hemmings muscle machine in oct 2005 had a math section and the formula that is used for figuring hp does not say if it is wheel or flywheel but the formula is as follows : hp=total vehicle weight x (mph + 234)3,the 3 is to the third power(my egghead daughter had to help me figure mine).i believe it is going to be flywheel do to i am pretty close to the figures my engine shop said i would be at for flywheel
Being as the calculation is how fast a mass is accelerated in a set distance it cannot be flywheel. To truly get flywheel all of the losses in the driveline up to the flywheel as well as the parasitic losses off the engine would have to be calculated. Thats a boat load of calculations. In other words, this calculation does not know... and cannot know if you have a 12 bolt rear, 9" rear, brakes dragging or not, u-joint losses due to pinion angle, transmission losses due to proper/improper build, water pump losses, bla bla bla yada yada yada on and on...... Mass, distance, velocity. Rear wheel...Not flywheel. As far as dyno numbers not jiving, unless the dyno is calibrated using N.I.S.T. tracable standards...the dyno is suspect. Example, our Chassis dyno here at work had "dyno cal" where the dyno alone ran a series of runs and calculated losses for calibration. Great, however, if the torque cell supplying the input is not calibrated to known standards the losses are off....so the "dyno cal" is off. We instituted a dead weight cal of the torque cell so we had a known output.
True in theory. However, I've researched the origin of these horsepower equations you see floating around. I did this because I found it hard to believe that all the factors necessary to calculate even rear-wheel horsepower (let alone flywheel) could condense down into such a nice neat equation. Turns out these equations (there's several of them out there) are based on empirical results. That is, they plot a whole bunch of measured ETs and MPHs vs the known peak flywheel horsepower for those cars, then curve-fit and develop an equation that approximates the curve. Of course, this approach cannot possibly be accurate with any certainty for any given car. The known flywheel horsepowers used to develop the equations were almost certainly peak horsepower at one RPM -- and we all know that the area under the curve over a broad range of RPMs is more important. The average (read: constant) rear-wheel horsepower necessary to accelerate a known mass to a known velocity in a known time is actually quite easy to calculate. It's also quite a bit lower than the peak horsepower of the typical engine which would produce such an average horsepower.
F=Ma (Did I spell that right?) That's all I have to say on the subject. Rest is blah, blah, blah....... None of our cars are as fast or have the hp of any car (that's too nice to race) at any cruise or car show on any specific night anywhere on this planet. Merry Christmas, all. :moonu:
Hp If it is flywheel HP that would make my numbers line up decently between the dyno on my RA IV but not with the HO. I had my 340+6 only on a chassis dyno and it made upper 280's to the rear wheels but made 323 by Dan's estimates when we cert'd in '04. This would equate to 11% change for drivetrain losses. It never seems to work perfectly for my cars consistantly. Plus the dyno's also leave me wondering about their consistancey with adjusting to weather conditions. It seems when we dyno in the winter and the dyno is correcting for the weather we always come out with better numbers than the summer sessions. Even when the raw uncorrected numbers for the same motor are similar from season to season yet the final numbers vary a lot. Mark
Hemi vs. Stage 1 Time to kick this dog again... John as we were speaking about this race with 100% original, PS cars and Fast cars to compete in an uprated version of the old MCR race. I was assuming we would use 2 cars in each class to keep it from being cumbersome to the rest of the event. You had offered the Buick Indy HP Nats as a venue, and I have talked with Dan and he would also be willing to host it at the PS race at Staten this Fall. Likely we would have a decent portion of the cars/racers already at Staten but I would not want to stomp on your generous offer to let us come to your venue. What I am trying to find out is if the 6 people that we narrow it down to would have it easier attending at one location or the other. Why I am trying to narrow the items down is Steve Statam at Muscle Car Enth. has expressed a deep desire to cover this event as a feature article in the Magazine. He would do pre-advertising for it to amp the race and magazine article. I would write the article and Dan Jensen has also offered to pitch in. With this in mind I was hoping to see if we could lock down six participants and the location if there is still interest. I figured you and I have accepted and Lynden Hughes has shown interest through Dan and Bob Boden to also do the 100% stock class if it would make it easier on you to not have to convert your car back. Lynden is pushing forward with his project and would have an easier time meeting a fall dead line it sounds like. Everyone who is interested in this if you could respond so John or I could get a feel if it is viable I would greatly appreciate it. I see people like Dave Hemiker (PS GS), Dave Dudek (FAST Hemi), GTX Joel (FAST Hemi), Bob K. (PS Hemi), Greg G. (FAST GS), you, Lynden and myself as the possible 100% Factory cars as prime canidates if they/we are interested. I am open to either venue. Us Hemi guys going into Buick's Indy Lion's pit or nuetral ground at Stanton. I hope we can make this work John as it is undeniably an interesting race. Mark
Virgin Stock Mark -- I can make either event. From Indy's perspective, George Mattar from Hemmings Muscle Machines is extremely interested in covering the event and is planning on coming to Indy to cover it and help promote it in his magazine. And, Horsepower TV is planning on Indy as well. My Classic Car is planning Indy the last I knew as well. Maybe not "neutral" ground as you say but perhaps a better location logistically. Dan has offered to come to Indy and tech the cars. I have also put the word out to the "new" cars like the Hemi Charger camp to bring some of their cars to compare "old vs. new" under Virgin Stock. Maybe we can get a Viper and Z06 too, which although they are Virgin Stock, they would more closely fit "Stock Appearing" class as they have already had all stops pulled out by the factory. From here, it looks like Indy would be the place since it is already in motion, but maybe we could also have a Virgin Stock race at Stanton with some different cars and faces. Thoughts and opinions? JKC
Indy looks good to me then. With all the wheels rolling we should have something special. We need to wrap up who will be doing the racing. Dan and Bob both have offered to come down and tech. I will have to get the car sent down from Port Washington WI for the race. I will get that put together. I will not have time to do so before the race and they need the car for the Senior class at the Mopar Nats in August and some other scheduled shows before the race. Finally I will get to use this car, I drove it once for a mile or so with my daughter. It will be good to have it doing what they should do. Mark
Indy! Now, as you say, Mark, we need to figure out who ELSE is coming! Need some stock appearing and some F.A.S.T. cars. Not just Hemi vs Stage 1 either. Where's the SCJs, LS6s, RA4s 440-6, W30s, etc? Excellent chance to get your car featured on TV or in magazines! JKC
To get the kind of magazine and TV coverage that is apparently going to be present at Indy anyway hopefully will be a supervening consideration over the choice of venue. It would be hard to beat Indy as a facility notwithstanding the fact that it was booked originally for a Buick event.
shootout Patrick, I think this needs to be clarified. I have been working with Hemmings for several months now on putting together a shootout for all. Dave D. then suggested the Stage 1 vs. Hemi race again and I offered Indy as the place of venue. It really makes no difference to me where it is held and if there are additional cars invoved but thought that Indy was a possibility. If Hot Rod desires a separate shoot-out, that's fine too. I don't think other make cars involved will dilute this race -- I think it would still be the main attraction. Ultimately it is up to Hot Rod and the participants when and where. Options are good. JKC
Half, if not more, of the proposed cars will be at The F.A.S.T. and Factory Stock race at Matin June 16th and 17th. How about doing it there?
Location I talked with Dan, John C., and Dave Dudek last night. The location for the Hemi vs. S1 shootout will be at Stanton. Dave Hemker I was going to call you this week to discuss it with you. Cars proposed at this piont: Virgin Stk: Lynden Hughes S1/Mark Weymouth Hemi PS: I would like to see Dave Hemker S1, and you sound willing/Bob K. Hemi if he is willing. FAST: I need further discussions with Dan and the FAST guys. This may clear a few items up. Anyone who has interest please let myself or Dan Jensen know. We plan to have two cars per shotout (one of each brand). Your car if you participate will be covered in a feature article for MCE on the shotout. Mark
Stanton? So this final shoot-out is going to happen during the weekend of the Pure Stock Drags? Which day? Qualifying day, or is there going to be time to squeeze it in at some point before/during/after the regular 2/3 shootout's? o No:
Time? Dan has not confirmed when but I would forsee it at the end of the race day, or between our race day rounds. Donny, Dan and I are working on something that I have your car specifically in mind for along with a few friends to make it more fun for you. It would be the following year :TU: Hold on one more year and you could have some extra fun yourself, without being on the sidelines. Mark
