Upgrading a 981 PDK Cayman

[ralphmusic]

Jeff,

But then I'd have to upgrade brakes and suspension again and end up selling two ex(p/t)ensively modified cars - doesn't work.

 

[carreraboy]

Electric motor Ralph .... just think about all that torque ....

 

[Motorhead]

Jeff,

But then I'd have to upgrade brakes and suspension again and end up selling two ex(p/t)ensively modified cars - doesn't work.

Sad but true Ralph.

Looks as though it's the 981 for the foreseeable future then, and taking the PowerKit route would seem to be the next logical step. You must have clocked up a fair number of miles by now, presumably many of those on track, so a top end "refresh" could be beneficial.

Jeff

 

[ralphmusic]

....You must have clocked up a fair number of miles by now, presumably many of those on track, so a top end "refresh" could be beneficial.

Jeff

Jeff,

The engine has only done 26k miles, most of which are travelling to and from sunny Devon. It even went to Spain and Portugal in a covered transporter.

Ralph

 

[ralphmusic]

Some further performance upgrades for the 981 GT4 engine from the USA. Dundon Motorsports have developed intake runners and claim an additional 100whp when combined with their other performance upgrades as follows:

1. Race Headers: our design provides a stronger suction wave than other designs and is necessary for the intake runners to perform optimally. 2. GT3 Muffler Adapter Kit: The stock PSE becomes a restriction above 380whp or so and the car really starts building heat in the cylinder due to the restriction. Our kit also allows you to add cats back to the car so you don’t have to be catless. 3. Cobb Accessport with our pro tune 4. Intake runners/ IPD Plenum/ GT3 TB: The last bit after the above mods are done, adds power where the car needs it and shifts the resonance peaks up as well. They have posted the dyno graph below on rennlist

Middle is Dundon Race Headers+Pro Tune

Bottom is Stock GT4

Top is Dundon Race Headers, Intake Runners, IPD Plenum, GT3 TB, GT3 Muffler Adapter, Pro Tune

In another thread, an Australian poster reported they could not get much of a power increase over stock after fitting the X51 Powerkit* (with 82mm throttle body) and applying a tune. They then replaced the multi-valve X51 plenum with an IPD plenum and got a significant increase in power. Is the IPD better than the X51 plenum? I'd guess unlikely and their issue was not tuning the valving correctly, but who knows for certain.

* Consists of new (gas flow improved) heads, camshafts and multi-valve plenum + remapped ECU

It is now probably cheaper for most to buy a new 718 GT4...

 

[ChrisW]

Ralph, thanks for all your help with Jens .. I'm going for his Stage 3 conversion but also with his 62.5mm diameter unvalved exhaust with downward facing premium exhaust tips !

The exhaust should gain a useful 3dB quieter over standard and add a further 10bhp to the Stage 3 tally ... with a bespoke re-map (and the flasher).

I will be leaving the car with Jens on the 22nd May ... I have a few days driving in Germany on a Porsche motoring trip and I'll collect the car on the 27th.

Mannings have told me that my insurance premium will increase in proportion to the power gain ... I wonder for the return journey, what this will be ?

385bhp goes to 435bhp ?? Or ???

What thoughts ?

 

[ralphmusic]

Chris,

Sounds good. I too ran the car for a week in Germany after my engine swap.

Insurance, mine is on a 991.1 Carrera rating so you could suggest yours is 991.1 GTS equivalent.

Lockton don’t seem to care about mods quoting mine as a standard Cayman S but their mileage loadings were ridiculous and track less convenient.

Classicline might be work checking.

Also see my post in Club Trackdays on insurance.

Ralph

 

[Motorhead]

+1 for ClassicLine Chris - I swapped to them from Mannings a few years ago.

Competitive price which includes full UK and European breakdown coverage as well as track days. The claim I had last year (hit a kamikaze cat..!) was handled speedily and efficiently and doesn't appear to have had much impact - if any - on my premium. Worth speaking to them for a quote.

Jeff

 

[carreraboy]

I recall the hot laps round Spa with you Chris in my first GT4 Experience.

Great car only you could feel it wanted to give more "flow" ..... never so obvious Porsche down tuning a car to align with their product range.

My God if they could give it the PDK too ...

 

[ChrisW]

Des, you know, against the flow, that I like PDK

I'm on a mission and the passenger seat is always available

There those who now say I make them feel sick. They are clearly too timid to tell me whilst I am doing it !

I would stop. Honest !!

 

[TDT]

Des, you know, against the flow, that I like PDK

I'm on a mission and the passenger seat is always available

There those who now say I make them feel sick. They are clearly too timid to tell me whilst I am doing it !

I would stop. Honest !!

LOL - it was me that posted that from the RS day @ OP. Very honestly I was actually fine in the car - having been out with you a few times before - so there was no reason to say anything. I phased it as such to punctuate how much grip your car can generate and the way that you can control it...marvellous... and I was learning the whole time.

 

[Brian_Innes]

Chris,

I'm looking forward to a passenger ride in your newly uprated GT4 at Knockhill in August. The dips and blind crests will be good fun, and your driving a joy to behold as always.

The extra poke will be handy also.

Brian

 

[Rocket_Rabbit]

I know this thread is largely a 3.8 thread which is great. However, I'm looking for gen on the 3.4 981 S engine. If it is mechanically tthe same as the 991 3.4 engine, then it is capable of 350bhp easily. I'd like to get to 360bhp (as to have at least a fighting chance against remapped Fiestas!) and was thinking 82mm throttle, catless manifolds and a Cobb AP. I'm sure one could go a lot further, but for now I think this would be enough. Anyone have any experience of the above, particularly the Cobb AP?

 

[ralphmusic]

I know this thread is largely a 3.8 thread which is great. However, I'm looking for gen on the 3.4 981 S engine. If it is mechanically tthe same as the 991 3.4 engine, then it is capable of 350bhp easily. I'd like to get to 360bhp (as to have at least a fighting chance against remapped Fiestas!) and was thinking 82mm throttle, catless manifolds and a Cobb AP. I'm sure one could go a lot further, but for now I think this would be enough. Anyone have any experience of the above, particularly the Cobb AP?

To answer your several questions:

1. The 3.4L engine makes 380PS in VLN Cayman race cars, my old 3.4L engine is still racing in VLN

2. In the Cayman GTS it makes another 10PS due to a different tune. In the S version, the throttle slide starts to close at around 4.5k from c85% open, slowly reducing to 55% over the rest of the rev range, even though the driver has their foot to the floor

3. With a factory level PIWIS you can lay the GTS mapping onto an S version ECU

4. The installation in the Carerra is different (aside from orientation) with different length intake and exhaust runs. These by themselves will produce a natural difference in PS and torque characteristics. The 3.4L Carerra has the smaller 78mm throttle body but has different mapping for throttle opening and the intake and exhaust differences v Cayman

My advice is to start with the tune (mapping) and find out who will provide it. Do Cobb have an off the shelf tune for the hardware changes you are considering? If yes, get the hardware that the tune supports and enjoy.

If Cobb don't, and you find a company that you have confidence in to do a modified tune, then you should sit down with them and decide on a hardware package for which they can map the car to benefit from the different parts.

As to the parts, with the larger throttle body, you should also consider an IPD plenum, and BMC airfilter. On exhaust, a 200 cell cat manifold would be my choice but it is louder than OEM (catless is far too much). M&M do back boxes that will reduce noise levels if that is a problem.

For a validated/respected hardware and matched tune package, try Jens Ehresmann in Dusseldorf. A number of UK owners have installed his package with no problems reported.

 

[Motorhead]

Ron,

Some sound advice from Ralph there, particularly in his recommendation of Ehresmann for properly tried-and-tested packages. Companies like Softronic and Cobb are a good starting point for a DME remap, although I'm sure that there are many others. Unfortunately, unlike turbo engines the actual power gain is relatively small but you'll probably get better throttle response and driveability (and perhaps better fuel economy?), and you'll be into the significant expense of throttle-body, plenum, manifold/cat and fliter upgrades to get anything wortwhile.

Back in April a Guest was offering a Cobb Accessport for sale on here [ [link=https://www.porscheclubgb.com/forum/tm.aspx?m=995028&high=cayman+cobb]https://www.porscheclubgb.com/forum/tm.aspx?m=995028&high=cayman+cobb[/link] ] so it might be worth contacting him for advice and to see if it's still for sale if you're interested.

Jeff

 

[Rocket_Rabbit]

Yeah, thanks for the advice I've done a good deal of preliminary research on the Cobb and various other forms of 'mapping'. What puzzles me is that they state the 'after' values of both the GTS and the S as differing numbers (as a percentage increase of the original power - both in the range of 5%). In other words, I'm curious as to the ability of these devices to perform a true ignition/fuel/TPS alteration and not just some sort of piggyback values/delta interception. I've had similar things to these before for bikes and cars and you get full access to the ECU to do what you want. For the best part of £1800 for the Cobb (including the PDK access), I'd expect nothing less for what is essentially a software license with a fancy piece of gadgetry thrown in to make their wares tangible.

 

[ralphmusic]

The car that started this thread is now with another owner, soon to be on its way to the South of France for a tour. Many happy memories ending with Nordschliefe a few weeks ago,

following in the footsteps of its predecessor here at Spa

 

[ralphmusic]

I have my spare set of wheels and tyres (actually never used) for sale on the For Sale section. These are really very smart with MPSS tyres and fit 981 and 718 non-GT models. Really good price here [link=https://www.porscheclubgb.com/forum/tm.aspx?m=1051534]https://www.porscheclubgb.com/forum/tm.aspx?m=1051534[/link]