I GOT SPANKED!
Oct 7, 2005 | 10:34 AM
#92
Trailblazer
Joined: Jun 2003
Posts: 31
Likes: 0
I GOT SPANKED!
Hi Freez, here is a Dyno run you asked for. This is a 10.8:1 730 with our trail cams and race porting with 36mm carbs.
This is not the best HP we have seen with our 730's but it's the best one I have scanned right now. We can export Dyno runs directly from the software, you wouldn't be able to see it, so we have to print the sheet and then scan it to e mail/post.
Whoops, I don't see how to post it here, I can E mail it to you if you want.
Thanks,
Ray
This is not the best HP we have seen with our 730's but it's the best one I have scanned right now. We can export Dyno runs directly from the software, you wouldn't be able to see it, so we have to print the sheet and then scan it to e mail/post.
Whoops, I don't see how to post it here, I can E mail it to you if you want.
Thanks,
Ray
Oct 7, 2005 | 05:28 PM
#95
Extreme Pro Rider
Joined: Oct 2002
Posts: 4,433
Likes: 0
I GOT SPANKED!
try not to argue too much. freez is pretty much right.
i was actually thinking the same thing as he was.
although, like another fella said. you can do some real facinating things with dyno software.
i was actually thinking the same thing as he was.
although, like another fella said. you can do some real facinating things with dyno software.
Oct 7, 2005 | 05:44 PM
#96
Thread Starter
|
Pro Rider
Joined: Feb 2003
Posts: 1,218
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I GOT SPANKED!
I don't think that we're arguing with his math. I think that we're all aware that Dyno's are only tools to measure from point A to point B (if you are using the same dyno of course). I think that the quagmyer here is that he feels that certain things are impossible, and that no matter what anyone says, if it doesn't fit into his formula than they are wrong.
Remember when you were in Kindergarden and they told you that there is no such thing as "Always" or "Never". I think that this is one of those cases.
Remember when you were in Kindergarden and they told you that there is no such thing as "Always" or "Never". I think that this is one of those cases.
Oct 8, 2005 | 05:54 PM
#99
Pro Rider
Joined: Aug 2003
Posts: 391
Likes: 0
I GOT SPANKED!
Guys, let me explain something, since people are getting the wrong picture.
What I said was that the math tells me, that making 100HP at 7500 RPM with 12:1 compression and a 730cc motor, is not possible. Not the RPM, Size of the motor and compression.
The reason for this is that we work with a lot of constants. Yu need 3 things in a motor to make power. 1, fuel, 2, Oxygen and 3, spark.
Air is more or less constant with only 21% oxygen. The fuel to, since normal and racing fuel based on normal gas only burns at a certain rate and spark, as long as it is a good spark, the motor will run. So how do you use these basic elements to make more power.
1 is easy, make the engine capacity real big, and 2 make the motor spin faster, to move more air thru it, basically up the RPM. Let’s forget about turbos and so on.
So, the math is accurate, since the 3 basic elements hardly change. Engine compression makes a big difference in how the power potential from the fuel is “harvested”.
So, when you start out you set yourself a goal, let’s assume 100HP, and you have a 700cc stock motor to start with. The aim is to make each and every cc work for you, meaning you aim for a VE value of 100% or higher. So you do the math and you see you will need around 14 000 RPM to make 100HP with a stock KFX700 motor.
Doing that is very difficult, since the motor is not designed to do it. So, the other option is to make it bigger, add more compression and with 12:1 compression, 730cc and 9000 RPM and it will make 100HP, if you have been able to make the head flow perfectly and VE can get to 110%.
It takes real skill and lots of experience to do that, so to get 91HP at 8800 RPM with a 730cc 12:1 compression motor will give you a VE of 104%. The motor is flowing great.
You can also use the VE math to check if you are on track or the dyno figures are right. If you get VE values of around 90% or lower, you know there is more power there, waiting for you., If you get VE values of around 120%, then the dyno is wrong, or someone is not telling the truth.
So, now that we have the right figures, great work. Keep it up.
What I said was that the math tells me, that making 100HP at 7500 RPM with 12:1 compression and a 730cc motor, is not possible. Not the RPM, Size of the motor and compression.
The reason for this is that we work with a lot of constants. Yu need 3 things in a motor to make power. 1, fuel, 2, Oxygen and 3, spark.
Air is more or less constant with only 21% oxygen. The fuel to, since normal and racing fuel based on normal gas only burns at a certain rate and spark, as long as it is a good spark, the motor will run. So how do you use these basic elements to make more power.
1 is easy, make the engine capacity real big, and 2 make the motor spin faster, to move more air thru it, basically up the RPM. Let’s forget about turbos and so on.
So, the math is accurate, since the 3 basic elements hardly change. Engine compression makes a big difference in how the power potential from the fuel is “harvested”.
So, when you start out you set yourself a goal, let’s assume 100HP, and you have a 700cc stock motor to start with. The aim is to make each and every cc work for you, meaning you aim for a VE value of 100% or higher. So you do the math and you see you will need around 14 000 RPM to make 100HP with a stock KFX700 motor.
Doing that is very difficult, since the motor is not designed to do it. So, the other option is to make it bigger, add more compression and with 12:1 compression, 730cc and 9000 RPM and it will make 100HP, if you have been able to make the head flow perfectly and VE can get to 110%.
It takes real skill and lots of experience to do that, so to get 91HP at 8800 RPM with a 730cc 12:1 compression motor will give you a VE of 104%. The motor is flowing great.
You can also use the VE math to check if you are on track or the dyno figures are right. If you get VE values of around 90% or lower, you know there is more power there, waiting for you., If you get VE values of around 120%, then the dyno is wrong, or someone is not telling the truth.
So, now that we have the right figures, great work. Keep it up.
Oct 8, 2005 | 07:31 PM
#100
Extreme Pro Rider
GOT BOOST!
GOT BOOST!
Joined: Jan 2004
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I GOT SPANKED!
As usual, good post Freez. A very good explanation of why you can get only so much power out of a given engine at a given RPM. I may still need those intake spec's for my race 2 liter. The driver and I had a falling out over the car. I told him that I will not tell him how to drive if he does not tell me how to tune (he wanted to do both). Having a meeting tomorrow to see if we can work something out. I will give you the port length and size when/if the time comes.
PS, one thing that will skew the figures on math software is the type of fuel. As I'm sure you know, even gasoline with small amounts of an oxidizer will bump the HP. I'm sure some of these engine guys that are having HP wars are using every trick in the book. I know I would!!!
PS, one thing that will skew the figures on math software is the type of fuel. As I'm sure you know, even gasoline with small amounts of an oxidizer will bump the HP. I'm sure some of these engine guys that are having HP wars are using every trick in the book. I know I would!!!
