Drivetrain Cold air intake and pulley q's????
#1
09-19-2005, 07:27 PM
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Cold air intake and pulley q's????
I have looked up to get a little upgrade for my MCS and thought about a cold air intake and possibly a pulley upgrade. Here are few strange questions. On the cold air intake, it looks like most cold air intakes I have seen seem to quite possible get only hot air as they are not even close to get COLD air from the scoop or anywhere else. So does that upgrade really make sense? And on the pulley, why a smaller or why a larger one? What does each do? And does the pulley change hurt the waterpump?
Cheers,
Herbert
Cheers,
Herbert
#2
09-19-2005, 07:33 PM
#3
09-19-2005, 08:00 PM
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The idea of taking in cooler air to make horsepower is lost in this application. Because we are taking that air and running through a supercharger thus reheating it. The intakes that make horsepower on the MINI are doing so because they are more free flowing. Andy's HAI proved that. 
Smaller supercharger pulley spins supercharger faster.
Larger crank pulley apparently does the same.
You are spinning the waterpump faster, is that hurting it ? Uh, I don't know !
Try doing a search on water pump cavitation. This is one of many threads.
https://www.northamericanmotoring.co...ump+cavitation
Smaller supercharger pulley spins supercharger faster.
Larger crank pulley apparently does the same.
You are spinning the waterpump faster, is that hurting it ? Uh, I don't know !
Try doing a search on water pump cavitation. This is one of many threads.
https://www.northamericanmotoring.co...ump+cavitation
#4
09-19-2005, 08:08 PM
U know!!
U would think that by now "CAI's" would not be marketed for forced induction motors....i might be goin' overboard w/this!?!?
Originally Posted by 400ex
The idea of taking in cooler air to make horsepower is lost in this application. Because we are taking that air and running through a supercharger thus reheating it. The intakes that make horsepower on the MINI are doing so because they are more free flowing. Andy's HAI proved that.
Smaller supercharger pulley spins supercharger faster.
Larger crank pulley apparently does the same.
Smaller supercharger pulley spins supercharger faster.
Larger crank pulley apparently does the same.
#5
09-19-2005, 09:25 PM
While it is true that the supercharger will heat the intake air through compression, it is not true that it doesn't matter what the intake temp is. The air through the s/c can be calculated using this formula:
Temp Rise = Inlet Temp + Inlet Temp multiplied by pressure ratio to the .0263 power -1 all divided by comperssor efficiency
Pressure is absolute pressure (boost plus 14.7 on a standard day) divided by atmospheric pressure. Temp is Rankin scale, roughly add 460 to Fahrenheit I think. Plug in a number less than one for compressor efficiency, and do the math (Andy should like this one!). Let's use 12 psi as our boost, and 80F for the first inlet temp.
So, you take 80F + 460 to get 540R
Outlet temp = 540 + 540[(1.82^.263)-1]/.73
Outlet temp = 540+540(.17)/.73
Outlet temp = 665.7R - 460 = 205.8F
Now let's look at a 100F inlet temp and see what the change is:
100F + 460 = 560R
Outlet temp = 560 + 560[(1.82^.263)-1]/.73
Outlet temp = 560 + 560(.17)/.73
Outlet temp = 690.4R - 460 = 230.4F
What you find is that the inlet temp is even more important on a force induced car than a normally aspirated car. The outlet temp delta (24.6F) was more than the inlet temp delta (only 20F).
The Alta intake takes its air from the cowl area as well as the black ram tube, and uses a heat shield to enclose itself from the hot air of the engine compartment. It also uses silicaon as a tube to the throttle body which is much more heat resistant than the aluminum tubing used on some of the intakes. It is a cold air intake, and on the dyno, makes more than any of the intakes I've tested to date, including the "hot air intake".
Hope that helps!
Randy
Temp Rise = Inlet Temp + Inlet Temp multiplied by pressure ratio to the .0263 power -1 all divided by comperssor efficiency
Pressure is absolute pressure (boost plus 14.7 on a standard day) divided by atmospheric pressure. Temp is Rankin scale, roughly add 460 to Fahrenheit I think. Plug in a number less than one for compressor efficiency, and do the math (Andy should like this one!). Let's use 12 psi as our boost, and 80F for the first inlet temp.
So, you take 80F + 460 to get 540R
Outlet temp = 540 + 540[(1.82^.263)-1]/.73
Outlet temp = 540+540(.17)/.73
Outlet temp = 665.7R - 460 = 205.8F
Now let's look at a 100F inlet temp and see what the change is:
100F + 460 = 560R
Outlet temp = 560 + 560[(1.82^.263)-1]/.73
Outlet temp = 560 + 560(.17)/.73
Outlet temp = 690.4R - 460 = 230.4F
What you find is that the inlet temp is even more important on a force induced car than a normally aspirated car. The outlet temp delta (24.6F) was more than the inlet temp delta (only 20F).
The Alta intake takes its air from the cowl area as well as the black ram tube, and uses a heat shield to enclose itself from the hot air of the engine compartment. It also uses silicaon as a tube to the throttle body which is much more heat resistant than the aluminum tubing used on some of the intakes. It is a cold air intake, and on the dyno, makes more than any of the intakes I've tested to date, including the "hot air intake".
Hope that helps!
Randy
Last edited by RandyBMC; 09-19-2005 at 09:58 PM.
#6
09-19-2005, 09:30 PM
Originally Posted by Moskito
I have looked up to get a little upgrade for my MCS and thought about a cold air intake and possibly a pulley upgrade. Here are few strange questions. On the cold air intake, it looks like most cold air intakes I have seen seem to quite possible get only hot air as they are not even close to get COLD air from the scoop or anywhere else. So does that upgrade really make sense? And on the pulley, why a smaller or why a larger one? What does each do? And does the pulley change hurt the waterpump?
Cheers,
Herbert
Cheers,
Herbert
Webb Motorsports FAQ
And another:
15% Pulley
Hope that helps!
Randy
#7
09-20-2005, 06:22 AM
6th Gear
Randy,
You seem to have forgotten that we have an intercooler. See this thread:
https://www.northamericanmotoring.co...ad.php?t=25654
I measured a 5 degree F difference in air temp inside the filter compared to ambient at 80F on the highway. I doubt the stock even does that well.
Where are your dyno results showing the Alta making more power than the HAI?
You seem to have forgotten that we have an intercooler. See this thread:
https://www.northamericanmotoring.co...ad.php?t=25654
I measured a 5 degree F difference in air temp inside the filter compared to ambient at 80F on the highway. I doubt the stock even does that well.
Where are your dyno results showing the Alta making more power than the HAI?
Originally Posted by RandyBMC
While it is true that the supercharger will heat the intake air through compression, it is not true that it doesn't matter what the intake temp is. The air through the s/c can be calculated using this formula:
Temp Rise = Inlet Temp + Inlet Temp multiplied by pressure ratio to the .0263 power -1 all divided by comperssor efficiency
Pressure is absolute pressure (boost plus 14.7 on a standard day) divided by atmospheric pressure. Temp is Rankin scale, roughly add 460 to Fahrenheit I think. Plug in a number less than one for compressor efficiency, and do the math (Andy should like this one!). Let's use 12 psi as our boost, and 80F for the first inlet temp.
So, you take 80F + 460 to get 540R
Outlet temp = 540 + 540[(1.82^.263)-1]/.73
Outlet temp = 540+540(.17)/.73
Outlet temp = 665.7R - 460 = 205.8F
Now let's look at a 100F inlet temp and see what the change is:
100F + 460 = 560R
Outlet temp = 560 + 560[(1.82^.263)-1]/.73
Outlet temp = 560 + 560(.17)/.73
Outlet temp = 690.4R - 460 = 230.4F
What you find is that the inlet temp is even more important on a force induced car than a normally aspirated car. The outlet temp delta (24.6F) was more than the inlet temp delta (only 20F).
The Alta intake takes its air from the cowl area as well as the black ram tube, and uses a heat shield to enclose itself from the hot air of the engine compartment. It also uses silicaon as a tube to the throttle body which is much more heat resistant than the aluminum tubing used on some of the intakes. It is a cold air intake, and on the dyno, makes more than any of the intakes I've tested to date, including the "hot air intake".
Hope that helps!
Randy
Temp Rise = Inlet Temp + Inlet Temp multiplied by pressure ratio to the .0263 power -1 all divided by comperssor efficiency
Pressure is absolute pressure (boost plus 14.7 on a standard day) divided by atmospheric pressure. Temp is Rankin scale, roughly add 460 to Fahrenheit I think. Plug in a number less than one for compressor efficiency, and do the math (Andy should like this one!). Let's use 12 psi as our boost, and 80F for the first inlet temp.
So, you take 80F + 460 to get 540R
Outlet temp = 540 + 540[(1.82^.263)-1]/.73
Outlet temp = 540+540(.17)/.73
Outlet temp = 665.7R - 460 = 205.8F
Now let's look at a 100F inlet temp and see what the change is:
100F + 460 = 560R
Outlet temp = 560 + 560[(1.82^.263)-1]/.73
Outlet temp = 560 + 560(.17)/.73
Outlet temp = 690.4R - 460 = 230.4F
What you find is that the inlet temp is even more important on a force induced car than a normally aspirated car. The outlet temp delta (24.6F) was more than the inlet temp delta (only 20F).
The Alta intake takes its air from the cowl area as well as the black ram tube, and uses a heat shield to enclose itself from the hot air of the engine compartment. It also uses silicaon as a tube to the throttle body which is much more heat resistant than the aluminum tubing used on some of the intakes. It is a cold air intake, and on the dyno, makes more than any of the intakes I've tested to date, including the "hot air intake".
Hope that helps!
Randy
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#8
09-20-2005, 06:52 AM
After a long day of driving I put my hand into the compartment where my Alta intake is and it is nice and warm, not much above outside temp. I then put my hand in outside of the heat shield in the engine, and it is hot has hell! So I think the better term would really be 'fresh air' intake, or 'ambient air' intake.
- John
- John
#9
09-20-2005, 07:28 AM
sounds much better then "COLD"
Originally Posted by asterix2112
After a long day of driving I put my hand into the compartment where my Alta intake is and it is nice and warm, not much above outside temp. I then put my hand in outside of the heat shield in the engine, and it is hot has hell! So I think the better term would really be 'fresh air' intake, or 'ambient air' intake.
- John
- John
#10
09-20-2005, 07:31 AM
Originally Posted by andy@ross-tech.com
Randy,
You seem to have forgotten that we have an intercooler. See this thread:
https://www.northamericanmotoring.co...ad.php?t=25654
I measured a 5 degree F difference in air temp inside the filter compared to ambient at 80F on the highway. I doubt the stock even does that well.
Where are your dyno results showing the Alta making more power than the HAI?
You seem to have forgotten that we have an intercooler. See this thread:
https://www.northamericanmotoring.co...ad.php?t=25654
I measured a 5 degree F difference in air temp inside the filter compared to ambient at 80F on the highway. I doubt the stock even does that well.
Where are your dyno results showing the Alta making more power than the HAI?
I didn't forget that we had an intercooler Andy. The person, 400ex, was making a point saying that the inlet temp of a force induced car doesn't matter - something widely belived that certainly isn't true.
If your inlet temp to the intercooler is lower, than the outlet temp from the intercooler will be that much lower - again depending on efficiency. My point was that it does matter what the intake temperature is. That won't be intercooler dependent.
I will post those dynos soon. Do you have any comparison dyno runs of the two with the bonnet closed and a fan on the front of the car? It makes sense that the car would make power if you have the bonnet open and are blowing air right on the throttle body....
Randy
#11
09-20-2005, 07:50 AM
6th Gear
Originally Posted by RandyBMC
I will have to get the software and put all of the dyno runs on a disk so you can read them. It is on my list.
I didn't forget that we had an intercooler Andy. The person, 400ex, was making a point saying that the inlet temp of a force induced car doesn't matter - something widely belived that certainly isn't true.
If your inlet temp to the intercooler is lower, than the outlet temp from the intercooler will be that much lower - again depending on efficiency. My point was that it does matter what the intake temperature is. That won't be intercooler dependent.
I didn't forget that we had an intercooler Andy. The person, 400ex, was making a point saying that the inlet temp of a force induced car doesn't matter - something widely belived that certainly isn't true.
If your inlet temp to the intercooler is lower, than the outlet temp from the intercooler will be that much lower - again depending on efficiency. My point was that it does matter what the intake temperature is. That won't be intercooler dependent.
80F air at the filter:
Outlet temp = 205.8F
Difference from ambient = 125.8F
Intercooler outlet temp = 125.8F * (1-0.70) + 80F = 117.7F
100F air at the filte:
Outlet temp = 230.4F
Difference from ambient = 150.4F
Intercooler outlet temp = 150.4F * (1-0.70) + 80F = 125.1F
So, in the two scenarios, the difference in the temp of the air in the filter is 20F yet the difference in the temp of the air leaving the intercooler is only 7.4F. Hence, "cold air" matters more in a system without an intercooler (like a MC) than it does in system with an intercooler (like an MCS)
Originally Posted by RandyBMC
I will post those dynos soon. Do you have any comparison dyno runs of the two with the bonnet closed and a fan on the front of the car? It makes sense that the car would make power if you have the bonnet open and are blowing air right on the throttle body....
Randy
Randy
#12
09-20-2005, 07:54 AM
OK, fair enough, but the point is still valid, no? If you have a colder intake temp, the end result will be a more dense intake charge, intercooler or not.
I'll get the dyno runs up shortly. Anyone else have a dyno run showing an improvement wiht the HAI? I am just curious, not being antagonistic.
Thanks!
Randy
I'll get the dyno runs up shortly. Anyone else have a dyno run showing an improvement wiht the HAI? I am just curious, not being antagonistic.
Thanks!
Randy
#13
09-20-2005, 08:02 AM
6th Gear
Originally Posted by RandyBMC
OK, fair enough, but the point is still valid, no? If you have a colder intake temp, the end result will be a more dense intake charge, intercooler or not.
Originally Posted by RandyBMC
What you find is that the inlet temp is even more important on a force induced car than a normally aspirated car. The outlet temp delta (24.6F) was more than the inlet temp delta (only 20F).
Seriously, you should read the HAI thread. It should explain a lot.
#14
09-20-2005, 08:10 AM
#15
09-20-2005, 08:11 AM
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#16
09-20-2005, 08:15 AM
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You're going to have trouble finding a correlation like that. Not only does IAT affect the number of air molecules being sucked (or blown) into the engine, but it also affects the engine's resistance to detonation. Hotter temps = more likely that the DME will retard timing due to feedback from the knock sensors, and hence, lower power. In general, colder air is better ... as long as everything else is kept the same.
Originally Posted by planeguy
So the real question here is this. Can any one show a direct and calculable corelation between each degree drop in intake temp and increase in whp? Lets see the numbers......or better yet, a formula that is proven by test data.
#17
09-20-2005, 08:16 AM
#18
09-20-2005, 08:57 AM
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It just seems like one ought to know the hp gained by each degree in temp drop before spending money to lower the temp 20F or 7F for that matter.
Every thing has a mathematical relation, even things we cant explain (like Gravity) but we still know their relations, Though extremely complicated, there is a relation. Can any one provide it?
Every thing has a mathematical relation, even things we cant explain (like Gravity) but we still know their relations, Though extremely complicated, there is a relation. Can any one provide it?
#19
09-20-2005, 09:02 AM
6th Gear
Agreed, there is definitely a scientific relationship between IAT and whp in the MCS. I don't think anyone has that relationship written down except possibly an engineer or two at BMW/MINI/Siemens/etc. You could try to figure out that relationship experimentally, but you would need to maintain very tight control over your variables to make sure you are changing one and only one thing at a time.
Originally Posted by planeguy
It just seems like one ought to know the hp gained by each degree in temp drop before spending money to lower the temp 20F or 7F for that matter.
Every thing has a mathematical relation, even things we cant explain (like Gravity) but we still know their relations, Though extremely complicated, there is a relation. Can any one provide it?
Every thing has a mathematical relation, even things we cant explain (like Gravity) but we still know their relations, Though extremely complicated, there is a relation. Can any one provide it?
#20
09-20-2005, 09:09 AM
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Originally Posted by planeguy
... there is a relation. Can any one provide it?
Last edited by flyboy2160; 09-20-2005 at 09:10 AM. Reason: spelling
#21
09-20-2005, 09:30 AM
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#24
09-21-2005, 08:34 AM
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Originally Posted by andy@ross-tech.com
Agreed, there is definitely a scientific relationship between IAT and whp in the MCS. I don't think anyone has that relationship written down except possibly an engineer or two at BMW/MINI/Siemens/etc. You could try to figure out that relationship experimentally, but you would need to maintain very tight control over your variables to make sure you are changing one and only one thing at a time.
..and that the only ones who know the relationship between all the variables and are the BMW engineers.
#25
09-21-2005, 10:31 AM
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Originally Posted by planeguy
You mean the companies who are selling certain aftermarket products making hp claims have not tested thier products maintaing tight control over variables..... ..and that the only ones who know the relationship between all the variables and are the BMW engineers.
..and that the only ones who know the relationship between all the variables and are the BMW engineers.But only to point out that in general, aftermarket products do not have the same amount of engineering and R&D as OEM products (e.g. JCW) do to optimize performance and reliability of our cars.