posted
In the 60's and 70's the horsepower was for exapmle a 454 LS-6 had 450 Gross H.P. what was the net? Today we have the LS1 with 345 Net Horsepower what would be the gross to compare with back then?
-------------------- 2002 SS LE Z4C, all options plus 12 disc Cd changer,ASR,Rear defogger,A-4 Trans. SLP Options: Cm Exhaust, 345 Airbox, Bilstein, Auburn, 35 Ann mats, 35 ann rear deck mat, 35 ann car cover, portfolio, birth certificate key fobs + dash plaque, special Camaro GM Portfolio. Autographed by FBODYFATHER Scott Settlemire, SSOA & WWCA Member! Slp owners Assoc. Posts: 184 | From: Chicago,IL. | Registered: Apr 2003
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quote:Originally posted by 2002 SLP SS: In the 60's and 70's the horsepower was for exapmle a 454 LS-6 had 450 Gross H.P. what was the net? Today we have the LS1 with 345 Net Horsepower what would be the gross to compare with back then?
Well the net on those back then would be less than the net on the new LS1's not only did they come up with gross H.P. in different ways but the drive trains were less efficiant and they lost more from everything on the motor and the drive train before it got to the wheels. Some engines were put on a engine dyno with no plulleys turning anything not even the water pump was turning and no exaust hooked to the motor. For example a 428 Super Cobra Jet 435 H.P. in the 60's dynoed 295 at the wheels.. On average a good rule of thumb today is you lose 15% for a M6 car and maybe 18% for a A4 car some say less than that but that is close. Cars back then lost more and they went about getting gross different also. They were selling gross H.P. back then and they used all the tricks to get the most to show up. Then came a time they started underrateing the HP for insurance and government regulations
-------------------- Willard (Mike) Scott Worldwide Camaro Club North Carolina state Rep. 2001 SS convertible with all SLP opts. Sunset Orange Neutral top Neutral leather http://community.webshots.com/user/wmss Posts: 737 | From: Siler City N.C. | Registered: Sep 2003
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posted
I have heard some where that you devide your flywheel hp by .75 and that would be the gross hp. So if you had 400 net hp at the flywheel, you would have 533 gross hp.
-------------------- http://community.webshots.com/user/sscamaro02 AMERICAN CAMARO ASSOCIATION 2002 SS (M02-2022)(Build Date 9/10/01) T-Top,Bright Rally Red,Ebony Leather,Hurst Shifter,SLP Options: 345HP,SS Grille,SS Floor Mats,Personalized SS Rear Deck Mat,17"X 9" ZR1 Type Chrome Wheels,SS Cover,Engine Plaque. Additional Mods:GMMG Chambered Exhaust,FLP LT Headers,SLP CAI,K&N Filter,Silver Hood Stripes, Silver Letters on Rear Facia and Spohn Performance LCA, Panhard,SFC and Adj. Torq Arm w/Drive Shaft Loops.384/rwhp and 381/rwtq
1969 SS396 Olympic Gold.Unrestored,L34(350HP),M21 close ratio 4-Speed,Cowl Hood,Spoilers Front and Rear,Console w/Gages.Second owner since Nov.1971. 1 of 2018 Produced Posts: 828 | From: Denver,PA | Registered: Dec 2001
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posted
Gross HP= engine output with NO accessories...no water pump, alternator, P/S, A/C or anything attached...its what the enigne is capable of doing.
Net HP= crank output in the configuration it will be in in the car...with all accessories attached, even if they're not turning (ie: A/C compressor).
Basically, what we consider 'crank HP' is the old 'net HP' term. As far as driveline losses, I've heard 8-10% for a modern manual transmission, with the same loss for an auto, if the TC is locked up. 12-15% if the TC isn't locked.
Byrdman
-------------------- Yep, its me! Posts: 47 | From: Kannapolis, NC | Registered: Feb 2004
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quote:Originally posted by MCKNBRD: Gross HP= engine output with NO accessories...no water pump, alternator, P/S, A/C or anything attached...its what the enigne is capable of doing.
Net HP= crank output in the configuration it will be in in the car...with all accessories attached, even if they're not turning (ie: A/C compressor).
Basically, what we consider 'crank HP' is the old 'net HP' term. As far as driveline losses, I've heard 8-10% for a modern manual transmission, with the same loss for an auto, if the TC is locked up. 12-15% if the TC isn't locked.
Byrdman
Ditto, except I've heard 12%-18% drive train loss. So you take your rwhp and dived by .85 (for a 15% loss) and that'll give you a theoretical Net. The only way to get gross that I know of is with an engine dyno.
Posts: 545 | From: Gardnerville, NV. | Registered: Aug 2003
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quote:Originally posted by SSHEETS: Ditto, except I've heard 12%-18% drive train loss. So you take your rwhp and dived by .85 (for a 15% loss) and that'll give you a theoretical Net. The only way to get gross that I know of is with an engine dyno.
I think those numbers are outdated, but I've heard the same thing. I like the idea of going with about 8%, as it artificially inflates the crank HP numbers, and no one ever calls you on it anyway!
And you are correct, gross is engine dyno with a stripped engine...
Byrdman
-------------------- Yep, its me! Posts: 47 | From: Kannapolis, NC | Registered: Feb 2004
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posted
I can tell you the Nascar crews would kill to get below 11% loss 15% I think is more close.
-------------------- Willard (Mike) Scott Worldwide Camaro Club North Carolina state Rep. 2001 SS convertible with all SLP opts. Sunset Orange Neutral top Neutral leather http://community.webshots.com/user/wmss Posts: 737 | From: Siler City N.C. | Registered: Sep 2003
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quote:Originally posted by sscamaro: I have heard some where that you devide your flywheel hp by .75 and that would be the gross hp. So if you had 400 net hp at the flywheel, you would have 533 gross hp.
Not even close.
Posts: 1163 | From: Rochester Hills, Mi | Registered: Feb 2000
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posted
The only way to tell is from dyno testing before and after. So much depends on emission controls, engine management schemes, PCM, ECM, set-ups, electronic vs. hydraulic controls, drivaeablity set-ups, limited slip transmissions, fuel economy concerns. NASCAR vehicles want no-slip, bang it home, lock ups; consumers want good fuel economy, comfy rides. The F-car trannies are really very good and very low on drive loss. We ahd some GM testing and saw the actual numbers and they were much lower than any one thought. The end result was that all of those owners that thought they had 400HP at the flywheel had a lot closer to 350.
Posts: 1163 | From: Rochester Hills, Mi | Registered: Feb 2000
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-------------------- Willard (Mike) Scott Worldwide Camaro Club North Carolina state Rep. 2001 SS convertible with all SLP opts. Sunset Orange Neutral top Neutral leather http://community.webshots.com/user/wmss Posts: 737 | From: Siler City N.C. | Registered: Sep 2003
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posted
Ok, so if I dyno 409 at the rear wheels (this is on the same dyno I pulled 327 stock with lid and y-pipe), do I 409/.85 (for 15% loss mn6) and get 481 hp? That seems like alot of pony's. But if its in the ball park, I'll take it!!!
-------------------- Brian
2001 red SS Convertible #5479 out of 6332 CME, Grill, Chrome 10 spoke, Dash plaque, Cover Absolute Speed 5.3L stg. 2 heads, comp 978 dual springs, ti retainers, AS ported ls6 intake, AS ported 78mm TB, TR224/.564 114lsa, TTS headers,gmmg exhaust,and more.... 409/382 rwhp/rwtq tuned Posts: 216 | From: Western NC | Registered: Apr 2002
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posted
That would not be much off Brian should be within 10 hp anyway
-------------------- Willard (Mike) Scott Worldwide Camaro Club North Carolina state Rep. 2001 SS convertible with all SLP opts. Sunset Orange Neutral top Neutral leather http://community.webshots.com/user/wmss Posts: 737 | From: Siler City N.C. | Registered: Sep 2003
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posted
Jeff read your reply thanks but,(sorry I went to public school) what would be the Gross horsepower of out SS? advertised is 345 with airbox so if SLP dyno tested or GM tested these cars what would be equal to groos Horsepower!
-------------------- 2002 SS LE Z4C, all options plus 12 disc Cd changer,ASR,Rear defogger,A-4 Trans. SLP Options: Cm Exhaust, 345 Airbox, Bilstein, Auburn, 35 Ann mats, 35 ann rear deck mat, 35 ann car cover, portfolio, birth certificate key fobs + dash plaque, special Camaro GM Portfolio. Autographed by FBODYFATHER Scott Settlemire, SSOA & WWCA Member! Slp owners Assoc. Posts: 184 | From: Chicago,IL. | Registered: Apr 2003
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quote:Originally posted by 2002 SLP SS: Jeff read your reply thanks but,(sorry I went to public school) what would be the Gross horsepower of out SS? advertised is 345 with airbox so if SLP dyno tested or GM tested these cars what would be equal to groos Horsepower!
I doubt they did any specific testing on the SLP package, without it being a real-world (ie: net) HP reading. If you stripped the LS1 down, and you're looking at 345 as a realistic number at the crank, you'd probably get about 360-365, at best. Today's accessories are incredibly low drag compared to the 'good old days'.
That said, if you tried whipping out gross vs net vs crank vs wheel hp numbers at a car show, you'd probably spend more time explaining the differences than looking at the cars there.
JMHO, of course...and SLP could very well have stripped an LS1 down to bare-bones to see what the base powerplant did, but I doubt we'd ever get those numbers..something about GM under-rating their engines...
Byrdman
-------------------- Yep, its me! Posts: 47 | From: Kannapolis, NC | Registered: Feb 2004
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That said, if you tried whipping out gross vs net vs crank vs wheel hp numbers at a car show, you'd probably spend more time explaining the differences than looking at the cars there.
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