GT2 expansion manifold
10-24-2007, 02:58 AM
#31
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It helped me! Thanks for the awesome explanation. I also liked your explanation on the 997 forum about how a K&N air filter works, or doesn't. Hope you can visit us again.
Greg H.
Greg H.
10-24-2007, 10:12 AM
#32
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same principles used in promoting exhaust scavenging - interesting, but still lies the issue of the prudence of boosting to 1.4bar to compensate for the additional pressure/density drop.
10-24-2007, 12:47 PM
#33
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Posed the question yesterday to the UK authorised CGT tech, he didn't know the answer but by today he had spoken to his contacts in Germany.....
What we concluded was correct and the actual boost going into the combustion chamber is quite a bit LESS than 1.4bar which is what the VTGs have to produce to get the expansion effect working.
Apparently the air intakes on the rear wing which provide the ram air effect into the intake are much more than just for marketing appeal, they lower the VTG temps and help significantly in keeping the VTG temps in check whilst running at these boost levels......
Haggis -thanks for your explanation, interesting
What we concluded was correct and the actual boost going into the combustion chamber is quite a bit LESS than 1.4bar which is what the VTGs have to produce to get the expansion effect working.
Apparently the air intakes on the rear wing which provide the ram air effect into the intake are much more than just for marketing appeal, they lower the VTG temps and help significantly in keeping the VTG temps in check whilst running at these boost levels......
Haggis -thanks for your explanation, interesting
10-24-2007, 01:01 PM
#34
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I can see it now - the best mod route for the Gt2 will be the elimination of the expansion intake system for the regular TT intake. I would imagine such a car would be 550-580hp, perhaps more if charge cooling could be optimized with better intercoolers
10-24-2007, 05:08 PM
#35
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Yes Eclou,
Plus I wonder if the stock titanium exhaust might be more restrictive than aftermarket pieces whose change could help get the car another 20-50HP and easily to 600HP without much else needed besides the intake and ECU mods.
Plus I wonder if the stock titanium exhaust might be more restrictive than aftermarket pieces whose change could help get the car another 20-50HP and easily to 600HP without much else needed besides the intake and ECU mods.
10-24-2007, 05:25 PM
#36
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That is very interesting topic TB, thanks.
Have to read all these many times to understand also these theory parts.
Would be great to see if somebody just test fit this new GT2 manifold to 993TT and do dynotests before and after.. I would even pay from these test results
Have to read all these many times to understand also these theory parts.
Would be great to see if somebody just test fit this new GT2 manifold to 993TT and do dynotests before and after.. I would even pay from these test results
10-24-2007, 07:17 PM
#37
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I'm pretty certain the GT2 exhaust is not going to be using 100 or 200 cell cats like aftermarket - so it's a safe bet that the aftermarket exhausts will have less backpressure. I am wondering if Porsche has ever released a 1.4 bar street car and if there were any high temp endurance testing?
