Cayman GT4: Where are we up to now?
- Thread starter Motorhead
- Start date
Steve Brookes
Moderator
ian harvey said:
I think you'll find the feeling at the rear is mostly down to the significant changes in the rear suspension that have taken place since Porsche put the Weissach effect rear trailing arms on our 964s nearly 30 years ago! My 987 boxster moved about at the rear in a similar way to you describe. So did 997s that I've been in. The 964 tends to just 'set' on the curve you choose which can then be adjusted on the throttle. The best way I can describe the difference is that rear wheels on a modern 911/boxster/cayman feel independent where as they are more joined together on the old 964.
I have to say I am a bit surprised at the rear moving around at road speeds. My somewhat non-standard 981S moves around on track, particularly at Goodwood's Madgewick which is an off camber 80mph double apex corner. I put that down to the slightly flexible rear suspension mountings which some in the USA have attempted to remedy with support bars from Schnell and RSS. The GT4 has a reinforced arrangement so the reported behaviour might be an alignment issue with different cambers or toe across the axle, not unknown from the factory...
Brookspeed pointed me at a more robust rear support bar for non-GT4 Caymans from Ultra Racing and am awaiting them finalising the 981 version.
Brookspeed pointed me at a more robust rear support bar for non-GT4 Caymans from Ultra Racing and am awaiting them finalising the 981 version.
picked my reg plate today from a list of crap reg plates and having a new geo as part of my PDI, I don't want to drive it oem.
should pick up the car in 2 weeks.
GT3 RS in white was waiting to go out from Leicester.
I see cargraphic have made some GT4 manifolds
I run these on my Spyder and they transformed the car, tempting to buy a set for the GT4 must be able to get 430bhp quite easy on this car.
seems Porsche have stopped the TB opening 100%, just need a hack and get some free BHp. Keep up with Ralph then ;-)
should pick up the car in 2 weeks.
GT3 RS in white was waiting to go out from Leicester.
I see cargraphic have made some GT4 manifolds
I run these on my Spyder and they transformed the car, tempting to buy a set for the GT4 must be able to get 430bhp quite easy on this car.seems Porsche have stopped the TB opening 100%, just need a hack and get some free BHp. Keep up with Ralph then ;-)
MrDemon said:I see cargraphic have made some GT4 manifolds
seems Porsche have stopped the TB opening 100%, just need a hack and get some free BHp. Keep up with Ralph then ;-)
The 3.4L ECU reduces the throttle butterfly opening from around 4,000 rpm where it is around 87% to low/mid 50%'s by 4,900 rpm and holds that level to maximum revs. I don't have that level of detail from GT4 dyno runs but it seems an established feature to manage air intake volume, irrespective of hardware modifications.
Talk to Jens in Dusseldorf - he has an off the shelf solution giving 415PS with 991 3.8L 82mm throttle body, IPD plenum, Cargraphics 200 cell headers and tune. You could also go for a full M&M exhaust system with larger bore and noise.
You won't get much more than Jen's numbers without internal engine modifications. His Powerkit 991 3.8L engined Boxster has 435PS.
Cobb claim to be working on a 981/NA 991 OBD tune for December 2015 availability so there might be an alternative to Jens but I don't know if it will be adjustable for various hardware configurations.
Can you adjust GT4's camber with shims or is it eccentric bushing/top mounts?
Ralph
3.4L dyno run showing throttle opening 3 pages.
Ian, great to hear that your red car is matching your expectations
I can't say that I have felt anything other than smooth transitions in the suspension department --- it chinked slightly at fasted tilt so far on a 60 mph slightly bumpy right hander but caught itself before I thought about it --- unless I caught it before I thought about it
If I don't need to be in the Far East I will do the PCGB Oulton day on the 4th November -- come what may ! I should know next week ...
By the end of next weekend I hope to have done 1500 miles and have had the engine and gearbox oil and any filters changed.
I won't do a proper geo until the suspension has settled properly after my first gentle track day ...
Chris
I can't say that I have felt anything other than smooth transitions in the suspension department --- it chinked slightly at fasted tilt so far on a 60 mph slightly bumpy right hander but caught itself before I thought about it --- unless I caught it before I thought about it
If I don't need to be in the Far East I will do the PCGB Oulton day on the 4th November -- come what may ! I should know next week ...
By the end of next weekend I hope to have done 1500 miles and have had the engine and gearbox oil and any filters changed.
I won't do a proper geo until the suspension has settled properly after my first gentle track day ...
Chris
any one going to fit RSS rear toe links ? stops rear steer and it seems the rear is a bit limited at -1.4 camber max oem !
as for front you can drop In a shim on the GT3 LCA, I'll goto -2 up front, rear ARB to stiff and prob some RSS toe links to stop play and give me a solid rear end.
that will give me a fast road set up, which will pass on the very few track days I do.
as for front you can drop In a shim on the GT3 LCA, I'll goto -2 up front, rear ARB to stiff and prob some RSS toe links to stop play and give me a solid rear end.
that will give me a fast road set up, which will pass on the very few track days I do.
Matt Prior from Autocar recentry drove th GT4 & reckons 'only around 50 are destined for the UK'. Does anyone have any further knowledge of numbers currently being imported ?
Monday October 5 was apparently the build date of my GT4, in GT Silver, so I am hoping for delivery between the 20th & 27th !
Monday October 5 was apparently the build date of my GT4, in GT Silver, so I am hoping for delivery between the 20th & 27th !
There have been a few numbers banded about regarding UK units but it has always been more than that. My OPC still works on the number of 129 built across 2015 & 2016.
To be honest we won't know until production is finished.
A good friend of mine had a call from an OPC he deals with last week asking him if he would be interested in a GT4, I was surprised when I was told this and they had fed him some cock and bull story and told him it is being sold at list price. I asked how much and it was £103k, told my mate after looking at the spec. it is £30k over list. How can an OPC try and sell a car stating it's list price at £30k over, my mate went ballistic at them
To be honest we won't know until production is finished.
A good friend of mine had a call from an OPC he deals with last week asking him if he would be interested in a GT4, I was surprised when I was told this and they had fed him some cock and bull story and told him it is being sold at list price. I asked how much and it was £103k, told my mate after looking at the spec. it is £30k over list. How can an OPC try and sell a car stating it's list price at £30k over, my mate went ballistic at them
So only 70 cars between now and the end of production in Spring next year spread over ~40 Porsche Centres.
With high demand and limited production slots in Osnabruck for all the N/A Caymans before the flat-4 turbos arrive, it seems doubtful that Porsche will be able to meet over-demand for the GT4. Not very encouraging news D.
Jeff
With high demand and limited production slots in Osnabruck for all the N/A Caymans before the flat-4 turbos arrive, it seems doubtful that Porsche will be able to meet over-demand for the GT4. Not very encouraging news D.
Jeff
Re factory and assignments, production of the Cayman will be gradually shifted back to Zuffenhausen by the end of 2016, so perhaps even stronger reason for no extension of production volumes.
Ralph,
I recall you mentioning that after your factory visit earlier this year, with the Osnabruck capacity being taken up by Cayenne production (?).
Obviously Zuffenhausen has sufficient capacity to manufacture all the sports cars, which makes me wonder why Cayman 981 production wasn't shifted there in the first instance when Valmet production ceased.
Jeff
I recall you mentioning that after your factory visit earlier this year, with the Osnabruck capacity being taken up by Cayenne production (?).
Obviously Zuffenhausen has sufficient capacity to manufacture all the sports cars, which makes me wonder why Cayman 981 production wasn't shifted there in the first instance when Valmet production ceased.
Jeff
Motorhead said:
200 is better than Autocars 50 quoted lol given that about 5 are for sale and prob only about 10 in the UK atm, not many people are keeping them !
I cannot see anyone paying £30k overs though so there they sit !
Seems a lot of cars coming in Oct so will be interesting to see if any more pop up for sale, mine rolls of the production line today, just need to ship it here now which is about 10 days.
MrDemon said:
For what it is worth, with standard "S" rear suspension I have -1:45 degrees camber, and with front Powerflex bushing -2:00 degrees at the front. I am at CG in a couple of weeks for extra bits and pieces and set up so hopefully will have greater adjustability and better handling at the limit after their magic.
I think until we see some actual GT4 alignment data there will be an air of uncertainty as to the standard possibilities.
Interestingly the axle ride heights for the GT4 are Front 106mm Rear 133mm versus Front 126mm Rear 163mm for a PASM S and therefore different rake. Mind you at speed, the S has lift at the front and downforce at the rear per SportAuto.
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