I was waiting for the "aerospace cores" argument to come back again...

TB, please provide some quantifiable results that directly show why your $13K "aerospace" IC cores are superior to the "cheap" cores used by various US tuners. As a mechanical engineer who is well versed in thermodynamics and fluid mechanics, I am very interested to see this data.

Thanks.

 

Are you the guy off 6speed who thought intercoolers were expensive because they may somehow "wear out" in a race and hence why some were costly to produce ?eidt: can't be you if you are an engineer.....sorry (the guy I was on about has "951" in his screenname)

No back to back tests exist so as you know this is not possible. You can read all MY data on Rennlist which I did for my own satisfaction. There is ZERO other data like this anywhere else on the web even from tuners who sell 100s of their intercoolers. I said their cores are cheap ie inexpensive and they are. Mine are hand made by the people who make for Formula 1 - they are expensive and in my test up to 280kph the standard I/Cs IAT went up by 41DegC and mine went up by 15DegC (graph below)

I had these intercoolers made as a personal project to disprove that Secan were the only people capable of producing this high end quality and I am happy that I achieved my goal.

Most people don't really go into the whole IAT thing hence why "tuners" can sell cheap intercoolers like hot cakes which may or may not work that well - people ask for "dyno proof" which says it all really !!

What I find amusing is that the inference is that there are "idiots" out there who have spent $20K on Secan technology when they could have had similar for $2.5K...... funny

 

"in my test up to 280kph the standard I/Cs IAT went up by 41DegC and mine went up by 15DegC"

By "standard" do you mean OE I/Cs or are you still referring to aftermarket?

 

standard issue, stock, OEM

 

It would be interesting to see what the difference would be if our I/Cs were used in that same test.

 

Thanks for posting that chart, I have a few questions.

Where is the data for the standard IC from 160-190 kph?

Was it 17C ambient for both runs?

If so, why does the standard IC test start at approximately 41C?

This graph clearly shows that the standard IC's were already heat soaked before starting the run, and the "Aerospace" cores were cold soaked at near the ambient temp of 17C. This is far from comparable data, because ANY core would show a similar temp offset if it was previously heat soaked in this manner.

What your graph does show is that the cores have a similar slope, which is very interesting. This means that if the standard cores had the same starting temperature (near 18C instead of 41C), that the heating rate would have been very close between the two across that speed range. But since heat flux is of course driven by temperature differential, the rates which the standard core sheds heat to ambient are slightly higher at the elevated temps shown in this chart, making the slope look slightly better than it would be at lower temps. So it’s difficult to say just how close the two would be without having the same start temp and start speed.

There is no data regarding acceleration rate for both runs, load, boost level, charge air pressure drop across the core, and most importantly time duration. A higher load (such as accelerating up a hill for the standard cores) will certainly increase the heating rate without an accurate reference when your only comparison axis is speed. It’s also easy to make a core that displays great charge air temps if you pay zero attention to maintaining a low pressure drop. The charge air may be cooler, but the higher pressure drop will hurt you due to increased backpressure from the higher turbine wheel speed(and thus decreased power) to reach the same boost level at the intake manifold.

There is also no mention regarding shrouding or end tank design of the two IC's. Proper end tanks and shrouding will make or break any IC setup, regardless of how good the core is.

I appreciate that you took the initiative to do some testing. Your aerospace cores seem to perform well, but using this graph to justify the exorbitant price (and call all others "cheap" by comparison) is essentially useless and not rooted in any sound engineering fundamentals. I could produce a similar looking graph with my 993 using the data logging capabilities of the standalone I am running, but my IC didn’t cost anywhere near $20K, $13K, or even $2.5K... But without all of the variables I mentioned above for a real thorough and scientific comparison, it wouldn’t really prove a thing.

 

I didn't start the WOT run until ~190.

Yes same day within a couple of hours

Your statements are understandable but wrong. You are drawing conclusions but have never tested standard intercoolers on a GT2.

On the GT2 courtesy of high stpck boost levels (up to 1.5bar) the IATs are much higher than say a 996tt or 997tt (this is because the 997GT2 is tuned to work withthe expansion manifold which cools the air as it enters the combustion chamber) A stock GT2 even cruising around has a high starting IAT, forget your heatsoaking and cold soaking. I looked at loads of data on the stock I/Cs and just cruising around using little boost the IAT is constantly 20DegC above ambient before you even wind in any boost !!

Apply some boost and the temps shoot up - a guy in the mid east who posts on Rennteam sees IATs over 100DegC with a big reduction in power.

I have loads of other data where I was looking at "recovery" of the two I/Cs and the aerospace ones are much much faster to lose the heat and in cruise mode where the stock ones would be at 20DegC above the aerospace would be at 5degC above or less.....

The data is sound on the graphs - as you can see I took the numbers and put them in excel to get the graphs so if I was that way inclined could make them show whatever I wanted but trust me (or don't ) this is a fair comparison.
I know all that stuff but I'm afraid it is waffle compared to my data which is what is happening on the car on a flat road in the same ambient temp under the same full loads through the same gears. the pressure drop difference compared to stock is negligable a non issue for these.

shrouding is stock, end tank on stock coolers is crap as we know, mine are perfect

I hope my answers above persuade you otherwise ?

If they don't..... well tough really, I don't care but feel free to ask more stuff if you want..... They were tested entensively by RS Tuning on the Autobahn using some pretty severe loadings and based on their findings my engine was tuned using appropriate low IATs which they know these I/Cs can perform to.... (I have the IAT data to which my engine was mapped on the engine dyno and it means RS consider that they work which is good enough for me)

 

Brett
If you want some more intercooler testing relevant to your 993 checkout this thread

9M Prototype intercooler test report - Rennlist Discussion Forums

 

Here is another one for you Brett at slighly higher ambient but lower terminal speed:




And another of stock intercoolers in 22.5degC ambient through 4th and 5th gears: All the graphs are with stock ECU program BTW)

 

I'm sorry, but if you are trying to prove the superior efficiency of one intercooler vs. another, my statements are far from incorrect. You didn't really understand nor address most of my concerns with the testing that you ran. Also, you have no idea what I have and have not tested.

In fact, your comments reinforce what I have been stating. The standard cores were heat soaked from whatever driving conditions you put them through prior to starting this WOT test, whereas the aerospace cores were not. Your own graph shows this clear as day. When you take that "data" and then claim the aerospace cores significantly outperformed the standard cores during a WOT run then you are completely incorrect, as your conclusions are false and those two “tests” aren’t even reliably comparable with the given starting conditions.

I am not saying that your magic aerospace cores aren’t somewhat better, I would imagine that they are. But you are trying to justify the exorbitantly higher cost of those cores with the chart you posted that supposedly shows a significant performance improvement, when in fact that chart shows that your testing methodology is completely flawed. Even better, that chart shows nearly identical slopes (comparable heat flux rates) for both the standard and aerospace cores, the only real difference is the offset in the starting temperature and speed. I don’t know if you don’t understand these fundamentals, or if you are just refusing to acknowledge them because you are invested in proving that you weren’t essentially robbed blind by your exalted Euro tuners.

Start both of those cores at the same temp and speed, test them for the same time duration, and the differences in IAT will likely be minimal as shown by your own chart. Characterization of a heat exchanger is a very basic problem, engineers have been doing these sorts of calculations and experiments since the first automobile got a radiator over 100 years ago.