Originally Posted by SPAZZ
I believe they all use the hp @ the crankshaft because it looks better. shawn
Originally Posted by SPAZZ
I believe they all use the hp @ the crankshaft because it looks better. shawn
1COOLVX
That's right, 215HP at the crank. Virtually no production auto manufacturer quotes wheel horsepower as it always looks better to tout what's at the crank.Originally Posted by psychos2
Over 20 years of Isuzu enjoyment...
I never would have bought the VX with a pathetic engine output rating at crank of 157 . I could have sworn that they advertised that it was at the wheel not at crank of over 200hp.
hmm time to start stripping and swapping or just time to get rid of the VX then if this is true.
The VehiCROSS is rated at 215 crankshaft hp... with slight mods you are putting 157 to the ground. Cool! Now, my VX has the fender intake elbow removed & a PV1 cat-back exhaust system... I wonder what hp I'm getting? Maybe I'll take a trip down there to see.
Or, maybe I'll get my Yamaha V-Max tested. I have heard that this bike is rated at @ 140hp (crank) and @ 90hp to the ground.
They both seem to lose @ 50hp along the way to putting the power to the ground. The VX weighs 3995 lbs. for a power to weight ratio of 18.5... the V-Max (at 624 lbs.) has one of "only" 4.5, but seems much faster than the VX somehow. I'll have to go out & do more seat-of-the-pants testing!
Last edited by nocturnalVX : 08/20/2006 at 10:39 PM
haha of course the v-max is faster.. the lower your power/weight ratio the better
Those are weight to power ratios, not power to weight. So its no surprise that the v-max feels faster, its got 4x more hp per lb than the VX.Originally Posted by nocturnalVX
Sorry guys- hold out one more day for the graph. I went to see Robert at lunch. Luckily its only 2 miles from work. Today he was lunching/chatting with a few enthusiasts and a photographer about a dyno day and some strategic planning about being able to make the dyno available to a few local car clubs and the scheduling time available. All we had time for was chatting about that. He does seem interested in doing some VX stuff- I can sense that he is a little worried about investing dough right now after dropping all of the duckets for the dyno. At the very worst, it may just have to wait a couple of months until he can recoup some of his money. At least we can plan until then. I dont know how deep he wants to go into the R & D side of making stuff, but he has me to design and test, and he owns the other stuff needed.
I called Robert today. I am having pc problems at work, He will be posting this afternoon directly to the site.
Don't fault car manufacturers for their power specs. They don't state the numbers whichever way it "looks better". It ALWAYS "looks better" to state engine output rather than driven-wheels output, but it's also more meaningful, too. Anyway, it's not up to the manufacturer how to do it, it's up to the Society of Automotive Engineers (aka, SAE). That abbreviation probably looks familiar to most people - they also set standards for fuels, oils, hydraulic fluids, etc. It's better to have an independent body of experts set the rules rather than each competing manufacturer doing it differently. SAE defines standard test procedures and conditions, so that each manufacturer's claims can be meaningfully compared.
Can you imagine the mess it would be to understand power output when the same engine was installed in two different cars with different drive trains? They would be rated totally differently in a 2WD vs an AWD car.
Anyway, throwing your car on a Dynometer isn't exactly compliant with the SAE test procedure, and there are dozens of uncontrolled variables, so two runs on two different days will give you two very different graphs, and peak power ratings (at the wheels) that could easily vary +/- 20% for the SAME CAR in the SAME CONFIGURATION, so you have to take that data with a pretty big grain of salt. What is representative of one car on one day is not going to be representative of a different car on another day.
Which is all summarized by my new tag-line...
EVERYTHING is ALWAYS more complicated.
Here is a link to when we had our VX's dyno'd on a 4wheel dyno. With a overlapping dyno scan of mine with the SC and John's without.
http://www.vehicross.info/forums/sho...highlight=Dyno
Last edited by Cyrk : 08/23/2006 at 10:48 AM
Most ALL dyno software in use today is able to normalize conditions so that the calculations are VALID for the same vehicle on different days with different temps and humidity.