How to blow a EXPY
Senior Member
Joined: May 2000
Posts: 1,317
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From: Virginia Beach, VA
Crash,
Just curious, what boost levels were you at when you took those readings? As for the ATI, I don't doubt the efficiency at all. One of my friends said a Paxton car with an ATI cooler on a 'Stang was similar. He said after a load down dyno pull the exit pipe of the intercooler was almost as cool as it was before, and could easily be grabbed with bare hands.
Ian,
If you look at the data, the intercooler DID remove more heat at higher temps regardless of which blower was on it. The significant difference is in the intake temps.
To say that efficiency of an intercooler should remain a flat percentage is simply wrong. A water to air cooler is simply a radiator, and just like a radiator is more efficient within certain ranges. If water flow does not increase you will reach a point at which the fluid begins to heat soak, since the cooler will not pull out the heat as efficiently.
Also consider the high temps the intercooler is dealing with. At 10.4 lbs boost out of the Eaton the intercooler inlet temp was 265 degrees. This would work the trucks RADIATOR hard, and is obviously overtaxing the intercooler.
I fully agree that the Eaton has the advantage at lower boost levels, and would likely be more suitable in a truck at these lower levels. At boost rises however it becomes much less efficient. The Eaton is being driven at a higher than recommended speed even at stock boost levels, and this is where the problem IMO comes into the picture. Bumping boost is simply pushing it past its' efficient range.
As for HP required to drive either, I have yet to see any actual data, and both claim to be more efficient. The data that is available shows that the KB compresses air more efficiently, and at a lower rpm. This alone does not indicate an advantage in power required to drive the blower, nor do the differences in blower speeds required to acheive a set boost level. For either to claim an advantage in this aspect is pure speculation IMO. The article states the KB requires less power, but I see no data to back up this claim.
It is easy to claim that the test was cooked, however I have serious doubts that it was. All data including differences in intake temps, etc were displayed. If the test was cooked it would have been simple to delete intake temp data, and also the data that showed the Eaton to have an advantage at lower boost levels.
I personally only considered the data taking the intercooler out of the picture on the KB, since the intercooler does not come with the kit. At a given boost level the KB is cooler without being intercooled.
As I've said before, if anyone has any data to support otherwise I'd be interested to see it. I currently own neither blower, so for me seeing hard facts had no bias attached to it, and no reason to support any speculation from either side of the debate.
Let me also add that the data I have seen HERE indicates that the Magna does not respond well to boost level increases, showing only modest HP gains when bumping boost.
Just curious, what boost levels were you at when you took those readings? As for the ATI, I don't doubt the efficiency at all. One of my friends said a Paxton car with an ATI cooler on a 'Stang was similar. He said after a load down dyno pull the exit pipe of the intercooler was almost as cool as it was before, and could easily be grabbed with bare hands.
Ian,
If you look at the data, the intercooler DID remove more heat at higher temps regardless of which blower was on it. The significant difference is in the intake temps.
To say that efficiency of an intercooler should remain a flat percentage is simply wrong. A water to air cooler is simply a radiator, and just like a radiator is more efficient within certain ranges. If water flow does not increase you will reach a point at which the fluid begins to heat soak, since the cooler will not pull out the heat as efficiently.
Also consider the high temps the intercooler is dealing with. At 10.4 lbs boost out of the Eaton the intercooler inlet temp was 265 degrees. This would work the trucks RADIATOR hard, and is obviously overtaxing the intercooler.
I fully agree that the Eaton has the advantage at lower boost levels, and would likely be more suitable in a truck at these lower levels. At boost rises however it becomes much less efficient. The Eaton is being driven at a higher than recommended speed even at stock boost levels, and this is where the problem IMO comes into the picture. Bumping boost is simply pushing it past its' efficient range.
As for HP required to drive either, I have yet to see any actual data, and both claim to be more efficient. The data that is available shows that the KB compresses air more efficiently, and at a lower rpm. This alone does not indicate an advantage in power required to drive the blower, nor do the differences in blower speeds required to acheive a set boost level. For either to claim an advantage in this aspect is pure speculation IMO. The article states the KB requires less power, but I see no data to back up this claim.
It is easy to claim that the test was cooked, however I have serious doubts that it was. All data including differences in intake temps, etc were displayed. If the test was cooked it would have been simple to delete intake temp data, and also the data that showed the Eaton to have an advantage at lower boost levels.
I personally only considered the data taking the intercooler out of the picture on the KB, since the intercooler does not come with the kit. At a given boost level the KB is cooler without being intercooled.
As I've said before, if anyone has any data to support otherwise I'd be interested to see it. I currently own neither blower, so for me seeing hard facts had no bias attached to it, and no reason to support any speculation from either side of the debate.
Let me also add that the data I have seen HERE indicates that the Magna does not respond well to boost level increases, showing only modest HP gains when bumping boost.
Senior Member
Joined: Feb 2001
Posts: 134
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From: Bozeman,MT, USA
I have a 2000 AWD Expy with the 5.4L and magnaflow catback, and gibson headers. I have the stock KB setup with the FMU and the Boost-a-pump. I love it, it is not a rocket ship but it really was a great addition of power. I bought the KB becuase i was planning on towing a 6000# trailer. I ended getting rid of the trailer and Jeep just after i got the KB installed and i never really got to try it towing.
I live in Buffalo, NY part of the year and bozeman, MT the other part. They are completely different in terms of the way the supercharged expy runs. In Buffalo at the sea-level elevation and 93/94 octane i get about 6.5 psi of boost and my Exhaust gas temps never go over 1400 degrees. It is also much faster. Then in Montana at 4000 feet elevation and 91 octane(ethenol) gas it only sees about 5 psi of boost and it feels slower. My EGT's will go to about 1600 degrees when pulling up a mountain pass. from what i have found, the KB does not need a intercooler to run properly.
I am planning of getting rid of the FMU and boost-a-pump this summer, and going to a bosch/lightning fuel pump and 42# injectors and 90mm MAF. This will really wake things up and it will make me feel much better about how the truck is running. I am installing a air/fuel guage and a fuel pressure gauge this week to see how the FMU and boost-a-pump really are working.
If i was to do it all over again i would still put the ATI behind the KB but i would look much harder at the MagnaCharger. The Magna and KB are very similar in the way they make hp but i think the Magna makes it easier to upgrade, The problem with the KB on the tritons is that if you go over 6 psi by changing pulleys you will need to redo the stock KB intake setup to allow for more air to get in. Doing this costs huge amounts of $$. And youw will also have to figure out how to adapt a intercooler or run a water injection system.
So i am very happy with my purchase and i am glad i choose KB, i would stay away from the ATI at all costs, i think it is the wrong choice for a truck(positive displacement blowers are the way to go on a truck)
Look at the KB and the magna.
I live in Buffalo, NY part of the year and bozeman, MT the other part. They are completely different in terms of the way the supercharged expy runs. In Buffalo at the sea-level elevation and 93/94 octane i get about 6.5 psi of boost and my Exhaust gas temps never go over 1400 degrees. It is also much faster. Then in Montana at 4000 feet elevation and 91 octane(ethenol) gas it only sees about 5 psi of boost and it feels slower. My EGT's will go to about 1600 degrees when pulling up a mountain pass. from what i have found, the KB does not need a intercooler to run properly.
I am planning of getting rid of the FMU and boost-a-pump this summer, and going to a bosch/lightning fuel pump and 42# injectors and 90mm MAF. This will really wake things up and it will make me feel much better about how the truck is running. I am installing a air/fuel guage and a fuel pressure gauge this week to see how the FMU and boost-a-pump really are working.
If i was to do it all over again i would still put the ATI behind the KB but i would look much harder at the MagnaCharger. The Magna and KB are very similar in the way they make hp but i think the Magna makes it easier to upgrade, The problem with the KB on the tritons is that if you go over 6 psi by changing pulleys you will need to redo the stock KB intake setup to allow for more air to get in. Doing this costs huge amounts of $$. And youw will also have to figure out how to adapt a intercooler or run a water injection system.
So i am very happy with my purchase and i am glad i choose KB, i would stay away from the ATI at all costs, i think it is the wrong choice for a truck(positive displacement blowers are the way to go on a truck)
Look at the KB and the magna.
Senior Member
Joined: Feb 2002
Posts: 1,002
Likes: 1
From: Newark,CA
Scott,
When you are ready to upgrade, check out the pricing on the items here-- http://www.got-pressure.com/yabbse/i...y;threadid=379
When you are ready to upgrade, check out the pricing on the items here-- http://www.got-pressure.com/yabbse/i...y;threadid=379
Senior Member
Joined: Feb 2001
Posts: 641
Likes: 0
From: Calgary, Oilberta
[QUOTE]Originally posted by signmaster
To say that efficiency of an intercooler should remain a flat percentage is simply wrong. A water to air cooler is simply a radiator, and just like a radiator is more efficient within certain ranges. If water flow does not increase you will reach a point at which the fluid begins to heat soak, since the cooler will not pull out the heat as efficiently.
That is not entirely true - heat transfer from any object is directly proportional to the heat transfer coefficient and the difference in temperature between the two mediums (delta T).
Heat soak occurs when the system cannot get rid of the heat as fast as it is absorbed because the exchanger (or the pump) is undersized for the application. This may cause boiling of the coolant in the intercooler, which would prevent heat transfer but it is pretty unlikely in a 10 second dyno run.
Intercooler efficiency calc's are used to compare apples to apples and should remain fairly constant, increasing slightly as the delta T increases. The equation for IC eff
IC %= (Inlet temp - Outlet Temp)/(Inlet temp - Ambient temp)*100
For the KB, effieciency ranges from 42-46%, which is fairly consistent, if not spectacular. For the Eaton efficiency ranges from 21 - 31%, which is inconsistent and poor.
To put it another way, lets compare inlet temp to inlet temp (temperatures from MM&FF's chart):
KBIn KBOut DeltaT Eff EatonIn EatonOut DeltaT Eff
190 __ 140 __ 50 __ 41 __ 185 __ 162 __ 23 __ 21
226 __ 157 __ 69 __ 46 __ 235 __ 185 __ 50 __ 32
260 __ 173 __ 87 __ 47 __ 265 __ 205 __ 60 __ 32
When running the KB, the IC consistently removes more heat than when running with the Eaton. This is why I say the results are suspect.
I fully agree that the Eaton has the advantage at lower boost levels, and would likely be more suitable in a truck at these lower levels. At boost rises however it becomes much less efficient. The Eaton is being driven at a higher than recommended speed even at stock boost levels, and this is where the problem IMO comes into the picture. Bumping boost is simply pushing it past its' efficient range.
We agree on this point. I have stated in the past that the Magnacharger kit for the 5.4 should have the M-112 compressor instead of the M-90, IMO. For the 4.6, the M90 should be adequate.
Ian
To say that efficiency of an intercooler should remain a flat percentage is simply wrong. A water to air cooler is simply a radiator, and just like a radiator is more efficient within certain ranges. If water flow does not increase you will reach a point at which the fluid begins to heat soak, since the cooler will not pull out the heat as efficiently.
That is not entirely true - heat transfer from any object is directly proportional to the heat transfer coefficient and the difference in temperature between the two mediums (delta T).
Heat soak occurs when the system cannot get rid of the heat as fast as it is absorbed because the exchanger (or the pump) is undersized for the application. This may cause boiling of the coolant in the intercooler, which would prevent heat transfer but it is pretty unlikely in a 10 second dyno run.
Intercooler efficiency calc's are used to compare apples to apples and should remain fairly constant, increasing slightly as the delta T increases. The equation for IC eff
IC %= (Inlet temp - Outlet Temp)/(Inlet temp - Ambient temp)*100
For the KB, effieciency ranges from 42-46%, which is fairly consistent, if not spectacular. For the Eaton efficiency ranges from 21 - 31%, which is inconsistent and poor.
To put it another way, lets compare inlet temp to inlet temp (temperatures from MM&FF's chart):
KBIn KBOut DeltaT Eff EatonIn EatonOut DeltaT Eff
190 __ 140 __ 50 __ 41 __ 185 __ 162 __ 23 __ 21
226 __ 157 __ 69 __ 46 __ 235 __ 185 __ 50 __ 32
260 __ 173 __ 87 __ 47 __ 265 __ 205 __ 60 __ 32
When running the KB, the IC consistently removes more heat than when running with the Eaton. This is why I say the results are suspect.
I fully agree that the Eaton has the advantage at lower boost levels, and would likely be more suitable in a truck at these lower levels. At boost rises however it becomes much less efficient. The Eaton is being driven at a higher than recommended speed even at stock boost levels, and this is where the problem IMO comes into the picture. Bumping boost is simply pushing it past its' efficient range.
We agree on this point. I have stated in the past that the Magnacharger kit for the 5.4 should have the M-112 compressor instead of the M-90, IMO. For the 4.6, the M90 should be adequate.
Ian
Last edited by Ian N; Jan 6, 2003 at 12:09 PM.
Member
Joined: Nov 2002
Posts: 42
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From: Plano, Texas
Originally posted by Ian N
When running the KB, the IC consistently removes more heat than when running with the Eaton. This is why I say the results are suspect.
Ian
When running the KB, the IC consistently removes more heat than when running with the Eaton. This is why I say the results are suspect.
Ian
I had read somewhere that the Roots type supercharger's lobes actually make contact as they rotate causing more heat (and noise) and that was one of the reasons that the KB charge temps were lower.
Senior Member
Joined: May 2000
Posts: 1,317
Likes: 0
From: Virginia Beach, VA
Ian,
Though I have no reason to dispute the intercooler efficiency formula you provide, I have seen others which use several more variables. I really don't know which are more accurate.
It seems to have logic that the flow across the intercooler should be a variable in the equation as well. If the temps are similar but the boost is different, then the formula would skew depending on what is optimum flow for the heat exhange to take place. To compare the two at equal inlet temps is allowing a variable in velocity and volume across the intercooler.
That being said, the numbers for the Eaton at 7.7 lbs boost seem very low IMO, and I suspect either a typo or another unaccounted for variable created this result.
Even if this was equal for both, I would assume that the direction of the flow across the intercooler core would have an affect as well. For example if one blower had an exit that diffused the air more evenly over the IC core, it should gain an advantage in doing so.
The large adapter plate used to mount the KB would IMO provide a possible heat sink effect to some extent, as well as change the flow over the cooler. The heat sink would be an obvious advantage, the flow over the cooler core in this case is an unknown.
As for the M112 over the M90, that is a point I have considered as well. It would be interesting to see how the low end torque is affected on the 5.4, and if the smaller blower would still have a low rev advantage.
BTW, I appreciate the debate. I'm not claiming to have all the answers and a well backed educated debate helps fill the voids in my knowledge of blower tech. As for requests for data, they are simply that.... I'm a data hound. Weeding out fact from fiction often takes some time, and is one of the reasons I seek such numbers.... even then some of them can be suspect and deemed as unreliable.
That's what is great about this site. People can disagree and debate without the thread deteriorating into a flame fest, and both sides win in the long run. Some of the most useful info I have found on the 'net was found in such debates.
Crash,
Great info. Have you or Skid ever taken any compressor exit temps? I have had a hard time finding any exit temps on centrifugals. It seems that even non intercooled centrifugals are obviously cooler than most roots blowers, but the temps would give a good indication of just how efficient they really are.
Though I have no reason to dispute the intercooler efficiency formula you provide, I have seen others which use several more variables. I really don't know which are more accurate.
It seems to have logic that the flow across the intercooler should be a variable in the equation as well. If the temps are similar but the boost is different, then the formula would skew depending on what is optimum flow for the heat exhange to take place. To compare the two at equal inlet temps is allowing a variable in velocity and volume across the intercooler.
That being said, the numbers for the Eaton at 7.7 lbs boost seem very low IMO, and I suspect either a typo or another unaccounted for variable created this result.
Even if this was equal for both, I would assume that the direction of the flow across the intercooler core would have an affect as well. For example if one blower had an exit that diffused the air more evenly over the IC core, it should gain an advantage in doing so.
The large adapter plate used to mount the KB would IMO provide a possible heat sink effect to some extent, as well as change the flow over the cooler. The heat sink would be an obvious advantage, the flow over the cooler core in this case is an unknown.
As for the M112 over the M90, that is a point I have considered as well. It would be interesting to see how the low end torque is affected on the 5.4, and if the smaller blower would still have a low rev advantage.
BTW, I appreciate the debate. I'm not claiming to have all the answers and a well backed educated debate helps fill the voids in my knowledge of blower tech. As for requests for data, they are simply that.... I'm a data hound. Weeding out fact from fiction often takes some time, and is one of the reasons I seek such numbers.... even then some of them can be suspect and deemed as unreliable.
That's what is great about this site. People can disagree and debate without the thread deteriorating into a flame fest, and both sides win in the long run. Some of the most useful info I have found on the 'net was found in such debates.
Crash,
Great info. Have you or Skid ever taken any compressor exit temps? I have had a hard time finding any exit temps on centrifugals. It seems that even non intercooled centrifugals are obviously cooler than most roots blowers, but the temps would give a good indication of just how efficient they really are.
