Engine HP = BHP = RWHP
Race Director
Joined: Mar 2007
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From: Marlton. Increasing performance one speeding ticket at a time! NJ
So if you have a manual with 350hp, it should have about ~310rwhp.
Auto would be less at ~290rwhp.
Drifting
Joined: Sep 2007
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From: Goldsboro NC
Team Owner
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From: Raleigh / Rolesville NC
Drifting
Joined: Sep 2007
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From: Goldsboro NC
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Safety Car
Joined: Jun 2009
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From: Frederick, Maryland
Hope you don't mind..mods in his profile....
"Patriot heads & cam, LS6 Intake & injectors, ported LS6 oil pump, 160 degree thermostat, LS7 clutch & flywheel, Blackwing filter, ported/descreened air flow sensor, Cold Air Screens, Corsa Touring Exhast, Drilled & Slotted Bendix rotors, Black calipers, BPP short shifter, Ipod2Car interface."
"Patriot heads & cam, LS6 Intake & injectors, ported LS6 oil pump, 160 degree thermostat, LS7 clutch & flywheel, Blackwing filter, ported/descreened air flow sensor, Cold Air Screens, Corsa Touring Exhast, Drilled & Slotted Bendix rotors, Black calipers, BPP short shifter, Ipod2Car interface."
Safety Car
Joined: Oct 2004
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From: Plano TX
12% loss for mn6 and 18% for automatic.. Thats for our C5 Corvettes... There is also parasitic loss for independent suspension vs solid rear.. F-Body Trans Am and z28 with LS1 have solid rear so these numbers do not apply .. Also drive train loss on rear wheel vs front wheel drive cars..Irrelevant,, just an FYI.. so the mathematical formula is this350(BHP for stock LS1) x ( 0.82 for manual tranny) or 0.88 for auto trans
so 350 x 0.82 = 287rwhp for an auto
and350 x 0.88 = 308rwhp for a manual
478 x 0.88 = 420rwhp for your car so 478 brake horsepower is what you have.. This is not an exact science but pretty dang close
Last edited by David426; Jul 18, 2011 at 03:48 PM.
Race Director
Joined: Sep 2005
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From: Pasco WA
Stock '02 ZO6 is factory rated @ 405 HP, and most dyno about 345-360 RWHP corrected SAE, which is about a %13 drop. After I finished with my NA build, it did 483 RWHP corrected, and then the clutch gave up. I got some custom badges from this guy in Poland; set of 3 for $25 included shipping! They were ordered by some guy who never bought them, and they said 525HP. I figured this was pretty conservative, and I couldn't pass up the price. However, the quality wasn't up to the standards of that Justin guy that does them in the USA, for a lot more money. Now, of course, they're not even close, and they're coming off when I finally remove my BSMs.
Drifting
Joined: Sep 2007
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From: Goldsboro NC
wait what? Im confused. I was just commenting off of yours from earlier and agreeing with you in saying if it was an LS1 it wouldnt be that high at all. Infact thinking about it and knowing some of my old buddies cars....that would have to be one hell of a monster cam to make 420rwhp w/o heads....
or one happy dyno.
or one happy dyno.
Team Owner
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From: East Meadow NY
St. Jude Donor '12
Team Owner
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From: NJ
Basicly the way to go is engine HP minus 12-15% = RWHP.
Racer
Joined: Apr 2009
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From: Myrtle Beach SC
Here's my $0.02 on the subject: my engine made 602 hp on an engine dyno, and then made 519 rwhp on a chassis dyno. So, 519/602= 86%, or a 14% loss through my drivetrain. I have always used the thumb rule of a 15% loss through a manual transmission, and my dyno numbers seem to support it...
Safety Car
Joined: Oct 2004
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From: Plano TX
Rear wheel horsepower is at best a ballpark number and is only relative to the dyno being used. Hot Rod did a write up not so long ago and compared several RW dyno's on the same car they got wildly different values varying as much as +/- 100 hp.
Basicly the way to go is engine HP minus 12-15% = RWHP.
Basicly the way to go is engine HP minus 12-15% = RWHP.
Yes, I have done a Thread on this subject.. People just refuse to believe this or just ignore it and think that a dyno is a dyno, or its like getting on a scale and weighing yourself.. NOT! The Dyno is just a Ballpark figure at best.. Way too many variables..
Last edited by David426; Jul 21, 2011 at 01:31 PM.