ZO6 hp claims underrated?
#1
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ZO6 hp claims underrated?
As with many performance GM engines over the years, I've heard rumors that my '03 Z might have closer to 430 hp as opposed to 405 hp? Any truth to this rumor?
Cheers.
Cheers.
#5
Burning Brakes
The crank horsepower numbers have been underrated, but not by much.
Normally 02-04 Z06 Corvettes dyno in the 347-360 rwhp range (stock).
For example: My stock 03' Z06 dynoed at 356 rwhp stock.
There are always exceptions though.
Normally 02-04 Z06 Corvettes dyno in the 347-360 rwhp range (stock).
For example: My stock 03' Z06 dynoed at 356 rwhp stock.
There are always exceptions though.
#7
Le Mans Master
Years ago, they sometimes overrated engine horsepower (actually it was due to the method of rating horsepower, called gross horsepower). For example the 1967 427 cu-in 435 horsepower was rated without accessories (alternator, power steering pump, water pump, etc.) and exhaust.
Our 345-350 HP Coupes and Convertibles would rate about 415 HP using this system. Which would explain why in conjunction with better tires our C5s have slightly better performance than these monsters.
However, they did underrate some engines, the 1969 427 cu-in 430 HP L88 "racing engine" was actually about 500-520 hp (using 103 octane gas).
Our 345-350 HP Coupes and Convertibles would rate about 415 HP using this system. Which would explain why in conjunction with better tires our C5s have slightly better performance than these monsters.
However, they did underrate some engines, the 1969 427 cu-in 430 HP L88 "racing engine" was actually about 500-520 hp (using 103 octane gas).
Last edited by Oldvetter; 03-28-2011 at 11:47 AM.
#8
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Every car can be a little different on the actual hp numbers that are achieved out of the car, but I doubt there would be that much of a difference. Only way to tell is get the car dyno'd and then work back to the crank HP.
#9
Melting Slicks
Remember the DZ302...
Chevrolet produced a special 302 cu in (4.9 L) (referred to as 5.0 L) engine for Trans Am racing from 1967–1969. It was the product of placing the 3-inch stroke crankshaft into a 4-inch bore block. The 302 used the same crank as the 283.[5] When the journal size increased to the standard medium journal size, the crankshaft for the 302 was specially built of forged steel.[5] This engine was used only in the first-generation Camaro Z28. Conservatively rated at 290 hp (216 kW), actual output was around 472 hp (352 kW). This block is one of 3 displacements that underwent a transformation for the 1968/1969 period when the main bearing size was increased from 2.30 in to 2.45 in.
Chevrolet produced a special 302 cu in (4.9 L) (referred to as 5.0 L) engine for Trans Am racing from 1967–1969. It was the product of placing the 3-inch stroke crankshaft into a 4-inch bore block. The 302 used the same crank as the 283.[5] When the journal size increased to the standard medium journal size, the crankshaft for the 302 was specially built of forged steel.[5] This engine was used only in the first-generation Camaro Z28. Conservatively rated at 290 hp (216 kW), actual output was around 472 hp (352 kW). This block is one of 3 displacements that underwent a transformation for the 1968/1969 period when the main bearing size was increased from 2.30 in to 2.45 in.
#11
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Remember the DZ302...
Chevrolet produced a special 302 cu in (4.9 L) (referred to as 5.0 L) engine for Trans Am racing from 1967–1969. It was the product of placing the 3-inch stroke crankshaft into a 4-inch bore block. The 302 used the same crank as the 283.[5] When the journal size increased to the standard medium journal size, the crankshaft for the 302 was specially built of forged steel.[5] This engine was used only in the first-generation Camaro Z28. Conservatively rated at 290 hp (216 kW), actual output was around 472 hp (352 kW). This block is one of 3 displacements that underwent a transformation for the 1968/1969 period when the main bearing size was increased from 2.30 in to 2.45 in.
Chevrolet produced a special 302 cu in (4.9 L) (referred to as 5.0 L) engine for Trans Am racing from 1967–1969. It was the product of placing the 3-inch stroke crankshaft into a 4-inch bore block. The 302 used the same crank as the 283.[5] When the journal size increased to the standard medium journal size, the crankshaft for the 302 was specially built of forged steel.[5] This engine was used only in the first-generation Camaro Z28. Conservatively rated at 290 hp (216 kW), actual output was around 472 hp (352 kW). This block is one of 3 displacements that underwent a transformation for the 1968/1969 period when the main bearing size was increased from 2.30 in to 2.45 in.
Its a fun high revving engine.
#13
Tech Contributor
358rwhp when my Z06 was stock.
I think GM was on target with the 405 rating.
I have seen in person a 370rwhp dyno on a stock 2002 Z06 though. I think its rare, but it happens to see one above the average.
Toque
I think GM was on target with the 405 rating.
I have seen in person a 370rwhp dyno on a stock 2002 Z06 though. I think its rare, but it happens to see one above the average.
Toque