xfi 292
04-26-2010, 03:05 PM
#44
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Answer my question.
Once you post your support for 'dead wrong' I will explain where my numbers come from. I have an idea what you will say and I want to make sure you lock down to your rational before I show the method.
Since you stated 'dead wrong' and suggested it came from my *** you must have a method for determining the 'correct' number.
So please explain your method.
Once you post your support for 'dead wrong' I will explain where my numbers come from. I have an idea what you will say and I want to make sure you lock down to your rational before I show the method.
Since you stated 'dead wrong' and suggested it came from my *** you must have a method for determining the 'correct' number.
So please explain your method.
04-26-2010, 03:09 PM
#45
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You can't just take an ET and weight to determine the amount of power needed. There are tons of other factors such as traction, transmission, gear, aerodynamics, weather, etc...
You said "if the race weight is 3650 it takes 328 rwhp to go 13.0". RWHP numbers are pretty much worthless since dynos can be manipulated to say whatever you want them to. Also a manual car is always going to dyno higher than an automatic car.
So I am curious, how much power should I have to be running the numbers I am?
You said "if the race weight is 3650 it takes 328 rwhp to go 13.0". RWHP numbers are pretty much worthless since dynos can be manipulated to say whatever you want them to. Also a manual car is always going to dyno higher than an automatic car.
So I am curious, how much power should I have to be running the numbers I am?
04-26-2010, 03:21 PM
#46
Many people have asked for what is in your set-up and for dyno graphs, but you just keep complaining that nobody will help you. Nobody here can help you without the information they need to be able to diagnose a problem. Saying you have ported heads tells us nothing, that cam is very big, my cc306 pulls to 6700 rpm or so, has been doing it since it had 50 miles on the rebuild. And the 306 is quite a bit smaller than the xfi292. You are going to have to pull rpms, or your car is going to be a turd.
04-26-2010, 04:52 PM
#52
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Ok start by reading this site: http://www.stealth316.com/2-calc-hp-et-mph.htm
When you read the linked page you will begin to understand the efforts on these calculations that began in the 1950’s and continue today. The calculators use various methods to correlate the data and determine the horsepower, mph given the weight and one of the other 2 parameters.
It is strange how people can accept a number from a dyno as gospel, but those same people think this method is wrong.
Dyno’s and calculators are TOOLS that allow comparisons, there are no absolute values that can be measured or calculated. Meaning you might have a higher Hp on a dyno, but go slower than an identical car with lower hp.
There are many reasons: the variations of the dyno, the torque convertor, the dyno operator, gearing, transmission type, differential, etc.
There isn’t one number that is right, just many tools that allow you to measure a value and make predictions. Like when someone says stupid things we often say he is just a dumbass but do we really know for sure?
Good luck
When you read the linked page you will begin to understand the efforts on these calculations that began in the 1950’s and continue today. The calculators use various methods to correlate the data and determine the horsepower, mph given the weight and one of the other 2 parameters.
It is strange how people can accept a number from a dyno as gospel, but those same people think this method is wrong.
Dyno’s and calculators are TOOLS that allow comparisons, there are no absolute values that can be measured or calculated. Meaning you might have a higher Hp on a dyno, but go slower than an identical car with lower hp.
There are many reasons: the variations of the dyno, the torque convertor, the dyno operator, gearing, transmission type, differential, etc.
There isn’t one number that is right, just many tools that allow you to measure a value and make predictions. Like when someone says stupid things we often say he is just a dumbass but do we really know for sure?
Good luck
04-26-2010, 04:53 PM
#53
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You can't just take an ET and weight to determine the amount of power needed. There are tons of other factors such as traction, transmission, gear, aerodynamics, weather, etc...
You said "if the race weight is 3650 it takes 328 rwhp to go 13.0".
RWHP numbers are pretty much worthless since dynos can be manipulated to say whatever you want them to. Also a manual car is always going to dyno higher than an automatic car.
So I am curious, how much power should I have to be running the numbers I am?
You said "if the race weight is 3650 it takes 328 rwhp to go 13.0".
RWHP numbers are pretty much worthless since dynos can be manipulated to say whatever you want them to. Also a manual car is always going to dyno higher than an automatic car.
So I am curious, how much power should I have to be running the numbers I am?
To go that ET you MUST have at least the HP stated, you can have more, but you can not have less! If you had more hp it would mean your setup is not ideal. Wrong gears, body flex, wrong shift rpm, etc.
My calculator in fact takes into account the type of transmission. HOW?
Well automatics traditionally have more parasitic loses and the hp is considered to be .8 while a standard is considered to be .85 of flywheel hp. IF you read you will find these values are the commonly used values.
My method is based on empircal data, and uses a scientific methodology and I provided a link with references, you by contrast have not justified your statement.
I think it is obvious how well thought out your statements are. So read the link and learn, and give your head some fresh air occasionally.
I am at work and the application is not on my work PC. So you will need to calculate your own hp, it is time you did some mental exercise before it all turns to slush.
Good luck
04-26-2010, 04:53 PM
#54
I have an XFI280 and its pulling like a ************ up to and past 6500rpm, the XFI292 is considerably larger, basically what i'm trying to say is since you were only turning 5800 rpm's. I'm a little surprised you didn't make LESS hp.
Get yourself a custom grind cam (or at least something that doesnt have .600 lift) and a good set of heads and you'll be happy.
This point was brought up on the first page, just FYI. Maybe you should quit complaining about the lack of help and learn to read your own post.
P.S-please please please don't ever base your cam knowledge off what you read from CC's website. All they want is for you to buy the cam, remember that.
Get yourself a custom grind cam (or at least something that doesnt have .600 lift) and a good set of heads and you'll be happy.
This point was brought up on the first page, just FYI. Maybe you should quit complaining about the lack of help and learn to read your own post.
P.S-please please please don't ever base your cam knowledge off what you read from CC's website. All they want is for you to buy the cam, remember that.
04-26-2010, 05:04 PM
#55
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Well I can prove you wrong with one car. My car dynoed 330rwhp and has run 11.941 @ 112.98. All of the calculators on that site say that I need more horsepower in order to run that ET.
It is one thing to equate horsepower with MPH in the 1/4 but to try and say that a certain amount of power will run a certain ET is retarded when you don't take into effect how the car is setup.
Look at some of the NHRA/IHRA Stock Eliminator cars. They dyno in the high 300's at best and still run in the 10's.
I stick by my original statement that you are dead wrong when saying that "you have to make at least 328hp to run 13.0 @ 3650 lbs"
All I'm trying to say is that calculators are just tools and guesses. You can't make black and white statements like you did based off a calculator.
Last edited by buzz12586; 04-26-2010 at 05:14 PM.
04-26-2010, 05:17 PM
#56
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I gave you the benefit of the doubt before, but you ARE an IDIOT!
Now you want to use what even you said is WORTHLESS as proof my calculator is wrong.
WTF it is obvious you can’t admit you're wrong. NO one will believe what you say if you continue to show only ignorance and the inability to say you made a mistake.
GO AWAY I don’t play with ignorant people and you are definitely the Villiage idiot! I won’t respond to someone who ignores his own words!
WTF it is obvious you can’t admit you're wrong. NO one will believe what you say if you continue to show only ignorance and the inability to say you made a mistake.
GO AWAY I don’t play with ignorant people and you are definitely the Villiage idiot! I won’t respond to someone who ignores his own words!
04-26-2010, 05:20 PM
#57
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The dyno numbers and track results don't mean much to me because A. dyno #'s can vary all over the place, and B. You had no traction and you didn't turn the engine to it's needed peak RPM much less past it.
However, the HP peak RPM's from the dyno do seem very low for that camshaft and 383".....so I would say that definately points to a valvetrain issue. Even if the heads were stock, it should still peak at higher RPM than that. If heads choked engines to such low RPM's then you wouldn't see Stock/Super Stock class racers turning their engines to extreme RPM's with unported cylinder heads. (Yes I know they spend a lifetime blueprinting!)
I don't think you, me, or anyone on here should even consider your track results as a reference of your engine's power until you first get it to hook up either completely, or at least only light spin at launch and chirps on gear changes....and secondly...until you turn it up higher before shifting. (If your valvetrain is capable as someone else mentioned.)
I can completely understand your reserve as far as twisting on what is not only your DD, but also a car that has alot of sentimental value to you. I just don't think you are going to get the results you are looking for with such a large cam if you aren't willing to rev it up where it works.
I'd save up for a smaller grind if for no other reason, but your wanting to not lean on it too hard. In the meantime, I'd listen to the reply that said to try your best to use what you have. Alot of us aren't made of money, so when we get a combination that isn't optimum, we have to just make do.
Hope you stick around this forum, and keep us updated. If nothing else, your skin will thicken up some.
However, the HP peak RPM's from the dyno do seem very low for that camshaft and 383".....so I would say that definately points to a valvetrain issue. Even if the heads were stock, it should still peak at higher RPM than that. If heads choked engines to such low RPM's then you wouldn't see Stock/Super Stock class racers turning their engines to extreme RPM's with unported cylinder heads. (Yes I know they spend a lifetime blueprinting!)
I don't think you, me, or anyone on here should even consider your track results as a reference of your engine's power until you first get it to hook up either completely, or at least only light spin at launch and chirps on gear changes....and secondly...until you turn it up higher before shifting. (If your valvetrain is capable as someone else mentioned.)
I can completely understand your reserve as far as twisting on what is not only your DD, but also a car that has alot of sentimental value to you. I just don't think you are going to get the results you are looking for with such a large cam if you aren't willing to rev it up where it works.
I'd save up for a smaller grind if for no other reason, but your wanting to not lean on it too hard. In the meantime, I'd listen to the reply that said to try your best to use what you have. Alot of us aren't made of money, so when we get a combination that isn't optimum, we have to just make do.
Hope you stick around this forum, and keep us updated. If nothing else, your skin will thicken up some.
04-26-2010, 05:22 PM
#58
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You are the one trying to correspond RWHP to an ET number. It doesn't work like that for the numerous reasons I mentioned. You can run a faster ET with 328hp @ 3650lbs than you are saying. I am done with this discussion.
04-26-2010, 05:24 PM
#59
He is dead wrong. Hey calculator hero, how bout you go actually DO something (ie race your car) instead of being an internet expert and you might be able to teach us something. Until then, STFU.
The only calculators that ate close ate the weight vs trap speed ones. Everyone knows the ET ones are a home because too many factors go into running a good et, with HP being only one.
A buddies car makes 960 HP and ran a mid 11 the only time it went to the track.
Bet that pisses your little calculator off.
PS it trapped 156 on that run...
The only calculators that ate close ate the weight vs trap speed ones. Everyone knows the ET ones are a home because too many factors go into running a good et, with HP being only one.
A buddies car makes 960 HP and ran a mid 11 the only time it went to the track.
Bet that pisses your little calculator off.
PS it trapped 156 on that run...