DIY air to water intercooler

This is the documentation of my Air-to-Water intercooler setup (AWIC). I am basic stage 2, running E85 in the summer.

 

Why Air-to-Water?

 

·I want to do something unique and different.

·I want a clean and clutter-free engine bay. FMIC pipes aren’t too bad, but they are big.

·I wanted a TMIC but with increased cooling characteristics to a traditional TMIC. I am actually going to test the efficiency of the Water-to-air IC to see if this is really the case.

·Running water lines is simple and easy, which allows me to do it on my own.

 

What did it take?

 

Here is my full parts list with pricing:

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/awic_part_list_jpg.jpg

 

Possible ways to cut costs from the above list:

 

You could cut some costs, such as the AVO TB hose. I was just sick of dealing with the foreskin on the stock hose. It bothered me. The AVO hose made things a little more difficult because it is longer and just as stiff - so it really forced me to wiggle everything around to get it all to line up. Its a nice piece. I used a t-bolt clamp on the TB, highly recommended.

 

You could also recess the AC condenser a little bit so that the 7" fan that came with the kit will fit behind the heat exchanger. I moved it a little bit to fit the SPAL fan, but noticed it could probably be moved more, which means the fan that came with the kit (which is .5" deeper than the SPAL) might have fit with some work. I wanted a nice SPAL fan, though the one that came with the kit did not look too bad.

 

Just those two items lower the cost about ~$115.

 

That being said, I got such great deals on the other items that it just might be a wash. For instance, the welding and flanges were cheap, and I made my own overflow can. Anyway, you could probably put together a kit for slightly less.

 

 

Why did I choose what I did?

 

·TMIC – This intercooler was small and easily fit where the stock TMIC goes. It was rated for 450 CFM, which is plenty. The inlet and outlet are in a good location, and from what I read this is a good end-tank configuration.

 

·Heat Exchanger – The size fits in the bumper well. Also, it is a dual pass, meaning the water goes across the top, makes a U-turn, and then goes across the bottom. PROS: water velocity is higher, CONS: The hot water immediately hits only half the vertical surface area rather than the whole area (single pass style). From my research, having the velocity and lower restriction is slightly preferred to having the single pass. This is subjective. In reality, the water is exposed to the same surface area, just with a different flow path. It will have a hotter spot right at the inlet.

 

·Pump – Well, it came with the kit. BUT, I did do my research. I contacted the company that makes the pump and it is rated for 600 hours of continual use without burning up the motor. It is rated for 500 GPH under continuous use which is 8.3 GPM. This is right around the other flow-rates I have seen for AWIC packaged systems. The motor is water-cooled so that is nice (hopefully it’s not heating up my water too much). It can also be used with glycol-based coolant just fine according to the engineer I spoke to. It also allows you to swap the motor in and out of the housing in case it does fail. Further research showed that people we really happy with this pump. I will use it until it gives me a reason not to.

 

·Hose – I chose ¾” hose because the pump had these fittings and it just kept things simple. The more fittings, the more restrictions. The filler cap also had these fittings. It might be overkill, I have seen 5/8” on other systems. I found a good flexible hose, and it fits in the space well. No sharp bends were needed with my routing.

 

·Brass fittings – They are common and not too bad on the wallet. They should work fine.

 

·Mixture – 50% water, 40% anti-freeze, 10% wetter. I read this on a few other forums and other manufacturers also recommended this. Until I hear otherwise, it’s what I am going to use. After filling pu the system, it took about ¾ jug pre-mized (50/50) and a bottle of water wetter. So, my ratio is slightly different. Supposedly the watter wetter with the 50/50 coolant has the same cooling properties as 100% water. This is according to data given by Redline.

 

How did you install everything?

 

The pictures are pretty self explanatory:

 

[Pictures with bumper off to come later - there you will see pump and pipe routing and heat exchanger mounting]

 

Cold pipe - its short!

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12375.jpg

 

This gasket works great for the turbo outlet:

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12382.jpg

 

Ingredients:

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12389.jpg

 

I am going to make a shield for the rubber hose over the turbo.

 

The water runs the opposite direction of the air. The cold water comes from the driver's side, then goes through the TMIC, then down the passenger side.

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12384.jpg

 

Bracket makes use of the bolt on the t-bolt clamp. Brilliant!

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12385.jpg

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12392.jpg

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12386.jpg

 

Again, this hose will have a shield for the turbo heat:

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12393.jpg

 

I will get better daytime pics...

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12390.jpg

 

IAT sensor - not hooked up yet:

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12394.jpg

 

 

Efficiency of this system:

 

I purchased 2 GM IAT sensors and I am going to place them at the inlet and outlet of the TMIC. I will then measure the difference between the inlet and outlet temperatures. This will allow me to find out how well it is doing, especially with heat-soak. This data is pending. One sensor (outlet) is installed thus far.

Notes:

 

- The pump was hooked up to ignition 12v - there is a source below the fuse box in the engine bay

 

- The pump runs continuously. It supposedly can be run for long periods of time - some setups trigger the pump off throttle or other ways

 

- I had to trim off the divider in the hood-scoop. It hit the TMIC right at the TMIC inlet because it sits a little higher right there. IT barely hit but I just took the whole divider out.

 

- Heatsoak is a concern - when the water gets hot it will stay hot. Hopefully I will be able to eventually trigger the fan off delta IAT. i.e. when the outlet temp starts creeping up with respect to the inlet temp, trigger the fan. Hopefully running the pump all the time will also help with this. Its quite a large heat exchanger I am using.

 

- After my first drive, though short, the TMIC was not warm whatsoever. In fact the outlet felt cold (because its metal) - but at least I know its not too hot. After sitting after the drive, I could not tell a temperature difference with my hand. Surface thermocouples will really help with quantifying this.

 

- I used an Atmega microcontroller, 5V regulator, and 4-digit display to put together a little module that will read the GM IAT sensors and display them on the screen. A momentary push-button will scroll through inlet temp, outlet temp, and delta. Someday I will drive the heat exchanger fan based off delta. Right now I plan to just hook the fan up to the factory radiator fans which already have some logic built-in. If that is not sufficient, I can have the fan come on more often by controlling it myself. Add a relay and a transistor to the board and I am all set.

 

- If I keep the fan hooked up to the radiator signal - here is the factory logic:

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/Raditor_fan.jpg

 

Here are more pictures:

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12396.jpg

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12398.jpg

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12399.jpg

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/SNC12400.jpg

i want to see now!!

In for pictures...

some pics added.... more to come

Outstanding work. I think you will find A/W setup you have superior to A/A systems....

 

Cant wait to see more results.

 

Again, good job.

Outstanding work. I think you will find A/W setup you have superior to A/A systems....

 

Thanks. Its a highly debated subject, that is for sure. My theory is, as long as I can keep air flowing past the heat exchanger, I am good. Nice SPAL fans and good "logic" should keep that water nice and cool. Since the pump runs continuously, the water is in the engine bay for very little time. That being said, it is also in the heat exhanger for very little time. Due to the volume of the heat exchanger, I think its safe to say it stays in there for a larger percentage of the time.

 

I am staying out of boost for now (for the most part). Just to make sure everything stays connected as it should. Then I will slowly test the strength of my TMIC hose connections. There is only one I am concerned about, at the outlet, because there is a lot of stress on that one. I held it on as I tightened the clamp kinda thing. Its on there good, but it does not necessarily want to be. Maybe over time the hoses will relax, which will help.

Also, you could cut some costs, such as the AVO TB hose. I was just sick of dealing with the foreskin on the stock hose. It bothered me. The AVO hose made things a little more difficult because it is longer and just as stiff - so it really forced me to wiggle everything around to get it all to line up. Its a nice piece. I used a t-bolt clamp on the TB, highly recommended.

 

You could also recess the AC condenser a little bit so that the 7" fan that came with the kit will fit behind the heat exchanger. I moved it a little bit to fit the SPAL fan, but noticed it could probably be moved more, which means the fan that came with the kit (which is .5" deeper than the SPAL) might have fit with some work. I wanted a nice SPAL fan, though the one that came with the kit did not look too bad.

 

Just those two items lower the cost about ~$115.

I would switch it over to t-bolt clamps to help lock it down.

 

Ive been a big believer in a/w systems since my Mr2 days (going way back) we found that you could cut the trunk apart and run scoops to the trunk and lay the Ic flat and have the hot air run out the bottom....and then fabricate a rather elaborate heat shield for the exhaust work, but then the A/W idea got huge, and it proved substantially more efficient.

 

A/A is fine, its 'less moving parts' but when space is at a premium and you are backed into a corner to working/fabricating anyway, the A/W system reaps benefits.

I don't get it, but nice job and I hope it works well for you

I don't get it, but nice job and I hope it works well for you

 

Thanks! FYI - I read all of your posts in ClimberD's original thread about this same subject, so I understand the first part of your statement.

 

Hopefully I will be able to get some data with this to see how well it is doing. I'm the type of guy to try something, analyze the data, and make my own conclusions. If it does not work I will not be upset - its more like a project for me. I just need something to keep me busy and the mouse wheel in my head spinning.

Nice work! I'm looking forward to the data.

subscribed foer results

UPDATE:

 

First - I added pictures above.

 

Second - Did some city driving today. The IC was cold to the touch when I go to my destination. It was 55-60 out today, so not that hot out either.

 

Third - I got into some boost briefly and it seemed to hold boost well. I need to do some logs though, but I want to give it some more time. After I did some spirited driving the turbo was very hot to th touch, and the coupler going into the TMIC was warm. The hot-side of the TMIC felt warm to the touch, but the TMIC outlet still felt cold to the touch. So - I know its cooling. No data yet though.

 

Fourth - I did a lot of driving in closed loop and did some logging. Attached are old fuel correction plots (with stock TMIC) - and some new stuff. Not much data on the new stuff yet. It is colder out than it was with the first set of logging, and the gas here might be changing. So, its tough to compare the differences.

Here are before and after LV's. Looks like I had some timing pulled in the upper end - that must be from the spirited driving I did briefly today. Perhaps I am hitting more boost than what I was tuned on? More load? Its safe to say I will need some additional tuning. I am going to stay out of boost for now.

 

The first image is before the TMIC - I tuned MAF and the engine load compensation table with the stock TMIC on. (tuners on here helped). The second image is with the limited mileage I have thus-far. I did not reset the ECU when I put the new TMIC on. Perhaps I should do that.

So that leads me to ask the question - when you change the TMIC, what are some of the tuning things you will run into? Let's say this TMIC is cooling better, or perhaps has less pressure drop... would timing and WGDC perhaps need adjusted? Does the pulled timing in the upper end make sense considering I did not change the tune?

 

How does winter blend 93 octane effect the MAF scaling? If more or less fuel needed to achieve the same result? Are the changes in winter blend petrol significant enough for it to show up on the A/F learning? I thought the MAF scaling would not change much with a TMIC since I kept the intake system exactly the same.

Rough generalizations:

 

If it's cooling better, your setup just gets safer, since cooler charges are less prone to detonation.

If it's not cooling as well, you're more prone to detonate, so you'd want to tweak the tune to mitigate that (less timing, richer AFR, and/or less boost).

It it's more restrictive, you'll end up with lower boost. Probably safer, but less fun. I say "probably" because there's a possibility that the timing in the lower-load cells hasn't been verified for safety.

If it's less restrictive, you'll end up with more boost, which is more likely to put you into unproven cells, and if not accompanied by increased cooling might also require a reduction in timing.

 

Bottom line is you just need to do some logging and see what's different.

 

You apparently only got one knock event in the high load area, I'm not sure if there's cause for concern yet. I'm not sure what to make of the knock in the low-rev / mid-load cell. The stock tune has random knocks so I guess some noise is normal. To be honest though I'm not sure yet what constitutes acceptable random knock vs. too much. I am pretty sure I erred too much on the side of caution with my current setup, and I've been adding some back in lately.

 

As for the AF learning, it only changed by a couple percent, and they move around some, so again I wouldn't make changes just yet. Also, how certain are you that the trims had stabilized before you took the 'before' learning view?

 

Are you able to datalog from the temp sensors you added?

^^ awesome, thanks for the response.

 

I just did about 40 minutes of CL logging and everything is pretty much the same, just more data points. I did not do an LV JUST prior to doing the install - so perhaps they had already shifted due to fuel, etc. I would rather have a lower value in AF Learning D since it applies that across OL. Does it matter if that number is high? If its "real", I guess that's a good thing its making adjustments.

 

I only got into boost a couple of times, so that is why there is not a lot of knock up there. IAM is still 1.0, it would go lower with more events on the high end, right?

 

I will not be able to log my IAT, but I will drive with someone in the car and have them keep an eye on it. I might be able to log it to the extra memory on the micro-controller and pull it out later. Don't know.

 

After I got off the highway and stopped the car, the TMIC was freezing cold! Even the rubber hoses felt REALLY cold to the touch. The rubber hose right over the turbo (the outlet water of the TMIC) even felt cold - and its right over the turbo. So I am really happy there. I would imagine my IAT at idle is much lower - at least right now when its in the 50's out. That TMIC stayed cold even after sitting for a while. The true test will be next summer though.

It seems like my outside air temp sensor reads a little higher than it did before. Its pretty much in the same location, but now there is a radiator in front of it. The orientation might be a little different too, I just pulled it out of the hole it was mounted to, and snapped it into another hole that was out of the way.

good work. Very impressed with your sensor setup. I had to get my display built by a gauge guy, no idea how you did what you did there. I actually have the same sensor setup you have, believe it or not. At least the IAT GM sensors are the same.

 

Only big difference is you built the thing, as where mine is in boxes in the garage still, and I'm at work being a bum.

 

Holler if you have any specific questions or any issues arise. Chances are I've already found a solution, as I've researched air water to death. BTW, keep an eye on your rule pump. It's built for marine application IIRC. I have the bosch pump, and for $100 it's definitely the way to go IMO. OE on Mustangs and Lightnings and such. That said, if it keeps working, no problem.

^^ thanks.

 

As for the gauge - I used an ATmega micro-controller, some resistors, some capacitors, a voltage regulator, an ISP port, a button, and a 4-digit display. Stuff costs pennies and I had them sitting around anyway. I got the sensors for $9 shipped with connector and everything - I bought two - so $18. All in all, I have less than $25 in the IAT gauging. I will probably put it in a little box and have a window for the display, so it won't be anything pretty... but very useful.

 

Car seems to be running well and nothing is breaking / leaking, etc. So I will probably do some logs and get into a little boost to see what things look like.

 

This BOV is nice. It is very responsive and my shifts are cleaner and smoother for just driving around granny shifting. Its closes more quickly.

 

So far I am liking this. Every time I get out of the car the tubes feel ice cold. And they stay like that for quite a while. Unfortuneately I am out of town the next two weekends so I will not be able to get much progress on this.

^^ thanks.

 

As for the gauge - I used an ATmega micro-controller, some resistors, some capacitors, a voltage regulator, an ISP port, a button, and a 4-digit display. Stuff costs pennies and I had them sitting around anyway. I got the sensors for $9 shipped with connector and everything - I bought two - so $18. All in all, I have less than $25 in the IAT gauging. I will probably put it in a little box and have a window for the display, so it won't be anything pretty... but very useful.

 

Car seems to be running well and nothing is breaking / leaking, etc. So I will probably do some logs and get into a little boost to see what things look like.

 

This BOV is nice. It is very responsive and my shifts are cleaner and smoother for just driving around granny shifting. Its closes more quickly.

 

So far I am liking this. Every time I get out of the car the tubes feel ice cold. And they stay like that for quite a while. Unfortuneately I am out of town the next two weekends so I will not be able to get much progress on this.

 

Very impressive. I'm not an EE, so I had a guy build my one-off display with 2x IAT and 1x water temp sensors integrated.

 

Anyways, I have my predictions ready and waiting for your test results. Your setup feels ice cold because a colder material with high thermal conductivity is against your skin; numbers could be high and you would still feel the ice cold. The only time it would not feel cold is when it approaches 90+ degrees F. As you will continue to confirm, radiant heat from the turbo hotside/exhaust pipes does not heat soak top-mounted air water intercoolers under 'normal' conditions (stop lights for instance). You will notice though that the IC will get heat soaked when you have been running hot for a while and then you park your car for 30 minutes and come back to it. The idea is to add in a timer that will click on for a minute every 5 minutes. It will cycle the air from the IC to the heat exchanger, thereby allowing some of that heat-soaked water to cool in the front. OR, you can just insulate the intercooler. Not pretty, but effective. When you get into boost a lot, you'll notice the water temp will hover an easy 10F over ambient air temp. This is my one big issue with a Air-Water intercooling. Despite all that there is to gain, you can still end up starting further back with a slightly warmer air charge post IC. The math required to figure the extent of the issue is insane. Too many variables. I couldn't find or even approximate a way to test it theoretically, so I am still compelled to test it out in real life and see how much of the issue can be mitigated. I am very interested to see how you fare as well.

I understand the thermal conductivity properties of the different materials. That is why I always feel the rubber hose as well as the TMIC. It makes sense they are cold, because it is colder outside, so the heat exchanger is cold, plus it is seeing air velocity.

 

I don't see any heat soak issues that are not fixable with some smart logic. Cycling the pump is a good idea. Cycling the fans is also a good idea. Cycling the pump and fans somewhat simulates driving and is a REALLY good idea. All of these are doable. If you know the ambient temp, then eventually everything should equilibrate to that, or at least close. But yes I understand the entire slug of metal that is the engine will be dumping its heat outwardly. You could easily measure ambient and as the liquid temp starts to creep too far beyond it, you could cycle the pump and fan. Just continue that cycle until eventually it reaches a stable temp that is closer to ambient.

 

The other option would be that once you start your car, have it check the temp of the water - and if the temp of the water is too high (due to heatsoak) - turn on the fans and maybe even blast the heat exchanger with some alcohol water mist to do a quick "hyper cooling" of the coolant. Again, this is getting complex. But its all fun stuff and its all doable. I love it.

 

EDIT: Can't you just run the fans and pump for, say, 5 minutes after you get out of the car... kinda like a turbo timer? That is really simple logic, I would just feed constant 12V and ignition 12V into the micro-controller so that I can tell when the car is off (and yet still have power). The micro-controller would control the pump and fans fully. The logic would be - when the car is running, the pump is running. When the car is running AND the outlet air temp is too close to the inlet air temp, the pump AND fans are running. When the car is turned off, start a timer and run the fans and pump for 5 minutes.

I did a little more spirited driving tonight. No knock thus far, but I did not take it past 4,000 RPM. I just wanted to go wide open briefly, peak out the boost, and see where I sit. So far nothing looks out of the ordinary, and I hit high 10's, low 11's on the wideband so those are in-line. Next step is to ride it a little further and see if it pulls timing after 4k.

 

I hit 17.6 psi an the hoses all look to be in place. Did not stay there long. I don't want to pop a hose in the dark and have to deal with it on the side of the road. I will test it out a little harder during the limited daylight I have these days.

 

Here is a preliminary plot. Its much colder outside with the AWIC plots (approx 20 degrees ambient colder). The Perrin TMIC data was taken in late summer.

 

http://i827.photobucket.com/albums/zz199/LGTSpecB/prelim_plots.jpg

Here is a Pivot Table showing knock events. I log all of my driving, so this includes both OL and CL driving.

 

I am not sure what my tune was looking like before, and I am not sure what is acceptable. As you can see by the number of data points, this is a total of about 150 minutes of driving - all city. In that amount of time I had a total of 334 perceived knock events... most of which occurred in the low end.

 

I also attached total corrections vs. MAF and I am still getting some weird negative corrections in the low end - I was getting these before as well. I am beginning to think its the injectors or something....