speedengineer Posted November 12, 2011 Share Posted November 12, 2011 Here is my suggestion as to what I think is the simplest 'good' way to determine effective horsepower. I did not say it was simple, just the simplest one that would work well. 1) RPM_band = Rev_Limit*0.75 Define an RPM band that is proportional in width to how many rpms an engine drops on a downshift. The width of this band is proportional to the rev limit of the car, and also the difference in gear ratio between gears. Picking a constant, such as 0.75 or some other number prevents it from having to be looked up for each car, different gears, etc. 2) Calculate the average horsepower within this rpm band, with the band located to result in the highest possible average for the particular dyno hp curve (shifted all the way right to the redline for 95% of cars). Is this method a little bit tedious?...Yes. It's certainly not as simple as plucking the peak tq and hp off of a plot. It is, however, actually an accurate way to do what we're trying to accomplish. That said, I doubt something like this would be adopted. It's not exactly complicated, but probably too tedious for what we are looking for. That said, (tq+hp)/2 is not an accurate way to do it, so I vote that either the rules stay as they are, or we do it right. Quote Link to comment Share on other sites More sharing options...
brkntrxn Posted November 12, 2011 Share Posted November 12, 2011 If you guy make the hp:wt calculations as complicated as the SCCA rules, you are going to drive people away. The current hp:wt rule works, why mess with it??? The only thing I ask is to have an AWD dyno in operation if a Two Wheel Drive dyno is in operation at an event. THAT is not fair. Quote Link to comment Share on other sites More sharing options...
sperkins Posted November 12, 2011 Share Posted November 12, 2011 If you guy make the hp:wt calculations as complicated as the SCCA rules, you are going to drive people away. The current hp:wt rule works, why mess with it??? The only thing I ask is to have an AWD dyno in operation if a Two Wheel Drive dyno is in operation at an event. THAT is not fair. EXACTLY! Quote Link to comment Share on other sites More sharing options...
Joshua Posted November 12, 2011 Share Posted November 12, 2011 ...I even agree with you about not going too overboard with a fancy formula. But automatically using a peak torque number is too simplistic however.Just like using a peak wheel horsepower number is too simplistic . For the same power rating would you rather have a peaky engine like in an S2000 or one with a "meatier" powerband like the ones in BMW, Corvette or Mustang? Until we see the secret sauce formulae that are used in the base and re-class rating of cars, it's not that easy to speculate on how to work towards greater equity. Quote Link to comment Share on other sites More sharing options...
wlfpkrcn1 Posted November 12, 2011 Share Posted November 12, 2011 Horsepower sells cars. Torque wins races. You have to take torque into account when classing cars not just HP. You guys in the higher classes with big V8s and monster turbo cars aren't as effected by it as the lower class cars. My NA rotary can make the same HP but will never make the same torque let alone the flat torque curve of a FI Miata in TT/PTD. Quote Link to comment Share on other sites More sharing options...
brkntrxn Posted November 12, 2011 Share Posted November 12, 2011 Horsepower sells cars. Torque wins races. You have to take torque into account when classing cars not just HP. You guys in the higher classes with big V8s and monster turbo cars aren't as effected by it as the lower class cars. My NA rotary can make the same HP but will never make the same torque let alone the flat torque curve of a FI Miata in TT/PTD. We have the same issues in the bigger V8s in the same platform (ie Corvettes). An LS1 makes more torque than horsepower, yet an LS6 usually makes equal horsepower and torque or the opposite. The guy running the LS1 gets to weigh less due to less horsepower AND have more torque. But you know what??? Those are the rules and we always have the freedom of changing cars. -Kevin Quote Link to comment Share on other sites More sharing options...
ILIKETODRIVE Posted November 12, 2011 Share Posted November 12, 2011 Just do like I did when you lack torque: take the +3 for altered gear ratios and get them as close as you can! Quote Link to comment Share on other sites More sharing options...
wlfpkrcn1 Posted November 12, 2011 Share Posted November 12, 2011 I wasn't complaining. Just giving an example as to why torque should be part of the classification procedure Quote Link to comment Share on other sites More sharing options...
speedengineer Posted November 12, 2011 Share Posted November 12, 2011 I wasn't complaining. Just giving an example as to why torque should be part of the classification procedure Wheel torque could be part of the discussion, not engine torque. Torque at the engine does not tell you how fast a car will accelerate because every car has different gear ratios! Torque is not conserved across a gearbox, hp is. This means that high engine speed with little torque at the engine can be CONVERTED to normal output speed with HIGH torque! For example, a rotary engine makes no torque, but revs to the moon. Since it revs so high, it will have larger gear reductions than cars that don't rev as high. Since torque is NOT conserved across a gearbox, engine torque CANNOT be used to determine acceleration rates WHEN COMPARING DIFFERENT CARS with different gearboxes. Horsepower is what you need to use. Now, when people talk about a 'flat torque curve' or 'more torque down low', that is an important aspect to how fast a car can accelerate. However, You can't measure it using the shape of the torque curve for the reasons above, you have to measure it using the shape of the hp curve, aka the 'average' hp available to the driver. Quote Link to comment Share on other sites More sharing options...
wlfpkrcn1 Posted November 12, 2011 Share Posted November 12, 2011 I agree with some of that statement and disagree with other parts. I'm not going to argue it Quote Link to comment Share on other sites More sharing options...
clydesdale Posted November 14, 2011 Share Posted November 14, 2011 ...For example, a rotary engine makes no torque, but revs to the moon. Since it revs so high, it will have larger gear reductions than cars that don't rev as high. ... I wonder if I could get a reclass on my engine swap? Quote Link to comment Share on other sites More sharing options...
King Tut Posted November 15, 2011 Share Posted November 15, 2011 That looks like alot of apex seals that will fail. Quote Link to comment Share on other sites More sharing options...
Varkwso Posted November 15, 2011 Share Posted November 15, 2011 That looks like alot of apex seals that will fail. Sound like a runaway herd of weedwackers... Quote Link to comment Share on other sites More sharing options...
drivinhardz06 Posted November 15, 2011 Share Posted November 15, 2011 Sound like a runaway herd of weedwackers... I'd just ban them Quote Link to comment Share on other sites More sharing options...
jason Posted November 15, 2011 Author Share Posted November 15, 2011 That looks like alot of apex seals that will fail. Sound like a runaway herd of weedwackers... It's like a million corner workers screaming in pain... Quote Link to comment Share on other sites More sharing options...
cucamelsmd15 Posted November 16, 2011 Share Posted November 16, 2011 How does one reclass a rotary that has 700whp and 7wtq? Quote Link to comment Share on other sites More sharing options...
kbrew8991 Posted November 16, 2011 Share Posted November 16, 2011 How does one reclass a rotary that has 700whp and 7wtq? well lets average the torque and horsepower... so 353.5 (what's good for the goose is good for the gander - or we can actually look at the power curve and do what makes sense instead) Quote Link to comment Share on other sites More sharing options...
sperkins Posted November 22, 2011 Share Posted November 22, 2011 Almost a week and no new posts? What gives? Quote Link to comment Share on other sites More sharing options...
kbrew8991 Posted November 22, 2011 Share Posted November 22, 2011 silly season got too silly I guess? Quote Link to comment Share on other sites More sharing options...
jason Posted November 22, 2011 Author Share Posted November 22, 2011 Is it too late to take it all back and just leave everything alone? Quote Link to comment Share on other sites More sharing options...
kbrew8991 Posted November 22, 2011 Share Posted November 22, 2011 I'm ok with small tweaks (and banning Mustangs) Quote Link to comment Share on other sites More sharing options...
sperkins Posted November 22, 2011 Share Posted November 22, 2011 Is it too late to take it all back and just leave everything alone? I agree. Quote Link to comment Share on other sites More sharing options...
Varkwso Posted November 22, 2011 Share Posted November 22, 2011 I'm ok with small tweaks (and banning Mustangs) As much as I hate to admit to agreeing with anything from Ken - I agree.. Quote Link to comment Share on other sites More sharing options...
drivinhardz06 Posted November 22, 2011 Share Posted November 22, 2011 I don't really care what the rules change to, but any tire changes would be nice before the Dec 15 Hoosier Cut-off. Quote Link to comment Share on other sites More sharing options...
obzezzed350 Posted November 22, 2011 Share Posted November 22, 2011 I propose that MR2s must give up 50% of their peak TORQZ Quote Link to comment Share on other sites More sharing options...
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