>I just got a response from a guy in Atlanta that has a DynoJet .
>
>He told me that he has put a Paxton on a '98 R/T and it raised the
>rear-wheel HP from 190 to 330 HP .
>
>Now that's great and all , but here comes the dumb question :
>
>Is the 250 Peak HP that Chrysler claims the HP at the flywheel or what ?
>
>I thought they stopped that in the seventies and started doing them all at
>the rear wheels ?
>
>I hate to sound stupid , but maybe I am ......
>
>Jack Hilton
>
>Black '98 R/T Club Cab
>
Jack
In the 60's and 70's they used Gross power readings. These were readings
without any accesories - water pump, fan, pulleys, etc. hooked up. Around
1972 manufacturers changed to Net power readings. These power readings
were taken with all the accessories hooked up - water pump, emissions
stuff, pulleys, fan, etc. That's one reason why power levels seemed to
drop. Manufacturers still use net readings today.
Power at the real wheels is what is really important. Evidently, there is
around a 60 hp drop in power due to friction in the transmission,
driveshaft, and rearend on the Dak R/T. Two similar vehicles can have
different rear wheel hp readings, though. BTW - Manual trans vehicles
usually make more rear wheel power because they have less friction in the
trans.
191.7 is what Hot Rod got in their test on a Dak R/T CC with 1230 miles
(rear wheel horsepower). Here's a list of others they tested on a Dynojet
248C chassis dynamometer. All are 1998 models, except where noted.
Horsepower Torque
Cadillac Eldorado ETC Advertised 300 @ 6000rpm 295 @ 4400
Observed 216.1 @ 5800rpm 222.0 @ 4400
Potiac Firebird Trans Am 305 @ 5200 335 @ 4000
292.8 @ 5400 307.5 @ 4400
Chevrolet Corvette 345 @ 5600 350 @ 4400
285.6 @ 5400 301.2 @ 4100
Dodge Neon R/T 150 @ 6500 133 @ 5500
117.1 @ 6000 110.9 @ 2800
Dakota Club Cab R/T 250 @ 4400 345 @ 3200
191.7 @ 4500 252.2 @ 3300
Dodge Viper GTS 450 @ 5200 490 @ 3700
406.7 @ 5300 445.1 @ 4200
1997 Ford Mustang GT 215 @ 4750 290 @ 3500
180.9 @ 4200 250.6 @ 3400
Ford SVT Mustang Cobra 305 @ 5800 300 @ 4800
256.6 @ 5800 260.3 @ 4200
Pontiac Grand Prix GTP 240 @ 5200 280 @ 3200
197.2 @ 5600 262.8 @ 2900
Please note two things. First of all the 'Vette made less power than teh
Trans Am. Also, for some reason, trucks usually always have less power on
a chassis dyno than a similarly horse powered car. Why, I don't know. 20%
is the average loss for any vehicle on a chassis dyno. Maybe the Trans Am
is a ringer?!?!
Brian
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:09:09 EDT