718 Cayman GT4 is here – at long last.!

[geoff lane]

Not long to wait now for either the GT4RS or the 992GT3, on the pictures of the RS I like the look with the exception of the rear wing and the centre lock wheels. why oh why do you need to fit centre locks []

Don't think I'm interested I have hardly used my car since getting it last December and in fact have sorn it for a couple of months until we see where Covid takes us.

For my usage I would sooner have the manual involvement, give me lower gearing to let me rev it out more on the road and a louder more raw sound and I don't need anything else. So near an exceptional car.

 

[Motorhead]

I wouldn’t be surprised to see the centre-locks making into production Geoff; Porsche seem to favour them on their GT cars, even though I’m not convinced that they’re all that popular with their owners.

I’m sure that we’ll be seeing the 992 GT3 quite soon given the long gestation period but I can’t see Porsche announcing the GT4 RS until later in the year - for MY2022 in Q4 perhaps? - to give a decent separation time between the two cars. With no rumours circulating of a 718 replacement, maybe it’s announcement will coincide with yet another refresh for the mid-engine cars?

Jeff

 

[ralphmusic]

The current EU emissions regulations should be valid for certifications up to end 2024. After that Euro 7, which apparently will be finalised by end 2021. This is expected to require Lambda 1.0 at all load conditions and 50% reduction in NOX on a cold start, which some say is impossible.

So the lifespan for registrations of current 718 range and *soon to be announced* GT4RS certification vehicles will likely run to December 2025.

At the end of this year (2021), Euro 7 should be defined. This will indicate whether IC vehicles might be able to meet requirements assuming serious R&D will be applied by vehicle manufacturers. Some think this is the end of IC powered vehicles.

So within the 5 year production window thru December 2025 when a sea change in IC efficiency is required, I'd expect an "updates/specials model evolution" strategy (like 987) rather than a new generation.

 

[geoff lane]

Ralph ,

Could you achieve using hybrid ?

 

[ralphmusic]

Geoff,

Not if it has an IC engine, start up & Lambda still would apply.

A thought on the GT4(RS) evolution, the current ECU is limited to 8,150 revs (GT3 uses different ECU), so more revs more power. Will the valve train cope, probably without big changes up to 8,500 rpm, improve the cylinder head gas flow. You can't eliminate the GPF so some marginal exhaust efficiency all in all up to say 450PS. Why not 500PS? these engines are getting close to what is possible with Euro 6d with the new this year tighter test conditions (applicable to models certified from Jan 1st).

And in any event even if it ever had 500PS, the rear suspension architecture will always keep it behind the GT3 in performance.

 

[Motorhead]

Ralph,

Your projection that 718 production could run through to the end of 2025 sounds about right and quite possibly could include some form of mild hybridisation in the form of an integrated starter-generator. This length of production must have formed part of the decision by Porsche to invest considerable resources into developing the 4.0L F-6 engine for the car. Beyond that it’s anybody’s guess what’s going to happen with ICE use and I can foresee a lot of haggling between the car industry and the regulators since only so much can be accomplished technologically in such a short time period.

I would guess that Porsche will be aiming for a nice round 450PS for the GT4 RS which will probably be achievable with some DME tweaks along with mods to the intake and exhaust and maybe the cams/valves/heads as well. An extension of the rev range also could be on the cards because I think the 4.0L uses a valve actuation mechanism more like that in the GT3 with finger-operated valves, although Porsche will want to avoid the expense of using more exotic materials for a relatively small production run even if they can charge a significant premium over the base GT4.

Jeff

 

[Twinfan]

For my usage I would sooner have the manual involvement, give me lower gearing to let me rev it out more on the road and a louder more raw sound and I don't need anything else.

Me too. I have a LWFW and rear silencer which has really transformed the car, plus I now have 434bhp. This is more than enough for me and it really suits the car as a whole package. I can't wait for better weather to get back out there enjoying it on the road and at the PCGB Donington and Oulton days []

The gearing isn't worth bothering with IMHO. Sharkwerks and Ninemeister both offer re-gears of 3rd/4th/5th but from my understanding this basically gives you two second gears so you then end up using 3rd/4th in the same plane rather than 2nd/3rd across plane. 1st and 2nd stay the same for traction reasons and 6th stays as an overdrive gear for motorway crusing. So unless you need the lap times it seems very expensive and pointless to re-gear.

I think the RS will be a great car but unobtainable to mere mortals and still flawed versus a GT3. Plus it'll be PDK only so not my cup of tea, but it may have a few bits I can port over to my car...

 

[PeterRH]

Not had much chance to try the PS4S tyres recently due to the weather. The one run out I did have on 22 nd Dec was great , the tyres certainly had better grip in the partly wet and cold conditions and seemed to grip quicker than the cup2s. I also saw this article regarding the exhaust which is interesting as I do miss the sound of the 3.8 engine with sports exhaust.

https://www.litchfieldmotors.com/blog/porsche-718-gts-gt4-exhaust-development/

 

[Dylan1]

Peterh

im so impressed with the PS4S I fitted in august .they’ve transformed the ride of my 991

brilliant tyres in all conditions

and I’m still enjoying the 3.8 PSE

I do love the look of your GT4 though!

you doing the Manx rally in may? dyl and linda x

 

[PeterRH]

Hi Dylan

Glad you are pleased with the tyres as well

No, I haven't booked any events yet.

(waiting to see what happens with the vaccine)

Hope to catch up with you both soon

 

[snowy999]

To have something to look forward to I have booked the GoldTrack Silverstone day on May 13th. If any of you do likewise (TDT is you car back from Germany - we missed each other at my last track day?) do drop me a message.

Wishing you all well during this tough/complicated time !

Snowy

 

[ralphmusic]

I am less confident on timing of normality so have booked June 21st at Silverstone as a first day.

I was going to start the year as normal with LoT at Goodwood end February but I am not confident I can get accommodation I'll be comfortable with so hunkering down for a while again.

 

[snowy999]

Agreed Ralph I might be being optimistic. I have the antibodies and at 53 weight about 17 stone. So I do really think that, if they can get the older and infirm people - who are clearly at risk - inoculated then the rest of us can be more risk taking......that said one of my younger friends has been in for 48 hours on oxygen to help her turn the corner. She had the new variant. Anyway May and June are a lifetime away ! I have also registered for some of the Hill Climbs in the Porsche Motorsport in June so I hope you are right too.

 

[ralphmusic]

Add 24 and deduct 3.5 for me but with some risk factors so should be early but have "child-bride" and a daughter with more serious risk factors so like many others, safety is not a single dimension judgement... The CEO of a firm I am a director of is self-isolating, the first employee out of 120 to have Covid-19, the worrying bit is that it is all a rather random.

 

[Motorhead]

Fancy a £4,951 Akrapovic exhaust for your GT4?

https://www.pistonheads.com/news/ph-porsche/akrapovic-exhaust-for-718-cayman-gt4/43573

Jeff

 

[Twinfan]

Nope! Only 5.9bhp, which must mean it's very heavily silenced lilke the OEM silencer is.

The problem all exhaust guys are having is drone at lower revs. Porsche solved it by making the exhaust very, very restrictive via silencing. Open up the breathing and some drone appears. Akra seem to have gone down the route of minimal drone, which will mean more silencing along with less noise and less increase in power. There is no magic bullet to fix the sound of the 718 GT4, there are compromises to be made with every option. I'm more than happy with my reasonably priced 9m solution, I just keep the revs up!

 

[MannyLon]

Fancy a £4,951 Akrapovic exhaust for your GT4?

https://www.pistonheads.com/news/ph-porsche/akrapovic-exhaust-for-718-cayman-gt4/43573

Jeff

It still surprises me that most exhausts are so expensive. Add to that, most do not sound much louder than standard. I bet the Akra had a valve controller open on the vids.

 

[Twinfan]

That's the Porsche tax for you!

The GPFs really restrict the sound so if you want earsplitting loud you'll need to remove them. I find a silencer swap makes it just the right kind of loud and hopefully fine for 105dB track days.

 

[OliR]

Hi All,

Been having some rubbing noise coming from the offside rear brakes on my GT4, it's been doing it since new and I just thought it was one of the foibles of having such large performance brakes. However it seems to be getting worse, and a brief discussion on the Cayman register call caused me to think a bit more about it. In my previous 718, If I came to a stop on a hill say for some traffic lights the "HOLD" light would appear on the dash and the car would keep the brakes applied for me, then release them when I came to drive off. I get the same operation in my GT4, however no light appears on the dash (HOLD or Handbrake warning) and it takes a lot more effort (revs) to get the brakes to release. I'm thinking this sticky operation could be related to the noise I'm hearing, I've had the rear wheel off and can't see anything obvious, the car is going back to Porsche to be looked at on the 23rd, I just wondered from other owners:

- Does the green HOLD light appear on the dash when performing a hill start?

- How much effort does it take to get the parking brake to release here?

- Do your brakes make any rubbing sounds?

I've had a look through the manual and there's nothing under Hill Hold Assist, I suspect my issue may be being caused by the handbrake system as the behaviour doesn't seem typical to me, but would like to hear of others experiences.

Many Thanks,

Oli

 

[Twinfan]

Hi Oli. As I said on the call last night, it does sound like your hill hold system isn't quite working right. It could be the angle/incline sensor? I'll be heading out for a drive in a sec so I'll see if I can find a hill to test my hill hold system to see what happens.

I had slight squeaking/rubbing of one brake disc/pad combo when new but it wore off fairly quickly. The temperature check suggestion last night was a good one to see if you have a sticking pad or caliper.