Horsepower/Torque Ratings

[keleko]

yeah, that's what i thought you meant but wasn't sure. it looks like you don't need to add anything to the numbers. we were all doing some calculations and it looks like the numbers that we got is what the cars should be putting out.

well, then what was all that about adding 17%?

seriously, losing 40hp through the driveline is just fuking insane, even for an a/t

 

[YellowMP5]

yes, the guys did mention that supposedly we need to add 17% or so to the number to get to the number that a dynojet would put out. mustang dyno and dynojet use slightly different ways of calculating the HP. supposedly, dynojet ADDS to the HP that it calculates. i have been trying to research this i think i came to conclusion that what mustang dyno puts out is about right. since the two dynos use different tests, it is not a true measure of what your HP is. the best way of course is to dyno the engine but who is gonna go this far unless you are building it from the ground up. calculating HP at the wheels and the resulting loss through the driveline is very hard and not an exact science.

here is one of just numerous articles on the subject http://www.germanmotorcars.com/Dyno_load vs inertia_1.htm

 

[AzMz3]

yes, the guys did mention that supposedly we need to add 17% or so to the number to get to the number that a dynojet would put out. mustang dyno and dynojet use slightly different ways of calculating the HP. supposedly, dynojet ADDS to the HP that it calculates. i have been trying to research this i think i came to conclusion that what mustang dyno puts out is about right. since the two dynos use different tests, it is not a true measure of what your HP is. the best way of course is to dyno the engine but who is gonna go this far unless you are building it from the ground up. calculating HP at the wheels and the resulting loss through the driveline is very hard and not an exact science.

here is one of just numerous articles on the subject http://www.germanmotorcars.com/Dyno_load vs inertia_1.htm

This is not right at all.
Usually Mustang dynos will read lower because the operator has to enter certain values. Dynojets do not add to the HP it calculates!

I don't see why it is even nesseccary to figure your crank hp anyway.

 

[YellowMP5]

crank hp is obviously the exact horsepower your engine is putting out, knowing that is better than knowing wheel hp, imho

 

[keleko]

crank HP is already set

160hp, so sez mazda

??

 

[YellowMP5]

obviously. but what was the point of dynoing the car then? if one dyno puts out one thing and another puts out another then how do you know which one is right. who is to say that dynojet is more "accurate" than the mustang? maybe the mustang is better? dynoing the car in a shop while the car is still and a fan is blowing at the radiator and the hood is open will obviously not give you the correct HP of what your car is putting out.

testing the engine will show what the engine is putting out and then installing the intake on it and testing it again will give you a much better idea of whether you gained or lost hp. as you have yourself witnessed, your second set of runs was inconclusive to find out whether that intake added or subtracted HP. i think a gtech pro will give you a better idea of whether the intake is working or not than the dyno

 

[AzMz3]

obviously. but what was the point of dynoing the car then? if one dyno puts out one thing and another puts out another then how do you know which one is right. who is to say that dynojet is more "accurate" than the mustang? maybe the mustang is better? dynoing the car in a shop while the car is still and a fan is blowing at the radiator and the hood is open will obviously not give you the correct HP of what your car is putting out.

testing the engine will show what the engine is putting out and then installing the intake on it and testing it again will give you a much better idea of whether you gained or lost hp. as you have yourself witnessed, your second set of runs was inconclusive to find out whether that intake added or subtracted HP. i think a gtech pro will give you a better idea of whether the intake is working or not than the dyno

You obviously know nothing about dyno's!
And it really shows from that last statement you made.
If you or anyone is so concerned with crank HP you would be pulling the engine to dyno it then.
(cabpatch)

 

[keleko]

well adding the cai added 4hp and 4lb/ft, accoring to the mustang dyno

so i'll go with that

i'll also go with adding that 17% to make it 140hp too

 

[RHAGEL]

well no kidding sherlock. i was merely trying to get the point across that he will end up wasting money as opposed to trying to confuse anyone with mathematical equations.

there is always a smartass waiting to add their .02......

Hey man, I wasn't trying to be a smartass I was just trying to educate. There are a lot of people out there that have no idea about how to calculate interest. I minored in economics, what can I say?

 

[tsunami]

knew it... 140hp at the wheels in an auto does equal bs... dude i would say you are some where around 130hp or so.... but then again if you dynoed it and you got 116 and the mp3 got 110 i would say that you may have an issue... your defrost wasn't on or ac or something was it? that can subtract power as well...

 

[YellowMP5]

You obviously know nothing about dyno's!
And it really shows from that last statement you made.
If you or anyone is so concerned with crank HP you would be pulling the engine to dyno it then.
(cabpatch)

well, why don't you explain it then if you think you know it all

 

[romecandleboy]

I'm still wondering why certain cars have these 'pzev' ratings....i've noticed the Mazda3, Camry, Accord, etc. have these ratings and others (MX-5 miata, RX-8, don't list them) Does it have to do with production numbers in those relative states -ie) more popular vehicles that sell in higher numbers have to follow these guidelines...?

 

[YellowMP5]

sounds like pzev is partiall zero emmissions vehicle. what that has to do with horsepower?

 

[AzMz3]

And the PZEV have extra emission equipment on them....extra cat, different intake or other changes to the exhaust.

 

[WetsuitxNinja]

I live in CA, my intake doesnt look different from others, and my exhaust sys. has two cats. I am thinking it has something to do with the ECU...

 

[AzMz3]

I live in CA, my intake doesnt look different from others, and my exhaust sys. has two cats. I am thinking it has something to do with the ECU...

Unless your car had the PZEV listing on the dealer sticker, you don't have a PZEV model. And I'm sure on the Mazda3 there is a difference with the exhaust. It is in the Service Hightlights Manual.
I'm sure there are differenecs in the ECU also.

 

[YellowMP5]

It would take a million post just to get you to understand! You might want to search, maybe goto a dyno.

dude, either you can educate people if you think you know better or don't post that people are wrong. i did read on the dynos, and i just came back from a dyno and watched 15 cars get dynoed. have YOU seen 15 cars get dynoed?. i wasn't trying to say gtech is better than dyno. but cai works when the car is moving, when you are dynoing it, it does not. so i was trying to make a point that maybe gtech will show better results than a dyno for a cai since the car is moving.

 

[WetsuitxNinja]

Unless your car had the PZEV listing on the dealer sticker, you don't have a PZEV model. And I'm sure on the Mazda3 there is a difference with the exhaust. It is in the Service Hightlights Manual.
I'm sure there are differenecs in the ECU also.

yeah I definately do have the pzev, 153 hp @ crank according to that paper that is in the window when you buy the car. All I really wanted to relay is exhaust and intake wise it looks*** to be the same.

 

[keleko]

dude, either you can educate people if you think you know better or don't post that people are wrong. i did read on the dynos, and i just came back from a dyno and watched 15 cars get dynoed. have YOU seen 15 cars get dynoed?. i wasn't trying to say gtech is better than dyno. but cai works when the car is moving, when you are dynoing it, it does not. so i was trying to make a point that maybe gtech will show better results than a dyno for a cai since the car is moving.

sez who?

not all of them have air forced over/to them when the car is moving

mine, for example, has NO direct airflow going to it, it draws ambient air from around the filter which is surrounded by the front and side of the bumper cover, the skid plate, and the transmission

 

[YellowMP5]

yes, very true. its not exactly ram air. but the car is still moving compared to it sitting in a bay with a fan blowing upfront and ambient air around the filter.