True HP rating of the LS1
07-02-2018, 07:33 PM
#43
07-03-2018, 11:19 AM
#44
Melting Slicks
While this is resurrected from old, the net results do not change. Every dyno will give different results on the same engine with different pulls. Years ago we had several of our club members who worked in the engine room at the Milford proving grounds. According to them, after thousands of testing the LS1 engine on the stand they developed calibrations so the cars were consistently putting our 345 engine hp. In 2001, with the engine changes they changed the calibrations to 350 hp. The Z06 engine development for 2002-2004 were very consistently at 405 hp. When we would ask them what was the drive train loss, they all agreed the c5 chassis suffered around 12% loss on a non load bearing dyno. They further explained that they could manipulate the chassis dyno to show more or less hp and still meet the standardized testing requirements. That is why you will find multiple engine calibrations for any given year for the C5.
Since then I have always taken dyno results as how the engine was working that particular day. If you are measuring changes made the same day and conditions you will measure what improvement were really made. When all the new HP improvements were introduced years ago we had one club member who bought almost every new product on the market. If you added up all the claims and bragged he made an additional 28 hp, when he went to the drag strip, his et's and trap speed were still the same as before. Needless to say he was bummed. Years ago John Heinracy took his new Corvette to a large sway meet and they persuaded him to put it on a dyno that was available. This dyno was calibrated to standard conditions and pressures and he made more HP than the stated engine HP. Everyone assumed he had already modified the engine and were happy with what they saw. The car had never had any engine tuning at that time, he had just finished the suspension work up to that time.
Since then I have always taken dyno results as how the engine was working that particular day. If you are measuring changes made the same day and conditions you will measure what improvement were really made. When all the new HP improvements were introduced years ago we had one club member who bought almost every new product on the market. If you added up all the claims and bragged he made an additional 28 hp, when he went to the drag strip, his et's and trap speed were still the same as before. Needless to say he was bummed. Years ago John Heinracy took his new Corvette to a large sway meet and they persuaded him to put it on a dyno that was available. This dyno was calibrated to standard conditions and pressures and he made more HP than the stated engine HP. Everyone assumed he had already modified the engine and were happy with what they saw. The car had never had any engine tuning at that time, he had just finished the suspension work up to that time.
07-04-2018, 02:15 PM
#45
Melting Slicks
The factory rated the early cars at 345 bhp, the later years at 350. Z06's higher of course.
Remember - you "buy" horsepower, but you drive torque.
A 350 cu in, 350 bhp, 350 ft.lbs. rated engine is a good "balanced" unit. When bhp numbers are way higher than torque, you have to rev it like crazy to get anywhere.
Remember - you "buy" horsepower, but you drive torque.
A 350 cu in, 350 bhp, 350 ft.lbs. rated engine is a good "balanced" unit. When bhp numbers are way higher than torque, you have to rev it like crazy to get anywhere.
07-04-2018, 06:15 PM
#46
Drifting
While this is resurrected from old, the net results do not change. Every dyno will give different results on the same engine with different pulls. Years ago we had several of our club members who worked in the engine room at the Milford proving grounds. According to them, after thousands of testing the LS1 engine on the stand they developed calibrations so the cars were consistently putting our 345 engine hp. In 2001, with the engine changes they changed the calibrations to 350 hp. The Z06 engine development for 2002-2004 were very consistently at 405 hp. When we would ask them what was the drive train loss, they all agreed the c5 chassis suffered around 12% loss on a non load bearing dyno. They further explained that they could manipulate the chassis dyno to show more or less hp and still meet the standardized testing requirements. That is why you will find multiple engine calibrations for any given year for the C5.
Since then I have always taken dyno results as how the engine was working that particular day. If you are measuring changes made the same day and conditions you will measure what improvement were really made. When all the new HP improvements were introduced years ago we had one club member who bought almost every new product on the market. If you added up all the claims and bragged he made an additional 28 hp, when he went to the drag strip, his et's and trap speed were still the same as before. Needless to say he was bummed. Years ago John Heinracy took his new Corvette to a large sway meet and they persuaded him to put it on a dyno that was available. This dyno was calibrated to standard conditions and pressures and he made more HP than the stated engine HP. Everyone assumed he had already modified the engine and were happy with what they saw. The car had never had any engine tuning at that time, he had just finished the suspension work up to that time.
Since then I have always taken dyno results as how the engine was working that particular day. If you are measuring changes made the same day and conditions you will measure what improvement were really made. When all the new HP improvements were introduced years ago we had one club member who bought almost every new product on the market. If you added up all the claims and bragged he made an additional 28 hp, when he went to the drag strip, his et's and trap speed were still the same as before. Needless to say he was bummed. Years ago John Heinracy took his new Corvette to a large sway meet and they persuaded him to put it on a dyno that was available. This dyno was calibrated to standard conditions and pressures and he made more HP than the stated engine HP. Everyone assumed he had already modified the engine and were happy with what they saw. The car had never had any engine tuning at that time, he had just finished the suspension work up to that time.
Interesting about the 12 percent loss. This makes sense and I always thought they lose much less than the rule of thumb most use. Assume the 12% is manual?
Last edited by Andrew; 07-04-2018 at 06:20 PM.
07-04-2018, 07:48 PM
#47
Melting Slicks
Exactly. Early LS1's make 345 crank HP, later made 350 in Vettes. Early LS6 made 385 and late made 405. GM did not under-rate these motors. If they did, then they seriously underrated the 330 hp C4 LT4, that can keep up with early LS1's. Chasis dynos folks use to measure rwhp can be manipulated. They should be used as a tool to understand before / after mods, shift points, torque curve and set gearing.
Interesting about the 12 percent loss. This makes sense and I always thought they lose much less than the rule of thumb most use. Assume the 12% is manual?
Interesting about the 12 percent loss. This makes sense and I always thought they lose much less than the rule of thumb most use. Assume the 12% is manual?
07-04-2018, 07:58 PM
#48
I had a 2000 a4 and with a cat back and vararam it made 293 rwhp. After installing long tube headers, hi flow cats and a dyno tune it rang in at 315 rwhp. thats all folks. those are real numbers on a mustang dyno. the same car a year later had a cam and vortech supercharger installed and made 505 rwhp. My 2003 z06 makes 480 without a power adder n/a. fyi.
07-06-2018, 01:48 AM
#50
Le Mans Master
My bet would be pretty much what they rated it at. With manufacturing tolerances on these motors, I'd guess they fluctuate maybe 5HP.
07-06-2018, 09:34 AM
#51
Melting Slicks
In 2001, a fewl changes were made to the engine and the biggest difference was the intake manifold. All 2001-2004 Corvettes received that same (Z06) manifold which made making 350 hp and 375 ft/lb of torque. The Z cars had a slightly different manifold but makes the same HP on the LS1.
07-06-2018, 11:08 AM
#52
In 2000 if you had pup cats on your exhaust system, it was tuned to make 345 hp, if you lived in the in many of the other states, you did not have pup cats and your car was detuned by GM to make 345 hp.
In 2001, a fewl changes were made to the engine and the biggest difference was the intake manifold. All 2001-2004 Corvettes received that same (Z06) manifold which made making 350 hp and 375 ft/lb of torque. The Z cars had a slightly different manifold but makes the same HP on the LS1.
In 2001, a fewl changes were made to the engine and the biggest difference was the intake manifold. All 2001-2004 Corvettes received that same (Z06) manifold which made making 350 hp and 375 ft/lb of torque. The Z cars had a slightly different manifold but makes the same HP on the LS1.
07-06-2018, 07:54 PM
#54
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not enough
07-07-2018, 10:37 AM
#55
Melting Slicks
( The '01s and up also had a hotter cam and a different tune... )
Many will argue 2000 cam was the best base LS1 cam because of the higher lift. When GM came out with the pup cats they thought they would loose HP so changed the cam profile to a higher lift for a 1 year only cam. The lift of the 01-04 cam was very similar to the 97-99 cam
Many will argue 2000 cam was the best base LS1 cam because of the higher lift. When GM came out with the pup cats they thought they would loose HP so changed the cam profile to a higher lift for a 1 year only cam. The lift of the 01-04 cam was very similar to the 97-99 cam
07-07-2018, 10:52 AM
#56
( The '01s and up also had a hotter cam and a different tune... )
Many will argue 2000 cam was the best base LS1 cam because of the higher lift. When GM came out with the pup cats they thought they would loose HP so changed the cam profile to a higher lift for a 1 year only cam. The lift of the 01-04 cam was very similar to the 97-99 cam
Many will argue 2000 cam was the best base LS1 cam because of the higher lift. When GM came out with the pup cats they thought they would loose HP so changed the cam profile to a higher lift for a 1 year only cam. The lift of the 01-04 cam was very similar to the 97-99 cam
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07-09-2018, 08:25 AM
#59
Last edited by grampi50; 07-09-2018 at 08:26 AM.
07-09-2018, 03:47 PM
#60
In 2000 if you had pup cats on your exhaust system, it was tuned to make 345 hp, if you lived in the in many of the other states, you did not have pup cats and your car was detuned by GM to make 345 hp.
In 2001, a fewl changes were made to the engine and the biggest difference was the intake manifold. All 2001-2004 Corvettes received that same (Z06) manifold which made making 350 hp and 375 ft/lb of torque. The Z cars had a slightly different manifold but makes the same HP on the LS1.
In 2001, a fewl changes were made to the engine and the biggest difference was the intake manifold. All 2001-2004 Corvettes received that same (Z06) manifold which made making 350 hp and 375 ft/lb of torque. The Z cars had a slightly different manifold but makes the same HP on the LS1.