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Discussion Starter #1 (Edited)
You wanted it, you got it!

Part 1: I'm going to post a complete how-to installation thread with suggestions, pitfalls and all of the collective Forum wisdom compiled into one place. There are several great threads and references, but it's time to have a single depot for this popular - yet deceptively frustrating modification.

Part 2: I'm going to datalog a standard Stewart EMP vs a high output / "reprogrammed" Stewart EMP and see how much that extra RPM makes. Feel free to save all of the bickering for a different thread!


(Please be patient - I am finishing up the installation and photos today; pump comparison over the next few days)


Introduction
Basic premise: the key to low IAT2 temperatures in this platform is fluid capacity. In my previous tests, adding an under-hood fluid reservoir, such as the BMR, NorCal or others, I saw a significant IAT2 reduction during WOT pulls relative to baseline. When I then swapped out the Varimax for a standard Stewart EMP W29 pumps, I found further improvement - but not nearly to the degree as when I simply added more fluid volume to my setup. I also suspect this is partly why the "Track Attack" and other aftermarket heat exchangers do so well: they are much larger than the stock unit and thus add fluid volume (in addition to larger cooling surface area, fin design, etc).

In other words, the bulk of heat creation is the supercharger, and the primary means of expelling this heat is airflow over the heat exchanger. The intercooler fluid is just the vehicle for moving this heat energy from one place to another - and in any given system, the heat exchanger is limited by:
* how much heat energy can be transferred from air to water based on the fluid (dexcool vs straight water),
* airflow or vehicle speed and atmospheric conditions,
* the intercooler fluid velocity / circulation rate,
* and the cross-sectional area of the heat exchanger.
These are big picture assumptions on my part, so don't take me to task on tiny details. BUT, for the purposes of testing we will try to mitigate as many of those variables as possible and I will focus primarily on the differences in increased capacity (5x or more that of a stock system) and lastly the differences in fluid circulation.

Both of those referenced comparison tests above (reservoir tank and pump comparison) were done using 3/4" hose, deleting the factory metal "hard lines" from the intercooler system and using a ZL1 lid. I did my best to keep the dexcool ratios similar; and limit the little design tweaks that inevitably crop up, like hose length, routing, the number of fittings or sharp bends, etc.

Ergo, the mother of all capacity increases: a ~10 gallon trunk tank. Yay, Wagons!

Part 1:
Disclaimer: You are going to have a large water reservoir in the trunk of your car, with electrical connections / terminals and the very REAL risk of a leak at some point. Bear this in mind when running cables, fuses and securing unused connectors up and out of the way. You WILL need a "drain" for the trunk, as pumps, fittings and water filling will inevitably leave you with overflow that needs a way out.

Costs:
A tank made to my custom specs ($250)
A Stewart EMP pump ($450)
50 feet of 3/4" ID heater hose ($50)
10 feet of 1" ID heater hose ($20)
Assorted hose clamps ($10)
Assorted hose adapters ($30)
Assorted wiring connectors, etc ($10)
4-5 gallons of antifreeze ($100)
Approximate cost for the DIY project: $900+
Time for installation: 6-8 hours

General Concept:
* You don't need a huge tank. I went with approximately ~10 gallons, and it's probably twice as big as I really need; and water is heavy! Check below for suggestions on a better tank!

* You WILL use 3/4" ID hose for the bulk of the runs and in wheel wells. I've tried more than once to get 1" ID hose to work and it's just too big of a jump to fit without excessive kinking. Since the Stewart pumps use 1" outlets, you will need a few feet of 1" ID hose, and some adapters. These are uncommon, so you'll either need to source them online or buy a few from me (have have several extras!).

* Recommended Routing:

The benefit here is long contiguous runs of hose, that will NOT be exposed to road hazards or visible from behind, and only two fittings are needed (the 1-3/4" adapter and a 3/4" 90" elbow for the rear rocker cover transition). You also won't have a bunch of holes in your subframe from an Aldo install like TriTexan (haha!).

* Alternate Route:

The hoses run straight down from the trunk area using bulkhead fittings - the hoses have to be secured near exhaust or onto the frame rails as they travel up, and pass through the inside of the engine compartment right next to your headers / exhaust. This is arguably a more labor-intensive, and less efficient way to do the installation. Example here:

Here's an example of the tank design itself:


Starting off: MEASURE THREE TIMES, CUT ONCE! You don't want any unnecessary holes in your trunk. :D

Step 1: Visualize the layout of your tank, and where your hoses will run. Test fit often as you go. DO NOT CUT ANYTHING until you have your tank - and don't order your tank until you really think about what you're trying to do, and whether or not you will modify anything beyond my suggestions here (ie a nitrous bottle or other goodies nearby).
Here is the general layout: a custom tank, two hose connections and room for a pump. Although we have generous space in the spare tire well, each variant (Wagon, sedan, Coupe) will have slightly different dimensions, etc. Again, check below for suggestions on how to custom build your own tank for $250 or less.


Here, a hose is exiting the spare tire area over the passenger-side muffler, from the tank shown above:


Note: I've run the 3/4" hose over the gas fill to help support it - NO need for drilling hose clamps or mounts at any time.

Step 2: Time to cowboy-up! Using a metal hole saw of 1.25" diameter or up to 1.5", cut a hole in the rocker transition area as show. I suggest cleaning up with degreaser and applying a rustoleum product to limit future rust.


Note: this is the one area where you're likely going to kink the hose. It's very tight, but either leave plenty of slack or consider a 90* elbow fitting here to ensure full flow. You'll push the hose all they way to the front of the car before cutting or splicing, to make sure you have enough. MEASURE THREE TIMES, CUT ONCE, asshole!

Step 3:
Remove the front wheel liners by popping out the plastic retainers. Very easy, and there is plenty of room to run hose here, and I secured mine with zip ties using existing holes in the body panels.



Step 4: Decision Time!
IF you are a daily driver like me, and will not ice very often - run your hose through the front of the car to the passenger side fitting of the Track Attack. The Track Attack is non-directional, no need to cross back and forth. The idea here is your coolant will be cooled off by the heat exchanger and then go straight to the supercharger (then the return line to the back of the car).
IF you are primarily a drag racer, or you throw a bag of ice in the trunk every morning before work... then you will use the "alternate" route: run the hose up through the passenger side front quarter panel, near where the ECM and hood latch are. There you will see how you can easily reach the lower inlet of your ZL1 (then down to the heat exchanger)


I chose to use the first option, and that is what I'll outline here: The hose running to the front of the bumper / heat exchanger:



Step 5: I used the Dayco hose to tackle that tight area on the driver's side of the Track Attack, and ran that up to the ZL1 lid - it fit without any need for splicing additional hoses.


Step 6: Run your hose from the supercharger to the driver's fender, down to the rocker and back to the driver's rear wheel just as you did moving to the front of the car on the passenger side:


Step 7: Time to nut-up again, and drill another hole for for the hose to pass through the rear of the rocker cover:


Step 8: Up and over the wheel well - you'll have to lean on that liner cover to get it back in place with the hose there. Check your fit frequently - but again no need to drill or secure the hose.

Step 9: Drill another hole in your trunk on the driver's side, to get the return line in there and run it over the muffler. The muffler does not get hot enough to melt heater hose (I tried) - but I secured the hoses on both sides up against the frame by then using metal zip ties and running them through existing holes.
Note: If you don't have enough room with the wheel liners loosened or off, you can also easily drop the muffler: using silicone lubricant, pop off the three rubber hangers with a large screwdriver - no need to take the exhaust apart. I used more zip ties to wrap my heat shielding around the hoses for good measure:


Step 10: Secure your hoses to the tank and pump: You'll wind up with something like this:


Regarding the spare tire well: Remember that the spare tire area is thin metal, so any elevations (such as the hump for the spare tire attachment) can easily be hammered down for clearance - no need to cut them out. It is very easy to cut through this material and bend it to shape (see drain petcock photo below).

Step 11: Install the drain petcock. Thankfully, due to running the hoses in the rocker panels, this install is almost invisible from the exterior. The only visible portion will be the drain (for icing, etc), and the drain / thread size will depend on what you specify when ordering your tank. You may need a small extension so that the drain valve can be turned without interference.

Here's mine (1/2" NPT ball valve w/ a 1/2" extension for clearance):



So is it LOUD?
Actually, no - even with the unsealed area near the petcock, the Steward EMP is a very quiet pump. It sounds much like the fuel pump energizing: the radio has to be off, and you have to be expecting it to notice. I have not even secured the pump yet and there are no obvious noises or vibrations from the driver's seat (with the trunk cover open, no less). The short of it is, I can't tell it's even there under normal conditions.

[continued in next post]
 

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Discussion Starter #2 (Edited)
Wiring in the pump:
Wiring your pump - if inside or near the rear of the car, is rather straight forward. It's even easier with the Stewart pigtail that comes with your pump. Using quality connectors, we will tie directly into the (+) and (-) battery leades, as well as use a key-on signal in the fuse panel directly above the battery:



The key-on source will most likely be a grey or green wire in this location, but may vary (or not exist!) in 2009-212 years. I recommend you use a voltmeter to verify ANY signal before hard-wiring your pump harness. If you screw it up, you'll either get a dead battery the next morning (since your pump ran all night), or the pump won't energize.

Use quality connectors and sound techniques for your 12v leades, and make sure any connectors are elevated or ziptied out of the way. Think about the inevitable water leak, and where will that water go?

Building your tank:
Step 1: Mock up your tank using cardboard boxes! Really think about where you want your hoses to enter/exit the trunk area; raise the car and measure/inspect for variables like muffler placement, suspension pieces, etc. I did this and still wound up wanting to do it different! Don't forget to account for the hoses wanting to kink with too sharp of a bend, so you may need to factor in pre-formed hoses as I did. Think about how your pump is going to sit in relation to your tank.
I personally did not want to utilize a Rule bilge pump, as they tend to fail after 1-2 years. My goal was to see if I could get a single Stewart W29 to work, and that's how I designed my system. HornEtrader has had success with two pumps as have others, and it seems to work well - but that was not my goal here.

Step 2: Mock it up again - now think about where you want your outlets, and where you want your drain, and how the tank will be secured in your trunk area. Think about the orientation that your pump can/will be mounted (I screwed up here). Assume one gallon of water is around 10 pounds - that adds up. You want your pump to sit LOWER than the tank outlet, to prevent air lock! so keep that outlet around mid-level on the tank.

This is what I sent to Chisledperformance:


Regarding the spare tire well: Remember that the spare tire area is thin metal, so any elevations (such as the hump for the spare tire attachment) can easily be hammered down for clearance - no need to cut them out.

Step 3: Order your tank and wait. I used http://www.chiseledperformance.net and had this custom tank shipped to my door for under $250, and I received it in ~3 weeks. There are others; caveat emptor.

Here was my tank: Note the 1 1/4" outlets, the extra drain on the side (a mistake by the welder) and the wire mesh for icing.



Here it is installed - it turned into a bit of a hodgepodge because I neglected to think about the unique mounting requirements of the Stewart, as well as how "bendable" the various hoses would be. Learn from my mistakes. !)



Basic trunk tank recommendations:
I suggest you limit your dimensions to around 5-6 gallons.
Think about any trunk covers or other items that you want to preserve - allow yourself at least a 1/2" margin of error in every direction when having a tank made.
Use 1" inlet/outlet fittings (likely 1 1/4" NPT threads on the tank) - source these first to ensure compatibility.
Use a single drain petcock - but source this first so you know what threads to specify... Typically 1/2" NPT
Don't try to squeeze anything else into the trunk space
Consider using a Rule to feed the EMP in a front-mount setup, I think that actually makes fitting the tank easier given the mounting requirements of the Stewart. See this thread for suggestions on mounting your Stewart at the front of the car.


RESULTS!

First test: using the same "standard speed" Stewart pump from my underhood tank setup last year, I compared IAT2 to the new trunk tank setup - which has roughly 4-5x the water volume as the underhood setup. Pump speed was the same - HOWEVER remember that total RESISTANCE to flow has increased dramatically. This means the fluid velocity was likely noticeably slower with the trunk tank setup. After all, it takes ~40 feet of 3/4" lines to run from the trunk to the front of the car - and yet, no major difference in the IAT2 curve (accounting for gear changes) or in maximum IAT2 observed after a run:


Second test: I compared the standard speed Stewart to the MAX speed repogrammed stewart in only the trunk tank setup with identical ambient air temperatures (78*F about a week apart). Clearly, the MAX speed pump was able to overcome the additional resistance noted above. As other members have mentioned, the primary way heat is expelled from the intercooler system is the temperature delta of the water in the heat exchanger relative to ambient air temperature. Faster flow = more heat dissipation:



IAT2 delta was 15* lower for the reprogrammed pump - that is a NICE looking curve! I do have a similar comparison against the underhood circuit from last year, it was almost identical to the standard speed IAT2 curve plotted above so I won't clutter up this post with another graph.... Clearly, "speed" wins!

Third test: Next I compared the MAX speed trunk tank to some data logs I have from the original "standard speed" underhood setup. The trunk tank wins... BUT that's likely due specifically to the additional fluid velocity (beyond that of an underhood tank!); after all, I previously showed that markedly increasing total fluid volume by itself didn't do much:



Last test: I added the underhood tank / STD pump data with the trunk tank MAX and STD pump run all with the same ambient air temperatures in one final graph, to show that by my best ability to measure, the primary benefit to all of this shit was a stronger pump:



I have multiple comparisons that validate this overall comparison - I think it's fair to say that although there are other variables, the MAX speed reprogrammed stewart pump is the single largest contributor.

-----------------------------------------------------------------------------------------------------------------

Upcoming tests, weather permitting:
Hose routing: I will be switching to the "alternate" hose routing outlined in my first post - so that the hottest water from the intercooler brick goes to the intercooler, maximizing the "delta" of coolant temperature to that of ambient air. That should hopefully reduce water temps in the tank and increase heat shedding.

Additives: After this (or maybe at the same time), I will be adding ~3 bottles of water wetter to the system, and seeing if that makes any appreciable difference. After all, my trunk tank data so far is all using straight water, but the "underhood tank" data had some dexcool and 1 bottle of water wetter in it, and it's possible that accounts for a few degrees in IAT2 measurements.



RECOMMENDATIONS:

At this point, for simplicity and cost, my recommendation to anyone without a coolant reservoir is this: an underhood tank of your choosing (Norcal, BMR, D3PE, etc), a reprogrammed Stewart pump, and use 1" hose as much as possible. A larger aftermarket heat exchanger is likely beneficial... but I never tested one by itself. !) Lastly, I would say the ZL1 lid is still helpful, but I would put it last on the list due to cost.

*** Remember that I DID get a beneficial improvement in IAT2 with the underhood BMR tank! So more volume over the stock system IS a good thing. I just had "enough pump" to utilize it, and drastically improving volume further with the trunk tank just didn't give me the "WOW!" effect I was expecting, being offset by the additional resistance. So some extra volume is still good - it just looks like 1-2 gal is great, but 10 gal is too much.*** The stronger pump makes a much bigger difference in this scenario.

The trunk tank will be useful for drag racers specifically for allowing the maximum volume of ICE - but for a daily driver I do not recommend it. It's slightly more costly, but the length of hose needed to go from the trunk to the engine then back again is significant, and it's very challenging to use 1" hose. So you're adding what I believe to be significant resistance in the form of 3/4" hose over ~40 feet that is just not needed for a daily driver.


Lastly, understand that there IS variability in my measurements. Your mileage may vary - and there is quite a bit of variability in my testing, much less from one person's car to another. I've done my best to mitigate variables but at the end of the day it is what it is. I recommend taking other members' results with a big grain of salt as we're all using different combos, coolant ratios, hose sizes, etc; so saying one guy sees "___ over ambient" is likely not an apples-to-apples comparison with my combo and my testing.

And I am limited by my resources, my time and my patience, so this is not the be-all for cooling system efficiency, BUT I think it's a pretty good groundwork. IAT2 is NOT a direct comparison to power, nor is it a direct equivalent to literal "air temperature" as the air is heating flowing water that is being read by my IAT2 sensor - but it's as useful a approximation as I can come up with for these purposes. I may add additional comparisons as I acquire more data over the next few weeks.

Enjoy!
 

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WHAT! No updates yet? It's already been 20 minutes /ragequit
 

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Discussion Starter #6
Will you also monitor amp draw and supply voltage?

This will probably earn a sticky.
I can check- I have it up and running so I will get the install part done. Have to chase a few leaky connectors and putz around with some possible kinks in the hose, but I'm starting with the standard pump.

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sub'd, thanks Random!!
 

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What tank are you using? Very interested especially if I can remove my under hood ice tank only because it makes working on the motor on the passenger side a nightmare. It works and fits perfectly though.
 

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Awesome thread. Some pics aren't working.

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This has already been done by Hornetraider. Lol

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To be fair, the videos on my channel were just when I reprogrammed a pump. So it doesn't demonstrate the restrictions that a V would have since it's essentially an open loop.
 

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Discussion Starter #14
Awesome thread. Some pics aren't working.

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Give me some time, kids. I know it gets lost in the shuffle, but I have kids, a wife and a sore back so it will take a few days to get all the links and data in there.

I will also be going over some tank sizing suggestions based on my mistakes. :D

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Discussion Starter #15
This has already been done by Hornetraider. Lol

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That's like saying "Hey Sal, Ben already makes an aftermarket splitter."

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That's like saying "Hey Sal, Ben already makes an aftermarket splitter."

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Sals out of the V game first person..... I think he's buying a Vette.

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Discussion Starter #18

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Yes but in that case mine is far better and costs half as much. Plus I actually reply to my customers but we're getting off subject. LOL

It was a joke dude. Check your panties for a knot. ;)

Everyone's so fucking touchy these days.



That's like saying "Hey Sal, Ben already makes an aftermarket splitter."

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