2 questions for the experts here - turbo smart people
06-27-2003, 07:31 AM
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2 questions for the experts here - turbo smart people
well the first one is a stupid question but I'm feeling retarded. If a 250HP car makes 205 on a dyno what is the drive train loss? I did 205/250 and got .82. Isn't that 18 percent?
now the real question. I was thinking about this and maybe it's a dumb question but I really do want to understand more about these cars. A lot of people say a turbo is good for X amount of HP. People seem to say the K04's are good for 460-470 crank HP. Now why is that?
Why does a turbo give you such a solid limit on HP? I ask because I always thought boost was just one factor in the car going along with timing, air to fuel and some other stuff. Now say a k04 car is making 465 on 100 octane...(just a made up number) and this car can run without 02 censors and the driver through's in 118 octane and cranks the timing way up. Could he not get 15 more hp (or whatever gain)? Is the turbo going to limit this?
Also if someone hits the car with a shot of NO they are basically cooling the crap out of the intake air right? Is that how it works? The car gains a ton of power but the turbos havent' done any thing different have them? I'm only using NOS because it's just one way I can see of a power gain. Any thoughts would be much appreciated and informative. I guess basically the question is, what limits a car's power based on what turbo a turbo has?
and sorry about the stupid math question but help me out here
now the real question. I was thinking about this and maybe it's a dumb question but I really do want to understand more about these cars. A lot of people say a turbo is good for X amount of HP. People seem to say the K04's are good for 460-470 crank HP. Now why is that?
Why does a turbo give you such a solid limit on HP? I ask because I always thought boost was just one factor in the car going along with timing, air to fuel and some other stuff. Now say a k04 car is making 465 on 100 octane...(just a made up number) and this car can run without 02 censors and the driver through's in 118 octane and cranks the timing way up. Could he not get 15 more hp (or whatever gain)? Is the turbo going to limit this?
Also if someone hits the car with a shot of NO they are basically cooling the crap out of the intake air right? Is that how it works? The car gains a ton of power but the turbos havent' done any thing different have them? I'm only using NOS because it's just one way I can see of a power gain. Any thoughts would be much appreciated and informative. I guess basically the question is, what limits a car's power based on what turbo a turbo has?
and sorry about the stupid math question but help me out here
06-27-2003, 07:40 AM
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There is an optimum air/fuel mixture. If a turbo can blow a certain amount of air, given the a/f
ration, you can calculate how much power can potentially be made (tons of variables effect this of course).
06-27-2003, 07:41 AM
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Dyno loss is not a percentage, and turbos can only flow a certain CFM
I think the rule is 1.5cfm = 1hp
Another rule is that whatever fuel injectors flow at 3.0 bar in cc's = amount of hp they can support. (360cc@3.0 bar = 360HP)
K04's just can't supply enough air to get to 500HP on their own.
Read maximum boost by Corky Bell.
Another rule is that whatever fuel injectors flow at 3.0 bar in cc's = amount of hp they can support. (360cc@3.0 bar = 360HP)
K04's just can't supply enough air to get to 500HP on their own.
Read maximum boost by Corky Bell.
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06-27-2003, 07:42 AM
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awesome I just wanted to make sure god was wrong last night
<ul><li><a href="https://forums.audiworld.com/s4/msgs/1298116.phtml">https://forums.audiworld.com/s4/msgs/1298116.phtml</a></li></ul>
06-27-2003, 07:43 AM
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Yeah, but it really shouldn't be.
While 18% might hold true for a stock car, it probably isn't the case with a car with a lwfw on a hub dyno. Drivetrain drag is a constant, not a percentage.