Modified 981 GT4 - Page 3 - Porsche General - PistonHeads UK

So here’s a question ... Accepting that I have to observe none if the politically correct legislative requirements that are required of Porsche when models are evolved by them, am I ahead of the curve or behind it ? Spec to follow ...

Well, that worked ... The first generation of upgrades were with JZM .. Manthey lower suspension arms to reduce the ridiculous amount of tyre wear on the outside shoulders, and KW 3 way Clubsport dampers (with fast bump) set to Manthey Nurburgring settings ... Result ? Acceptable front tyre wear across the whole tyre width ... though still two to three fronts per rear, and a car that will run the curbs flat so long asthe inside wheel is comparatively unloaded ..

The second generation of upgrades was the boxing up of the PCCB’s and the fitment in place of these, of a set of Surface Transform long fibre sold carbon disks with RS brake ducts. The result ? No difference to either brake tactility or braking power, but enormous endurance and a reduction by a factor of five in the number of pad replacements because the whole system now runs so cool ... in fact after two cooling down laps at Oulton Park we measured 140 C front and just 70C on the rears ... In fact, the tyre temperatures needed watching more than the brakes ...

And now to phase three ... of course the new GT4 will be a 4.0 litre thug ... Wouldn’t it be great also to be able to adjust the Caster and gain steering feel with uniball bushes ... And maybe even a wide bore exhaust without the silly noise flaps to help with quieter track days ? Enter Jens Ehressman with his Stage 3+ engine conversion and self-confessed obsession with 981 ... So here’s raising the bar Porsche, what can you do ?? Cool number plate ... now how to rotate it ??

P.S. I must confess that my OPC did tell me that I wouldn’t get a new GT4 because I hadn’t bought enough new cars from them ... The new cost of this work has been £30k in total on top of the original purchase price from Leeds OPC, but I have an awful lot of parts to return the car to standard, including a little used set of PCCB’s ... a PASM set etc etc ... Now it’s time to be brave on-track, passenger rides welcome when you catch-up with me 😉

ChrisW. said: So here’s a question ... Accepting that I have to observe none if the politically correct legislative requirements that are required of Porsche when models are evolved by them, am I ahead of the curve or behind it ? Spec to follow ... That's a lovely Cayman R in the background, any details on that?

Nice work Chris, looking forward to seeing it perform on track.

Amazing , please buy the bbs fi-r to finish it off. See you at donny soon.

Excellent work Chris - so c'mon then now that is has been uncorked...whats it like? can't wait until Donington. How did you find the logistics of getting the car to Jens and back? - did you drive over? or have it picked up and delivered?

ChrisW. said: P.S. I must confess that my OPC did tell me that I wouldn’t get a new GT4 because I hadn’t bought enough new cars from them ... The new cost of this work has been £30k in total on top of the original purchase price from Leeds OPC, but I have an awful lot of parts to return the car to standard, including a little used set of PCCB’s ... a PASM set etc etc ... Now it’s time to be brave on-track, passenger rides welcome when you catch-up with me ?? ..... I better find you another two seconds before you start the rides!!!

These are all conversations and experiences yet to have ... another beginning ! Thanks to all for sharing the journey ... regarding the very nice Cayman R ... I understand that it may be for sale ?

Budflicker said: That's a lovely Cayman R in the background, any details on that? That's Kevin' s car I believe, about as good as they come https://www.cheshiresportclassics.co.uk/cars/porsc...

Great read Chris. Sounds awesome, look forward to seeing it at Donington.

freedman said: That's Kevin' s car I believe, about as good as they come https://www.cheshiresportclassics.co.uk/cars/porsc... It is ... thanks !

Thanks ... I caught the ferry from Hull to Rotterdam, Dusseldorf is only 2.5 hours away so arriving with Jens for lunch was really easy. We discussed the plan and I then caught a tram to the railway station and a train to Stuttgart. I had planned three days driving in the Black Forest with Porsche Experience ... this starts in Ludvigsburg which is around 25Km away from Zuffenhaussen where the factory and museum are, so I planned the work that Jens was doing around this. I should have booked the trains earlier ... a tad expensive ... and for convenience and time saving took couple of moderately expensive cabs ... but it really was very easy ! It is worth mentioning that Jens does not do all the manual work himself ... he chooses the best companies with which to work and I can't praise the quality of the outcome highly enough. In the build we suffered a Lambda Sensor failure and a couple hours was spent sourcing and collecting this to finish on time. In addition Porsche Motorsport twice sent the wrong suspension parts ... the last components for this element of the work arrived on Monday morning and was being fitted by the time I arrived at around 10.00am. For anybody that wants to undertake this journey I'll happily share full details / hotel / best transport options / etc ... This is what Jens wrote: https://www.facebook.com/9x1.org/posts/11157581586... Edited by ChrisW. on Tuesday 28th May 21:52

This is where the work was done ... look at the other cars and everything is there with the exception of the rolling road !

And this is how all the bits to return the car to standard found their way home ... You have to love the Cayman format !

I should add that it was all packed like this for me ... ! Passport control were a little concerned at what was in there ... but they took my word for my having an exhaust system in the passenger seat !!

ChrisW. said: I should add that it was all packed like this for me ... ! Passport control were a little concerned at what was in there ... but they took my word for my having an exhaust system in the passenger seat !! any plans to goto Donny sooner than later for a shake down ? what is your gut feeling having 40bhp more, has it bought the car alive ?

I am at Donnington on the 18th ... it’s an unlimited day and I need to find out how loud the quiet exhaust is in practice. First real impressions are this morning ... I went into work early to get new front tyres fitted and not only does it pull like a train to the limit in third (I didn’t want to do more and brought it straight back down to 75) but it sounds and feels visceral, ... so alive. The steering is noticeably more free and with the revised Geo it handles in a significantly more responsive way ... so far ! P.S. I discovered that the ARB’s have been set front mid and rear hard ... I may need to play with this ... Edited by ChrisW. on Wednesday 29th May 15:31

ChrisW. said: I am at Donnington on the 18th ... it’s an unlimited day and I need to find out how loud the quiet exhaust is in practice. First real impressions are this morning ... I went into work early to get new front tyres fitted and not only does it pull like a train to the limit in third (I didn’t want to do more and brought it straight back down to 75) but it sounds and feels visceral, ... so alive. The steering is noticeably more free and with the revised Geo it handles in a significantly more responsive way ... so far ! P.S. I discovered that the ARB’s have been set front mid and rear hard ... I may need to play with this ... Edited by ChrisW. on Wednesday 29th May 15:31 Sounds good. I ran those that ARB set up for the second half of the season last year - makes the front end very positive by taking some grip away from the rear - therefore 'easier' rotation. I ran it at Silverstone 2nd &3rd days, Goodwood 2nd day, and Oulton Park. I've went back to Med/Med for the start of this year - Oulton Park and Spa - and will run Silverstone and Donny (Porsche GT days) with Med/Med and then go back to Med/Hard for the next Silverstone and Donny (PCGB days) back to backs.

if the car works (ie stable) at full stint down craner rear ARB hard then you can keep it hard all the time I would say. I think if you have 2 or 3 way shocks, I would run med/med and add an extra click on the rear bump setting instead.

So you've gone and done it then Chris. Good on ya! Looking forward to a future passenger ride.

TDT said: Sounds good. I ran those that ARB set up for the second half of the season last year - makes the front end very positive by taking some grip away from the rear - therefore 'easier' rotation. I ran it at Silverstone 2nd &3rd days, Goodwood 2nd day, and Oulton Park. I've went back to Med/Med for the start of this year - Oulton Park and Spa - and will run Silverstone and Donny (Porsche GT days) with Med/Med and then go back to Med/Hard for the next Silverstone and Donny (PCGB days) back to backs. For really fine tuning, you can set one side of the ARB at say, middle hole and the other on harder or softer holes.

An interesting problem yesterday, fitted new front tyres and had a valve failure ..

The NSF lost 15 lbs in five hours ... lucky that the OPC was close to ProTyre ( who sorted it FOC thanks) !

Update from Donny ... The very kind people at race control monitored the noise level throughout the day. The maximum drive-by measured was 98.7dB ... GT4's etc often measure 100dB ... a Lambo on the day measured 111dB. So, the new exhaust is probably quieter than the standard exhaust .... and the quality of the sound is amazing ... As for performance ? It just pulls ... and it handles ... it is now a very cohesive package ... Standard GT4 + 20% ?? I'll let the passengers answer that one

ChrisW. said: Update from Donny ... The very kind people at race control monitored the noise level throughout the day. The maximum drive-by measured was 98.7dB ... GT4's etc often measure 100dB ... a Lambo on the day measured 111dB. So, the new exhaust is probably quieter than the standard exhaust .... and the quality of the sound is amazing ... As for performance ? It just pulls ... and it handles ... it is now a very cohesive package ... Standard GT4 + 20% ?? I'll let the passengers answer that one This sounds like a weapon on track with the new set-up. Do you have any lap time comparisons from your trip to Donington?

No, this was on the full GP circuit which is in my experience rarely used ... At the end of the day we had driven a 1:48.2 with passenger ... good ??

Gonna write up my passenger review of the package later today. Chris, I’ve sent you link to YT vid of the first session of me running behind you. Will also upload the late afternoon session later today.

HI Chris , thanks for the ride , the car is as you say a "race car" for the road . You have it working really well hence have great confidence in it . For me the most impressive was on the brakes and late turn in at the chicanes and hairpins . Impressive package , worth the expenditure

It felt like a mid engine GT3 and just pulled at any revs with no dive or roll on those 3 ways. Great car. I am not sure what impressed me the most, the new engine, the shocks or the brakes, all 3 are now mega. Be interesting to see a national track time in that now over what you have done before, if you book on another day let me know and I'll book the GT3 on.

hunter 66 said: HI Chris , thanks for the ride , the car is as you say a "race car" for the road . You have it working really well hence have great confidence in it . For me the most impressive was on the brakes and late turn in at the chicanes and hairpins . Impressive package , worth the expenditure ........Late turn-in??? Have you forgotten how to find those extra seconds ChrisW??

It’s all comparative ... that’s why I keep taking coaching Thanks for the feedback, I thoroughly enjoy giving passenger rides ... at Snetterton with PCGB next week !

ChrisW. said: It’s all comparative ... that’s why I keep taking coaching Thanks for the feedback, I thoroughly enjoy giving passenger rides ... at Snetterton with PCGB next week ! Yes, I'll be there Chris, with plenty of corners for early and progessive turn-in!! Look forward to seeing you there, H

Look great Chris, the pull vs stock on the straights is easy to easy on TDT's video. You were in the mirrors when I was coaching my brother.

TDT said: Gonna write up my passenger review of the package later today. Chris, I’ve sent you link to YT vid of the first session of me running behind you. Will also upload the late afternoon session later today. Just watched your vid mate. Chris has always been very quick in his car but bloody hell it's mega quick now. A new out of the box 718 GT4 is not going to keep up with that! p.s Nice driving from you as well!

Who's carried out the mods for you OP? So nice to see people tinkering with these rather than being slaves to their OPC warranty.

IMI A said: Who's carried out the mods for you OP? So nice to see people tinkering with these rather than being slaves to their OPC warranty. Jens Ehresmann and JZM/Manthey I

^^^ Doh sorry thought they were all off the shelf kits

IMI A said: ^^^ Doh sorry thought they were all off the shelf kits they sort of are. If hope it's ok to post as this is all what Chris car has and his stages. 1st off as the GT4 is fixed at the rear and lacking a set up is the Manthey stage 1 road kit. This allows a basic track set up. Chris then wanted to swap out the disks to ST and that's been great as they just don't wear out. after that he wanted a proper Manthey set up so went for their GT4 full racing 3 way kit with a ring set up geo. this car does not dive or roll, and it must also save tyre wear as the GT4 is too soft oem and does wear edges badly. A few CUP race car parts with monballs were added to reduce play and add feel and also allow for caster adjustments. and last the engine mods to 430 HP / 345 LBF-FT with a new M and M big bore full system and Jens magic on the RR. I think some BBS Fi-R wheels next and some bbi wing uprights would finish it off very nice :-) lol So yes pretty much off the shelf parts, put picked well and fitted by experts. Edited by Porsche911R on Thursday 20th June 14:57

Porsche911R said: IMI A said: ^^^ Doh sorry thought they were all off the shelf kits they sort of are. If hope it's ok to post as this is all what Chris car has and his stages. 1st off as the GT4 is fixed at the rear and lacking a set up is the Manthey stage 1 road kit. This allows a basic track set up. Chris then wanted to swap out the disks to ST and that's been great as they just don't wear out. after that he wanted a proper Manthey set up so went for their GT4 full racing 3 way kit with a ring set up geo. this car does not dive or roll, and it must also save tyre wear as the GT4 is too soft oem and does wear edges badly. A few CUP race car parts with monballs were added to reduce play and add feel and also allow for caster adjustments. and last the engine mods to 430 HP / 345 LBF-FT with a new M and M big bore full system and Jens magic on the RR. I think some BBS Fi-R wheels next and some bbi wing uprights would finish it off very nice :-) lol So yes pretty much off the shelf parts, put picked well and fitted by experts. Edited by Porsche911R on Thursday 20th June 14:53 Edited by Porsche911R on Thursday 20th June 14:56 Awesome For the track driver I think this is a much more compelling approach than the latest iterations of the GT4

LaSource said: Porsche911R said: IMI A said: ^^^ Doh sorry thought they were all off the shelf kits they sort of are. If hope it's ok to post as this is all what Chris car has and his stages. 1st off as the GT4 is fixed at the rear and lacking a set up is the Manthey stage 1 road kit. This allows a basic track set up. Chris then wanted to swap out the disks to ST and that's been great as they just don't wear out. after that he wanted a proper Manthey set up so went for their GT4 full racing 3 way kit with a ring set up geo. this car does not dive or roll, and it must also save tyre wear as the GT4 is too soft oem and does wear edges badly. A few CUP race car parts with monballs were added to reduce play and add feel and also allow for caster adjustments. and last the engine mods to 430 HP / 345 LBF-FT with a new M and M big bore full system and Jens magic on the RR. I think some BBS Fi-R wheels next and some bbi wing uprights would finish it off very nice :-) lol So yes pretty much off the shelf parts, put picked well and fitted by experts. Awesome For the track driver I think this is a much more compelling approach than the latest iterations of the GT4 Got to agree here... I'm on step 1 of this journey. With the MR Track Day Kit.

So to add my view on Chris' upgrades from the passenger seat. 1st thing to say is that Chris can DRIVE. He knows how to handle the mid-engine layout and really knows this car, having developed it in stages. But really this car now is a package - and as you improve one part you quickly realise other parts might need optimising, and Chris' car now is truly optimised. As a package it feels like something like this should have come from the factory. I was saying all day on Tuesday... after the 718 GT4 announcements... Chris has already built it.. his car is a 718 GT4 Prototype, apart from his car has more power, ride and handles better and has more braking. As Peter and David said - the performance of the whole car is in such balance, you can't pick out one thing over the other... it feels like stock + 20% in every dynamic respect. Which I think is a major compliment. Power delivery is smooth - and the power carries all the way through the rev range. It feels meaty. Sounds meaty too - slightly different that stock now... quieter according to donny sound traps - which is good for getting on Track days. The exhaust is designed for power - not wasting it in sound - but it is loud enough. With proper unfettled purpose. For me though its the suspension that is stand out sparkling from the passenger seat. Unbelievable body control - no roll, pitch or dive - but can take bumps and low kerbs without upsetting the car at all. It means then that all of that new power can really be deployed with great effect. I'll post a couple videos later which have some comparisons on track...but remember there is a big driver deficit also.... so be kind!. This is the route to take for 981 GT4 owners if they want to develop the car.... Package. Edited by TDT on Thursday 20th June 16:06

ChrisW. said: No, this was on the full GP circuit which is in my experience rarely used ... At the end of the day we had driven a 1:48.2 with passenger ... good ?? Nicely done Chris, I checked my data logger after the day and discovered that just plugging it in isn’t enough there is actually an open button as well (who new). So in the end no data, but viewing the GoPro it appears I managed 1:48:6 a couple of times with passengers. I’ll link some YT to the other thread in a bit you can here ED giggling as I mess up McCleans on one of the laps. My 997.1 has similar upgrades to your Gt4 ie bigger brakes 3 ways mono ball suspension and extra bhp and torque. I’ve always thought the standard Gt4 and 997.1 GT3 where similar pace on track and it appears modded once’s are too. Looking forward to Oulton Jon P.s can’t do snetterton

Thanks everybody ... this is a "labour of love" so it's great to see so many others sharing the process ... and David, many thanks for making a far more eloquent job than I of modularising the process. Thank-you I noticed a comment regarding the increased weight of the 718 GT4 ... and since we have a local weigh bridge, I thought I'd weigh mine ... full of fuel ... plus or minus 20Kg's but I was told that it was recently calibrated. The score on the door ? 1440 kilos without driver, but with 200 grams of boiled sweets in the door pocket ! So, strip out 50 kilos of fuel, less the carbon seats and brakes, plus the roll cage ... does 1390 kilos make sense ? If I can run to the Manthey BBS F1R wheels they will save 14 kilos so that's 1375 ... of course the unsprung mass element adds a multiplier to the effective weight saving ... The only other thing that I anticipate at some stage is replacing the ultimately worn out LSD for a Gards ? unit ... Porsche do talk about the enhanced aero of the 718GT4 ... but it's only an extra 12Kg's (50%) at 200kph. And now a question ... If Porsche ever build a GT4 RS ...what engine will it have ?

ChrisW. said: Thanks everybody ... this is a "labour of love" so it's great to see so many others sharing the process ... and David, many thanks for making a far more eloquent job than I of modularising the process. Thank-you I noticed a comment regarding the increased weight of the 718 GT4 ... and since we have a local weigh bridge, I thought I'd weigh mine ... full of fuel ... plus or minus 20Kg's but I was told that it was recently calibrated. The score on the door ? 1440 kilos without driver, but with 200 grams of boiled sweets in the door pocket ! So, strip out 50 kilos of fuel, less the carbon seats and brakes, plus the roll cage ... does 1390 kilos make sense ? If I can run to the Manthey BBS F1R wheels they will save 14 kilos so that's 1375 ... of course the unsprung mass element adds a multiplier to the effective weight saving ... The only other thing that I anticipate at some stage is replacing the ultimately worn out LSD for a Gards ? unit ... Porsche do talk about the enhanced aero of the 718GT4 ... but it's only an extra 12Kg's (50%) at 200kph. And now a question ... If Porsche ever build a GT4 RS ...what engine will it have ? Good to see you an the banana Chris. It's sounds like a slippery slope. I think your at a point you get less for your money mods. The way I see it is, it needs to go on a mega diet but then that compromises the ability to drive comfortably to the track. I think your at a point where you could maybe run a better semi slick tyre, upgrade the LSD like you have mentioned (if it needs doing), otherwise I'm not sure anything else will be of benefit whilst keeping the road/track balance.

Like this alot, i too am now thinking its time to mod the gt4, i have in the past been a huge modified car guy but with ford RS cars. But like quite a few 981 GT4 owners, the new 718 GT4 is not really doing it and for the price difference not much point. I had a center gravity set up many years ago, but looking at engine bolt on's and a bit more suspension adjustment. Like what you have done engine wise and fancy something the same, plus would be interesting to here more about it please. I was looking at keeping the standard shocks but adding the uprated control box for better control. Take it you went over to Germany to get the engine bits fitted ?

Yes, Jens is near Dusseldorf and I really like the way he works : 1. Drive the car to hi. 2. Have such and explain what you want to achieve. 3. Give him reasonably free rein to interpret the best solutions and either fly home or go and do something else for a fe days. 4. Go watch the car being finished and discuss your geo requirements with the people doing it. 5. Drive home and start getting to know the car again. Jens is an extremely well informed project manager / race engineer. He doesn't for the work himself, but he knows who he trusts to do all his race car work ... so he doesn't just talk it, he does it. Yes there may be other people who can do this closer to home, but who ? When I was at Oulton there was a UK engine modified GT4 that was experiencing electrical alerts .. not at-all what I wanted .. but possibly a situation that will be recovered ... also to watch. On which subject, so far so good and will keep everybody posted. Did I say thatI also love offering passenger rides .... ?

Cunno said: Nicely done Chris, I checked my data logger after the day and discovered that just plugging it in isn’t enough there is actually an open button as well (who new). So in the end no data, but viewing the GoPro it appears I managed 1:48:6 a couple of times with passengers. I’ll link some YT to the other thread in a bit you can here ED giggling as I mess up McCleans on one of the laps. My 997.1 has similar upgrades to your Gt4 ie bigger brakes 3 ways mono ball suspension and extra bhp and torque. I’ve always thought the standard Gt4 and 997.1 GT3 where similar pace on track and it appears modded once’s are too. Looking forward to Oulton Jon P.s can’t do snetterton John, many thanks for the feedback ! In fairness I should be faster ... next time I'll ride with you if you'll ride with me ?? Very useful

Passenger ride at some point would be nice, as i am still getting my head round rear wheel drive as been a fwd guy for years and 4wd. But have done lots of track days over the years. Do you feel that with the extra grunt the car can over come the long gearing, or maybe thats your next move along with fly wheel ? But seeing yours and others views on the power gained is great as i have looked for views on engine mods before and its very hard to find

Noise update from Snetterton ... 101dB at 4800 rpm ... this compares to 104dB with the original set-up at Oulton Park, both static. I then re-tested at 5250rpm just to check the upper ceiling, and it read 105.5dB. Max revs are 7600 at the red line. Report from Snetterton ... it did take me a while to get up to speed, thank-you Howard for our 2/3rds tank session ! I was always faster than almost any GT4, I was always faster than a lot of GT3 and RS's ... there were always some GT3RS' that were faster than me .... That is still the case ... it is very hard to make the rear end of a GT4 perform as well as the multilink system of the GT3RS and they still have a power advantage ... But the car feels absolutely fantastic ... the biggest difference being that it's now possible to run a higher gear in complicated corners or sections, reducing the potential frenzy of gear changes and leaving the car more balanced, allowing the torque to haul the car through. So is the gearing now an issue ? The gearing will always be an issue unless it's track variable. As an example, at the end of the Bentley straight I was up into fifth seeing a max of almost 135mph ... but from there dropped to third all the way round and out of the bomb-hole ... where otherwise I would have had to use second ... two gear changes saved and much smoother transitions through the section.

ChrisW. said: it is very hard to make the rear end of a GT4 perform as well as the multilink system of the GT3RS There's a fix for that! https://www.autoquestcars.com/custom-09

There has been much talk of the max 310 lb-ft torque limit on the Cayman box even applied to the new GT4. These mods are about 10% above this limit, any special precautions recomended by the tuners?

ras62 said: There has been much talk of the max 310 lb-ft torque limit on the Cayman box even applied to the new GT4. These mods are about 10% above this limit, any special precautions recomended by the tuners? The torque limit of the box is strictly limited to 310lb/ft from an EU licencing POV and nothing can be done to side track that..If the gearbox goes pop(especially 3rd) then the Porsche warranty won't cover the replacement AFAIK..I'm looking at tuning my Spyder however in hindsight breaching the gearbox's torque limit holds me back somewhat..

This is a very interesting question, particularly considering the tuneability of the turbocharged engines. They don't rev, but they do torque ... These are engineering specs, my car was one of the very first I assume with the splined third gear, and driving fast on track has to be smooth otherwise you are off ! But the bottom line is that if trouble comes to me, I'll just replace the box and make any gearing and diff changes that suit me. It's still much cheaper than racing and you know ? I really don't expect trouble.

TDT said: There's a fix for that! https://www.autoquestcars.com/custom-09 Now that is naughty, I'll have to take a look (Thanks !)

One of the problems I have is that with a little help `i can drive around geometry issues ... it's not so fast but it feels faster! So I've replied to this and let's see what comes .. thanks Tyrone !

ChrisW. said: One of the problems I have is that with a little help `i can drive around geometry issues ... it's not so fast but it feels faster! So I've replied to this and let's see what comes .. thanks Tyrone ! Center Gravity have worked with this kit, on Tim (Ravon's) car, to excellent effect, i hear. Not sure if he still has the car or the kit?

Gearbox, quoted limit of 310lbft is nothing to really worry about, and certainly not a turn off for modding... which will compromise your warranty anyway?.. As Chris says - if there is a problem... then can just get it fixed and upgraded anyway. Also we need to understand what the peak torque limitation actually is, and why it is implemented... ultimately its for driver comfort and to save some stress on the engagement of the clutch and transfer of load through the drive train. It's not necessarily the ultimate limit of the gearbox. The GT3 only has a bit more torque.... 339lbft and really the manual gearbox is largely the same, athough the ratios are different and it spins the other way.

Chris, Have you seen products from Verus Engineering? https://www.verus-engineering.com/porsche-products Whilst the benefits of aero may be questioned in general by some, their analytical material suggests advantages for fast track work. Having been round Spa in the low powered version of your car, their products might worth considering....

gtsralph said: Whilst the benefits of aero may be questioned in general by some, their analytical material suggests advantages for fast track work. Having been round Spa in the low powered version of your car, their products might worth considering.... More aero will make a car faster. Minimal perhaps on heavy road cars but faster is faster I'd admit even if I am and have been of the opinion downforce on road cars is mostly marketing claptrap. The question though imo is why.... Would more downforce actually make the car more enjoyable to drive on track, especially given iirc the gt4 as standard is fairly evenly balanced aero wise (front/rear quite well distributed). Going faster per the stopwatch is in many respects neither here nor there if one is simply bolting on go faster parts. I'm all for better suspension/setups and other such things as they can materially improve the driving experience of a car as well as producing better times but the former very much is the key thing to address rather than the latter. 50kg of downforce at typical cornering speeds at Spa (say 100mph) would make a car faster but I am not convinced it will make a big difference to the driver in terms of feel as no matter what aero bits one sticks on, a gt4 or gt3 or any typical road going car will never feel like a proper aero car (or Radical).

Sorry, late to reply to this ... I think that 100kilos of downforce could be significant but downforce is something that has to be learnt .... and most manufacturers evolutions offer so little extra ... for example the new GT4 increases downforce by 50% ... 12 Kilos at 200 kph ? There is far more confidence to be gained in simply offering the wheels the best opportunity to breathe with the road ... via better suspension and lower unsprung mass. I also like the idea of a car from the outside and inside, looking more or less standard ...

'Just ordered a set of BBS F1R's .... David, you got me in the end ... (Having said I had planned to do nothing more than coaching this year!)

ChrisW. said: 'Just ordered a set of BBS F1R's .... David, you got me in the end ... (Having said I had planned to do nothing more than coaching this year!) Lol, I’ve been looking at these over the last couple of days also... what colour did you got with?

Platinum silver ... I have also bought a set of titanium wheel bolts with locking bolts from ACERRacing in the USA ...

ChrisW. said: Platinum silver ... I have also bought a set of titanium wheel bolts with locking bolts from ACERRacing in the USA ... Nice choice on colour. I’ve read mix things on whether or not Ti bolts are a good idea for track work. No doubt they will look good.

I’m on the verge of going down the performance tuning route. I wanted to run the car for the first half of the year at stock power so I can prove the improvement to myself as a driver, before adding more performance to the car, but as this has been scuppered - timeline might dictate I end up doing the power earlier. I’m also going to get my cam adjust bolts switched out from Alu to steel as a precaution, as there have been a few reports of these letting go with a lot of track use, and nuking engines, so easy fix, 6 new bolts and few hours labour, for some piece of mind. Also PFC V3 steel rotors as per the GT4 Clubsport race cars, and MR pads all around and braided lines.

TDT said: Nice choice on colour. I’ve read mix things on whether or not Ti bolts are a good idea for track work. No doubt they will look good. I bought them for the reduced unsprung mass so I will be appreciative of any intelligence you can offer ... I am not tied to them ! Ditto, I'm certainly into preventative maintenance ... Edited by ChrisW. on Monday 11th May 21:38

Sorry, I just don't know.

Ref the Ti bolts, they can seize, and also there is some question about the strength at a lighter weight than the OEM bolts. Ti is stronger than steel at the same volume, but if the volume is reduced.… so is the strength. This, and the seizing makes me wary for track use. For road only, less of a risk. Also if you’re taking your wheels off and on regularly may mitigate somewhat? Ref the cam sprocket/adjuster bolts, this is just to fix something that Porsche took a retro step on. Pre 981/991 they used steel bolts. 2013 onwards they have used Alu bolts (cost cutting) which can shear.

anonymous said: [redacted] I’d say give one of the reputable independents a call. They’ll easily be able to answer. They might re-use nuts/bolts that can be, if even Porsche would official say or charge for one time use. Anything that is a stretch bolt will replaced, and you should get those parts back to you in a box.

Interesting but ... where is the volume reduced ? As a matter of interest the Conrod Bolts of the GT3R engine were Titanium and use once only .... and turned down to minimise weight ... I'll try to attach a pic ! Edited by ChrisW. on Monday 11th May 22:25

ChrisW. said: 'Just ordered a set of BBS F1R's .... David, you got me in the end ... (Having said I had planned to do nothing more than coaching this year!) I’ve got some on order for my 991.2 GT3....they were supposed to be here May/June (ordered in Feb)....not holding my breath !

ChrisW. said: Interesting but ... where is the volume reduced ? As a matter of interest the Conrod Bolts of the GT3R engine were Titanium and use once only .... and turned down to minimise weight ... I'll try to attach a pic ! Edited by ChrisW. on Monday 11th May 22:25 I’ll try to recall some of the sources. I was reading a BBS Fi-R thread just today as it happens and saw these comments about Ti fasteners and then you posted, so thought it in good conscience to mention, especially as it’s safety critical. But also the info could require further validation.

woollyjoe said: TDT said: Ref the Ti bolts, they can seize, and also there is some question about the strength at a lighter weight than the OEM bolts. Ti is stronger than steel at the same volume, but if the volume is reduced.… so is the strength. This, and the seizing makes me wary for track use. For road only, less of a risk. Also if you’re taking your wheels off and on regularly may mitigate somewhat? Ref the cam sprocket/adjuster bolts, this is just to fix something that Porsche took a retro step on. Pre 981/991 they used steel bolts. 2013 onwards they have used Alu bolts (cost cutting) which can shear. No car knowledge, but from cycling... and old memory and possibly slightly wrong... Ti seizure is simply galvanic corrosion and prevented with anti seize - no biggie and doesn't bother cyclists. The primary advantage in Ti is usually its fatigue resistance. Titanium as well as having the strongest strength to weight ratio of all metals (I think), is also the only metal to not fatigue (may be another word). Carbon, steel, aluminium etc - they all fatigue - all metals except Ti. Aluminium the worst and why the first jet airliners fell out the sky... they didn't know this plus square windows. I digress... Ti components stay as strong as they were the day they were made. I’d agree with all of that, and this was 100% my thinking. I had seen some counter-information, which could be right or wrong… up to everyone to do their due diligence. I’ll need to dig further also.

TDT said: I’d agree with all of that, and this was 100% my thinking. I had seen some counter-information, which could be right or wrong… up to everyone to do their due diligence. I’ll need to dig further also. TDT is right to bring up the suitability of Titanium here I think, and he's right about the potential seizing issue, here' some further info on titanium which highlights it's worrying tendency to gall when threads are basically used multiple times. Now they may well be perfectly safe for wheel nuts/studs as I doubt they'd be made otherwise, but I'd think lubrication and close inspection after each use might well be required as a minimum. I think anyone using them might want to read this extract from a helicopter gearbox failure report a while back, it does say at the bottom anodizing and plating does increase resistance to corrosion, wear and galling, but I don't think eliminates it completely. ------------------- 'Titanium is desirable in certain applications due to its corrosion resistance and lighter weight as compared to steel. Sikorsky selected the titanium alloy stud because these had been used successfully on other Sikorsky products, such as the CH-53E Sea Stallion which utilizes six titanium studs to attach the oil filter bowl to the MGB. Also, Sikorsky declared that there was no reported history of in-service titanium stud failures. Galling is a type of adhesive wear, whereby material is removed or displaced from a surfaceFootnote 3. The Selection and Use of Titanium, A Design GuideFootnote 4, provides the following information about titanium galling: The surfaces of titanium and of all commercially produced alloys of titanium have relatively poor wear resistance. In particular, titanium surfaces in contact with each other or with other metals readily gall under conditions of sliding contact or fretting. Even with light loading and little relative movement, complete seizure of surfaces can occur. This situation is caused by adhesive wear in which microscopic asperities on the metal surfaces come into contact as a result of relative sliding and they tend to weld together forming a bond at the junction which can have rupture strength greater than the strength of the underlying metal. Fracture then takes place at one of the asperities causing metal to be transferred from one surface to the other. The debris so formed gives rise to the accelerated wear that occurs with titanium. The fastening system for the oil filter bowl of the S-92A used anodizedFootnote 5 titanium alloy studs, silver-plated steel nuts and cadmium-plated steel washers. Anodizing and plating increases resistance to corrosion, wear and galling.' The complete report here is quite interesting and includes a few pictures of damaged titanium studs found on the helicopter gearbox. https://www.tsb.gc.ca/eng/rapports-reports/aviatio...

woollyjoe said: Suppose I could read that. Got a few days off with no where to go! It's not compulsory, and if you're not into titanium maybe not worth the hassle

All great stuff to read, what lubrication would anybody suggest to avoid thread damage ? I can see the engineering problem in my minds eye ... while the tensile strength is there the metal has a softness ... you can see this from the way in which matt surfaces polish themselves over time ... A good flag Tyrone Thankyou ! In terms of corrosion resistance and mass reduction I will be in-front --- I reckon I've found a little over 1Kg of unsprung mass saving ... and I'll let you know how I get on

The Titanium threads are also mated to the steel hub and there should be very little if any slippage that could cause galling --- says he optimistically ! I did once have a wheel that tried to fall off ... this was caused by powder coating being left on the mating surface of the alloy wheel to the hub. This got very hot melting the powder coating and allowing the wheel to vibrate against the hub, unwinding the wheel bolt enough to cause a rather low clunk around Mansfield at Cadwell Park ! Thankfully the exit from the circuit is just around the next corner !

Cheib said: I’ve got some on order for my 991.2 GT3....they were supposed to be here May/June (ordered in Feb)....not holding my breath ! Mine are supposedly in stock at BBS ... we shall see !

Acerlug say to use copperslip or nothing ...

ChrisW. said: Acerlug say to use copperslip or nothing ... That's a bit debatable in my opinion, there's a big difference between dry and wet (oo-er). https://pagid.com/2014/11/24/should-wheel-fastener... There's a bit of info there but struggled to find a really good source, I've done a good few thread calculations in my time and the torque differences are much much more than you think (between different lubes and of course dry). Apologies for attempting to put more spanners in the works

Search Bimmer Forum titanium lugs there is a picture of an M3 letting go of its rear wheel as the studs failed - all five. Apparently they all sheared. Some long discussion there about the product too. Snowy

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Snowy999 said: Search Bimmer Forum titanium lugs there is a picture of an M3 letting go of its rear wheel as the studs failed - all five. Apparently they all sheared. Some long discussion there about the product too. Snowy I think the key to their safe use probably comes down to lubrication and religious regular inspections. The only issue there is the lubrication would really need to be removed to be able to inspect properly, a little time consuming maybe but might just have to be done.

Very interesting ...I've certainly seen galvanic corrosion on Magnesium wheels fitted using coppaslip .. As a matter of interest ... what do Porsche say about using lubrication on steel studs?

Tef-gel is used in marine circles where Galvanic corrosion is a major problem. It’s pretty easy to get hold of.

Seen the pics of the new wheels on your car Chris. Looks mega.

Where is that ? I couldn't post them because I'm waiting for the Photobucket data centre to get back on-line ... ! I only took them yesterday ;-)

JZM’s Instagram feed, I recon.

ChrisW. said: Where is that ? I couldn't post them because I'm waiting for the Photobucket data centre to get back on-line ... ! I only took them yesterday ;-) Are you still bothering with that photo bucket s te I’ve gave up and just conceded that I’ve lost all my old pics..

Photobucket are trying to resurrect themselves ...

jcosh said: JZM’s Instagram feed, I recon. Yep

Amazingly, the weight savings are not overstated ...

Are you concerned about the inner face of these being damaged by stones trapped between the calliper and wheel, like the OEM set up?

ChrisW. said: Amazingly, the weight savings are not overstated ... They do look good, and the weight saving definitely looks useful. When you put them next to the standard wheels like you have in the shot… makes the OEM design look pretty tame.

jcosh said: Are you concerned about the inner face of these being damaged by stones trapped between the calliper and wheel, like the OEM set up? No ... I have had it with the standard wheels and it just happens. I am guessing that it will take a lot to do any serious damage ... the worst thing is the noise ... Stop. Drive forwards ... ouch !!! . Reverse ... phew ! But I've also had small stones in the calliper which have sounded much worse on the disk backing plate. My carbon discs are skimmable ... PCCB's ? Sorry.

Really nice Chris are they 20"? btw have you taken your rear cage out to save another 25kg?

Loved a TSW Venom back in the day

Snowy999 said: Really nice Chris are they 20"? btw have you taken your rear cage out to save another 25kg? They have to be to fit over the PCCB's ... I specified the cage and full harnesses for safety reasons, why would I take these out ?

LaurasOtherHalf said: Loved a TSW Venom back in the day

LaurasOtherHalf said: Loved a TSW Venom back in the day

Just read this thread through from start to finish. Very interesting, any updates?

keo said: Just read this thread through from start to finish. Very interesting, any updates? TDT had the performance mods he mentioned and his car is now mega. Races up to 8k revs with no stalling at 5.5k like the standard car.

someone here already tried this kit out? 560hp NA engine to 4.5L and a better geared gearbox, sounds nice. yes it cost some, but say, your original engines goes bang at some point, maybe its interesting then? Also wonder if some other tuners in Europa, offer the same sort upgrade. https://demanmotorsport.com/4-5l-cayman/

GTRene said: someone here already tried this kit out? 560hp NA engine to 4.5L and a better geared gearbox, sounds nice. yes it cost some, but say, your original engines goes bang at some point, maybe its interesting then? Also wonder if some other tuners in Europa, offer the same sort upgrade. https://demanmotorsport.com/4-5l-cayman/ Capacity increases are available, from tuners on the continent, and yes attractive option if your original engine needs a rebuild anyway. Ehresmann has all the options available up to 4.5L…. It was these guys that helped some of the US guys develop their packages, which they have then taken onwards and made their own. BGB goes up to 4.3L Deman goes up to 4.5L Still, there are some pretty good options for the 3.8… with a couple of different flavours for power delivery, dependant upon if your prioritising circuit work or street/auto-cross/hill climbs. Edited by TDT on Tuesday 22 June 02:06

Thanks @TDT indeed, you could first build the 3.8 engine up with some products you also use in the big bore options, say inlet and headers/exhaust etc that gives you more torque and power, so extra fun, and then when it goes, or if it goes, you could do the increasing of cc, the rest you then already have. edit, indeed they got that already in 2016 some upgrades and 440ps, nice. https://youtu.be/94P6COIXTHM Edited by GTRene on Tuesday 22 June 15:51

GTRene said: Thanks @TDT indeed, you could first build the 3.8 engine up with some products you also use in the big bore options, say inlet and headers/exhaust etc that gives you more torque and power, so extra fun, and then when it goes, or if it goes, you could do the increasing of cc, the rest you then already have. edit, indeed they got that already in 2016 some upgrades and 440ps, nice. https://youtu.be/94P6COIXTHM Edited by GTRene on Tuesday 22 June 15:51 Yep, a few of us have started to play with 981 GT4/Spyder. I guess one school of thought though is to not bother with the interim bolt-ons and just do everything in one big bang.... you'd be avoiding a double spend in some area for labour and time of having the car in the workshop and/or engine out. Edited by TDT on Friday 6th August 23:17

Thread resurrection, thanks Tyrone ! In the end I removed the Titanium lugs ... I found that at 120 Lb Ft they squeeked on torquing up and when wheels were changed small slivers of thread material could be seen ... not good. So I went back to steel ...

These images are numerically successive, but I can't see how ? Maybe the golf was just catching me up ? Edited by ChrisW. on Saturday 4th June 21:06