After about 4 years of running the 997.2 intercoolers, I’ve finally decided to embark on a better intercooler solution that would surpass anything that is currently available on the market. There are many aftermarket choices available but very few if any have proven to surpass the performance of the OEM 997.2 for those looking for all around performance for moderate power (up to 650whp or so). This has been proven repeatedly in real world testing as reported by Earl who has tested them against many aftermarket options out there. The 997.2s ICs are excellent intercoolers for street as well as track use and are an excellent value. They do however have their limitations and I have seen IATs with them on very hot track days in excess of 170F on my car and 200F + on my friends VTG 997.1TT. While there is not really anything better for road course use, there are obviously much better choices for the high HP 0-60 and 1/4mile guys where low restriction is more important than thermal recovery and this type of use is what most of the large thick aftermarket ICs are aimed at.

With that said, Porsche Motorsport has chosen Secan as their intercooler of choice in their race cars. Unfortunately these intercoolers are out of reach for 99.9% of people as their cost is in the $15-20K range for the cores alone. After looking at all the options, I collaborated with Sean at SRM to come up with a solution that would be in the realm of “affordability” for a larger, albeit still very small, segment of enthusiasts. SRM, among turbos and fuel systems, makes a very nice set of their own intercoolers which in my opinion are the best of the aftermarket. My goals were simple. The intercoolers must utilize a genuine “aerospace” core, have proven manufacturer supplied data, be a direct drop in to both 996/997.1 shrouds with minimal to no modification, lightweight, and performance wise surpass anything in the market place. Rest assured that I do not like to compromise and as such wanted an intercooler solution that would rival or exceed the mighty Secans.

After speaking with numerous aerospace suppliers in the US and Europe, we were able to narrow the choice down to a core that would meet all of these requirement. By agreeing to purchase a batch of cores, the manufacturer in turn agreed to design aerospace cores to our specific size and performance specifications. Due to economies of scale, we are able to procure these at a much better cost that the $12K+ it would have taken in the past to purchase such cores. The manufacturer that will be supplying us the cores currently makes intercoolers and heat exchange devices for Boeing, Airbus, numerous military and aerospace applications, and also Formula 1. This is no mom and pop operation!

These aerospace cores are 37% larger than the benchmark OEM 997.2 ICs, and 60% larger than the OEM 996TT/GT2/997.1 ICs (for those wondering, the 997.2s are 17% larger than 996TTs).

The performance data for each aerospace core is as follows listed for both 600hp and 1200hp applications:

HP application:___________600whp (both cores)______________1200whp (both cores)

Charge Air Mass Flow______720 Kg/hr (per core)______________1420 Kg/hr (per core)

Charge Air Temp IN________180ºC (356ºF)__________________180ºC (356ºF)
Charge Air Temp OUT______35.6ºC (96ºF)___________________55.7ºC (132.2F)

Charge Air Press Drop______75.9 mbar (1.1 psi)______________233.3 mbar (3.43 psi)
@1.8bar (26.4 psi)
operating press

Ram Air Velocity___________10 m/s (22.4 mph)______________10 m/s (22.4 mph)
(speed of cooling air
through exterior of core)
(corresponds to vehicle
speed of 150mph)

Ram Air Temp IN___________30ºC (86ºF)____________________30ºC (86ºF)
Ram Air Temp OUT_________60.5ºC (140.9ºF)________________82.5ºC (180.5ºF)

Ram Air Press Drop_________20.7 mbar (0.3 psi)______________20.7 mbar (0.3 psi)


As can be seen by the numbers above, the efficiency of the aerospace cores is quite astounding. Keep in mind that this data is for continuous duty replicating wide open full throttle operation where the core is fully heat soaked and thermally stable, not just a 20 or 30 second datalog snapshot of a highway pull.

Looking at the 600whp application column on the left, note the huge temperature drop of the boosted air entering and exiting the intercooler (356F vs. 96F). Keep in mind that the ECU starts pulling timing right around the 35C (95F) point. Also note the minuscule drop of 1.1 psi of boosted air through the core. This shows how free flowing this aerospace core is even at 1.8bar of boost. In comparison, the 997.2 core has almost 3x the resistance of 3 psi of pressure drop through the core at similar air flow but lower boost.

Even when using these cores in a 1200whp application, the performance is amazing but we see the intercooler outlet temps higher at 132.2F while the pressure drop through the core is now 3.43 psi. Again, keep in mind that these are fully heat soaked continuous wide open throttle #s.

While we do not have exact weight figures, we anticipate the completed IC with end tanks to weigh around 10lbs each which will only be only slightly more than the 997.2s and substantially less than other larger aftermarket offerings. The reason they are so light is because the cores are made of much better/thinner materials that one will find on normal commonly used consumer cores such as Bell or others.

We should have these cores in hand middle to latter part of January. Once they arrive, SRM will be welding on specially designed aluminum end tanks with full 2.5” inlets and outlets designed for hoses with T-clamps or worm clamps. Projected price will be $6950 including all 4 hoses and clamps. Hoses will be available for both the 996TT/GT2 and 997TT/GT2 platforms. While not cheap, these will satisfy the niche market of those looking for the best intercooler you can buy for the 996/997 platform. I suspect these will really shine on the 997TT platform which has to deal with the hot running VTGs. No shortcuts, no compromise..

I will be posting pictures as work progresses and will be testing them in the spring at the start of track season.

Cheers!

 

Subscribed.....

 

According to the specs pwdrhound posted, these new cores are roughly 6% more efficient than the Marston 'lites' that GTR Nick used. That's a huge difference, especially at this level (not that Nick's are bad by any means).

FWIW, 10m/s through the actual core exterior would take a vehicle speed somewhere in the 140-160mph range.

Looking forward to updates, nice work!

 

Good choice moving forward with SRM.

 

I'm familiar with GTR Nicks coolers. They are quite a bit smaller than what we are using and only have 12 charge / 13 cooling rows. Our aerospace cores are utilizing 14 charge rows / 15 cooling rows. Again, we are looking at a product that will surpass anything used in the past including the 3.5" thick Marston coolers that Toby uses on his 7GT2. We looked at data on various thickness coolers and there is a definite improvement in thermal recovery and flow in cores larger than 3.5". As such, we chose to go with larger cores at the expense of a marginal increase in weight. There is however a point of diminishing returns by going thicker and thicker on top of packaging constraints, greater weight, etc..

 

Earl,
10 m/s equals 22.4mph. Are you saying that a vehicle traveling at 140-160mph only has 22.4mph of air flowing throughout the IC duct? Out of curiosity, where did you get that data? That does not seem right as the ducting is generally very efficient. I would see some losses but not an 80% loss in airflow through the core. 50% loss would seems more realistic which would equate to a vehicle traveling about 50mph. Just thinking out loud.. Thanks for all your contributions over the years!

 

I have seen the hard work and dedication going into this. I love how SRM is one stop all in house. Nice work! If anyone sets demand on IC's it's John!

 

Its great to see this unfold and I'm sure it'll be fun to see data and this project unfold. However, the ultimate intercooling will not come from an air to air intercooler so the approach to me just seems flawed to start with. Don't take this in a negative way. I have been there done that countless times and I certainly don't know it all. However, a simple air to water heat exhanger setup will beat this setup day in day out out there. Also, using water injection or methanol will surpass efficiency of any intercooler setup at a fraction of the cost. I realize water injection isn't for everyone but $7k intercoolers are far less so in my honest opinion.

 

Water/Meth injection or air to water cooling is simply not an option due to weight, complexity, reliability, packaging / installation constraints in road course / track use applications. As such, a direct no fuss bolt on approach was the only option I would entertain. Yes, $7K is about double what the better aftermarket consumer grade IC options sell for but considering hoses are included for a truly bolt on set up, it's reasonable. These are not aimed at the masses for sure. That is not the intent.

 

I am sorry but I disagree. Far more serious race teams around the globe employ air to water intercooling setups. I can't even count how many use water injection. All I am saying is that a great intercooler core is just that a great intercooler core and heat exchange properties of water or alcohol cannot be nearly matched let alone surpassed. Good luck with the project though in all honesty. I love seeing new hardware perform and look forward to real world data. I am assuming you have the data from your current setup that you can use as a baseline and repeat the tests after with the new setup?

 

I'm not arguing, just saying that water inter cooling / meth injection is not anything I want to entertain for the reasons previously stated. A simple 1 hr bolt on solution that surpasses any air to air intercooler in the market place is the goal.

Yes, I have countless hours of MoTec track data with my current set up that will be used as a baseline for an apples to apples comparison.

 

I somewhat agree with oldbooster if, your limiting your run time. If I were running 1/4mi ect. Water to air make sense due to quick and rapid recovery time but, if the run is for an extended period of time (20-30 mins,) you still experience heat soak which wouldn't recover as fast and you would still have additional weight. If I could get a comparable yet very recoverable "air to air" intercooler without the addition of weight, why wouldn't I consider it?

When considering this option "Water to Air," I couldn't by-pass the thought of water in my intake if I experienced a leak at some point. I know, this is an "if" but, now I added "but" into it also.

With the TT 911 stock intercooler position setup, this is relative to the problem. Would "water to air" help? With custom tubing cost, it may. I think there is one member that has done this on the GT3 forum. He decided to turbocharge his GT3 setup without the side intakes and resorted to "water to air." Car seems to be running fine. I have no idea on what power levels and usage though.

 

I tried to get some data about water-to-ice ICs effiency in this thread
BBi did not answer... When Zwart's car was at first time at Pike's Peak I asked the same question and got one answer, not from BBi directly though, and the message more or less was "one run uphill is the max."
My car would benefit (NB with VTGs) from water-to-ice IC's like in Zwart's car, but I do not want to do any experiments just to find out that after 5 or 6 laps the system is saturated.
The beauty of air-to-air ICs is the simplicity of the system. No pumps to fail, no tanks to get empty. Fail safe.
John's ICs seem to be "real thing", now I would like to see them flow bench tested to Champion's ones... =p

 

Water-air heat soaks, so is typically used for glory runs. Since F1 went back to turbo, they are using air-air from the same company we are sourcing these cores from. The only way to make an water-air setup work effectively would be to run cores of the same efficiency as these out front to dissipate the absorbed heat. The cores BBI used look like Bell, and I doubt they put aerospace grade cores in the front bumper, rather relying on an iced water tank. Would be cool to see more info on that build, likely running a large ice tank.

 

Many people will attempt to go on a quest in solving heat issues by introducing better intercooling when in fact they should really take a step back at times and review their system as a whole to begin with starting with the tune on the car.

First and foremost you have to review what sort of driving you're building your particular setup for, what are your goals. One goal listed above is a power goal and that's a great start. You have to first look at the efficiency of your turbos given where your current tune is sitting. The reason I say this is that people will try running their non-purpose built non-road course type tunes on road courses in 20-30 minute sessions and will heat soak whatever they have on the car whether it is the most efficient intercooler core on the market today or not. Once you have the tuning (boost/airflow levels required to support your power levels) then you start on the quest to build the ultimate intercooler solution and you may be lucky to pull it off with an air/air setup that will fit your goals.

My opinion is that there really is no so called 'ultimate' hardware unless its backed by a goal and purpose built to fit that specific scenario in the best way possible. Exactly the same principles apply to tuning.

Any and all of the above options can be ultimate solution if they satisfy your needs from the performance point of view. Personally I'm a huge fan of water/alcohol injection. I have tuned race teams around the world with it where the rules would allow for it but I also realize that a water/alcohol injection system isn't part of your goals here so there really isn't any point discussing it as the system needs to be built to your goals not mine

What is your current setup on the car, how much boost are you running, what octane, what type of road course, average speeds, how long are the sessions, altitude, is it flat level or hill climb, are you making sure you're running your turbos in their peak efficiency?

Dzenno@PTF