Horsepower Ratings for new car

[bogie1]

When they say the 2005 GTO has 400 HP or the 2004 Cobra has 390 HP is that Fly wheel or rear wheel hp?

 

[86brick]

Flywheel.

 

[bogie1]

tks.... gee my 18 year old GN with 136,00 miles ain't too shabby with 500 flywhell HP

 

[86brick]

Originally posted by bogie1
tks.... gee my 18 year old GN with 136,00 miles ain't too shabby with 500 flywhell HP

Yep just important to keep in mind that some of these flywheel ratings that they give are on the conservative side for the insurance companies and EPA.... For example I remember reading an article in GMHTP where they dynoed a stock '01 LS1 SS Camaro and it made 311rwhp (which makes the 325hp flywheel rating that they gave the car BS)... Just like in the 60's early 70's Muscle Car Era

 

[bogie1]

Take the rear wheel hp which the calculator in the web site gives and multiply by 1.175 for your flywheel HP.

http://www.prestage.com/community/C...+ET+and+MPH+using+HP+and+Weight+/default.aspx

I figured my flywheel HP from an 1/8 mile trap speed of 91.5 with a 3720 # car with driver. I was running a brand new TA 49 and had to let off becaue I leaned way out. I never realy had a chance to tune becaue on that run I ran almost 26# of boost and the chip was burnt for 19# I was spraying Julio juice like a fire hose. The 02's were 670 but I had 0 Knock due to the ALKY when I lifted.

J Cotton has my order for a BBCPT65. I will have the right chip for this one.
MT ET street radials came Fed EX yesterday. Can't wait fo the track to open back up.

 

[TommyV8]

Originally posted by 86brick
Yep just important to keep in mind that some of these flywheel ratings that they give are on the conservative side for the insurance companies and EPA.... For example I remember reading an article in GMHTP where they dynoed a stock '01 LS1 SS Camaro and it made 311rwhp (which makes the 325hp flywheel rating that they gave the car BS)... Just like in the 60's early 70's Muscle Car Era

Yeah, the first mag I bought when I got my Camaro in 2003 was Camaro Performers. In that issue they dynoed an '02 Z28 just like mine except that mine is an auto and the car in the mag was a 6-speed. Anyway, it made 304 at the wheels, making a complete mockery of the 310 flywheel rating. If you figure a 15% drivetrain loss that is 357.6 flywheel hp. If the drivetrain loss is 12% then its 345.5 flywheel hp. I believe the '03 Mustang Cobra is also underrated.
Weren't the Turbo Regals underrated? Even though 355 lb ft is a lot of torque, I would think it would take more than 245 hp to get one of those cars down the 1320 in 13.8 seconds at around 100 mph.

 

[85 TR]

man is that right ? it figured my car made 307 flywheel hp thats seems way too high?

 

[Harry Mash]

Our Buicks weigh about 3700 lbs. with fuel and driver. Knowing the weight and flywheel horsepower(245) the car should go thru the 1/4 traps at 95.5 mph.---- according to my old fashioned 1959 speed and hoursepower estimator wheel.

 

[bogie1]

To get a 3700lb Car to trap at 95.5 in the 1/4 mile you would need about 250 rear wheel horse power/295 flywhell HP.

 

[Harry Mash]

Could be Bogie 1. Maybe my old speed and horsepower estimator is measuring rear wheel horsepower--- it does not indicate which one ---only says "horsepower". as I recall in 1959 we all talked about flywheel h/p because that is what the car builders advertized.--- but that was 45 yrs. ago and now in the computer age I'm sure measurments are much more accurate.

 

[bogie1]

Harry,
The laws of pysics havn't changed. I am sure that your Horespower calc is very accurate. I bet it is in rear wheel power though.