2016 Cayman GT4 -> GT4RS Conversion
04-13-2019, 06:19 PM
#47
Three Wheelin'
04-13-2019, 06:27 PM
#48
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I can get you guys quotes and Monday i can send a video. sound good?
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porscheflat6 (04-19-2021)
04-14-2019, 09:07 AM
#49
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After several setbacks and a shipping mishap that sidelined us yet another month, the strongest Cayman/Boxster engine conversion we have ever executed is now complete. We owe an enormous amount of thanks to the car's owner for his patience. We have never ever ever ever had a car in our shop this for as long as this car has been here. We had a miscue with our machine shop and then UPS dropped something and then it seemed like 1 thing after another when it came to getting our parts in hand. We both began to wonder if this car would ever again be released from solitary confinement! HOWEVER, since apparently good things come to those who wait, we now have this to show for it.
We find it best to do a pre and post dyno analysis because every dyno seems to always read differently and we have to see the gains for ourselves before we release the cars to the customer. I have been going to the dyno more and more frequently with cars with standard bolt-ons because we have seen claims that you can get almost 450hp from a Cayman GT4 with an intake, exhaust and ECU upgrade but we have never been able to reproduce those numbers ourselves when we dyno them. Of the dozen GT4s we have dyno'd with different iterations of exhaust and tune combos from different tuners, they all dyno within 5 hp at or near the 365rwhp number on our Dynojet in town and this car was no different.
The blue line is how the car showed up on our doorstep with aftermarket exhaust, intake and ECU upgrades that were done prior to its arrival, none of which we were involved in selling to the owner. The red line is from today.The car is running 91 octane. The before and after peaks gains are + 80rwhp and + 40 rwlb/ft but at 7K RPM where the Cayman intake begins to starve for air, the numbers are +95rwhp and + 81rwlb/ft. These motors need to breathe and the gains are attributed to the addition of the stroke increase to 4.0L, a further bore increase to 4.25L, the addition of the X51 Power Kit with additional CNC porting and upgrading to the Cargraphic catless race manifold.
The owner was tired of the senseless GT3 bullying that occurs on race tracks across North America and we feel that we have finally leveled the playing field! Per the same 12.5% drivetrain loss number that i have used for the last 15 years, this equates to 506 hp and 383 lb/ft at the crank. At the moment the engine is still relatively new and we therefore did not opt to spin the car over 7600 RPM. When it's broken in and in the hands of the owner, it will be pushed further.
We find it best to do a pre and post dyno analysis because every dyno seems to always read differently and we have to see the gains for ourselves before we release the cars to the customer. I have been going to the dyno more and more frequently with cars with standard bolt-ons because we have seen claims that you can get almost 450hp from a Cayman GT4 with an intake, exhaust and ECU upgrade but we have never been able to reproduce those numbers ourselves when we dyno them. Of the dozen GT4s we have dyno'd with different iterations of exhaust and tune combos from different tuners, they all dyno within 5 hp at or near the 365rwhp number on our Dynojet in town and this car was no different.
The blue line is how the car showed up on our doorstep with aftermarket exhaust, intake and ECU upgrades that were done prior to its arrival, none of which we were involved in selling to the owner. The red line is from today.The car is running 91 octane. The before and after peaks gains are + 80rwhp and + 40 rwlb/ft but at 7K RPM where the Cayman intake begins to starve for air, the numbers are +95rwhp and + 81rwlb/ft. These motors need to breathe and the gains are attributed to the addition of the stroke increase to 4.0L, a further bore increase to 4.25L, the addition of the X51 Power Kit with additional CNC porting and upgrading to the Cargraphic catless race manifold.
The owner was tired of the senseless GT3 bullying that occurs on race tracks across North America and we feel that we have finally leveled the playing field! Per the same 12.5% drivetrain loss number that i have used for the last 15 years, this equates to 506 hp and 383 lb/ft at the crank. At the moment the engine is still relatively new and we therefore did not opt to spin the car over 7600 RPM. When it's broken in and in the hands of the owner, it will be pushed further.
For the folks that have driven both GT3 and one of the modified GT4s, how do they compare? I am first on the wait list at my local dealer for the 992 GT3 and need to decide if I want to spend the additional money on a GT3, which everyone seems to say is better than a GT4, or put it towards some mods to improve the experience in my GT4.
04-14-2019, 09:31 AM
#50
[QUOTE=jas49503;15772571]How much do you think that the X51 Power Kit add to the improvements? It is my understanding that the DeMann engine doesn't use that, but seems to have to similar gains. Also, those fenders look awesome but do they have any function? I have a personal hang up about not putting things on my car which have no real function.
I found the X51 heads and cams added quite a bit when the tune was sorted but we also found that the X51 intake plenum actually detracted from performance so I developed the car without out; just an IPD plus 82mm TB. I am keen to try either an entire GT3 intake system, new GT4 Clubsport system or just add Dundon runers......see my detailed thread on the development to date including standardised dyno runs.
I reckon my GT4 runs a genuine 440-450 BHP at the crank and it's fast for sure and I love the compact interior. I also have a 991.2 GT3 and that is quite a bit more powerful and exciting to drive. Having said that I'm keeping my GT4 as my track rat.
I found the X51 heads and cams added quite a bit when the tune was sorted but we also found that the X51 intake plenum actually detracted from performance so I developed the car without out; just an IPD plus 82mm TB. I am keen to try either an entire GT3 intake system, new GT4 Clubsport system or just add Dundon runers......see my detailed thread on the development to date including standardised dyno runs.
I reckon my GT4 runs a genuine 440-450 BHP at the crank and it's fast for sure and I love the compact interior. I also have a 991.2 GT3 and that is quite a bit more powerful and exciting to drive. Having said that I'm keeping my GT4 as my track rat.
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Toothengineer (04-19-2021)
04-19-2021, 09:13 AM
#52
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Bumping an old thread, but I think this car is for sale here:
https://www.celebritycars.com/detail...8gk192097.html
In case anyone is interested...
https://www.celebritycars.com/detail...8gk192097.html
In case anyone is interested...
04-19-2021, 09:20 AM
#53
Rennlist Member
Hard to get good information from the dealership. Mismatched rotors. Missing prior wheels. Wrap doesn't add value, but can hide sins. Hard to roll the dice at 117k for someone else's modifications.
Last edited by Ksdaoski; 04-19-2021 at 09:21 AM.
04-19-2021, 08:23 PM
#54
Nordschleife Master
gt4 all day long. Always hard to know if a car was built and setup right, unless you or someone you know did it.
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porscheflat6 (04-19-2021),
Toothengineer (04-21-2021)
04-19-2021, 10:56 PM
#55
After several setbacks and a shipping mishap that sidelined us yet another month, the strongest Cayman/Boxster engine conversion we have ever executed is now complete. We owe an enormous amount of thanks to the car's owner for his patience. We have never ever ever ever had a car in our shop this for as long as this car has been here. We had a miscue with our machine shop and then UPS dropped something and then it seemed like 1 thing after another when it came to getting our parts in hand. We both began to wonder if this car would ever again be released from solitary confinement! HOWEVER, since apparently good things come to those who wait, we now have this to show for it.
We find it best to do a pre and post dyno analysis because every dyno seems to always read differently and we have to see the gains for ourselves before we release the cars to the customer. I have been going to the dyno more and more frequently with cars with standard bolt-ons because we have seen claims that you can get almost 450hp from a Cayman GT4 with an intake, exhaust and ECU upgrade but we have never been able to reproduce those numbers ourselves when we dyno them. Of the dozen GT4s we have dyno'd with different iterations of exhaust and tune combos from different tuners, they all dyno within 5 hp at or near the 365rwhp number on our Dynojet in town and this car was no different.
The blue line is how the car showed up on our doorstep with aftermarket exhaust, intake and ECU upgrades that were done prior to its arrival, none of which we were involved in selling to the owner. The red line is from today.The car is running 91 octane. The before and after peaks gains are + 80rwhp and + 40 rwlb/ft but at 7K RPM where the Cayman intake begins to starve for air, the numbers are +95rwhp and + 81rwlb/ft. These motors need to breathe and the gains are attributed to the addition of the stroke increase to 4.0L, a further bore increase to 4.25L, the addition of the X51 Power Kit with additional CNC porting and upgrading to the Cargraphic catless race manifold.
The owner was tired of the senseless GT3 bullying that occurs on race tracks across North America and we feel that we have finally leveled the playing field! Per the same 12.5% drivetrain loss number that i have used for the last 15 years, this equates to 506 hp and 383 lb/ft at the crank. At the moment the engine is still relatively new and we therefore did not opt to spin the car over 7600 RPM. When it's broken in and in the hands of the owner, it will be pushed further.
We find it best to do a pre and post dyno analysis because every dyno seems to always read differently and we have to see the gains for ourselves before we release the cars to the customer. I have been going to the dyno more and more frequently with cars with standard bolt-ons because we have seen claims that you can get almost 450hp from a Cayman GT4 with an intake, exhaust and ECU upgrade but we have never been able to reproduce those numbers ourselves when we dyno them. Of the dozen GT4s we have dyno'd with different iterations of exhaust and tune combos from different tuners, they all dyno within 5 hp at or near the 365rwhp number on our Dynojet in town and this car was no different.
The blue line is how the car showed up on our doorstep with aftermarket exhaust, intake and ECU upgrades that were done prior to its arrival, none of which we were involved in selling to the owner. The red line is from today.The car is running 91 octane. The before and after peaks gains are + 80rwhp and + 40 rwlb/ft but at 7K RPM where the Cayman intake begins to starve for air, the numbers are +95rwhp and + 81rwlb/ft. These motors need to breathe and the gains are attributed to the addition of the stroke increase to 4.0L, a further bore increase to 4.25L, the addition of the X51 Power Kit with additional CNC porting and upgrading to the Cargraphic catless race manifold.
The owner was tired of the senseless GT3 bullying that occurs on race tracks across North America and we feel that we have finally leveled the playing field! Per the same 12.5% drivetrain loss number that i have used for the last 15 years, this equates to 506 hp and 383 lb/ft at the crank. At the moment the engine is still relatively new and we therefore did not opt to spin the car over 7600 RPM. When it's broken in and in the hands of the owner, it will be pushed further.
09-18-2021, 07:35 AM
#57
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Originally Posted by bldn10
Just sold again, this time on PCar, for $125,000 + $5000. Oddly, it sold as a 4.0 although the dyno chart above identifies it as a 4.25.
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bldn10 (06-13-2022)
06-11-2022, 11:45 AM
#59
Rennlist Member
After several setbacks and a shipping mishap that sidelined us yet another month, the strongest Cayman/Boxster engine conversion we have ever executed is now complete. We owe an enormous amount of thanks to the car's owner for his patience. We have never ever ever ever had a car in our shop this for as long as this car has been here. We had a miscue with our machine shop and then UPS dropped something and then it seemed like 1 thing after another when it came to getting our parts in hand. We both began to wonder if this car would ever again be released from solitary confinement! HOWEVER, since apparently good things come to those who wait, we now have this to show for it.
We find it best to do a pre and post dyno analysis because every dyno seems to always read differently and we have to see the gains for ourselves before we release the cars to the customer. I have been going to the dyno more and more frequently with cars with standard bolt-ons because we have seen claims that you can get almost 450hp from a Cayman GT4 with an intake, exhaust and ECU upgrade but we have never been able to reproduce those numbers ourselves when we dyno them. Of the dozen GT4s we have dyno'd with different iterations of exhaust and tune combos from different tuners, they all dyno within 5 hp at or near the 365rwhp number on our Dynojet in town and this car was no different.
The blue line is how the car showed up on our doorstep with aftermarket exhaust, intake and ECU upgrades that were done prior to its arrival, none of which we were involved in selling to the owner. The red line is from today.The car is running 91 octane. The before and after peaks gains are + 80rwhp and + 40 rwlb/ft but at 7K RPM where the Cayman intake begins to starve for air, the numbers are +95rwhp and + 81rwlb/ft. These motors need to breathe and the gains are attributed to the addition of the stroke increase to 4.0L, a further bore increase to 4.25L, the addition of the X51 Power Kit with additional CNC porting and upgrading to the Cargraphic catless race manifold.
The owner was tired of the senseless GT3 bullying that occurs on race tracks across North America and we feel that we have finally leveled the playing field! Per the same 12.5% drivetrain loss number that i have used for the last 15 years, this equates to 506 hp and 383 lb/ft at the crank. At the moment the engine is still relatively new and we therefore did not opt to spin the car over 7600 RPM. When it's broken in and in the hands of the owner, it will be pushed further.
We find it best to do a pre and post dyno analysis because every dyno seems to always read differently and we have to see the gains for ourselves before we release the cars to the customer. I have been going to the dyno more and more frequently with cars with standard bolt-ons because we have seen claims that you can get almost 450hp from a Cayman GT4 with an intake, exhaust and ECU upgrade but we have never been able to reproduce those numbers ourselves when we dyno them. Of the dozen GT4s we have dyno'd with different iterations of exhaust and tune combos from different tuners, they all dyno within 5 hp at or near the 365rwhp number on our Dynojet in town and this car was no different.
The blue line is how the car showed up on our doorstep with aftermarket exhaust, intake and ECU upgrades that were done prior to its arrival, none of which we were involved in selling to the owner. The red line is from today.The car is running 91 octane. The before and after peaks gains are + 80rwhp and + 40 rwlb/ft but at 7K RPM where the Cayman intake begins to starve for air, the numbers are +95rwhp and + 81rwlb/ft. These motors need to breathe and the gains are attributed to the addition of the stroke increase to 4.0L, a further bore increase to 4.25L, the addition of the X51 Power Kit with additional CNC porting and upgrading to the Cargraphic catless race manifold.
The owner was tired of the senseless GT3 bullying that occurs on race tracks across North America and we feel that we have finally leveled the playing field! Per the same 12.5% drivetrain loss number that i have used for the last 15 years, this equates to 506 hp and 383 lb/ft at the crank. At the moment the engine is still relatively new and we therefore did not opt to spin the car over 7600 RPM. When it's broken in and in the hands of the owner, it will be pushed further.
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RobC4sX51 (06-12-2022)
06-15-2022, 12:21 PM
#60
Forgive me for going off on a tangent and asking a stupid question to boot, but I wanted to ask whether the beginning of air starvation at 7k is endemic to the 981GT4 or is it affected by your mods? If it’s the former, that would seem to have implications for shift points. It would also be consistent with several dyno graphs I have seen. Thanks.
Intake system upgrade such as the X51 Manifold, the 718 Clubsport Intake Manifold or Dundon Intake Runners.. de-restrict, and can flow much much more volume overall.
With these you can rev the engine right out and power will continue to increase, rather than the feeling of need to still shift some way shorter with the OEM intake manifold.
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Jim Cobb (06-15-2022)