Only looking for the, "what works" solution at this point.


This was after 5 days at the track. 1 season for me. Maybe a poor investment.


They leak like hell. At some point, I'll pressurize them and drop them in a Bath tube to show the actual amount of leaks.


To think of the beating the stock 997.1 intercoolers would have taken. I had extreme lag last season with the stock setup take.

 

Yes, both the 996 and 997.1 versions of this kit are available and they're direct bolt on. Here's a link with some pictures:

http://www.protuningfreaks.com/colle...ooler-kit-do88

 

Something seems off there. JB Kwik is good up to 300 F,.. and the regular JB Weld is good to 600 F.

I used the regular JB Weld to repair a half-dollar sized hole in the cast iron section of the 2 million BTU steam boiler at my work (until summer, when I could replace it).

When we pulled that section,.. we couldn't break the repair with a ball-peen hammer. And it would have had 400 F air going by it for hours at a time, for 3 months.

I agree with you that the data provided doesn't make a compelling case.

997.2 GT2RS IC's are supposedly good for a 30 F delta over stock,.. and the Sambo TT ones for example are good for 40 F delta.
D088.............. ? F..... $1,300
997.2 GT2RS.. 30F..... $1,300
SamboTT 4.5". 40F..... $2,750
AMS 5"........... 45F..... $4,500 (Includes hoses, ducts and Y pipe)

These Do88 ARE an improvement (albeit a small one),.. are supposedly a direct bolt in (which is important for many), and have metal end-tanks (which is comforting). So it's not a bad product,.. just not the home run in terms of price per IAT reduction those who track their cars are looking for.

 

I think you may have missed that it was a 13 celsius delta for the test in question. 37C with the DO88 intercoolers vs 50C 997.1 OEM intercoolers in a 50-200 km/hr multi-gear pull done in 18C ambient temps.

37c is 98.6F
50c is 122F
Delta of 23.4F

AMS 5" kit is very frankly no comparison to this do88 kit. They are in completely different leagues, much larger cores, custom carbon fibre ducts/piping/y-pipe. They serve different needs/power goals and market. AMS' kit is the big daddy that will outflow every intercooler you've listed above and there should really be no comparisons between that kit and the do88.

 

It's a double edged sword. The 997.2 ICs are probably the best of the lot when it comes to continuous thermal recovery lap after lap for 30 minutes at a time. The reason is the lightweight but very dense core. The large 4.5 or 5" intercoolers (Champion included) will be great at initial thermal loading for a lap or so but once the huge 20lb mass of aluminum core and end tanks get heat soaked it's game over. 99% of people drive these cars on the street doing 60 to 130 pulls and as such will never subject the intercoolers to the extreme that Elite or I have. Both he and I have cores that leak on the 997.2s. I have 4 years of hard track duty (over 120 track hours) and my cores leak while the end tanks seal perfectly. I have no epoxy on them btw. Basically what is happening is the simple fact that the thin aluminum metal of the core has gotten fragile from the continuous heat cycling, pressure and vibration. My turbos run about 40-50ºF cooler compressor outlet temps than Elites VTGs (along with less boost) and as such I have gotten much longer life span out of the 997.2s. When fully heat soaked the highest IATs I generally see on Motec in the dead of summer is 145ºF (62ºC). The highest I've ever recorded was in the low 160s. On Elites car, we have seen in excess of 200ºF (+93ºC) IATs on his track data logs. That is huge. Keep in mind that we are at an elevation of 5280' where the air is less dense thus providing less cooling. In thin air, the turbos are also working harder to provide full boost which only raises compressor outlet temps even higher. In Elite's case, all this probably translates to 400ºF at the compressor outlet temps right where the air enters the intercoolers. This is where the discoloration on the JB weld is clearly apparent as it's a burnt brown as opposed to light grey color of the same glue at the outlet tanks. Neither of our end tanks or cores leaked at the IC outlet side which speaks volumes for the efficiency of the core.

With that said, clearly the 997.2s have a limitation, they are fragile and will not withstand continuous hight heat cycling over time. For steer and occasion track use it's not a problem. For continuous hard track use the 997.2s become a consumable item, especially with hot running VTGs. The long term solution would be an intercooler with a similar dense 16 row count as the 997.2 cores or maybe slightly thicker (maybe 4"). I am not aware of anyone that makes such a core on the medium price point coolers. They are all rather thick coarse 12 row cores which will flow great but not do much for cooling once thermal saturation sets in, which will be in a matter of one lap or two at the track. Again, for street use, these types of thick cores will perform great but it's apples to oranges as far as street and track use goes. As far as data goes, you need data not only for one pull to 200mph but instead you need data for continous hard use over 20 to 30 minutes to show how well the IC shed heat when fully heat soaked. This is what is important in the end for track use applications. The only solution I see is an aerospace type core one sees on Marson or Secan intercoolers that are used in the aerospace industry and top levels of motorsports. The drawback is money as Secans are upwards of $20K for a set. Ultimately, for serious track work without a lot of these issues that require big $$$ fixes, a GT3 is the way to go...

 

I did miss that.

So it was 33 F outside when the test was done,.. and these 3.5" inter-coolers produced a delta of 55 degrees F? Much better than even $4,500 AMS ones with their 5.5' cores? Wow

 

We were actually both wrong on the delta See updated post above. Once again, totally different leagues, no comparison.

 

All excellent points and agree that recovery on a similarly sized tube and fin intercooler will almost always be faster due to its lighter weight. However, a denser core while better for IAT control (air gets to stick around in the core longer) also creates more pressure drop so turbos need to work harder to make the same boost levels which in turn creates more heat and the vicious cycle repeats. The other area of pressure drop are to do with end tank design and this is where cast end tanks design through CFD software are in most cases superior to simply welded end tanks made to fit a given space/area on the car.

At the end of the day, for hard core road course guys, and you'll have to just trust me on this, add a water/meth injection kit! Nothing else will 'solve' the issue you're facing unless you severely pull back on boost. Turbos are hairdryers, they blow hot air and 30 minute sessions especially on road courses that see very long extended runs at WOT such as Laguna Seca and similar will make you wonder why your intercooler isn't working as well as you'd thought.

I also have a really hard time believing that even the most expensive of the cores out there in the size you can bolt-on in the space provided given airflow going across them on these cars would get the job done "well".

 

997.2 are decent coolers and work well, but gotta love all the guys who think they are the hottest thing around at a bargain basement price.

the cores are restrictive, they come apart because of that too, not a viable option for anyone shooting over 700hp. mine broke after 4-5 months, and had issues with hoses prior to that. when i got the 997, i did not even consider the .2s again.

 

I see that now.

The temp deltas range from 24/28C (75.2 / 82.4 F) Which is a delta of 7.2 Degrees F

To a best of 37/50C,..(98.6 / 122 F) which is a delta of 23.4 degrees F.

So they're;
- Cheaper (as they include the hoses)
- More reliable (better connections to the hoses, and metal end-tanks)
- Roughly 3/4 of the improvement over stock as compared to the GT2rs coolers

Not world-beating,.. but definitely a solid product to slip into the range of current offerings.

 

There is no need to buy new hoses for the 997.2 IC's, they fit plug n play with the oem 997.1 hoses.

 

Ahh where to begin!


I had been watching these coolers for a little while on the German forums. Look decent and I like that they have some data to show them at least better than stock (some aren't lol!). Really impressed that they advertise that there is a compromise between pressure loss and thermal efficiency. Would be good to some independent logs and here's why:


DO88 decided to compare against 997.1 and AWE coolers. Sounds good, AWE is your basic cast end-tank Bell cored option and a good benchmark. Here's the rub, DO88 claims AWE flows worse than DO88 (no surprise) and also flows worse than 997.1. ...but here's what AWE claims against the 997.1s:







Houston, we have a problem. Who to believe...





About 25C over ambient at ~1.5 bar (sustained loading) is about as good as it gets with even the best coolers. If ambient temps get into the 30s, you may still see timing come out. Interestingly enough, Porsche endurance racing guys run the thinnest core that can adequately meet acceptable pressure losses -the thinner cores are simply more thermally efficient in that environment and losses from high IATs are substantially worse than pressure losses.



I'm curious where these numbers came from. Any idea what car, turbos, boost, ambient temps, speed, time under load, elevation, etc? I bet I can saturate one of the thicker coolers on a road course and turn those numbers around... Reverse is probably true on the street / drag strip.




So who's gonna try a set of these Do88s?

 

^^^^^ we were all hoping you would try a set, Earl.

 

Totally OT from the topic...:

What I'm going to do (after seen Elite1's pics) is to install a temp probe to LH boost hose and measure IC inlet and outlet temps. Bot don't hold your breath, my transmission is kaputt (3rd gear) and it's about to start snowing here...
Another planned measurement device installation is a pressure probe to replace LH EGT probe temprarily. I wan't to see backpressure too.

 

That would be my choice as well! Let me know if you'd like to give these a shot Earl.

Good stuff! Our 997.1 is getting outfitted with a number of sensors at this point as well including EMAP on both sides, adding back EGT probes that were removed when we converted to Tial Alpha 3076s, fuel pressure and flex fuel.

Dzenno@PTF