Impala ss vs 76 vete
Thread Starter
Instructor
Joined: Oct 2008
Posts: 178
Likes: 1
From: windsor ontario
Impala ss vs 76 vete
My buddy just bought an Impala SS which he says has around 300 hp.
We never did a 1/4 mile but side by side driving he can pull away from me. My issue is that I figured that I had about the samed H.P. .What else comes into play here or maybe I just over estimated my HP.
We never did a 1/4 mile but side by side driving he can pull away from me. My issue is that I figured that I had about the samed H.P. .What else comes into play here or maybe I just over estimated my HP.
Safety Car
Joined: Oct 2000
Posts: 3,547
Likes: 12
From: Carbondale Pa.
What year is the Impaler SS, because the mid 90's ones had the LT-1 engine in them (with iron heads tho)along with cop cars that had the 9C1 package, they ran pretty nice for big ole boats. New one,,, well thats technology for ya. Peace,,,Moosie 
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Racer
Joined: Mar 2005
Posts: 294
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From: Racine Wisconsin
I'm not an automotive engineer but I have a C3 on each side of the 1972 horsepower rating change. I think the change was made from SAE gross brake horse power (flywheel horsepower without a reduction caused by the accessories like water pump and alternator; and, unrestricted intake and exhaust) to SAE net brake horsepower (flywheel horsepower with a reduction caused by driving the accessories, with stock air cleaner and stock exhaust). As I understand, neither horsepower rating was measured at the drive wheels which I've been told is called "effective" horsepower; a convenient way to dyno the vehicle. I think the rating system was changed again in 2005 to account for lower octane gasoline. IMHO this is all marketing strategy. One thing I would like to know is how the current crate engines are rated; pre-1972, post-1972 or post-2005.
Le Mans Master
Joined: May 2002
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From: Lebanon Township New Jersey
I'm not an automotive engineer but I have a C3 on each side of the 1972 horsepower rating change. I think the change was made from SAE gross brake horse power (flywheel horsepower without a reduction caused by the accessories like water pump and alternator; and, unrestricted intake and exhaust) to SAE net brake horsepower (flywheel horsepower with a reduction caused by driving the accessories, with stock air cleaner and stock exhaust). As I understand, neither horsepower rating was measured at the drive wheels which I've been told is called "effective" horsepower; a convenient way to dyno the vehicle. I think the rating system was changed again in 2005 to account for lower octane gasoline. IMHO this is all marketing strategy. One thing I would like to know is how the current crate engines are rated; pre-1972, post-1972 or post-2005.
A very good description of gross HP readings, before 1972 and net HP, 1972 and later. Same engine in 72 was rated about 10% lower than in 71. I don't know of any change in 2005 however. An exception is crate motors, to my knowledge they are rated in gross HP. Also correct that no manufacturer rates their HP at the driving wheels.