Best 997GT2 intercooler
Thread Starter
Addict
Rennlist Member
Rennlist Member
Joined: May 2001
Posts: 4,457
Likes: 123
From: UK
Toby, so you have no idea what the size (L x W x H) cores they used when they made your coolers? You never measured them? What about fin density and the amount of boost and cooling rows on the core? All of this is easy to measure and or count. Every Marston core I have seen has a tag on the side of it with a date of manufacture and other info. I'm surprised that when you spent the big bucks you were never curious about the specification of the product you were buying.
The reason I ask is that I have a fabricator that can acquire Marston cores but I wanted to know the specs (measurements) on yours so we can get the proper spec cores.
You mention above in your post that you priced a multiple set order but how do you price an order for anything if you don't have the specs and they are "top secret". I'm a bit confused. Obviously you must have some sort of part number when you call to get a quote other wise how would you order? Sorry for the dumb questions but something doesn't seem right. Can you at least post up the contact information of who you would order these from?
The reason I ask is that I have a fabricator that can acquire Marston cores but I wanted to know the specs (measurements) on yours so we can get the proper spec cores.
You mention above in your post that you priced a multiple set order but how do you price an order for anything if you don't have the specs and they are "top secret". I'm a bit confused. Obviously you must have some sort of part number when you call to get a quote other wise how would you order? Sorry for the dumb questions but something doesn't seem right. Can you at least post up the contact information of who you would order these from?
My engineer pal calculated lots of numbers for target flows, pressure drops etc and gave them to the Marston engineer and said they have to be as good as the offering from Secan (one of Marston's competitors on the airbus contracts I believe).
Believe it or not but my engineer pal put it in writing that he could not guarantee the performance of the new Marstons but "hoped" they would be much better than standard and approaching Secan levels so I paid the big bucks with zero guarantees.
The Marston guys did their stuff and didn't share any information, it is all proprietary ( I have the dimension schematics but that is all).
The only proof of how well or badly these intercoolers perform has been provided by me and my testing and I have documented much of this on here. They werre also endorsed by my tuner which is a big endorsement since they are virtually the sole supplier of the Secan intercoolers (apart from Porsche Motorsport back in the 993GT2 days).
If you want a quote for some I can PM you contact details for my engineer pal but you won't get any other info I'm afraid because we don't know it !
Rennlist Member
Joined: Dec 2010
Posts: 8,156
Likes: 2,866
I thought I wrote about how these came to be in earlier posts. These are not a "consumer" product they are built by an aerospace company. (who also make radiators for F1). My pal a Porsche turbo racer and engineer has a personal good friend who who works there. I provided him with a set of AWE intercoolers which were IMO the best of the bigger sized intercoolers in terms of fit and said they had to be that size.
My engineer pal calculated lots of numbers for target flows, pressure drops etc and gave them to the Marston engineer and said they have to be as good as the offering from Secan (one of Marston's competitors on the airbus contracts I believe).
Believe it or not but my engineer pal put it in writing that he could not guarantee the performance of the new Marstons but "hoped" they would be much better than standard and approaching Secan levels so I paid the big bucks with zero guarantees.
The Marston guys did their stuff and didn't share any information, it is all proprietary ( I have the dimension schematics but that is all).
The only proof of how well or badly these intercoolers perform has been provided by me and my testing and I have documented much of this on here. They werre also endorsed by my tuner which is a big endorsement since they are virtually the sole supplier of the Secan intercoolers (apart from Porsche Motorsport back in the 993GT2 days).
If you want a quote for some I can PM you contact details for my engineer pal but you won't get any other info I'm afraid because we don't know it !
My engineer pal calculated lots of numbers for target flows, pressure drops etc and gave them to the Marston engineer and said they have to be as good as the offering from Secan (one of Marston's competitors on the airbus contracts I believe).
Believe it or not but my engineer pal put it in writing that he could not guarantee the performance of the new Marstons but "hoped" they would be much better than standard and approaching Secan levels so I paid the big bucks with zero guarantees.
The Marston guys did their stuff and didn't share any information, it is all proprietary ( I have the dimension schematics but that is all).
The only proof of how well or badly these intercoolers perform has been provided by me and my testing and I have documented much of this on here. They werre also endorsed by my tuner which is a big endorsement since they are virtually the sole supplier of the Secan intercoolers (apart from Porsche Motorsport back in the 993GT2 days).
If you want a quote for some I can PM you contact details for my engineer pal but you won't get any other info I'm afraid because we don't know it !
Track Day
Joined: Aug 2014
Posts: 18
Likes: 0
http://www.ebay.com/itm/Twin-Left-Ri...a11c26&vxp=mtr
Anyone tried these?
They are worth the scrap price...
Anyone tried these?
They are worth the scrap price...
Rennlist Member
Joined: Apr 2004
Posts: 1,381
Likes: 318
From: Massachusetts USA
Thread Starter
Addict
Rennlist Member
Rennlist Member
Joined: May 2001
Posts: 4,457
Likes: 123
From: UK
Looks like Porsche is getting serious in intercooler intake function on the new GT2RS 
intake_zpshqg1bnpc.png
intake_zpshqg1bnpc.png
Rennlist Member
Joined: Dec 2010
Posts: 8,156
Likes: 2,866
To resurrect this thread, we finally got the Marston ICs finished. These are the exact same cores as used by Toby in this thread except they are thicker at 4" compared to Toby's 3.5" versions. We finally got through to the right person at Marston and they were able to provide us with the exact specs of the cores that they manufactured and sold to CTR who in turn built the coolers for Toby. This was actually very easy for them to do as all the intercoolers that Marston builds have a particular serial / part number that they keep a record of in their system. All they actually needed to make this even simpler is the ID tag on the cores. In the end, even though these are aerospace cores, getting the right info regarding the cores was not exactly rocket science (no pun intended). Marston provided us data for both the 3.5" cores and a 4" version of the same cores to compare. The data showed that the 4" cores were a further 14-17% more efficient than the thinner versions and that is what we went with. The only drawback with the thicker cores is that you have to shorten the upper duct slightly but that is a worthwhile tradeoff in my opinion.
For comparison, these 4" 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 997.1s).
The performance data for each 4" 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 4" 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.
The completed 4" IC with end tanks weighs 9.5 lbs. (4.3kg). This is only 2.5lbs more than the OEM 997.2 IC.
[url=https://flic.kr/p/WJThp2]
[url=https://flic.kr/p/VAdYDU]
For comparison, these 4" 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 997.1s).
The performance data for each 4" 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 4" 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.
The completed 4" IC with end tanks weighs 9.5 lbs. (4.3kg). This is only 2.5lbs more than the OEM 997.2 IC.
[url=https://flic.kr/p/WJThp2]
[url=https://flic.kr/p/VAdYDU]
Last edited by powdrhound; Aug 3, 2017 at 07:07 PM.
Thread Starter
Addict
Rennlist Member
Rennlist Member
Joined: May 2001
Posts: 4,457
Likes: 123
From: UK
You finally got them made - well done, great perseverance !
Can you tell a bit more about your testing, was it done on the road ?
Your testing mentions Ram air temp as 30C does this mean that intake temp was also 30C if yes then are you saying that your 600whp engine managed to cool the charge down to 35.6C ie 5.6c above ambient ? that cannot be right ?
Forr you 1200whp version you are at 25C above ambient which looks more likely although I am struggling to imagine how one tests a 1200whp 911 at "fully heat soaked continuous wide open throttle" - were you at Papenburg
?
Re the sizing of the coolers, I don't doubt the reasoning (and probably math) behind the claims that they are more efficient than smaller ones but what made me ponder is that the Alzen Mission 400 car which ran at 1100PS DIN FWHP used Secan coolers which are sized exactly the same as the standard 997.1 coolers and this engine was truly held at continous wide open throttle at Papenburg and achieved the calculated speed per hp objectives.
One last thing, I understood that it was around 55C that the 996/7 ECU is set up to start reducing timing/boost, 35C was for the 993 turbo model ?
Can you tell a bit more about your testing, was it done on the road ?
Your testing mentions Ram air temp as 30C does this mean that intake temp was also 30C if yes then are you saying that your 600whp engine managed to cool the charge down to 35.6C ie 5.6c above ambient ? that cannot be right ?
Forr you 1200whp version you are at 25C above ambient which looks more likely although I am struggling to imagine how one tests a 1200whp 911 at "fully heat soaked continuous wide open throttle" - were you at Papenburg
?Re the sizing of the coolers, I don't doubt the reasoning (and probably math) behind the claims that they are more efficient than smaller ones but what made me ponder is that the Alzen Mission 400 car which ran at 1100PS DIN FWHP used Secan coolers which are sized exactly the same as the standard 997.1 coolers and this engine was truly held at continous wide open throttle at Papenburg and achieved the calculated speed per hp objectives.
One last thing, I understood that it was around 55C that the 996/7 ECU is set up to start reducing timing/boost, 35C was for the 993 turbo model ?
Rennlist Member
Joined: Dec 2010
Posts: 8,156
Likes: 2,866
You finally got them made - well done, great perseverance !
Can you tell a bit more about your testing, was it done on the road ?
Your testing mentions Ram air temp as 30C does this mean that intake temp was also 30C if yes then are you saying that your 600whp engine managed to cool the charge down to 35.6C ie 5.6c above ambient ? that cannot be right ?
Forr you 1200whp version you are at 25C above ambient which looks more likely although I am struggling to imagine how one tests a 1200whp 911 at "fully heat soaked continuous wide open throttle" - were you at Papenburg ?
Re the sizing of the coolers, I don't doubt the reasoning (and probably math) behind the claims that they are more efficient than smaller ones but what made me ponder is that the Alzen Mission 400 car which ran at 1100PS DIN FWHP used Secan coolers which are sized exactly the same as the standard 997.1 coolers and this engine was truly held at continous wide open throttle at Papenburg and achieved the calculated speed per hp objectives.
One last thing, I understood that it was around 55C that the 996/7 ECU is set up to start reducing timing/boost, 35C was for the 993 turbo model ?
Can you tell a bit more about your testing, was it done on the road ?
Your testing mentions Ram air temp as 30C does this mean that intake temp was also 30C if yes then are you saying that your 600whp engine managed to cool the charge down to 35.6C ie 5.6c above ambient ? that cannot be right ?
Forr you 1200whp version you are at 25C above ambient which looks more likely although I am struggling to imagine how one tests a 1200whp 911 at "fully heat soaked continuous wide open throttle" - were you at Papenburg
?Re the sizing of the coolers, I don't doubt the reasoning (and probably math) behind the claims that they are more efficient than smaller ones but what made me ponder is that the Alzen Mission 400 car which ran at 1100PS DIN FWHP used Secan coolers which are sized exactly the same as the standard 997.1 coolers and this engine was truly held at continous wide open throttle at Papenburg and achieved the calculated speed per hp objectives.
One last thing, I understood that it was around 55C that the 996/7 ECU is set up to start reducing timing/boost, 35C was for the 993 turbo model ?
Ram air temp IN (30C) is the temp of the ambient air just prior to flowing through the core externally and ram air OUT (60.5C) is the temp after the air has gassed through the core having extracted heat from said core. Think of it as the air flowing through the IC cooling duct pre and post IC.
Charge air temp IN (180C) is the temp of the air post turbo compressor at the IC inlet and charge air temp OUT (35.6C) is the temp of the air after it has passed through the IC core internally. Charge air temp is your boosted air pre and post cooler essentially.
According to my tuner the 996 ECU starts pulling timing at 35C. This seems to be corroborated on logs on my 996 engine. I would imagine it's similar on the 997.
Thread Starter
Addict
Rennlist Member
Rennlist Member
Joined: May 2001
Posts: 4,457
Likes: 123
From: UK
The data I posted above is data that was provided to us by Marston. They gave us data in tabular form for both the 3.5 and the 4" cores at various flow rates (in kg/hr), ram air speeds, etc. For clarity sake I just posted the numbers that correspond to an engine producing both 600hp (similar to what you and I are running) and also a crazy 1200hp build.
Ram air temp IN (30C) is the temp of the ambient air just prior to flowing through the core externally and ram air OUT (60.5C) is the temp after the air has gassed through the core having extracted heat from said core. Think of it as the air flowing through the IC cooling duct pre and post IC.
Charge air temp IN (180C) is the temp of the air post turbo compressor at the IC inlet and charge air temp OUT (35.6C) is the temp of the air after it has passed through the IC core internally. Charge air temp is your boosted air pre and post cooler essentially.
According to my tuner the 996 ECU starts pulling timing at 35C. This seems to be corroborated on logs on my 996 engine. I would imagine it's similar on the 997.
Ram air temp IN (30C) is the temp of the ambient air just prior to flowing through the core externally and ram air OUT (60.5C) is the temp after the air has gassed through the core having extracted heat from said core. Think of it as the air flowing through the IC cooling duct pre and post IC.
Charge air temp IN (180C) is the temp of the air post turbo compressor at the IC inlet and charge air temp OUT (35.6C) is the temp of the air after it has passed through the IC core internally. Charge air temp is your boosted air pre and post cooler essentially.
According to my tuner the 996 ECU starts pulling timing at 35C. This seems to be corroborated on logs on my 996 engine. I would imagine it's similar on the 997.
It is pretty unlikely that your 1200whp engine has the same intake temp as a 600whp engine so really these numbers are all theoretical, I wonder where they got the whp numbers and data from in the first place ?
Rennlist Member
Joined: Dec 2010
Posts: 8,156
Likes: 2,866
Yeah, I understood what all the numbers meant I was just looking for a rule of thumb IAT compared to ambient but I guess they would not be too concerned about that as they've stated the cooling air temp and flow and also the intake temp (180C)
It is pretty unlikely that your 1200whp engine has the same intake temp as a 600whp engine so really these numbers are all theoretical, I wonder where they got the whp numbers and data from in the first place ?
It is pretty unlikely that your 1200whp engine has the same intake temp as a 600whp engine so really these numbers are all theoretical, I wonder where they got the whp numbers and data from in the first place ?
Rennlist Member
Joined: Nov 2010
Posts: 2,085
Likes: 170
From: Ontario
7th Gear
Joined: May 2019
Posts: 7
Likes: 0
First off all - this is a great thread with lot of data and explanation inside!!
I really enjoyed reading through it - so bit thumbs up !!
Did anybody have a look into 991 hardware in the meantime?
I mean, a Turbo S with 580 PS and or a GT2 with 700 should have serious hardware, even I know 991 GT2 RS parts are crazy crazy expensive (like a wheelset worth 40.000€)....
I personally have a 997 GT2 - bone stock, but may want to add some slight improvement, while maintaining stock software, which 997 GT2 RS bricks with plastic channels would probably be (I am still under Porsche approved, so parts must look OEM and no body from Porsche should know about....)
Cheers
Simon
I really enjoyed reading through it - so bit thumbs up !!
Did anybody have a look into 991 hardware in the meantime?
I mean, a Turbo S with 580 PS and or a GT2 with 700 should have serious hardware, even I know 991 GT2 RS parts are crazy crazy expensive (like a wheelset worth 40.000€)....
I personally have a 997 GT2 - bone stock, but may want to add some slight improvement, while maintaining stock software, which 997 GT2 RS bricks with plastic channels would probably be (I am still under Porsche approved, so parts must look OEM and no body from Porsche should know about....)
Cheers
Simon
Thread Starter
Addict
Rennlist Member
Rennlist Member
Joined: May 2001
Posts: 4,457
Likes: 123
From: UK
I've just ordered these side intakes, they claim 10% higher air pressure onto the intercooler probably theoretical but they look pretty functional to me. I also ordered the side skirts not sure how they'll look but my factory ones have never fit 100% right.
