[flamin]

Originally Posted by r12rex

This is definitely some good info. Numbers. Nice. Looks like you did the math correctly to me. Not bad for Sunday morning. It only makes sense though that a FMIC equipped car would produce more power than a TMIC equipped car. How much a gain could one get from a stock turbo STi and a FMIC set-up? I can't really see it being too much, but I'm sure the tempatures will be quite a bit lower.

I'd love a FMIC set-up, BUT...to keep it cop-friendly, I think I'll stick to my TMIC. Of course this could change in the future...


Kind Regards,
Ryan

yea i would like to know if its worth slaping on a FMIC on the stock snail...too

[RFFG]

es ti cky

Good info!

[berdugo]

Mike,

I tried to make an excel file of this, but I don't understand and justify the equation

"Figuring out the efficiency of this intercooler:
Compressor outlet temp minus ambient temp:
415 - 70 = 345 F {this is the temperature gain from ambient to what comes out of the turbo}"

because with that equation, the hotter the ambient temp, lets say 90 F, and the compressor outlet temp remains the same, it would be

415 - 90 = 325 F

That would mean the hotter the ambient air, the lower the temp from going in the intercooler would be!

I hope you can enlighten us about this.

[CenCali07STI]

Originally Posted by berdugo

Mike,

I tried to make an excel file of this, but I don't understand and justify the equation

"Figuring out the efficiency of this intercooler:
Compressor outlet temp minus ambient temp:
415 - 70 = 345 F {this is the temperature gain from ambient to what comes out of the turbo}"

because with that equation, the hotter the ambient temp, lets say 90 F, and the compressor outlet temp remains the same, it would be

415 - 90 = 325 F

That would mean the hotter the ambient air, the lower the temp from going in the intercooler would be!

I hope you can enlighten us about this.

I think your looking at it wrong. your compressor outlet temp is always going to go up with an increase in ambient. Example. The day he measured the compressor outlet temp ( I know it was just an example temp though) it was 415 degrees because the compressor at that load increased the air temp by 345 degrees but if the compressor is still going to increase it by the same amount in another situation but its a 90 degree day then the new compressor outlet temp is going to be 435 degrees. I think I explained that right.

[berdugo]

Originally Posted by CenCali07STI

I think your looking at it wrong. your compressor outlet temp is always going to go up with an increase in ambient. Example. The day he measured the compressor outlet temp it was 415 degrees because the compressor at that load increased the air temp by 345 degrees but if the compressor is still going to increase it by the same amount in another situation but its a 90 degree day then the new compressor outlet temp is going to be 435 degrees.

ok. let's assume this figures for computation's sake

Ambient temp = -5 F now we never had that in the Philippines, I don't know if that happens in USA or canada or other countries where it's very cold.

let's assume the compressor temp is only 200 F

now with the equation, it would be like this

200 - -5 = 205 F

now let's assume the ambient temp of +5 F, still very cold

200 - 5 = 195 F

does that mean a colder ambient temp would lead to higher air temp going to the IC? I really don't get it.......

[CenCali07STI]

Originally Posted by berdugo

ok. let's assume this figures for computation's sake

Ambient temp = -5 F now we never had that in the Philippines, I don't know if that happens in USA or canada or other countries where it's very cold.

let's assume the compressor temp is only 200 F

now with the equation, it would be like this

200 - -5 = 205 F

now let's assume the ambient temp of +5 F, still very cold

200 - 5 = 195 F

does that mean a colder ambient temp would lead to higher air temp going to the IC? I really don't get it.......

I think your still looking at it wrong. Your now subtracting when you need to be adding. Your adding ambient temp plus compressor temp to give you the total outlet temp.

ambient temp of 5+ PLUS compressor temp 200 = 205 outlet temp.

if ambient temp is -5 and the compressor increases the ambient air by 200 then your outlet temp is now 195 degrees.

make sense?

[berdugo]

Originally Posted by CenCali07STI

I think your still looking at it wrong.

ambient temp of 5+ PLUS compressor temp = 205 outlet temp.

if ambient temp is -5 and the compressor increase the ambient air by 200 then your outlet temp is now 195 degrees.

I agree with your equation about,

200 PLUS ambient temp of +5 = 205 F

Please take note of your equation PLUS

with Mike's equation,

Figuring out the efficiency of this intercooler:
Compressor outlet temp minus ambient temp:
415 - 70 = 345 F {this is the temperature gain from ambient to what comes out of the turbo}

he said MINUS AMBIENT TEMP.

I'm not an expert with this, and I'm not to prove that equation wrong or anything, I just want to know the accurate equation for that.

[CenCali07STI]

oh ok I think I see where your getting confused your looking at it backwards. Your first post questioning his equation was like this.

415-70= 345f (his example)

415-90=325f (your example)

your question was why at a higher ambient temp does the air going to the intercooler get colder.

This is where you seen it backwards. his 415 number was the temp going TO the intercooler. I think you were under the impression that his 345 number was the temp going to the intercooler. Thats why your not seeing it.

you should have been looking at it this way originally.

345f is how much the turbo increases the ambient air temp. so...

70 (ambient) + 345 (turbo increase) = 415f (going to the inercooler)

90 (ambient) + 345 (turbo increase) = 435f (going to the intercooler)

5 (ambient) + 200 (your number for turbo increase at that temp) = 205f (going to the intercooler)

-5 (ambient) + 200 (your number for turbo increase at that temp) = 195f (going to the intercooler)

What he was showing you in his equation was how to figure out how much the turbo was increasing the ambient air temp NOT what temp the air was going to the intercooler. He already new what temp the air was going to the intercooler and for his example was 415.

Here is what he was doing.

Known temp that he measured 415f coming out of the turbo. ( iknow it was an example and that he did not actually measure it just saying) And the ambient temp that day was 70f.

415f - 70f = 345f

[berdugo]

Originally Posted by CenCali07STI

oh ok I think I see where your getting confused your looking at it backwards. Your first post questioning his equation was like this.

415-70= 345f (his example)

415-90=325f (your example)

your question was why at a higher ambient temp does the air going to the intercooler get colder.

This is where you seen it backwards. his 415 number was the temp going TO the intercooler. I think you were under the impression that his 345 number was the temp going to the intercooler. Thats why your not seeing it.

you should have been looking at it this way originally.

345f is how much the turbo increases the ambient air temp. so...

70 (ambient) + 345 (turbo increase) = 415f (going to the inercooler)

90 (ambient) + 345 (turbo increase) = 435f (going to the intercooler)

5 (ambient) + 200 (your number for turbo increase at that temp) = 205f (going to the intercooler)

-5 (ambient) + 200 (your number for turbo increase at that temp) = 195f (going to the intercooler)

What he was showing you in his equation was how to figure out how much the turbo was increasing the ambient air temp NOT what temp the air was going to the intercooler. He already new what temp the air was going to the intercooler and for his example was 415.

ok i get it. Thanks for the explanation
The reason I'm doing it in excel is because I want to know how much power I will lose per degree of temp. I'm thinking if it's worth doing the automatic IC spraying when the boost kicks in.

Btw it's high 80s in here that is why I got very curious. In summer time we can reach to 120F so not a lot of power to be made

[CenCali07STI]

Originally Posted by berdugo

ok i get it. Thanks for the explanation
The reason I'm doing it in excel is because I want to know how much power I will lose per degree of temp. I'm thinking if it's worth doing the automatic IC spraying when the boost kicks in.

Btw it's high 80s in here that is why I got very curious. In summer time we can reach to 120F so not a lot of power to be made

Crap that sucks. I thought cali was bad. glad I could help. I get confused sometimes too on the simplest of things and then someone points it out and I am like wow how did I miss that haha.

[berdugo]

I've been to Cali before, I think it was may 04, went to see disney, man you have a very nice weather. Here when it hits Feb, temp shoots up to 100+ and more during april to may. when june comes, lots of rain and storm, but still hot as in high 70s to 80s.

And it's very humid too that is why I was asking Mike if the humidity affects the power of the car. Again thanks for the help man.

[Flycaster]

Originally Posted by berdugo

...Does humidity affect the power too? Lets say 80-90% humidity, if it affects the power at all. Thanks

Regardless of which side of the I/C you're on, the important thing to know is that the variables of pressure altitude, temperature and relative humidity all combine to give you local air density (known to pilots as "Density Altitude"). Relatively high humidity will negatively impact performance, but nowhere near as much as the the first 2 variables - it's almost negligible. And of the first 2, pressure altitude has, by far, the most impact: it takes a butt load of temperature drop to offset just a few thousand feet of elevation. IOW, a really cold, dry day at sea-level will give you most power (greatest air density), whereas a really hot, humid day at high alititude will give you the least power.

An I/C can, by definition, only affect the variable of temperature, but when you can achieve 100-200* drops, it's easy to understand why they are so important and have such a big impact on power. During the winter, I can pop the hood right after driving the car hard and the outlet pipe is too hot to even touch...and both the return pipe and the throttle body are freezing cold (FMIC). I'm still impressed.

[Turbineguy]

Originally Posted by Flycaster

Regardless of which side of the I/C you're on, the important thing to know is that the variables of pressure altitude, temperature and relative humidity all combine to give you local air density (known to pilots as "Density Altitude"). Relatively high humidity will negatively impact performance, but nowhere near as much as the the first 2 variables - it's almost negligible. And of the first 2, pressure altitude has, by far, the most impact: it takes a butt load of temperature drop to offset just a few thousand feet of elevation. IOW, a really cold, dry day at sea-level will give you most power (greatest air density), whereas a really hot, humid day at high alititude will give you the least power.

An I/C can, by definition, only affect the variable of temperature, but when you can achieve 100-200* drops, it's easy to understand why they are so important and have such a big impact on power. During the winter, I can pop the hood right after driving the car hard and the outlet pipe is too hot to even touch...and both the return pipe and the throttle body are freezing cold. I'm still impressed.

Just to put some #s behind Fly's comparo. The standard lapse rate for temp and altitude is 2 degrees C for every thousand feet of altitude. So if you go up 5000 feet you drop 10 degrees C. Even though this is occuring I run out of power in a Blackhawk at normal gross weight anywhere from 14k to 20k feet all based on the DA. It's definitely the pressure altitude in that circumstance. The temp is of most concern for me though because it deternimes if I can even get off the ground at a given weight. I have had a few situations where I couldnt get off the ground and waited until the next morning when the temp was much lower and was able to get off the ground no problem. Temp has a huge impact on lift and power.

[Flycaster]

All true, but as it relates to cars it's far more simple - both of our aircraft, as well as our cars (IF we were willing to turn up the boost high enough) can still make sea-level power up in Aspen (8K), even on a hot day; however, cars don't have to worry about the negative effects of high DA on lift or thrust. I can't "turbocharge" either my prop or my wings, nor can you your blades. Throw those factors into the E6B and we don't fly, period.

Here's a real world example, one I have to deal with every day: I live at 4K elevation, and I was tuned at sea-level by PDXT on pretty much a "standard" day, about 60 degrees, normal baro and RH. Now, for me to get the same air density (and to make the same power) I have 2 choices: on a standard, 60* day I can turn up boost by about 3-4 psi (assuming I'm tuned for it, which I am) or, I can run the same boost...and wait until the temperature drops to @ -10*.

IOW, it takes a 70* swing in temperatures to offset the 4K elevation....again, a butt load.

[Turbineguy]

Originally Posted by Flycaster

All true, but as it relates to cars it's far more simple - both of our aircraft, as well as our cars (IF we were willing to turn up the boost high enough) can still make sea-level power up in Aspen (8K), even on a hot day; however, cars don't have to worry about the negative effects of high DA on lift or thrust. I can't "turbocharge" either my prop or my wings, nor can you your blades. Throw those factors into the E6B and we don't fly, period.

Here's a real world example, one I have to deal with every day: I live at 4K elevation, and I was tuned at sea-level by PDXT on pretty much a "standard" day, about 60 degrees, normal baro and RH. Now, for me to get the same air density (and to make the same power) I have 2 choices: on a standard, 60* day I can turn up boost by about 3-4 psi (assuming I'm tuned for it, which I am) or, I can run the same boost...and wait until the temperature drops to @ -10*.

IOW, it takes a 70* swing in temperatures to offset the 4K elevation....again, a butt load.

Absolutely correct. I guess my analogy doesn't completely fit but I used it as an example to show how much temp has an effect on power.