GT4 - Unlocking the Power Potential!
03-02-2016, 05:15 PM
#451
The diligent reader may detect that I autocross. 
This is solo racing at
speeds between 30mph and 75mph, which is done mostly in second gear.
So, more acceleration is needed more often between 30mph and 45mph.
The auto-rev-matching may help the rare second-to-first shift, but for
autocross we want instant torque wherever we are, and a 'straight' is
anywhere we can touch the gas pedal to the mat for a half-second...
This is solo racing atspeeds between 30mph and 75mph, which is done mostly in second gear.
So, more acceleration is needed more often between 30mph and 45mph.
The auto-rev-matching may help the rare second-to-first shift, but for
autocross we want instant torque wherever we are, and a 'straight' is
anywhere we can touch the gas pedal to the mat for a half-second...
03-02-2016, 07:08 PM
#452
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He's using the Carrera's Plenum/runners, all one integrated unit, which is why there is a clearance issue. It's taller and has more interior air volume. You can use your 82mm TB, but the plenum is redundant. I'm sure someone would buy it from you at a reasonable price, the plenum is the same unit across the 981 I think.
Headers on the other hand, totally reusable - and likely necessary.
Headers on the other hand, totally reusable - and likely necessary.
How did the Carrera plenum/runner clearance issued get solved for the GT4?
03-02-2016, 07:41 PM
#453
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03-02-2016, 08:01 PM
#454
I will! When you live in a rural area and the nearest track is a 12 hour drive, autocross is a welcome option. Heck, even if I lived nearer a track, I think I would still autocross. I love the precision required, as well as the community.
03-02-2016, 10:23 PM
#457
03-02-2016, 11:07 PM
#458
I know of 5 GT4s in SoCal that autocross. It is a great platform for it. If only we had X51, and a lower Ring and Pinion (looking for a 74mph second gear)...
I like the big tracks too, and actual Real Wheel to Wheel Road Racing... But, AutoX is just more competitive most of the time, and easier to get away to do with the pressures of family and work.
I like the big tracks too, and actual Real Wheel to Wheel Road Racing... But, AutoX is just more competitive most of the time, and easier to get away to do with the pressures of family and work.
03-03-2016, 06:24 AM
#459
But if it means sacrificing any top end? I haven't found anything lacking in street driveability. At the low point of the dip at 3500 it has 15Nm less than the 991 Carrera S but the same torque as the 997.2 GT3 and RS and 30Nm more than the 991 GT3 RS. The only thing that makes it a dip is that it has significantly more torque than any of them at 2500. I'd rather have everything extra going into top end thrills for road and track.
03-03-2016, 10:04 AM
#460
The USA guys would rather Turbo torque lol it's a lost fight saying other wise.
It's lost on me all this 3k torque want, but there you go !
Makes you wonder if any one ever drove a GT3 !
It's lost on me all this 3k torque want, but there you go !
Makes you wonder if any one ever drove a GT3 !
03-03-2016, 10:35 AM
#462
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Originally Posted by mrd_spy
The USA guys would rather Turbo torque lol it's a lost fight saying other wise.
It's lost on me all this 3k torque want, but there you go !
Makes you wonder if any one ever drove a GT3 !
It's lost on me all this 3k torque want, but there you go !
Makes you wonder if any one ever drove a GT3 !
There is a big gap between the GT3 in feel based on power and gearing.
03-03-2016, 10:53 AM
#463
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When we did the first X51 install on a 981 I had prototyped the fitment. Since then I have a coolant tank being made so that it's literally a matter of swapping parts and not grinding anything anymore.
03-03-2016, 11:04 AM
#464
In the works as we speak! I will be on the dyno all day Monday with the car and helping build some Stage II maps for Cobb who will be releasing GT4 files shortly for cars that have headers, Plenums, etc. I will try and answer the rest of the questions shortly. I have recovered from the SwineFlu and we are on track at Sebring for 4 days with cars.
Just as suggestion tho, I'm a little unclear about whether there is an definitive answer to T/B + plenum without software update would have CEL? And also various findings discussed here. Maybe it will help to have some blog on your website to go through the various stages of mods
Cuz I remember seeing different Stage1 and Stage 2 earlier, but that seems to differ from the most recent set?
Thanks for sharing all the findings nonetheless. Certainly a lot of work has been put into this. And I know BGB is the place to buy my stuff when I need some of these mods
03-03-2016, 11:53 AM
#465
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After talking to multiple tuners, only one can guarantee that the CEL will not show up for too much air from the 82mm TB and that's the ECU from Germany. At this point, the U.S. offering is working on guaranteeing that the IPD/82mm TB won't set off a CEL with a modified tune but it's early to tell as most GT4 owners haven't jumped on board with the Plenum upgrade. However, my car is running GT4 firmware with porting, 82mm TB and X51 manifold and I only have CELs for the lack of cats but not for the MAP/MAF implausible so, as for right now, the same people who are 50/50 on whether or not their software accommodates for it, are ending up on successful side of the experiment.
I have finished 3 offerings that list what is in each stage and how much it costs. Should I post them here or start a new thread?
I have finished 3 offerings that list what is in each stage and how much it costs. Should I post them here or start a new thread?