Question for the GT2 guys, especially Toby
08-27-2011 | 10:20 PM
#31
Pro
Joined: Feb 2010
Posts: 573
Likes: 6
From: Qatar
all the time same story, lower boost is required.....or bigger turbines producing big amount of air at lower boost.
I talked with engineer responsible for cores design, he was also working on porsche turbo....he told me that the biggest problem of this car is intercooler position, there is not enough air passing the core and that's why it's never ending story.. he also told me that the best intake temp he ever noticed was 24C over the ambient.He mentioned about 996 turbo race car with 3 intercoolers, third one was on the top of the engine covered by special bonnet something like gemballa. 24C above the ambient was recorded during the race in summer.
Ps. Toby nice middle radiator core, I'm using same core as heat exchanger for liquid cooling system I have.
I talked with engineer responsible for cores design, he was also working on porsche turbo....he told me that the biggest problem of this car is intercooler position, there is not enough air passing the core and that's why it's never ending story.. he also told me that the best intake temp he ever noticed was 24C over the ambient.He mentioned about 996 turbo race car with 3 intercoolers, third one was on the top of the engine covered by special bonnet something like gemballa. 24C above the ambient was recorded during the race in summer.
Ps. Toby nice middle radiator core, I'm using same core as heat exchanger for liquid cooling system I have.
I think the car you are talking about with 3 intercoolers is the Alzen Turbo ?? Maybe Toby can confirm that..
regarding your liquid cooling system do you use fans with the system?
08-28-2011 | 09:25 AM
#32
Addict
Rennlist Member
Rennlist Member
Joined: May 2001
Posts: 4,446
Likes: 115
From: UK
My intercoolers are fully functional now with sealed lower ducts and I am wearing new Motorsport front radiator so did some data logging today to see if I could throw some more light on this subject.
The conclusion is I guess exactly what you would think but it is still quite sobering to see the data. Ambient air temp today was 18c
Prolonged heating of the VTGs by keeping them on boost results in high EGTs over 900C and peaking at 940 today and IATs a up to 62c
If one cruises at low boost speeds to get the EGT down to ~700c then hammer up from say 200-300kph even though the EGTs go to 900c for this "run" the IATs only reach 52c
There is some big heat soak in the system and it looks like it is the VTGs which are storing the heat.
Bare in mind I am using expensive Secanesque intercoolers and up to 1.55 bar boost here on 3.9 litre full spec RS Tuning engine build......
The better news for most users is that below 120mph on my set up at least, despite any manner of thrashing the IATs will not breach 40c
Looking at how the programming reduces boost and timing with these increasing IATs, and using today's conditions as a DIN measurement 18c/1030mbar I reckon the VTG engine is not able to go north of 700 real hp at 300+kph loading....
The plus sides of a VTG engine are so incredible that all the above is pretty academic but interesting
The conclusion is I guess exactly what you would think but it is still quite sobering to see the data. Ambient air temp today was 18c
Prolonged heating of the VTGs by keeping them on boost results in high EGTs over 900C and peaking at 940 today and IATs a up to 62c
If one cruises at low boost speeds to get the EGT down to ~700c then hammer up from say 200-300kph even though the EGTs go to 900c for this "run" the IATs only reach 52c
There is some big heat soak in the system and it looks like it is the VTGs which are storing the heat.
Bare in mind I am using expensive Secanesque intercoolers and up to 1.55 bar boost here on 3.9 litre full spec RS Tuning engine build......
The better news for most users is that below 120mph on my set up at least, despite any manner of thrashing the IATs will not breach 40c
Looking at how the programming reduces boost and timing with these increasing IATs, and using today's conditions as a DIN measurement 18c/1030mbar I reckon the VTG engine is not able to go north of 700 real hp at 300+kph loading....
The plus sides of a VTG engine are so incredible that all the above is pretty academic but interesting
08-28-2011 | 09:43 AM
#33
Instructor
Joined: Jan 2006
Posts: 130
Likes: 0
From: London
hmm so i guess the only thing that remains is that i try a similar run next time i am with my car (we live in different countries..!) and try what Toby just did at similar temperatures. We can see if the GT2 intake makes any real difference in that power level with VTGs.
At my previous recorded run with ambient at 10 degrees i got to 41 and then 36 degrees (!) from 80-300kms. But this was at lower ambient temperatures.
Only it may be difficult to find 18c ambient in s europe for a few more weeks..
At my previous recorded run with ambient at 10 degrees i got to 41 and then 36 degrees (!) from 80-300kms. But this was at lower ambient temperatures.
Only it may be difficult to find 18c ambient in s europe for a few more weeks..
08-28-2011 | 10:10 PM
#34
Pro
Joined: Feb 2010
Posts: 573
Likes: 6
From: Qatar
My intercoolers are fully functional now with sealed lower ducts and I am wearing new Motorsport front radiator so did some data logging today to see if I could throw some more light on this subject.
The conclusion is I guess exactly what you would think but it is still quite sobering to see the data. Ambient air temp today was 18c
Prolonged heating of the VTGs by keeping them on boost results in high EGTs over 900C and peaking at 940 today and IATs a up to 62c
If one cruises at low boost speeds to get the EGT down to ~700c then hammer up from say 200-300kph even though the EGTs go to 900c for this "run" the IATs only reach 52c
There is some big heat soak in the system and it looks like it is the VTGs which are storing the heat.
Bare in mind I am using expensive Secanesque intercoolers and up to 1.55 bar boost here on 3.9 litre full spec RS Tuning engine build......
The better news for most users is that below 120mph on my set up at least, despite any manner of thrashing the IATs will not breach 40c
Looking at how the programming reduces boost and timing with these increasing IATs, and using today's conditions as a DIN measurement 18c/1030mbar I reckon the VTG engine is not able to go north of 700 real hp at 300+kph loading....
The plus sides of a VTG engine are so incredible that all the above is pretty academic but interesting
The conclusion is I guess exactly what you would think but it is still quite sobering to see the data. Ambient air temp today was 18c
Prolonged heating of the VTGs by keeping them on boost results in high EGTs over 900C and peaking at 940 today and IATs a up to 62c
If one cruises at low boost speeds to get the EGT down to ~700c then hammer up from say 200-300kph even though the EGTs go to 900c for this "run" the IATs only reach 52c
There is some big heat soak in the system and it looks like it is the VTGs which are storing the heat.
Bare in mind I am using expensive Secanesque intercoolers and up to 1.55 bar boost here on 3.9 litre full spec RS Tuning engine build......
The better news for most users is that below 120mph on my set up at least, despite any manner of thrashing the IATs will not breach 40c
Looking at how the programming reduces boost and timing with these increasing IATs, and using today's conditions as a DIN measurement 18c/1030mbar I reckon the VTG engine is not able to go north of 700 real hp at 300+kph loading....
The plus sides of a VTG engine are so incredible that all the above is pretty academic but interesting
Toby what exhaust system are you using?? i guess RS tuning headers and 100 cel cats?? Maybe you need a more free flowing exhaust... i remember a thread about backpressure in 6speed where Stef from Europipe said how going to a larger exhaust tip diameter effects back pressure in his tests.. evrey little bit adds up...
Also did you datalog the water temperature to see if they are stable ??
08-29-2011 | 07:50 AM
#38
Addict
Rennlist Member
Rennlist Member
Joined: May 2001
Posts: 4,446
Likes: 115
From: UK
My exhaust system is in link below (and I mean MY system, I had this actual development one )
I can highly recommend it, it gives maximum flow when you need it and quiet when you don't.
http://www.cargraphic.de/index.php?/s,6,7,18,3647,3804/
Just the option in Durametrics, the "modelled" exhaust temp.....do we know how accurate this is ?
)I can highly recommend it, it gives maximum flow when you need it and quiet when you don't.
http://www.cargraphic.de/index.php?/s,6,7,18,3647,3804/
Just the option in Durametrics, the "modelled" exhaust temp.....do we know how accurate this is ?
08-30-2011 | 06:58 AM
#40
Pro
Joined: Feb 2010
Posts: 573
Likes: 6
From: Qatar
Im thinking of installing a Europipe catless exhaust 76.3mm instead of my catless oem exhaust system..
since akrapovic wont do a catless system
Stef from Europipe told me the cross sections on his stage 2 exhaust is 40% more than the oem system...
what do you guys think about that?? do you think there will be any gains??
Im pretty hesitant since my setup sounds really great and very underestimated till its on boost...
but ofcourse we all want better efficiancy....
*Edit*
GT , i came across an old thread of mine on rennteam about my previous Rturbo , you said that you experianced significant gains from swtiching to a modfied exhaust + cats to a cargraphic exhaust??
since akrapovic wont do a catless system
Stef from Europipe told me the cross sections on his stage 2 exhaust is 40% more than the oem system...
what do you guys think about that?? do you think there will be any gains??
Im pretty hesitant since my setup sounds really great and very underestimated till its on boost...
but ofcourse we all want better efficiancy....
*Edit*
GT , i came across an old thread of mine on rennteam about my previous Rturbo , you said that you experianced significant gains from swtiching to a modfied exhaust + cats to a cargraphic exhaust??
Last edited by TTurbine; 08-30-2011 at 07:56 AM.
08-31-2011 | 05:46 AM
#43
Addict
Rennlist Member
Rennlist Member
Joined: May 2001
Posts: 4,446
Likes: 115
From: UK
I am quite alarmed by how much crap is on the flap pipe, they are much worse now than that photo, I guess I am burning a lot of fuel
