I know no one cares/wants to hear/wants to read, etc... but please look at my prices
#24
Originally Posted by Braineack
even if i had a 1.8L i wouldn't go to a .63 myself. the only thing id be giving up is spoolup for possibly a tad more top-end. not worth it. again a 1.8L = 110 CI. 110CI * 7000RPM / 3456 / 14.47 = 15.4 lb/min....still under 17 lb/min.....
7000rpm, for this sake it can stay constant.
3456 our wonderful constant
We can assume temp is constant for this example, but 14.47 will not remain.
In the conversion from volume/time to weight/time we need to account for density. I will not be pushing the limits of the .48 t3 turbine with a stage 3 wheel anytime soon without a nice big compressor attached to it pressurizing my intake stream.
While I appreciate the fact that a 110CID motor theoretically flows 15lb/min @ 7000RPM at sea level at 120F, I think the amount of air I'll be flowing at 7000RPM is going to be mostly dependent on my compressor.
#26
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14.47 is simply converting CFM to Lb./min
it doesn't matter how much airflow is coming into it. your engine can only displace so much airflow. The volume is always the same (97.7 C.I. per every cycle / VE), the poundage varies.
it doesn't matter how much airflow is coming into it. your engine can only displace so much airflow. The volume is always the same (97.7 C.I. per every cycle / VE), the poundage varies.
#28
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then apply the damned Ideal Gas Law and change the multiplier....is still doesn't change the fact that you can only displace so much air, regardless of how much boost. so while i may see 14 lb/min through my exhaust, you may see 12, who the **** cares, what are you arguing again?
so to sum up:
**** ton of boost in the intake = 15 lb/min through the exhaust
no boost in the intake = 15 lb/min through the exhaust
so to sum up:
**** ton of boost in the intake = 15 lb/min through the exhaust
no boost in the intake = 15 lb/min through the exhaust
#29
then apply the damned Ideal Gas Law and change the multiplier....is still doesn't change the fact that you can only displace so much air, regardless of how much boost. so while i may see 14 lb/min through my exhaust, you may see 12, who the **** cares, what are you arguing again?
so to sum up:
**** ton of boost in the intake = 15 lb/min through the exhaust
no boost in the intake = 15 lb/min through the exhaust
so to sum up:
**** ton of boost in the intake = 15 lb/min through the exhaust
no boost in the intake = 15 lb/min through the exhaust
#30
No, you are wrong. One cfm at sea level weighs more than one cfm at altitude. You are converting from volume/time to weight/time. density/volume = mass, mass * gravity = weight.
The miata motor at sea level with 120* air in the intake manifold, based on only it's CID, flows 15lb/min. Once you pressurize that air, it is heavier. You are flowing more dense air through the same volume over time, which results in more corrected CFM or more corrected lb/min.
There is more air.
Arguing about what?? I politely responded to your lame point, made using some fancy mathematics most people probably don't bother to understand, and you called me a moron. Nice. Your point is lame because the airflow of the stock motor at sea level in 120* air is not nearly as relevant to turbine selection as power goals or the compressor. IMO it's not worth a damn to say, "this turbine is OK because during these completely arbitrary conditions you will never encounter that aren't even related to making power (who puts a turbo on and runs atmospheric pressure in the intake manifold?) you will be flowing less air than the turbine is rated to."
What's a t04e 50 trim flow compressor flow? 40lb/min?
The miata motor at sea level with 120* air in the intake manifold, based on only it's CID, flows 15lb/min. Once you pressurize that air, it is heavier. You are flowing more dense air through the same volume over time, which results in more corrected CFM or more corrected lb/min.
There is more air.
Arguing about what?? I politely responded to your lame point, made using some fancy mathematics most people probably don't bother to understand, and you called me a moron. Nice. Your point is lame because the airflow of the stock motor at sea level in 120* air is not nearly as relevant to turbine selection as power goals or the compressor. IMO it's not worth a damn to say, "this turbine is OK because during these completely arbitrary conditions you will never encounter that aren't even related to making power (who puts a turbo on and runs atmospheric pressure in the intake manifold?) you will be flowing less air than the turbine is rated to."
What's a t04e 50 trim flow compressor flow? 40lb/min?
#33
I agree. Personally I think .63 AR turbine is ideal for 250-350 whp. Anymore power than that and you should port it unless you are wanting 500+ and don't care in the least about spool... then go to the .8X AR.
The .48 doesn't seem to breath for **** in the top end and I'm only at 214 whp. I may change my mind on this after the new downpipe and exhaust arrive.
The .48 doesn't seem to breath for **** in the top end and I'm only at 214 whp. I may change my mind on this after the new downpipe and exhaust arrive.
#35
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IMO it's not worth a damn to say, "this turbine is OK because during these completely arbitrary conditions you will never encounter that aren't even related to making power (who puts a turbo on and runs atmospheric pressure in the intake manifold?) you will be flowing less air than the turbine is rated to."
What's a t04e 50 trim flow compressor flow? 40lb/min?
What's a t04e 50 trim flow compressor flow? 40lb/min?
the more pounds of air you move, the more power you will make. pounds = mass. not volume; the volume will always stay the same. you're not increase the displacement of the motor.
you know damn well you can easily factor in your atmospheric conditions and temps, stop being a ******* douche.
#36
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yes, the rods wont hold up. We typically start to thinking about beefing them up at 200-220rwtq.
#37
then apply the damned Ideal Gas Law and change the multiplier....is still doesn't change the fact that you can only displace so much air, regardless of how much boost. so while i may see 14 lb/min through my exhaust, you may see 12, who the **** cares, what are you arguing again?
so to sum up:
**** ton of boost in the intake = 15 lb/min through the exhaust
no boost in the intake = 15 lb/min through the exhaust
so to sum up:
**** ton of boost in the intake = 15 lb/min through the exhaust
no boost in the intake = 15 lb/min through the exhaust
#38
more boost doesn't mean that you'll displace more air. It's a simple equation to determine a good size A/R turbine based on your displacement and airflow volume.
the more pounds of air you move, the more power you will make. pounds = mass. not volume; the volume will always stay the same. you're not increase the displacement of the motor.
you know damn well you can easily factor in your atmospheric conditions and temps, stop being a ******* douche.
the more pounds of air you move, the more power you will make. pounds = mass. not volume; the volume will always stay the same. you're not increase the displacement of the motor.
you know damn well you can easily factor in your atmospheric conditions and temps, stop being a ******* douche.
Why do you keep saying pounds = mass and not volume, clearly I understand that. My first post addresses the relevancy of using a simple cfm -> lb/min conversion to a turbocharged motor.
"You know damn well you can easily factor in your atmospheric conditions and temps, stop being a ******* douche."
Ok, let me try again. I don't think I am explaining myself very well. The conversion you used factors in pressure and temperature, but the pressure you use in your calculations is 0lb. I don't care if the turbine can flow 0lb of boost, I care if it can flow 24lb of boost. An equation to determine ideal turbine size must take into account desired airflow.
#39
lb/min is weight/min; and since we know what gravity is all about we know what is the mass of the air we are using. 15lb/min is 15lb/min always, but 300cfm can be 15lb/min or 30lb/min depending on it's density. A pressurized intake manifold does change the lb/min out of the tailpipe, and will also change the corrected CFM. (corrected for density).