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the larger liquid volume WILL take longer to heat up, which means the temp differential between the heat exchanger in the blower and the air will be larger, which means more heat should be pulled out of the air. the fact that this seems to make next to no difference on the air temp would likely mean the brick is too small at the air flow through it to make meaningful difference in heat removal. That is hard to believe. wow.

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It seems that the weight penalty of a trunk tank plus the added cost and complexity would nullify any possible benefit except for ease of adding ice at the track. Great writeup. I'll stick to my underhood tank.
 
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Random84 - I don't recall but did you do a comparison of same pump, hx, lid etc... with underhood tank vs no tank with same weather conditions? Is an underhood tank a difference maker?

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Discussion starter · #104 · (Edited)
Another great write up and comparison. Are you going to compare loading up the bmr and trunk tank with ice?
No - not against the underhood reservoir anyway - I sold my BMR tank to recoup some of my costs. I will probably "ice" the trunk tank setup just for fun; but right now it's a 10 minute drive to Mexico for me so I'm not sure if it's worth the trouble.

If anyone wants to donate $10 towards the cost of a craft beer 6-pack, PM me privately for my paypal address! :D


the larger liquid volume WILL take longer to heat up, which means the temp differential between the heat exchanger in the blower and the air will be larger, which means more heat should be pulled out of the air. the fact that this seems to make next to no difference on the air temp would likely mean the brick is too small at the air flow through it to make meaningful difference in heat removal. That is hard to believe. wow.

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I know, right! I'm thinking there should have been a big difference if only because I'm using 3-4x the water volume. I DID see a nice improvement when I added the underhood reservoir - so there are a couple of possibilities here that I hope to clarify when I swap out for the stronger pump and mess with dexcool/water wetter, etc:

Option 1: What you've suggested - the brick is the bottleneck in some way (and anything beyond an under-hood reservoir is negligible in benefit).

Option 2: Because I've significantly increased the circuit resistance with the trunk tank (40+ feet of 3/4" hose); the SAME pump as the underhood comparison is not able to achieve an equal fluid velocity; in other words it's likely that with the bigger intercooler circuit using the same pump, I have significantly REDUCED the fluid velocity, but that the added capacity is offsetting the loss?
Perhaps a stronger pump will help me realize the benefits of this extra fluid volume by pulling more heat per second out of the brick with faster fluid flow (since I probably have less flow than the underhood setup)? In other words, I DID get a bump from a stronger pump when I swapped my varimax for a standard EMP. I DID get an improvement from capacity by adding the BMR underhood reservoir.
So.... now that I've added significantly more capacity so perhaps the PUMP is the limiting factor (second to the brick) and the velocity just isn't enough to give me the IAT2 reduction I was expecting. There has to be some matrix of volume vs restriction vs flow with the brick being a constant - I just may be to the extreme side of that equation now (lots of capacity, lots of restriction, and an underpowered pump)

Option 3: There may be significant benefits to dexcool/water wetter improving energy transfer (underhood setup) versus my preliminary testing here, which is straight water. Because I'll be changing things out I don't want to waste additives until the final setup, at which point I'll be adding that stuff back in for winter and we'll see if I can get any decent comparisons.


It seems that the weight penalty of a trunk tank plus the added cost and complexity would nullify any possible benefit except for ease of adding ice at the track. Great writeup. I'll stick to my underhood tank.
It's still early. See my comment above in this post - there are a few more things to consider. But the short of it is, I am right there with you: so far I have not seen any reason to favor a trunk tank at this point over an under-hood setup... BUT I have not used the reprogrammed pump yet either. People seem to think trunk tanks are better, so maybe I've done something wrong (or they're all mistaken)?

There is ONE thing I like about the trunk tank: it doesn't keep a box of water directly over your ECM, it unclutters the engine bay and makes changing spark plugs a HELL of a lot easier! lol. So for many of us who are always tinkering, having that Norcal or BMR tank sitting there with all the hoses can be a real pain sometimes. And putting the EMP pump in the fender well can also make it really hard to prime the pump / prevent airlocks whenever you open the system to add ice, ietc.

Random84 - I don't recall but did you do a comparison of same pump, hx, lid etc... with underhood tank vs no tank with same weather conditions? Is an underhood tank a difference maker?

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See my post above - and the links in my signature. The underhood tank DID give me a noticeable improvement - more than the EMP did vs the varimax - which is why I've been saying "CAPACITY!" is the king of the intercooler system for some time.

But I am not getting results that confirm that so far with the absolute King of Capacity: a 9 gallon tank with another ~1 gallon in the lines - so IF I get a nice improvement with the overclocked EMP pump, it just means I've added so much resistance to the system with the extra hoses and whatnot that the "Maxed out" Stewart will be required for a trunk tank setup to be advantageous. Again, that data will hopefully be coming in over the next week. I plan to swap pumps out today.

Now I'm interested in what all those guys with Aldo tanks and Rule pumps are seeing IAT2 wise - I can't say I've seen an honest comparison but the impression was always good.
 
Discussion starter · #105 · (Edited)
Just swapped out the pumps - noticeable increase in circulation. Still very quiet - but at 25 Amps that bitch will drain your battery fast!

I could watch battery voltage drop on my ampmeter:

Image


Original pump was only pulling 5 Amps- were going to see what the set speed was but that might explain the lackluster results.

Also the Max speed pump tends to stay about the same temp as the coolant to my infrared temp gun.

Two pumps, one tank coming up!
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I'll chime in with a little engineering input for what it is worth. Once you have proper flow sequence and enuf tank volume (volume of cold water and proper in/out nozzle location to avoid short circuiting the tank) to support the duration of your acceleration run with a constant supply of cold water, then it's all about maxing water flow rate aka velocity thru the brick to improve heat transfer and therefore IAT2 performance. If you have a very high water flowrate you can increase IAT2 performance just a bit more by flowing water into the top nozzle of the brick ... but, you need alot of flow to flood the brick for this to be effective.

So maximize flowrate by installing the highest flowing pump you can fit, minimize hose run lengths, bends (especially tight radius 90's), entrance/exit losses and run as large a hose diameter as you can. Make sure you feed the pump with a long smooth straight run into the pump suction, and if you can mount it below the tank to increase net positive suction head then do it to help avoid cavitation. Arrange the pump so that acceleration of the car will not push water away from the pump suction. And do not forget the brick entrance and exit losses as the stock brick nozzles are restrictive, open them up and smooth them out and upgrade them to as large a hose connection as you can run. Consider upsizing and relocating the nozzles on the exchanger & tank to minimize hose length, bends, diameter changes, etc.

I'll try to replicate your 45-130 run tonite and post up my IAT2 results.

Edit for IAT2 results ... started in 3rd and let it shift to 4th around 7k rpm, takes awhile vs starting in 2nd, passenger taking video to capture IAT2's same as before.

45-120mph run at 90degF ambient started at 105 ended at 120degF
45-130mph run at 88degF ambient started at 100 ended at 118degF
 
Discussion starter · #107 ·
Edit for IAT2 results ... started in 3rd and let it shift to 4th around 7k rpm, takes awhile vs starting in 2nd, passenger taking video to capture IAT2's same as before.

45-130mph run at 88degF ambient started at 100 ended at 118degF
Very nice!

That's exactly why I start in 3rd gear - 2nd is traction limited and I wanted a longer pull for maximum heat into the system.

I will see what happens with the new pump over the next few days, and try to match that.

What is your pulley ratio?

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What is your pulley ratio?
2.55/9.1

On my old IC setup from Vengence Racing (track attack, ZL1 lid, POS aftermarket pump, no tank) the car would go into thermonuclear meltdown in the summer months after a single 3rd or 4th gear pull ... 150 degF IAT2's.

When I decided to redo that POS system I left nothing untouched, unbelievable how little the aftermarket companies know about how to design, upgrade, and optimize these systems ... all they seem to do is bolt parts on and try to make them look pretty. And we the consumers are partly at fault, we want to be able to buy any single component and bolt/hose it in with the remaining stock components, and we want it to look good and be comparable to what all the cool people run on their cars.

Previously I had consulted with D3PE on the design of their ZL1 intercooler system so knowing it was well done I started with their CTSV kit and improved it to optimize water flow rate. I mapped out my custom hose routings and specified the new location and angles for all 1" nozzles to achieve the shortest possible hose lengths and the most efficient inlet/outlet config for both flow, heat transfer, and cold water utilization in the tank(this last step is important to avoid short circuiting hot water from inlet to outlet nozzles). Then had my buddies at D3PE weld up my new nozzles and here we are. Could have done more optimization on their heat exchanger design but could not justify the spend and development time.

If doing another system, might be tempted to install a killer chiller in lieu of my D3PE heat exchanger, insulate and store chilled water in the tank, would make a more aggressive pulley ratio (perhaps do a Jokerz max ported blower to lower discharge temps???) a consideration, and never have to worry about IAT2, ever, unless something fails. Might be "cool" to see hoses and the ZL1 lid inlet manifold sweating under the hood lol. Would need to verify the pressure drop on the water side thru the killer chiller at my flow rates to know what mods would be required to optimize my system around their hardware ...

Sorry for the thread dump, please forgive.

EDIT ... Helping a friend setup a killer chiller on a boosted C7 (target >>1000whp), we setup a test bench and did some flow testing on the water circuit and with a reprogrammed EMP flowing thru a killer chiller exchanger (welded plate exchangers used on both killer chiller and interchiller setups), lots of 1" hose, tank/reservoir, and a large air-water dual water pass IC core, we were getting ~19-20 GPM!!!! We substituted a ZL1 lid/brick that had opened up inlets/outlets and we still achieved ~17-18 GPM!!!! I havent flow tested my CTSV setup but looking at the above test data suggests my CTSV system is flowing 15+ GPM on the water side, the more flow the better the IAT2's.
 
Twokrx7 you got any photos of you install sounds very thought out.
Everything is hidden by the bumper and I don't take many pics during a build, not big into documenting my builds as I typically do the next build very different lol. You can do a search for D3PE CTSV intercooler and see their typ install pics. Recall I hung my EMP from the bumper support just behind the exchanger, it's cooler than being behind the radiator and I could not get it to fit behind the radiator as it was too tight for my tastes.

Here's an underhood pic, you can see the 1" lines to/from the lid and the 1" nozzles on the lid inlet manifold, and the D3 fill cap in the bottom left of the pic.
 

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My 5 gallon trunk tank keeps iat's in check much better than my underhood tank could. This is comparing both at the track with ice.
 
My 5 gallon trunk tank keeps iat's in check much better than my underhood tank could. This is comparing both at the track with ice.
Ice is a game changer, I need to try it one time just to see if my gage will display a number in the 30/40's. I keep pure water in my tank so the V never see's the outdoors in freezing weather ... cannot put any power down with winter ambient temps anyway.
 
Discussion starter · #114 · (Edited)
No ice tests, but clearly the more ice the better.

Here's my results:
UPDATED with preliminary 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:
Image


Second test: I compared the standard speed Stewart to the MAX speed repogrammed stewart in only the trunk tank setup. I purposefully used a test where the MAX speed pump had the disadvantage of a +6* F ambient temperature - yet the IAT2 curve was flatter and the peak IAT2 temperature was lower! 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:
Image


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:
Image


Last test: I added the underhood tank / STD pump data with the trunk tank / STD pump run, and then the worst-case scenario MAX speed pump run 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:
Image


You can see that the IAT2 curve is notably more blunted, and does not peak as high, as the other tests. 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, such as the Track Attack, 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.


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.

Finally, understand that there IS variability in my measurements and datalogs. Your mileage may vary - and there is quite a bit of variability in my testing, much less from one person's car to another, measured air temp, vehicle speeds, humidity, etc. 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 "water temperature" as we're measuring the flowing air heating the IAT2 sensor, that also transfers heat to the intercooler system (there is no intercooler temperature sensor) - but it's as useful a approximation as I can come up with for these purposes to measure "heat."

Enjoy!
 
Discussion starter · #115 ·
I put in a request to D3PE to see if they'll hook me up with a discount - but I'm not holding my breath!

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So it looks like you got the result you didn't expect with the STD vs Reprogrammed pump difference being huge. Dare I say you might have benefited closer to 20* differences in temps on the trunk tank if you started at the same temps STD vs Balls out EMP? That is a HUGE difference and actually more than even I expected.
 
Simple thermodynamics and heat transfer principles here, increase water velocity in the brick (or exchanger/radiator) and you improve heat transfer coefficient, in this application it means lower IAT2's. Velocity is the key to my IC system's performance.

random, get those velocities up some more by reducing pressure drop in the plumbing system and you will see IAT2 performance continue to improve. Beware, installing the D3PE exchanger is a PIA, gotta cut away a bunch of the bumper support.

If you see improved performance adding water wetter product I will follow suit as I'm running pure water IIRC
 
Just thinking out loud.... Any thought to running a second pump right before or after the SC lid? That's a lot of fluid that pump is pushing and a second pump could help velocity and pressure drop in the brick.
 
Discussion starter · #119 ·
So it looks like you got the result you didn't expect with the STD vs Reprogrammed pump difference being huge. Dare I say you might have benefited closer to 20* differences in temps on the trunk tank if you started at the same temps STD vs Balls out EMP? That is a HUGE difference and actually more than even I expected.
Yes, I will get some better readings with the MAX stewart in various weather over the next few weeks - but it was so obvious even with the disadvantageous temp difference I wanted to go ahead and post up data.


Simple thermodynamics and heat transfer principles here, increase water velocity in the brick (or exchanger/radiator) and you improve heat transfer coefficient, in this application it means lower IAT2's. Velocity is the key to my IC system's performance.

random, get those velocities up some more by reducing pressure drop in the plumbing system and you will see IAT2 performance continue to improve. Beware, installing the D3PE exchanger is a PIA, gotta cut away a bunch of the bumper support.

If you see improved performance adding water wetter product I will follow suit as I'm running pure water IIRC
I have not heard back from D3PE, so comparing that one will probably not happen - and I'm not spending another $500+ on a tank/relocation kit for shits and giggles; as much as I'd love to see if the 1" hoses and shorter travel would further bump things up! :)

I will get some water wetter/distilled water for the "final fill up" after i get a few more runs in this week. Check back, as I will post up the results either way!

Just thinking out loud.... Any thought to running a second pump right before or after the SC lid? That's a lot of fluid that pump is pushing and a second pump could help velocity and pressure drop in the brick.
Although I initially was not a fan of one pump feeding another, I'll say that using a rule to increase head pressure for the EMP is probably a great idea (others have already done this for some time, I've just never seen a comparison of them). The EMP NEEDS positive head pressure for maximum performance, either a smaller pump to feed it or gravity feed from the tank. A Rule+Stewart will have more velocity/pressure than a Stewart alone - but by how much I don't know.

Using dual pumps is great, and makes the Stewart EMP installation more flexible: you can keep the stewart in the front fender area (see my other threads), and use the Rule or similar to push air out of the lines and increase head pressure for the Stewart. Of course dual stewarts would be even better - but that's a steep price to pay and almost 50 amps of draw for your intercooler system; so that is unrealistic. !)

For me, I wanted to simplify somewhat, and using the single Stewart is good enough at this point. If I can do a 10+ second pull on the street (130+ mph!) in 85*F weather and not break 130's in IAT2, I am happy.
 
thanks for doing all this testing and documenting. I'm in the middle of my build and have not installed the trunk tank yet. I'm thinking of selling my trunk tank and going to a front fender tank as it appears flow is more important than thermal mass of the system. thermal mass helps but the fact that to add significant volume means rear tank and reduced flow due to all the piping it appears the benefits are nullified.

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