More power for the GT4 - any valid numbers?
#106
Race Director
Originally Posted by bretster
What setup are you running CAIexio? I looked through the thread but could not find it.
-plenum & tb
-Cobb protune
The best $5k option on the whole car.
#107
Rennlist Member
In my case I can say that the difference between my stock gt4 and my tuned gt4 is very noticeable ... the car feels very alive and aggressive... and this is confirmed by the dyno....these are objective data... if you see the dyno sheet you can see gains of over 25 hp and 3 Kgm in the midrange...and a little less at the upper rpm.... this additional power and torque in all the rpm range (with peaks in the midrange) makes the difference... i' m very very happy.....
#109
Working in the medical field, I'm all too familiar wth placebo effect.. human brain has a crazy way to make itself belief something it thinks it should believe. So maybe after we spend $ on mods we want to believe will work, then we actually feel them working. Maybe.
But I challenge anyone with a regular spyder or gt4 to get into mine and not feel a massive difference from stock. 'UUGE difference from stock. Before it was strangled, now it's an animal. Smoothness, torque fullness, lugging from lower gears it just continues to pull all the way to redline, let alone the increased volume after 4K rpm. It has made the car immensely more enjoyable to drive. So.. even if it's only Stout's #2 which changes, I still have zero regrets and would redo it all over again, especially considering how easily reversible everything is. but I'd be really surprised if #1 didn't change also.
But I challenge anyone with a regular spyder or gt4 to get into mine and not feel a massive difference from stock. 'UUGE difference from stock. Before it was strangled, now it's an animal. Smoothness, torque fullness, lugging from lower gears it just continues to pull all the way to redline, let alone the increased volume after 4K rpm. It has made the car immensely more enjoyable to drive. So.. even if it's only Stout's #2 which changes, I still have zero regrets and would redo it all over again, especially considering how easily reversible everything is. but I'd be really surprised if #1 didn't change also.
so this line "Smoothness, torque fullness, lugging from lower gears it just continues to pull all the way to redline, let alone the increased volume after 4K rpm" means nothing :-(
it seems people saying how good mods are, are all driving at 3k revs and should have bought a Turbo car or an oil burner
people using the car above 4k revs are seeing no real performance gains, only bum dyno gains :-(
the other issue is peak HP at 6.5k revs when the car goes to 7.8 or whatever.
I wonder if on track ones changes at 6.5k revs not red line the speed at the end of the straight might be higher ?
I'll data log a run from 30mph to red line in 4th, one changing at red line one at 6.5k see what's fastest.
the fab speed sport header loses bhp at 4k revs so that's a big no go for me to gain at 3.5 revs to loose at 4k !
Has any one owned a GT3 where you really get no real power till 6.2k revs ! lol
#110
#111
This is exactly the problem. I would have assumed that headers, plenum, tb and tune would at least move me from 238kph on the straight to mid 240's. But reality is i have not gained anythin on the straight.
#112
issue is I don't care about sub 4k performance or noise
so this line "Smoothness, torque fullness, lugging from lower gears it just continues to pull all the way to redline, let alone the increased volume after 4K rpm" means nothing :-(
it seems people saying how good mods are, are all driving at 3k revs and should have bought a Turbo car or an oil burner
people using the car above 4k revs are seeing no real performance gains, only bum dyno gains :-(
the other issue is peak HP at 6.5k revs when the car goes to 7.8 or whatever.
I wonder if on track ones changes at 6.5k revs not red line the speed at the end of the straight might be higher ?
I'll data log a run from 30mph to red line in 4th, one changing at red line one at 6.5k see what's fastest.
the fab speed sport header loses bhp at 4k revs so that's a big no go for me to gain at 3.5 revs to loose at 4k !
Has any one owned a GT3 where you really get no real power till 6.2k revs ! lol
so this line "Smoothness, torque fullness, lugging from lower gears it just continues to pull all the way to redline, let alone the increased volume after 4K rpm" means nothing :-(
it seems people saying how good mods are, are all driving at 3k revs and should have bought a Turbo car or an oil burner
people using the car above 4k revs are seeing no real performance gains, only bum dyno gains :-(
the other issue is peak HP at 6.5k revs when the car goes to 7.8 or whatever.
I wonder if on track ones changes at 6.5k revs not red line the speed at the end of the straight might be higher ?
I'll data log a run from 30mph to red line in 4th, one changing at red line one at 6.5k see what's fastest.
the fab speed sport header loses bhp at 4k revs so that's a big no go for me to gain at 3.5 revs to loose at 4k !
Has any one owned a GT3 where you really get no real power till 6.2k revs ! lol
#113
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I usually short shift climbing the Watkins Glen esses between the left and last right. The blue trace is me shifting there @ 7000 rpm @ the 3500' mark. The yellow trace is me running to red line on a later lap. Note that the speed traces are almost the same. The Blue was slightly faster earlier. The difference in speed at the brake zone is because I broke later.
__________________
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John@Fabspeed.com
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Porsche Performance Specialist
John@Fabspeed.com
215-618-9796
Fabspeed Motorsport USA
155 Commerce Drive Fort Washington, PA 19034
www.Fabspeed.com
#114
so looking at the graph changing earlier is faster. I wonder now if we change at 6.5 revs it would be faster again ?
you seen the blue line drop below the green line at the early change point, but then passes though the green line and over takes it.
here is the key point on the graph. 1/2 way though that picture the early change catches back up and is now ahead with the blue line riding higher.
you seen the blue line drop below the green line at the early change point, but then passes though the green line and over takes it.
here is the key point on the graph. 1/2 way though that picture the early change catches back up and is now ahead with the blue line riding higher.
#115
Three Wheelin'
I will have to go faster next time I am there :-)
currently I short shift to 4 before T2 and then to 5 after coming out of the esses.....
#116
Rennlist Member
1st and 2nd gears are the only ones that require you to take them to redline for optimal performance I think. On the 3-4 shift you can be early and not loose time, as long as you would have to make the shift anyway, of course. (But I still think shifting after 7k is better, just you don't need to take it to 7.6k for 3-4 or 4-5)
#117
why do you say shifting after 7k is better when the plot posted proves other wise ?
#118
Not sure if anyone else was at the PCA Sebring club race . Rick Deman had some serious juice in his #77 Cayman. He was 3 seconds a lap faster that the rest of the run group. Way to go Rick. You De Man.
#120
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