed forged rods/pistons, 9.2 comp
i realize there are a lot of varibles, with the afr's, tuning-
the engine is in my 69 chevelle-i have a lot of experience with prochargers, but on s/b's, b/b's-this is my first gen 3 engine
the car runs beautiful right now, just want to turn up the wick a little, get an idea where i might be-i am starting on the switch today
i realize most guys are running FI, (and i might this winter)but i should be in the neighborhood power wise-thanks
Last edited by forcd ind; Jul 23, 2008 at 06:48 AM. Reason: add info
But unless you change the pulley on that D1SC you will not be making the same boost as before.
That D1SC is going to flow a set CFM with whatever pulley you have on it. Swapping the heads and cam will change the amount of pressure "boost" that is required to force that amount of air threw the engine.
In short you will see a decrease in boost with the better flowing heads. The engine should make the same power though because it is still flowing the same CFM. "It might make a little more because less heat will be created resulting in a denser charge"
Now if you change the pulley and get the boost pressure back up to 12psi after the head/cam swap you should see a nice gain. The gain will come from the added CFM.
That D1SC is going to flow a set CFM with whatever pulley you have on it. Swapping the heads and cam will change the amount of pressure "boost" that is required to force that amount of air threw the engine.
In short you will see a decrease in boost with the better flowing heads. The engine should make the same power though because it is still flowing the same CFM. "It might make a little more because less heat will be created resulting in a denser charge"
Now if you change the pulley and get the boost pressure back up to 12psi after the head/cam swap you should see a nice gain. The gain will come from the added CFM.
