Originally Posted by 9Eleven

You don't seem to get it. It's not about who's car is faster, it's about knowledge. Like I said, just post your results and keep your ego in check. Only you feel that people are trying to prove each other wrong or right. As far as I can tell, and others will agree, there's hasn't been anyone on this thread that has been proven wrong or right.

Dude, I'm sorry that you have some self confidence issues. Please grow up. This will be my last reply to you because I feel like I'm having a discussion with a twelve year old. We'll be waiting for your results. Although I have a strange feeling, we'll be waiting a long, long time or more possibly never. Good luck.

Originally Posted by Jean

9Eleven you have the possibility to lock this thread. I think the longer it stays open the more you guys will get entangled and upset at each other, which would be a pity. Would be great if you lock it maybe and wait for data to come from Rickard, who will hopefully post it soon.

everyone.

Originally Posted by Red9

Rickard, I think everyone here understands the intent of your questions-- but the guys that you are having a go at are the wrong people to aim your scepticism at. Being objective-- 9Eleven & KPG have posted real data and urged others to do so. This is all in the search of real factual data for all to see. They ,in particular,have no commercial affiliation and are not pushing a particular line.They have been generous enough to share the results with us.This enriches us all-- with information .

Originally Posted by Red9

Rickard, I think everyone here understands the intent of your questions-- but the guys that you are having a go at are the wrong people to aim your scepticism at. Being objective-- 9Eleven & KPG have posted real data and urged others to do so. This is all in the search of real factual data for all to see. They ,in particular,have no commercial affiliation and are not pushing a particular line.They have been generous enough to share the results with us.This enriches us all-- with information .
By way of contrast - others come along with unsubstantiated( even this thread has had them) for whatever reason and turn it into a chidish- yes it is,no it's not arguement.There has been many US based claims( the "worlds fastest GT2") by those seeking to rationalise their decisions without any great interest in the facts . Clever marketing is no proof of actual performance but it is not just the US based marketeres guilty of this. Blind acceptance of any performance data thet has a direct line to the marketers(US,European or anywhere) needs to be questioned. That is why the results achieved by independants doing their own testing is important. Following that point- it is not reasonable to sit back in your position and rely on the provided data by your chosen "marketer" and then fire of bullets at those that are conducting checks. It is the very reason why the data you can collect becomes very important-- it may well verify the claims made for it -- but let us all see.
Lastly-- let us all avoind the pesonal insults based on anything-- I think everyone here has a strong common interest-- let us stick in that area without seeking to highlight irrelevent potential differences.

Originally Posted by Rickard 993 Turbo

Then ju have missuderstod me, i like KPG alot and i love all the things he do, i have not sad a bad word about the racelogic figures and i think they are very nice and belive them, the only thing i say is wrong is that trapspeed is one way to know the exak hp of a car, this has Jean proved again and again..

Originally Posted by Rickard 993 Turbo

the only thing i say is wrong is that trapspeed is one way to know the exak hp of a car, this has Jean proved again and again..

Originally Posted by Carver

First off, I'm Andrew, the guy who was working with Scott on the formulas.
My education and background is in mechanical engineering, working in the past for Borg-Warner as an ME and currently write financial market algorithms for index mapping software on the side in addition to my day job.
Scott and I were talking about why so many of the calculators out there are wrong. After looking at the data and the formulas, I came to the conclusion that it was an issue of the formulas being written too closely to theory and without adjusting the assumptions by taking enough real world data into account. A simple way to see this is through a graphical analysis of data points.
If you look at the Hale formulas along with the graphical points shown below, you can see that a) the formula is close, but needs slope and curvature adjustments to be more accurate, and b) there aren't enough points from a variety of vehicles to represent the outcome within a reasonable statistical confidence window for most cars.
What I did was include many more data points from multiple vehicles and graph the results next to the Hale equation lines. I then rewrote the algorithms to more closely represent the real world graphical results. These formulas now work well for street vehicles in the 50-1000bhp range. Adjustments to the algorithms would have to be made for pro drag vehicles that can transfer launch energy at a statistically abnormal rate.

Regarding the trap speed vs. e.t. discussion, there are multiple ways to visualize what is happening to make it more clear. And to be fair, both sides are correct for their given questions. The problem is that the specific question in each case is not clearly defined.
Think of the difference as transferred energy to the ground in time (e.t.) and transferred energy over distance (trap speed), which are two very different ideas, as we’ll see. If it weren’t for launch energy transfer and tire capabilities ie. all of the power/energy could be transferred on the launch immediately with consistent accuracy, we wouldn’t be having this discussion as e.t. would be as representative as trap speed. But that’s not the real world.

The force available to accelerate a vehicle from a stop to the first 30-60ft. is mostly based on traction or g-force capability. That’s why a mid-hp car can have similar 60ft. times to a very high-hp car. It’s not a good indicator of hp since the max g loading of street tires is around .5-.6g no matter what you do. In first gear along with a revved engine (significant stored flywheel/crank/piston/rod/pressure plate energy) most cars have the ability to generate .5-.6+ g or break the tires loose for some distance. That’s why as one car may hook better than another, they’re still limited to approx. .5-.6g on the launch….this enables a car that has spun its tires or bogged off the line to essentially re-match the other car’s acceleration and speed, at a given distance within the .5-.6g exceedance zone, very quickly since in the lower gears it’s a traction issue and not a power issue. Notice I said speed at a distance and not speed at a time. The time already left the station, so to speak, the distance didn’t.

And here is where people get the disagreement. The time measurement is a constantly moving reference which is unaffected by the car’s performance. But distance is not ie. as you are slower than another car, you have more relative distance left but not more time left. So if you make a mistake on the launch ie. excessive spin or bog, that time measurement will be permanently changed because time marched on unaffected by your mistake. But your rate of distance coverage was changed and reduced giving you some distance to make up the mistake. And in addition, the distance where the loss took place is approx. 3% of the distance of the race, and a distance where max power could not be transferred due to the .5-.6g tire limit….as a result, speed at a snapshot time ie. 2 sec., with time continuing at the same rate, was affected but speed at a distance past the spin/slip zone, with distance traveled reduced, along with the ability to rematch .6g quickly, had little to no change. If the tire spinning/bog continued much beyond the zone where the car could no longer exceed .5-.6g acceleration, then you would start to see the reduction in trap speed in addition to the increase in e.t. as overall avg. power over distance would start being affected. But since it takes place in this “.5-.6g max zone”, the speed at time is changed but not the speed at distance. This is why e.t. is significantly affected by launch and trap speed isn’t.

Now here is where it all comes together. Both cars weight the same. Car A runs a 1.7 60ft. and turns a 12.2 @ 120mph. Car B runs a 2.0 60ft. and 12.6 @ 120mph…..what happened? Car A got a better launch enabling a .3sec better 60ft., but car B had an extra .3sec at .6g to accelerate up to car A’s speed at the 60 ft. They were both going approx. the same speed after the 60ft., although car A reached that speed in less time, but the same distance, and have the same whp because they accelerated together after that point. Car A was able to transfer more avg. power to the ground over time ie. in 12.2 sec it had traveled farther and reached 120mph quicker but at the same distance as car B (the difference in time being in the launch energy transfer) although car B was still able to reach 120mph in the ¼ mi. distance ie. the same total power transfer with respect to distance showing whp and not transferred whp over time.
So as has been stated before, if you take the .5-.6g launch window out of the equation, and compare cars from say a 3rd. gear roll, you might as well throw away the e.t. too and go by trap speed because the e.t.'s variables are no longer in play.

1-1.2g (.5-.6/tire) and in this case a total of 1.5g of thrust....and the car is still losing traction in second gear. This is what causes e.t. to be launch dependent, or responsible for a time loss, and not responsible for a trap speed loss. Consider for a second the main point that I illuded to but didn't explain well enough in my previous post. Speed curves over distance look like 1/2 parabolic curves ie. they start off steeply vertical and than begin to shallow and converge at an asymptote as distance passes, with speed on the Y axis and distance on the X axis. One more way of saying this is that the whp of a vehicle is most influential to a car's acceleration as speed increases ie. as a greater percentage of the distance of the 1/4mi. elapses, the launch becomes a smaller percentage of the performance, and drag, and as a result whp, becomes the most significant factor. This favors a confluence or matching of trap speed, or speed at a given distance, for a given wt/whp and a lessening of the effect of the launch. This effect continues to build, throughout the run, obviously, since on a percentage basis the launch distance/total distance traveled, is decreasing at an increasing rate as speed increases while time of launch/time of run is decreasing at a fixed rate as time elapse rate is constant. This causes the et differences at the launch to be maintained while the trap differences at a given point or speed at distance tend to merge. That is your key.

Originally Posted by wross996tt

No to nit pick, but you guys are using the wrong word...accuracy deals with the AVERAGE deviation from a known value (like an acceptance standard, e.g., NIST, BSI, TUV...). The measurement system can be accurate and not be able to measure the hp on a vehicle at all. The more interesting question is precision (which deals with the variability of the measurement system e.g., repeatability and reproducibility). Without knowledge of the measurement system's precision (which I have yet to see studied or reported for any dyno or other speed/hp measurement system) most of the claims are just that...claims.

Originally Posted by M-Phibian

Okay...new rule. From now on, no professional Statisticians are allowed to post in this thread.

Originally Posted by wross996tt

OK...sorry, I know you prefer to live in fantasy land where you can make up any numbers you want ...I'll leave now

Originally Posted by M-Phibian

Okay...new rule. From now on, no professional Statisticians are allowed to post in this thread.

Originally Posted by 02 Carrera

Stock 02' GT2 is rated as 456 hp. The 03-04' GT2 increased the rating to 477 hp. They are obviously under rated from the factory (same goes for X50's). ...