Ask Porsche for a factory powerkit!
08-20-2016, 05:58 PM
#1
Rennlist Member
Thread Starter
Ask Porsche for a factory powerkit!
(As you all probably know), there is a Porsche factory powerkit available, with warranty, for the 991 carrera S, a car which has the same engine as the GT4. The powerkit is available from Suncoast Porsche (http://suncoastparts.com/product/SKU991X51.html) for $10,995 and it brings the output of the 991 carrera S from 400 hp to 430 hp, using intake cams, modified cylinder heads, variable resonance intake manifold, and a revised ecu.
Our engine makes 385 hp. Porsche claims the 15 hp decrease from the carrera S 400 hp is due to the exhaust, however, I don't think this is the case (see this post: https://rennlist.com/forums/gt4/8822...l#post13024874 Also, see the dyno plots in that thread). It's because our engine has a 74 mm throttle body and not the 82 mm throttle body in the carrera S.
So, for Porsche to make a 430 hp powerkit for the Cayman GT4, which would come with a warranty, all they would have to do is add a 82 mm throttle body (which is cheap) to the powerkit already available for the carrera S. I'm going to write a letter to Porsche North America requesting such a kit for street GT4s. We don't need 430 hp, but it would be fun to have 430 hp, especially with a warranty!
Our engine makes 385 hp. Porsche claims the 15 hp decrease from the carrera S 400 hp is due to the exhaust, however, I don't think this is the case (see this post: https://rennlist.com/forums/gt4/8822...l#post13024874 Also, see the dyno plots in that thread). It's because our engine has a 74 mm throttle body and not the 82 mm throttle body in the carrera S.
So, for Porsche to make a 430 hp powerkit for the Cayman GT4, which would come with a warranty, all they would have to do is add a 82 mm throttle body (which is cheap) to the powerkit already available for the carrera S. I'm going to write a letter to Porsche North America requesting such a kit for street GT4s. We don't need 430 hp, but it would be fun to have 430 hp, especially with a warranty!
08-20-2016, 06:55 PM
#3
Rennlist Member
Thread Starter
08-20-2016, 07:05 PM
#5
(As you all probably know), there is a Porsche factory powerkit available, with warranty, for the 991 carrera S, a car which has the same engine as the GT4. The powerkit is available from Suncoast Porsche (http://suncoastparts.com/product/SKU991X51.html) for $10,995 and it brings the output of the 991 carrera S from 400 hp to 430 hp, using intake cams, modified cylinder heads, variable resonance intake manifold, and a revised ecu.
Our engine makes 385 hp. Porsche claims the 15 hp decrease from the carrera S 400 hp is due to the exhaust, however, I don't think this is the case (see this post: https://rennlist.com/forums/gt4/8822...l#post13024874 Also, see the dyno plots in that thread). It's because our engine has a 74 mm throttle body and not the 82 mm throttle body in the carrera S.
So, for Porsche to make a 430 hp powerkit for the Cayman GT4, which would come with a warranty, all they would have to do is add a 82 mm throttle body (which is cheap) to the powerkit already available for the carrera S. I'm going to write a letter to Porsche North America requesting such a kit for street GT4s. We don't need 430 hp, but it would be fun to have 430 hp, especially with a warranty!
Our engine makes 385 hp. Porsche claims the 15 hp decrease from the carrera S 400 hp is due to the exhaust, however, I don't think this is the case (see this post: https://rennlist.com/forums/gt4/8822...l#post13024874 Also, see the dyno plots in that thread). It's because our engine has a 74 mm throttle body and not the 82 mm throttle body in the carrera S.
So, for Porsche to make a 430 hp powerkit for the Cayman GT4, which would come with a warranty, all they would have to do is add a 82 mm throttle body (which is cheap) to the powerkit already available for the carrera S. I'm going to write a letter to Porsche North America requesting such a kit for street GT4s. We don't need 430 hp, but it would be fun to have 430 hp, especially with a warranty!
08-20-2016, 07:27 PM
#6
Rennlist Member
Thread Starter
I agree it's a little unclear whether the difference really is 15 hp, and how much of the power difference is ECU tuning. I suppose my main point is that I don't think the exhaust is the biggest culprit and I think a good powerkit could be made without a new exhaust.
08-20-2016, 07:40 PM
#7
Banned
Join Date: Jan 2013
Location: Chicagoland Area
Posts: 26,142
Likes: 0
Received 5,388 Likes
on
2,509 Posts
The 9A1 3.8l motor in the 991S is slightly detuned. Porsche offers the PowerKit option to eak out 30 more HP for $18,600.
Trending Topics
08-20-2016, 08:01 PM
#8
Race Director
The next step would be a tune and Plenum/TB - I have this step going on this Friday. I already put on FVD Headers and their valveless exhaust.( Noticeable difference)
08-20-2016, 08:45 PM
#9
Racer
Join Date: Dec 2015
Location: TX & CA
Posts: 439
Likes: 0
Received 0 Likes
on
0 Posts
The good news: There will likely be a "power kit" available sometime in the near future.
The bad news: It won't be coming from Porsche corporate with Porsche warranty. I think BGB is furthest along in this development, using many Porsche parts.
08-20-2016, 09:25 PM
#10
Three Wheelin'
A set of LT headers already gets you over the 400 hp and also helps level out those dips for smoother acceleration.
The next step would be a tune and Plenum/TB - I have this step going on this Friday. I already put on FVD Headers and their valveless exhaust.( Noticeable difference)
The next step would be a tune and Plenum/TB - I have this step going on this Friday. I already put on FVD Headers and their valveless exhaust.( Noticeable difference)
I'd rather slap on slicks and upgrade suspension...it is worth a lot more on track then 15 hp IMO.
08-20-2016, 10:14 PM
#12
Is the warranty is gone with headers? According to my service manager when headers are installed, Porsche will fight a warranty claim...he just had a claim last year that Porsche denied.
I'd rather slap on slicks and upgrade suspension...it is worth a lot more on track then 15 hp IMO.
I'd rather slap on slicks and upgrade suspension...it is worth a lot more on track then 15 hp IMO.
...and if you slap the slicks you can also kiss the warranty goodbye as per the car manual...if you upgrade the suspension you can also kiss goodbye any warranty claim on any area around the suspension. IMO it would be a lot harder to pin an engine problem on the headers but that depends on how flexible your dealer is with mods. 15 hp may not sound like a lot but that's peak and it does make a big difference on track and specially on the street......
08-21-2016, 01:11 AM
#13
Race Director
Is the warranty is gone with headers? According to my service manager when headers are installed, Porsche will fight a warranty claim...he just had a claim last year that Porsche denied.
I'd rather slap on slicks and upgrade suspension...it is worth a lot more on track then 15 hp IMO.
I'd rather slap on slicks and upgrade suspension...it is worth a lot more on track then 15 hp IMO.
08-21-2016, 03:41 AM
#14
Rennlist Member
pag sets the tune to hold the gt4 back, they do it on purpose to maintain their product performance hieirarchy
if they wanted us to have 400, 405, 410 hp in the gt4 with smooth midrange torque we would have it
we can go get it aftermarket and bust out of their hieirarchy but we do so without their backing/warranty
that's exactly the way they want it too
if they wanted us to have 400, 405, 410 hp in the gt4 with smooth midrange torque we would have it
we can go get it aftermarket and bust out of their hieirarchy but we do so without their backing/warranty
that's exactly the way they want it too
08-21-2016, 12:21 PM
#15
Nordschleife Master
Originally Posted by jmartpr
...and if you slap the slicks you can also kiss the warranty goodbye as per the car manual...if you upgrade the suspension you can also kiss goodbye any warranty claim on any area around the suspension. IMO it would be a lot harder to pin an engine problem on the headers but that depends on how flexible your dealer is with mods. 15 hp may not sound like a lot but that's peak and it does make a big difference on track and specially on the street......
15hp is on paper only, for marketing/hierarchy purposes