What's up with HP Calculators?
 

I have this friend who has an 04 GT and it's pretty quick. He's my friend and all, but I think he's a little misled by an online HP calculator.

His mods are: JLT RAI and a Pypes catted X and catback. That's it. He can drive his car, and actually belted out a 13.8 pretty consistently at the track the other day.

He entered his ET with his weight and all the other necessary info, and came up with the number of 310rwhp. I wasn't there when he did this, but he swears everything was correct, and now absolutely refuses to believe that the number is most likely off by...a bit.

I've tried to tell him that there's absolutely no possible way that he's making that much power with cold air and exhaust, and it's getting into a pretty heated debate, almost to the point where he wants to bet me money that he'll put that down if we go to the local dyno. He also thinks that the 260hp that came stock in the 2v is at the tire, not the crank.

My question is what number do you think he's really putting down? And is there something I can reveal to him that's making this number so damn high in the calculator?

RE: What's up with HP Calculators?
 

those calculators are junk. Theres a guy on here named RSW that runs 12.8's with 250rwhp in a full weight car,i bet if you entered his numbers into the calculator it would come up with something close to 400

RE: What's up with HP Calculators?
 

http://www.fastcoolcars.com/hp_calculator.htm


That one is accurate to an extent. It takes into account ET and mph, but again, how fast you shift, 60' times etc will effect those calculators as well. Same power with slicks and quick 60's would mean better ET with the same power, but those calculators can't account for that. Either the calculator your friend used is REALLY generous, or he entered his weight wrong.

RE: What's up with HP Calculators?
 

$10 says he used the GVWR on the door as his weight.

RE: What's up with HP Calculators?
 

LOL, yeah, prolly.

RE: What's up with HP Calculators?
 

That one's a little more accurate from random numbers im throwing at it. He still refuses to believe me, even though I asked him to factor in the that he doesn't shift instantaneously, and he says the car was weighed. Ugh. I'll keep you guys posted on this battle, haha.

RE: What's up with HP Calculators?
 

According to that calculator I make 412 rwhp, I know for a fact that the current set-up only makes 377 rwhp, thats a pretty big differance IMO.

RE: What's up with HP Calculators?
 

i have used the quarter mile calculators and those are pretty accurate, they cant get it down to the hundreth of a second, but it can get pretty close

RE: What's up with HP Calculators?
 

Splitting hairs because of an online calculators is another form of internet racing. Shame on you.

Use it as a guideline and everyone will be happy.

ET is not a good form of measuring horsepower. MPH and weight is. For example. Running a stock Mustang with a crap tire on a slippery track. This can change the ET by about 1 second. 1 second is big in the calculator but did the HP change? NO.

RE: What's up with HP Calculators?
 

Even if you type in stock numbers its off by about 20hp at the crank

RE: What's up with HP Calculators?
 

The big problem is it has no way to take 60' into account. A radical ET change from a better 60' on those calculators throws them way off, even though the power is the same. They seem to be closer when it's on a car with street tires and like low 2.xx 60's maybe. They fun to mess with, and can maybe get you in a ballpark, but in the end all that really matters is what it runs.

RE: What's up with HP Calculators?
 

I did the hp calculator for my dads completely stock Mach 1 and it came out as 378 flywheel hp and 280 rwhp. Seems way generous to me.