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** The Enforcer **
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FWIW, I have a heatshield (with gold foil insulation) between my intercooler and the engine/exhaust as well (even though the 2-Eleven's intercooler is located far behind the Exige's location). And, FWIW... when I had my car dyno'd... the three pulls were also within a few HP of each other.

Sadly, I think real-life conditions are much harsher than dyno conditions.
My three pulls were within .55 whp of each other, and I think that's only because the car wasn't shutdown at the precise same rpm in the three pulls. When I say the lines are on top of each other it's literally that.

I think the RLS IC had enough thermal capacity (reserve) that it never even approached the point of heat soak, even without airflow to cool it.

San
 

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It's great to see more work being done trying to improve the airflow to the intercooler.

:clap:

However... as I've done a fair bit of tracking with my 2-Eleven, data logged the IATs... *and* fettled the 2-Eleven intercooler intake ducts, replaced the OEM ducting with high quality brake ducting... I think I can say with some authority:

Two 4" diameter cooling ducts are *still* not enough to keep the intercooler from becoming heat soaked in most (Southwest USA) race conditions.

From my data logs, I'd say I lose somewhere around 30-50 whp when the intercooler heat soaks under race/qualification conditions.
Thanks apk919, for your testing and data you have offered. This is the only informed way lotus owners can truely make informed choices on aftermarkets parts and mods.

I have to agree with your statement above, the 2-eleven is known to heatsoak. There is just not enough air getting to the back of these cars.

Although this true, I do believe (from testing I have read) that the 2-eleven shroud is the best of the increased airflow options available for the exige S.

I am very much leaning towards the 2-eleven shroud for this reason.

I was wondering apk919 if you have tried the shroud on the exige S and done any IAT temp tests. Would be interesting to compare different products maintaining all others as a control.

I think the forum would be appreciative of any data you could supply

Cheers

:popcorn:
 

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** The Enforcer **
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Thanks apk919, for your testing and data you have offered. This is the only informed way lotus owners can truely make informed choices on aftermarkets parts and mods.

I have to agree with your statement above, the 2-eleven is known to heatsoak. There is just not enough air getting to the back of these cars.

Although this true, I do believe (from testing I have read) that the 2-eleven shroud is the best of the increased airflow options available for the exige S.

I am very much leaning towards the 2-eleven shroud for this reason.

I was wondering apk919 if you have tried the shroud on the exige S and done any IAT temp tests. Would be interesting to compare different products maintaining all others as a control.

I think the forum would be appreciative of any data you could supply

Cheers

:popcorn:
Your post doesn't make sense as he's running the stock IC, not an aftermarket part (IC). Maybe I missed something.

San
 

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Your post doesn't make sense as he's running the stock IC, not an aftermarket part (IC). Maybe I missed something.

San
Okay let me explain as I understand it;

Apk919 initiated the thread with the air flow study, I am thanking him for the time he spent doing that. This makes us aware the roof scoop does not allow much air to the intercooler + some other supporting data.

Also from apk919's latest posts, if I am correct, he has a lotus 2-eleven.

Therefore I am asking can he take the 2-eleven shroud and fit it to his exige and see how it compares to stock temps. He could also change out any aftermarket ICs that vendors are willing to supply, with and without the 2-eleven shroud, compared to the stock setup. He could also compare the three air input shroud offered br pro alloy and RLS (again if vendors are willing to supply), or the homemade equivalent with different ICs.

I was just asking maybe if he had the time, as he has presented testing data before.

Sorry if this wasn 't clear earlier.

PS. If apk919 is willing, this could be an opportunity for vendors to clearly show if different ICs are superior to the stock unit applying differing air flows to the units.
 

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** The Enforcer **
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My point is that sitting on a dyno with a fan pointing at the front of the car (effectively no air reaching the top half scoop or side scoops) three back to back runs were within .55 rwhp of each other. There wasn't a hint of heat soak, even without airflow. I think this speaks favorably of the RLS IC (and heatshield).

The day following the dyno pulls I had the Blade 300 installation done. The following day I went back to the same shop to dyno and the results were very similar, just more horsepower. I didn't see any evidence of heat soak, despite the 55 rwhp increase. Again, no airflow to the top half scoop or side scoops.

6 months or so later I added the Reverie rear hatch lid which has a box section that vents the hot air out of the back of the IC and acts as a partial heat shield (in addition to the RLS heat shield with the gold foil on the underside).

I would like to be able to measure IATs and other relevant parameters to add more data to this thread.

San
 

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My point is that sitting on a dyno with a fan pointing at the front of the car (effectively no air reaching the top half scoop or side scoops) three back to back runs were within .55 rwhp of each other. There wasn't a hint of heat soak, even without airflow. I think this speaks favorably of the RLS IC (and heatshield).

The day following the dyno pulls I had the Blade 300 installation done. The following day I went back to the same shop to dyno and the results were very similar, just more horsepower. I didn't see any evidence of heat soak, despite the 55 rwhp increase. Again, no airflow to the top half scoop or side scoops.

6 months or so later I added the Reverie rear hatch lid which has a box section that vents the hot air out of the back of the IC and acts as a partial heat shield (in addition to the RLS heat shield with the gold foil on the underside).

I would like to be able to measure IATs and other relevant parameters to add more data to this thread.

San
Thanks for the data you found,
Cheers.

But there is two points to consider;
1. Apk919 did a similar test on the dyno but had a differing effect when on the track, so I believe he was suggesting that the dyno may not represent real driving senarios.
2. Tomasio has claimed due to his design (bar and plate, I believe he said) is superior to the oppositions design.

Therefore you need to change out different ICs maintaining all other controls to properly make comparisons.

Also different ICs may out preform each other with differing airflows.

The only way to find out is to do some testing.

Eg: my post.
 

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** The Enforcer **
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Thanks for the data you found,
Cheers.

But there is two points to consider;
1. Apk919 did a similar test on the dyno but had a differing effect when on the track, so I believe he was suggesting that the dyno may not represent real driving senarios.
2. Tomasio has claimed due to his design (bar and plate, I believe he said) is superior to the oppositions design.

Therefore you need to change out different ICs maintaining all other controls to properly make comparisons.

Also different ICs may out preform each other with differing airflows.

The only way to find out is to do some testing.

Eg: my post.
If you look at apk919's post above he did dyno pulls with variances of several hp (he didn't say how much). I had almost no difference (.55 whp) in three back to back pulls, and I believe that is attributed to the rpm when the pull was ended. I think that shows the RLS has a much greater degree of thermal capacity (reserve).

I honestly think the heat soak on the track is due to the limited amount of thermal capacity with the stock IC, not the airflow to the IC (although stock airflow isn't ideal either).

I'd love to swap out ICs to test theories but I don't have the time or desire to.

San
 

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Discussion Starter · #628 ·
The dyno plot is here: http://www.lotustalk.com/forums/f160/finally-going-dyno-2-eleven-114697/#post1730523

There was about a 3HP loss between dyno pulls... the plot notes an ambient temp of around 70F.

Honestly though, I don't think dyno pulls are going to say much about the real life performance of the intercooler. In race/qualy conditions, I'm on full throttle for well over 50% of the lap... in the video frames I posted earlier, there's likely more than a minute of WOT between them. If I have to qualify in hot conditions (over 70F), I need to be careful not to use too much full throttle on the out lap, and then make sure my first hot lap is a good one... by my second hot lap the car is noticeably down on power.

Unfortunately I don't have the time these days to swap out intercoolers or shrouds... :(
 

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The dyno plot is here: http://www.lotustalk.com/forums/f160/finally-going-dyno-2-eleven-114697/#post1730523

There was about a 3HP loss between dyno pulls... the plot notes an ambient temp of around 70F.

Honestly though, I don't think dyno pulls are going to say much about the real life performance of the intercooler. In race/qualy conditions, I'm on full throttle for well over 50% of the lap... in the video frames I posted earlier, there's likely more than a minute of WOT between them. If I have to qualify in hot conditions (over 70F), I need to be careful not to use too much full throttle on the out lap, and then make sure my first hot lap is a good one... by my second hot lap the car is noticeably down on power.

Unfortunately I don't have the time these days to swap out intercoolers or shrouds... :(
Thanks apk919,

Thought I would just ask. :wave:

Hope your enjoying the 2-eleven :UK:
 

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Dog Pilot
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My point is that sitting on a dyno with a fan pointing at the front of the car (effectively no air reaching the top half scoop or side scoops) three back to back runs were within .55 rwhp of each other. There wasn't a hint of heat soak, even without airflow. I think this speaks favorably of the RLS IC (and heatshield).

The day following the dyno pulls I had the Blade 300 installation done. The following day I went back to the same shop to dyno and the results were very similar, just more horsepower. I didn't see any evidence of heat soak, despite the 55 rwhp increase. Again, no airflow to the top half scoop or side scoops.

6 months or so later I added the Reverie rear hatch lid which has a box section that vents the hot air out of the back of the IC and acts as a partial heat shield (in addition to the RLS heat shield with the gold foil on the underside).

I would like to be able to measure IATs and other relevant parameters to add more data to this thread.

San

I'd say it is more likely that the IC was effectively immediately heatsoaked and the power numbers you are seeing are with a heatsoaked IC. That would account for your consistent pulls across the three without any air. The IC doesn't do any good if there is no air flowing across it... Without air it is by default then heatsoaked or the functional equivalent thereof. The usefulness of an IC only comes in to play when air is flowing across the fins, otherwise it might as well just be an inert piece of really thick piping. You'd see the same numbers if you just had a straight pipe in place of the IC, assuming there is indeed no airflow through it.

I bet you'd have much better numbers if you forced some air through the IC before, during and after the pulls.

I would imagine that if you swapped out the RLS IC for a stock IC and changed nothing else, you'd see a similar set of pulls.

You can't just get magic cooling benefits from hardware without some place for that heat to go. If there's no airflow, there's no cooling, besides passive radiation. Passive radiation provides virtually no cooling at all and is indistinguishable from the background given the surface area of any IC that would fit in the hatch in this type of scenario.
 

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I would imagine that if you swapped out the RLS IC for a stock IC and changed nothing else, you'd see a similar set of pulls.

You can't just get magic cooling benefits from hardware without some place for that heat to go. If there's no airflow, there's no cooling, besides passive radiation. Passive radiation provides virtually no cooling at all and is indistinguishable from the background given the surface area of any IC that would fit in the hatch in this type of scenario.
Wow... Umm that is completely wrong. I will GUARANTEE you will see better results from the RLS IC compared to the stock IC just for the fact that there will be less charged air pressure drop. Right there, that will give you a power bump.

On top of that, the RLS IC should have better heat transfer performance than the stock anyways since it is larger and has more surface area. This means that it has a greater effectiveness which in turn means it can transfer more energy even with the same amount of airflow as the stock IC.

Anyway you look at it the RLS IC will not hurt you, it should only help.

With that said, improving air flow will yield your biggest gain for sure and everyone's number one priority should be improving air flow, then improving the IC.
 

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Dog Pilot
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Wow... Umm that is completely wrong. I will GUARANTEE you will see better results from the RLS IC compared to the stock IC just for the fact that there will be less charged air pressure drop. Right there, that will give you a power bump.

On top of that, the RLS IC should have better heat transfer performance than the stock anyways since it is larger and has more surface area. This means that it has a greater effectiveness which in turn means it can transfer more energy even with the same amount of airflow as the stock IC.

Anyway you look at it the RLS IC will not hurt you, it should only help.

With that said, improving air flow will yield your biggest gain for sure and everyone's number one priority should be improving air flow, then improving the IC.

Did you just not read what I wrote before replying or what? I said if there is truly no airflow, then the RLS IC won't help you, since an IC without airflow is just a big pipe.

The charged air pressure drop won't give you any noticeable bump on a dyno when you're talking about the stock IC vs an RLS IC. There's simply not enough air and pressure to make a meaningful difference between the two. We're talking 8PSI... 10 if you're really pushing it. If you're going crazy at 15 PSI, eh... maybe. But I run my turbo's at 28 PSI (not on the Lotus) and changing the pressure drop yields maybe an HP or two on the dyno. At 8 PSI you'll see two things: Jack and **** and Jack left town about a week ago.

The volume of air that's moved via the SC on the Lotus is not enough to overpower even the stock IC.

If you have no airflow over the RLS or the Stock IC, you'll see the same performance out of the two. It's completely immaterial how much better the heat transfer performance is in the absence of airflow. That ONLY applies if you have no airflow, though. If you have meaningful airflow, then that changes things.

Again, nobody is saying the RLS IC is bad or that it will hurt you. But there's other things that need to be changed before you'll see an improvement from the RLS IC. Just dropping in an RLS IC without doing any other mods first will be like putting a fart can on the car and saying how much more HP you can feel.
 

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shay2nak
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Again, nobody is saying the RLS IC is bad or that it will hurt you. But there's other things that need to be changed before you'll see an improvement from the RLS IC. Just dropping in an RLS IC without doing any other mods first will be like putting a fart can on the car and saying how much more HP you can feel.
I beg to differ. I could actually feel the added torque from the RLS intercooler. Look at this dyno of before/after RLS intercooler. Ignore the 2 higher HP curves. Look at the RED one (after) and the BLUE one (before). Same dyno, same preperations, etc. I posted my findings like 3 or 4 pages ago when this thread came back to life. This was with the original Gotham tune.
 

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** The Enforcer **
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Did you just not read what I wrote before replying or what? I said if there is truly no airflow, then the RLS IC won't help you, since an IC without airflow is just a big pipe.

The charged air pressure drop won't give you any noticeable bump on a dyno when you're talking about the stock IC vs an RLS IC. There's simply not enough air and pressure to make a meaningful difference between the two. We're talking 8PSI... 10 if you're really pushing it. If you're going crazy at 15 PSI, eh... maybe. But I run my turbo's at 28 PSI (not on the Lotus) and changing the pressure drop yields maybe an HP or two on the dyno. At 8 PSI you'll see two things: Jack and **** and Jack left town about a week ago.

The volume of air that's moved via the SC on the Lotus is not enough to overpower even the stock IC.

If you have no airflow over the RLS or the Stock IC, you'll see the same performance out of the two. It's completely immaterial how much better the heat transfer performance is in the absence of airflow. That ONLY applies if you have no airflow, though. If you have meaningful airflow, then that changes things.

Again, nobody is saying the RLS IC is bad or that it will hurt you. But there's other things that need to be changed before you'll see an improvement from the RLS IC. Just dropping in an RLS IC without doing any other mods first will be like putting a fart can on the car and saying how much more HP you can feel.
You're making assumptions, and you know what they say.

An IC without airflow will become heat soaked. Duh. Two different ICs with different thermal capacities will heat soak at different points.

You're assuming that my IC was already heat soaked and that's why my tolerances were so tight. 281rwhp on the stock MP62 and the IC was heat soaked? Yeah, sure. I'd see the same rwhp on the stock IC? Whatever.

San
 

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Dog Pilot
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You're making assumptions, and you know what they say.

An IC without airflow will become heat soaked. Duh. Two different ICs with different thermal capacities will heat soak at different points.

You're assuming that my IC was already heat soaked and that's why my tolerances were so tight. 281rwhp on the stock MP62 and the IC was heat soaked? Yeah, sure. I'd see the same rwhp on the stock IC? Whatever.

San
Man, it's like you guys don't even read what's written. Mind boggling.

If you have no airflow over the IC, it is, by default, heatsoaked for all practical definitions. If there's no airflow it can not dissipate the heat. If the heat cannot be dissipated, it stays in the air passing through it. There is a reason there are fins on a radiator, they are there to increase the surface area, they aren't decoration. They are very thin and have very little mass. Without airflow they will heatsoak immediately.

Surface area * airflow = cooling capacity. What is any number * 0? That's your cooling capacity of an IC with 0 airflow. I'm sorry, but you can't change the laws of thermodynamics just because you want them to not be true.

I have a stock IC and stock SC in my Exige and I pull around 280 HP on the dyno if I recall (I have a lot of other mods as well, not saying it's just a tune). Phil did the tune himself, so feel free to ask him. I don't have the dyno plots unfortunately, or I'd post them. So unless BOE told me wrong, I don't know what to tell you.
 

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Dog Pilot
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shay2nak said:
I beg to differ. I could actually feel the added torque from the RLS intercooler. Look at this dyno of before/after RLS intercooler. Ignore the 2 higher HP curves. Look at the RED one (after) and the BLUE one (before). Same dyno, same preperations, etc. I posted my findings like 3 or 4 pages ago when this thread came back to life. This was with the original Gotham tune.
All i know is that the RLS intercooler with 3 inlet shroud and heatshield have shown by my monitoring to operate at lower IAT than stock and recovers quite fast after hard accelerations. And I gained +10whp/+10wtq when I first installed the intercooler and doesn't heatsoak nearly as bad as the stock unit.
And did your dyno runs have air flowing over the IC? If so, then it doesn't have anything to do with what we are discussing.

I also find it very difficult to believe you could "feel" a 3% increase in torque. 3% is easily within the margin of error for most calculations not done on a dyno, butt dyno's not withstanding. I know some fellas that can swear they feel the torque increase with their Type-R stickers, too... but we all know how that goes. But maybe your butt-dyno is more sensetive than most people, so I'll give you the benefit of the doubt on that one.

At the end of the day thermodynamics are thermodynamics. You can't change them. If you want to burn money on stuff, I'm totally fine with that. I completely support your right to throw money at problems left and right. Spend $15,000 on 2lbs of weight reduction and 1hp increase. Lord knows I've wasted money on many-a-car chasing rainbows and the need to believe that you didn't just spend $3000 for little to no improvement is strong. I've been there. I understand. This is like trying to argue with an audiophile about how wooden knobs and $10,000 power conditioners make the sound "richer" and "fuller."

I just have a problem when others entice people to waste their time and money on something that is simply not possible through all known laws of physics and thermodynamics. Lets stick to the known sciences and not woo-woo magical beans and psychic airflow.

I've said what I have to say here on this subject and I don't want this to turn into a flame war, so I stand by my statements and believe they stand on their own merits at this point. The rest is up to the reader.
 

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** The Enforcer **
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Man, it's like you guys don't even read what's written. Mind boggling.

If you have no airflow over the IC, it is, by default, heatsoaked for all practical definitions. If there's no airflow it can not dissipate the heat. If the heat cannot be dissipated, it stays in the air passing through it. There is a reason there are fins on a radiator, they are there to increase the surface area, they aren't decoration. They are very thin and have very little mass. Without airflow they will heatsoak immediately.

Surface area * airflow = cooling capacity. What is any number * 0? That's your cooling capacity of an IC with 0 airflow. I'm sorry, but you can't change the laws of thermodynamics just because you want them to not be true.

I have a stock IC and stock SC in my Exige and I pull 281 HP on the dyno, or so BOE tells me. If you don't believe me, go ahead and ask Phil. He did the tune on it personally.
So when I start my car since there is no airflow to the IC it's heat soaked? Seriously, where do you get this nonsense?

San
 

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And did your dyno runs have air flowing over the IC? If so, then it doesn't have anything to do with what we are discussing.

I also find it very difficult to believe you could "feel" a 3% increase in torque. 3% is easily within the margin of error for most calculations not done on a dyno, butt dyno's not withstanding. I know some fellas that can swear they feel the torque increase with their Type-R stickers, too... but we all know how that goes. But maybe your butt-dyno is more sensetive than most people, so I'll give you the benefit of the doubt on that one.

At the end of the day thermodynamics are thermodynamics. You can't change them. If you want to burn money on stuff, I'm totally fine with that. I completely support your right to throw money at problems left and right. Spend $15,000 on 2lbs of weight reduction and 1hp increase. Lord knows I've wasted money on many-a-car chasing rainbows and the need to believe that you didn't just spend $3000 for little to no improvement is strong. I've been there. I understand. This is like trying to argue with an audiophile about how wooden knobs and $10,000 power conditioners make the sound "richer" and "fuller."

I just have a problem when others entice people to waste their time and money on something that is simply not possible through all known laws of physics and thermodynamics. Lets stick to the known sciences and not woo-woo magical beans and psychic airflow.

I've said what I have to say here on this subject and I don't want this to turn into a flame war, so I stand by my statements and believe they stand on their own merits at this point. The rest is up to the reader.
Hi Nitrowolf,

I do believe I am in your camp, with how I see an IC to work.

What I do know, on full throttle the heat generated inside the intercooler is phenomenal! The ability of the metal (capacity) to absorb more heat over the stock one is negligible.
These devices are designed to exchange the heat to the outside air ie: air to air intercooler and need heaps of it!

The dyno pulls have returned data, but are not conclusive as only real track conditions swapping one component, at a time, will really prove this one way or the other.

Now these ICs are expensive and they want us to part with our money, so I can't see why the vendors can't sponsor an independent person to carry out tests comparing the different configurations and ICs.

Then the argument is over! The real life data will prove it.

:coolnana::nanner:
 

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So when I start my car since there is no airflow to the IC it's heat soaked? Seriously, where do you get this nonsense?

San
Physics. -poke-

Given,
Zeroth law of thermo: if temp A = temp B and temp B = temp C, then temp A = temp C
where
temp A = Before IC
temp B = IC temp
temp C = After IC
things in a linked system will eventually reach thermal equilibrium, so [IC temp] reaches [before IC] -> [before IC] = [IC temp] -> [before IC] = [after IC].

Proof:
Specific Heat equation:
Q=cm*dT
where
Q = unit of heat(energy in transfer). [constant in our case]
c = object in particular's heat capacity(aluminum, air). [constant in our case]
m = mass. [constant in our case]
dt = final temp - initial temp. [variable]

in the case of 0 airflow at equilibrium, aka 0 cooling.
final temp IS initial temp,
then dt = final temp - initial temp = 0,
so Q = cm*0,
therefore Q = 0, aka no heat transfer, ergo heat soak.

---
To take a step back to the original discussion:
Given Q = cm*dT and therefore Q/cm = dT, you may think doubling mass (2m) results in halved change in temp as in Q/(2cm) = dt/2
However, because all things reach equilibrium eventually, it just means it'll just take twice as long.

To put it simply:
If you place 1 pound of aluminum block and a 2 pound block on a heat plate(outputs energy at a constant rate), they'll both will reach the same temperature(equilibrium) as the heat plate. The difference is the 2 pound block will take twice as long. If you get a 100lbs block of aluminum on that heat plate, it'll also reach that thermal equilibrium. It'll just take that much longer.

In our case:
Say, if you hit 'heat soak' at lap 1 with 10lbs IC, you will have heat soaked at lap 2 with 20lbs IC.

To be fair, RLS IC could have better cooling efficiency due to larger surface area and/or bar&plate design when subjected through same amount of air.

IC is a device that depends on forced convection. The way to make it work better is by forcing more air through rather than adding mass. Besides, who'd want to add mass to the highest point away from the CoG?
On the other hand, A2W cooling would be more dependent on 'thermal mass', especially because water is has HUGE thermal capacity at ~4200J/kg*K. It takes a huge amount of energy to raise a kilo of water 1degreeC. It will stay at initial(ambient?) temperature for longer before it goes up in temp. Aluminum is comparatively tiny at ~900J/kg*K it'll go up in temp at the slightest chance.
Interesting thing is once the water in A2W heat soaks(eventually, preferably not before the race end), it'll just be as useless as heat soaked aluminum IC.

The point of my wall of text is not to bash RLS. I love their product. I'm just discussing science here.

---
West oz loti, there's no 'camp'. It's true whether or not one believes in it.
Prove me otherwise, then I'll stand corrected.
 

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Air speed in Intercooler compared to road Speed

Andy, I was looking at your data on the airflow velocity in the intercooler and tried to look at it another way. I tried to calibrate the vertical axis in the same units (mph) as the vehicle speed.
With your corrections (between average IC airspeed versus sensor), I end up with the flow through the IC approximately 5% of the vehicle speed.

This is way below what a front mounted intercooler would provide. Have I got this right?
 

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