do88 Bigpack Porsche 991 Turbo!
#31
I would say sooner or later even stock 911tt with upgraded intercoolers will heatsoak. Thats why we need sprayed intercoolers(gt2rs) or even better spraying before TB.
My 996tt with gtx2863 and only 0.9bar(oem boost level for a k24 based car) will show even 70-80C sometimes when hot outside(35-40C). Meth or at least water injection will keep things happy for longer sessions. For example I was able to hit my best lap on my home track by cruising only the initial lap and immediately made my record, tires were warm already from previous session. After that, performance is dropping a bit, not much, but if looking at the last .1s of a second, will do the difference. I have lots of vbox runs for 100-200; 60-130; 100-150 made at the track to show that. (Both 996tt and 991tt)
My 996tt with gtx2863 and only 0.9bar(oem boost level for a k24 based car) will show even 70-80C sometimes when hot outside(35-40C). Meth or at least water injection will keep things happy for longer sessions. For example I was able to hit my best lap on my home track by cruising only the initial lap and immediately made my record, tires were warm already from previous session. After that, performance is dropping a bit, not much, but if looking at the last .1s of a second, will do the difference. I have lots of vbox runs for 100-200; 60-130; 100-150 made at the track to show that. (Both 996tt and 991tt)
#32
I would say sooner or later even stock 911tt with upgraded intercoolers will heatsoak. Thats why we need sprayed intercoolers(gt2rs) or even better spraying before TB.
My 996tt with gtx2863 and only 0.9bar(oem boost level for a k24 based car) will show even 70-80C sometimes when hot outside(35-40C). Meth or at least water injection will keep things happy for longer sessions. For example I was able to hit my best lap on my home track by cruising only the initial lap and immediately made my record, tires were warm already from previous session. After that, performance is dropping a bit, not much, but if looking at the last .1s of a second, will do the difference. I have lots of vbox runs for 100-200; 60-130; 100-150 made at the track to show that. (Both 996tt and 991tt)
My 996tt with gtx2863 and only 0.9bar(oem boost level for a k24 based car) will show even 70-80C sometimes when hot outside(35-40C). Meth or at least water injection will keep things happy for longer sessions. For example I was able to hit my best lap on my home track by cruising only the initial lap and immediately made my record, tires were warm already from previous session. After that, performance is dropping a bit, not much, but if looking at the last .1s of a second, will do the difference. I have lots of vbox runs for 100-200; 60-130; 100-150 made at the track to show that. (Both 996tt and 991tt)
Is this how the GT2 RS keeps things cool? Spraying the surface of the cooler if I understand? Or is it spraying actually into the cooler or does the cooler have a water jacket like F1 cars? Seems to be very little info. Saw a post on 6Bling saying 991 GT2 RS turbos 70mm inducer. Interesting as AP says 67mm. Just shows we all measure even just the size of the VTGs differently!
#33
GT2RS system sprays outside of the coolers, like old subaru system, so only Water needed
M4 GTS for example, uses a system to spray inside the intake - better performing system for sure, and can use water or meth/water mix for even better results
Some guys are saying that the hp drop for gt2rs when not using water and getting heatsoaked is like 50hp, but I have no logs or anything to stay behind this
Gt2rs turbos are bigger, also the hotside and not only compressor side, even ducting is bigger, the compressor design, exhaust... there is a lot of engineering in there to make it work even for andurance racing type of events
M4 GTS for example, uses a system to spray inside the intake - better performing system for sure, and can use water or meth/water mix for even better results
Some guys are saying that the hp drop for gt2rs when not using water and getting heatsoaked is like 50hp, but I have no logs or anything to stay behind this
Gt2rs turbos are bigger, also the hotside and not only compressor side, even ducting is bigger, the compressor design, exhaust... there is a lot of engineering in there to make it work even for andurance racing type of events
#34
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Would the most significant IAT challenges under lapping conditions be volume of outside airflow to the IC, or IC fin design, or pressure drop through the IC and piping? I used to track a modified MR2 Turbo with insufficient airflow to the IC so upgrading the IC design was of limited benefit since it would still heat soak (just a lap later), nor did larger IC pipes have much effect, but the water-methanol injection just ahead of the throttle body seemed very effective. Just wondering where the TTS most significant weak points are.
I have datalogs for my own car with exact same tune on the dyno, drag strip and track, and you can clearly see how one lap at the track puts more load on the engine than anything else or any high speed run. I use a larger 4.5" intercooler but I am pretty much certain that the stock sized 991 turbo intercooler will do better at the track, the larger cooler acts like a heat sink after one lap and temps stay up there. A dyno run does not even show any timing retardation at 28psi boost, a drag strip run shows some, a track lap will be pulling your timing time and time again even at 20psi. Methanol does help a lot, I can see it on my logs doing its thing.
I think these DO88 coolers are really good value, based on the data that was posted above.
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4flynlow (12-17-2019)
#39
Former Vendor
Thread Starter
Let me know if you have further questions.
Regards
Isak, do88.
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4flynlow (12-17-2019)
#40
What is the stock hose size in diameter ? Pics of your hose ? Thanks.
#41
Former Vendor
Thread Starter
Hard to say the exact dimensions of the stock hose due to the shape but there´s no doubt the airflow is improved. More info here: https://www.do88.se/en/artiklar/pors...r-turbo-2.html
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4flynlow (12-17-2019)
#42
Hard to say the exact dimensions of the stock hose due to the shape but there´s no doubt the airflow is improved. More info here: https://www.do88.se/en/artiklar/pors...r-turbo-2.html
#43
Former Vendor
Thread Starter
Not at the moment, no. But the difference vs stock on these are bigger, speaking about figures, than it is on a 997.1 for which we have sold many, many over the years. Anyway, on that car a few guys have done dyno sheets and other tests. One of the most exhausting ones can be found here: https://www.6speedonline.com/forums/...-997-1-tt.html
#44
Not at the moment, no. But the difference vs stock on these are bigger, speaking about figures, than it is on a 997.1 for which we have sold many, many over the years. Anyway, on that car a few guys have done dyno sheets and other tests. One of the most exhausting ones can be found here: https://www.6speedonline.com/forums/...-997-1-tt.html