Why is 981 GT4 engine derided? - Page 3 - Boxster/Cayman - PistonHeads UK

As another thread on here and a few others - there seems to be a sense that the 3.8 engine in the 981 GT4 is somehow strangled, held back and has flat spots. Is this really the case? FWIW I have a 981 Spyder with the same engine and have never felt this is the case. Does the Spyder have a different map? Or is everyone wrong? Or am I missing something? For example see:

A couple of people saying they didn’t like it’s characteristics, doesn’t make it ‘derided’. Lol. 981 Spyder has a slightly different tune… makes slightly less hp on paper. Ultimately people have complained that the standard 9A1 3.8 in the 981 GT4/Spyder - should get better fuel economy, - has some dips in the torque curve - runs out of real puff after about 6.5k All of which has truth. As time has moved on… the 4.0 9A2 EVO came into existence… and it does address the aforementioned points. It’s cleaner, more powerful, revs hard to increase redline, building power all the way. But, it doesn’t sound as good standard, and then because its also very linear…. It could be said it is not as evocative/characterful. It just a hard charging unit. This dyno graph depicts the typical story… although the difference is greater than on paper. That said, doesn’t make the 9A1 a bad engine. Far from it. The engine can support higher states of tune, for 981 and 911… as per the factory x51 kit, It was (981 Clubsport) and is still (718 Clubsport) successfully raced. The listed ‘issues’ can be easily resolved with very light aftermarket tweaks, for not much outlay if the graph bothers you and you want to clean up the curves, or you want more engine performance, but you otherwise love the car. 4.0 9A2 EVO has only seen use in road cars, to date, in a couple of broadly similar states of tune +/- 20hp, and Porsche have not seemingly invested further into it. Maybe it can live on in the 992.2 with hybrid? Edited by TDT on Friday 17th February 22:11

I'm surprised at people complain about fuel economy, really, honestly never look at fuel figures when buying a fun car. My 360 guzzled fuel like crazy, my 3.4 GTS did 11mpg on a blast, who really cares lol. The 3.8 is fine, whilst the 3.4 was a fun revy motor, my adjustable spanner had more torque, flat as a pancake, still fun mind. A tweaked 3.8 like TDT's is perfect imo, I'd take that over the 4.0 that I drove and found none eventful. Not saying the 4.0 is a bad engine btw.

It's at least partially a question of expectations I think. For a 'GT' car, the 981 gt4's engine was not really comparable to either the 991 nor the 997 gt3 and while functional, never really sparkled in the way it should have. the power curve effectively flattening out after 6.5k was a large part of the issue I had. (Very) unfortunately, the 3.8 x51 as per the 991.1gts wasn't used despite already existing as a 'stock' solution as that's to my mind was an engine that had characteristics much better suited to the gt4 and indeed it did appear in the clubsport race car subsequently.

Definitely agree… it would have been spectacular (as I emulated, if i say so myself, thanks Jay), but x51 was a 10-12k option on the 911… so then 981 would not be a new unproven market entrant @65k and would have needed to be 70-75k… Like 718 GT4 was introduced at 4 years later… with a proven market demand… therefore investment justified. 996.1 GT3… was new entrant… and basically a Carrera with Aero kit. Barely made more power than normal Carrera… had tiny brakes … but was all about the chassis. When the business case and demand was proven… we can see the step change with the 996.2 GT3 and then again with the 996RS. So it’s a familiar product development life cycle. Edited by TDT on Friday 17th February 23:13

The Spyder has the non-GT "GTS" style mapping and is much nicer IMHO. The Spyder is the pick of the 981 range IMHO. I know TDT and others feel differently, but the 981 GT4 to me felt like a rushed and unfinished project. The auto blip button getting a pre-existing "Sport" label is a prime example. How long would it have really taken to get a proper button made up? A lot of people like that home-brew feel of the car but it wasn't for me. The engine is the soul of any car and I just found it rough. I'm well aware I'm in the minority though!

Twinfan said: The Spyder has the non-GT "GTS" style mapping and is much nicer IMHO. The Spyder is the pick of the 981 range IMHO. I know TDT and others feel differently, but the 981 GT4 to me felt like a rushed and unfinished project. The auto blip button getting a pre-existing "Sport" label is a prime example. How long would it have really taken to get a proper button made up? A lot of people like that home-brew feel of the car but it wasn't for me. The engine is the soul of any car and I just found it rough. I'm well aware I'm in the minority though! I agree

TDT said: Definitely agree… it would have been spectacular (as I emulated, if i say so myself, thanks Jay), but x51 was a 10-12k option on the 911… so then 981 would not be a new unproven market entrant @65k and would have needed to be 70-75k… Like 718 GT4 was introduced at 4 years later… with a proven market demand… therefore investment justified. 996.1 GT3… was new entrant… and basically a Carrera with Aero kit. Barely made more power than normal Carrera… had tiny brakes … but was all about the chassis. When the business case and demand was proven… we can see the step change with the 996.2 GT3 and then again with the 996RS. So it’s a familiar product development life cycle. It depends how one wants to look at it I suppose. With x51 pricing at £75k - the 981 gt4 would still have been 25% cheaper than the 991.1gt3.... that would have been the comparable market rather than vs a 981 gts to my mind anyway and the demand for that, if anything would have been at least as firm as what ultimately turned out. And I'd very much disagree the 996.1gt3 was anything like a 996c2 with powerkit. Engine for one was rather different and just a tad more costly to produce.......

Anyone know how to remap/modify to remove flat spots?

Billy_Whizzzz said: Anyone know how to remap/modify to remove flat spots? If you are in easy reach of Suffolk talk to PiePerformance.

Billy_Whizzzz said: Anyone know how to remap/modify to remove flat spots? I don't think it's as simple as that, aren't the intakes the issue? Not sure a simple remap can sort the curves out...

A remap will take care of most of the curves down low. Will take you to about 400hp with generally improved delivery overall. Some shops like to change the throttle body out to a 82mm version and an IPD or 991 plenum to accommodate it. Using the IPD or 991 plenum… it’s pretty straightforward and not that involved at all…. If you’re handy you ‘could’ do it yourself. Changing the tb requires a remap, so that’s why some shops say just do both. If you take the directions of the even bigger 718CS/991GT intake manifold that’s a bit more complex due to work spacing in the engine bay and the massive size of the parts. After intake there is exhaust side… but then you’re into spending more money. Edited by TDT on Saturday 18th February 08:57

I think that Porsche positioned the 981GT4 very carefully. It would have cost them almost nothing to give a little more geometry adjustment and solve the diabolical tyre shoulder wear on track. From new it would have cost them far less than £10k to add the higher tune of the current 718 Clubsport ... But they needed a cheaper na 6 pot for the run-out non turbo sports cars and they needed some volume to justify this modification of the existing standard 911 6 pot turbo engine ... so the GT4 volume was a massive help towards this. Even now the GT4RS whilst it carries a lot of emotional pull is not a GT3 ... I understand the geometry options remain far more limited than the GT3 ? But all the new found GT4 owners are being prospectively talked up to GT4RS money .... Clever stuff, if only they could maintain some enthusiast respect from some of their dealers ...

I think it sounds amazing, possibly even better than it does in my Carrera S. it does have a longer exhaust which robbed it of some power, and I think most people make the assumption that it was “deliberately strangled” based on that alone. Sounds like a remap could cure the dips, but other than that I wouldn’t change a thing about it. Especially knowing how quiet the 4.0 cars are.

Haribo Lecter said: I think it sounds amazing, possibly even better than it does in my Carrera S. it does have a longer exhaust which robbed it of some power, and I think most people make the assumption that it was “deliberately strangled” based on that alone. Sounds like a remap could cure the dips, but other than that I wouldn’t change a thing about it. Especially knowing how quiet the 4.0 cars are. Not me, I thought it felt stangled to drive - nothing at all to do with specs on paper External sound isn't everything, on full chat both the 3.8 and 4.0 sound pretty good inside the cabin to me...

To be totally honest I find the GT4 and Spyder in both generations to be a great car let down by an average engine. The 981 is the worst of the pair, I liken it to a high performance diesel, lots of torque but it all tails off as the revs rise and it certainly does not inspire. The economy is dreadful as well. The 4.0L has a much nicer torque and power curve but still fails to stir the soul. The general drone and hum in the cabin is horrible, it’s no sports car. The Spyder with its additional bulkhead is a much better daily driver but unless you drive it like you stole it the entire time it’s back to a flat monotone drone out of the back at normal speeds, blame the PPF for that I guess. Before I get shouted down by the GT4 fanboys my point of reference is my current V10 R8, which sounds sublime the entire time even when just pootling, along with lots of different GT3’s of all flavours. I never had any complaints about any of them. I have great hopes for the GT4RS, I really want that to sound and feel good at all speeds and restore my faith in Porsche fun cars.

All this remapping for 20bhp. It’d the crap gearing that kills it. A diff change and it’ll be 80bhp better

bigmowley said: To be totally honest I find the GT4 and Spyder in both generations to be a great car let down by an average engine. The 981 is the worst of the pair, I liken it to a high performance diesel, lots of torque but it all tails off as the revs rise and it certainly does not inspire. The economy is dreadful as well. The 4.0L has a much nicer torque and power curve but still fails to stir the soul. The general drone and hum in the cabin is horrible, it’s no sports car. The Spyder with its additional bulkhead is a much better daily driver but unless you drive it like you stole it the entire time it’s back to a flat monotone drone out of the back at normal speeds, blame the PPF for that I guess. Before I get shouted down by the GT4 fanboys my point of reference is my current V10 R8, which sounds sublime the entire time even when just pootling, along with lots of different GT3’s of all flavours. I never had any complaints about any of them. I have great hopes for the GT4RS, I really want that to sound and feel good at all speeds and restore my faith in Porsche fun cars. Its not a sports car, thats some statement. The GT4RS will have the same hum and drone in the car, likely to be just as loud or even louder I've heard. Your comparing a 65K car vs 130K cars remember. An R8 will do everything really well, but yet feel blunt, well the one I had did, front end felt very disconnected. GT3 is a step above the GT4 of expected to be better.

bigmowley said: To be totally honest I find the GT4 and Spyder in both generations to be a great car let down by an average engine. The 981 is the worst of the pair, I liken it to a high performance diesel, lots of torque but it all tails off as the revs rise and it certainly does not inspire. The economy is dreadful as well. The 4.0L has a much nicer torque and power curve but still fails to stir the soul. The general drone and hum in the cabin is horrible, it’s no sports car. The Spyder with its additional bulkhead is a much better daily driver but unless you drive it like you stole it the entire time it’s back to a flat monotone drone out of the back at normal speeds, blame the PPF for that I guess. Before I get shouted down by the GT4 fanboys my point of reference is my current V10 R8, which sounds sublime the entire time even when just pootling, along with lots of different GT3’s of all flavours. I never had any complaints about any of them. I have great hopes for the GT4RS, I really want that to sound and feel good at all speeds and restore my faith in Porsche fun cars. The 718GT4 is very prone to drone between 2 and 2.8k no matter what exhaust it has. The OEM back box does the best job of masking it but its still there. The GT4 RS will be the same or even worse is my guess. Blame the drone on the shape of the body more than anything else. Its the GT4's biggest flaw for sure

JayK12 said: bigmowley said: To be totally honest I find the GT4 and Spyder in both generations to be a great car let down by an average engine. The 981 is the worst of the pair, I liken it to a high performance diesel, lots of torque but it all tails off as the revs rise and it certainly does not inspire. The economy is dreadful as well. The 4.0L has a much nicer torque and power curve but still fails to stir the soul. The general drone and hum in the cabin is horrible, it’s no sports car. The Spyder with its additional bulkhead is a much better daily driver but unless you drive it like you stole it the entire time it’s back to a flat monotone drone out of the back at normal speeds, blame the PPF for that I guess. Before I get shouted down by the GT4 fanboys my point of reference is my current V10 R8, which sounds sublime the entire time even when just pootling, along with lots of different GT3’s of all flavours. I never had any complaints about any of them. I have great hopes for the GT4RS, I really want that to sound and feel good at all speeds and restore my faith in Porsche fun cars. Its not a sports car, thats some statement. The GT4RS will have the same hum and drone in the car, likely to be just as loud or even louder I've heard. Your comparing a 65K car vs 130K cars remember. An R8 will do everything really well, but yet feel blunt, well the one I had did, front end felt very disconnected. GT3 is a step above the GT4 of expected to be better. I am only talking about engines here, as per the OP and for me neither GT4 generation has an engine worthy of a top class sports car. Excellent cars overall, which is why I own both a GT4 and a Spyder. They could be so much better. Please can I have an R8 V10 in a GT4 chassis? Perfect

bigmowley said: JayK12 said: bigmowley said: To be totally honest I find the GT4 and Spyder in both generations to be a great car let down by an average engine. The 981 is the worst of the pair, I liken it to a high performance diesel, lots of torque but it all tails off as the revs rise and it certainly does not inspire. The economy is dreadful as well. The 4.0L has a much nicer torque and power curve but still fails to stir the soul. The general drone and hum in the cabin is horrible, it’s no sports car. The Spyder with its additional bulkhead is a much better daily driver but unless you drive it like you stole it the entire time it’s back to a flat monotone drone out of the back at normal speeds, blame the PPF for that I guess. Before I get shouted down by the GT4 fanboys my point of reference is my current V10 R8, which sounds sublime the entire time even when just pootling, along with lots of different GT3’s of all flavours. I never had any complaints about any of them. I have great hopes for the GT4RS, I really want that to sound and feel good at all speeds and restore my faith in Porsche fun cars. Its not a sports car, thats some statement. The GT4RS will have the same hum and drone in the car, likely to be just as loud or even louder I've heard. Your comparing a 65K car vs 130K cars remember. An R8 will do everything really well, but yet feel blunt, well the one I had did, front end felt very disconnected. GT3 is a step above the GT4 of expected to be better. I am only talking about engines here, as per the OP and for me neither GT4 generation has an engine worthy of a top class sports car. Excellent cars overall, which is why I own both a GT4 and a Spyder. They could be so much better. Please can I have an R8 V10 in a GT4 chassis? Perfect I agree, its not a top class sports car in Porsches range, thats why they do a GT3. The GT4RS answers your wishes really. For me for what you get for 65K is a great package still, and modding them like ChrisW and TDT takes them to another level. Btw I don't have one but driven some, might get one as a mostly track car as my Radical has gone and I can't be arsed with none road legal car.

Does anyone have a graph of the power curves of GT4 vs Spyder? Can anyone confirm that the Spyder is actually a different map? Isn’t peak power actually the same?

Officially: Peak for 981 Spyder is 375hp Peak for 981 GT4 is 385hp Peak torque is the same for both… 420NM/310lbft

jason61c said: All this remapping for 20bhp. It’d the crap gearing that kills it. A diff change and it’ll be 80bhp better Totally agree. The gearing really exaggerates the shortcomings of the engine. The flat spot at 5k wouldn't be such an issue if it didn't last for what feels like an eternity in 3rd gear. It's a GT car...you want to rev it out but the last 1000rpm feels like it takes forever, even in 2nd gear. With the 981 GT4, Porsche nailed the looks, handling, sound, gearshift, controls, and cabin feel (with the carbon buckets). Sadly the engine/gearbox doesn't quite live up to the rest of the package so I think a lot of the criticism is born out of frustration. Ultimately that's the reason I sold mine.

I don't find the gearing is an issue with the 4.0, it pulls through them just fine on road and track. The issue for me is the engine in 981, not the gearbox. They are the same in both GT4s.

Based on the Evo article, they seemed to think the gearing mod transforms the experience on the 718 GT4 too https://www.evo.co.uk/sports-cars/205234/stock-v-m... Evo said: There is no such thing as an unimprovable car, but some get closer to perfection than others. The 718 Cayman GT4 falls into the category of almost flawless. Our Car of the Year 2019 is a properly exciting and rewarding sports car that oozes character. It has a gearshift that’s short, snickety and as slick as if the lever dropped straight into the gearbox, while the swirling, detailed, gravelly note of the 4-litre flat-six is a shifting, evolving aural delight as it climbs from tickover to red line. Add in a perfectly judged brake pedal that makes heel-and-toe shifts a cinch, steering that feels meaty at low speed but is perfectly weighted and tactile in corners, and a chassis that’s poised and connected, and it’s five stars all day long. But it’s not perfect because the gear ratios of the six-speed manual are monumentally and occasionally frustratingly long. This is perhaps best illustrated by the fact that peak power (at 7600rpm) in second gear is 80mph, so in the UK you can only legally hit the red line on the public road in first. Oddly, such long gearing doesn’t feel like a great handicap on track. Most of the lap is in second gear, with third on the longer sections, and it’s such a flexible, torquey engine that it can still test the chassis at almost every corner, so you’re not missing the ability to adjust the balance with the throttle. The chassis is wonderfully transparent and malleable: dive for the apex, back off to shift the weight forward, get back on the throttle and exit with the car neutral or with as much oversteer as you want (and a trackday will allow…). Consequently, the benefits of the work of Porsche specialist RPM Technik are not as immediately apparent as you might expect. RPM has developed a new crownwheel and pinion that lowers the gearing by 14 per cent, so peak power in second gear is now at 69mph and in third 96mph (instead of 111mph). There’s also a lightweight flywheel but the engine delivers the same 414bhp and it rides on the same Michelin Cup 2 tyres. It is on lower, stiffer suspension developed by legendary Porsche fettlers Manthey Racing, but, as with the Litchfield Yaris, it hasn’t been dialled in for Anglesey and there is a little front-end push in the fastest corners. The upshot is that there is more kick available mid-corner, but as this is something that isn’t obviously missing in the standard car, it seems only a marginal gain. The twist is that I drove to Anglesey in the standard GT4 in convoy with RPM Technik’s commercial director, Darren Anderson, in the GT4 MR. We took the interesting route across country from Welshpool and I thought the stock GT4 had held its own. However, within a couple of miles of slipping behind the wheel of the GT4 MR I was utterly gobsmacked; on the road the shorter gearing completely transforms the experience. Suddenly the GT4 is alive, ever-ready with a solid slug of torque or power, and it revs out so much more quickly there’s so much more urgency to the car. Whatever the speed, it responds harder and quicker and revs faster, which changes the character of the engine, giving it an almost VTEC-like appetite. And thanks to the lightweight flywheel, heel-and-toe shifts are snappier and the shift feels even slicker. It’s sensational: a different, better car, almost like the regular GT4 but 200kg lighter. (On that subject, we weighed the stock car at 1460kg and the MR at 1439kg.) And, at a road pace, the chassis feels spot-on too, carrying speed more confidently into corners and never feeling weighty, which the standard car can occasionally.

As it says.. Shorter gearing may make it more fun on the road… but standard gearing was zero issue/not a handicap on track. Depends what you want.

Don't agree it's a gearing issue. The engine is the issue in the 981, specifically the way the power curve flat lines then falls over the last 10-15% of the rpm range. Shorter gearing would just mean one is faced with that lack of top end buzz even more often.

isaldiri said: Don't agree it's a gearing issue. The engine is the issue in the 981, specifically the way the power curve flat lines then falls over the last 10-15% of the rpm range. Shorter gearing would just mean one is faced with that lack of top end buzz even more often. Yep. That’s why I chose the direction to change the power curve I did with the powerkit changes on my 981, specifically boosting performance to the redline and at those higher revs, as well a power overall. You can see the difference of my 981 GT4 build vs OEM Standard 981 GT4. Shifting at near redline on track dropped me back into a rising part of the torque band, at a level that was above OEM peak and then was starting to drop off rapidly. Very emotive, really sharp at the top.

TDT said: isaldiri said: Don't agree it's a gearing issue. The engine is the issue in the 981, specifically the way the power curve flat lines then falls over the last 10-15% of the rpm range. Shorter gearing would just mean one is faced with that lack of top end buzz even more often. Yep. That’s why I chose the direction to change the power curve I did with the powerkit changes on my 981, specifically boosting performance to the redline and at those higher revs, as well a power overall. You can see the difference of my 981 GT4 build vs OEM Standard 981 GT4. Shifting at near redline on track dropped me back into a rising part of the torque band, at a level that was above OEM peak and then was starting to drop off rapidly. Very emotive, really sharp at the top. Apologies if you’ve said this already: what work did you do exactly?

My Powerkit consisted of the following: -718 Clubsport/991 GT Intake System - comprised of larger volume plenum and larger volume intake runners. -82mm Throttle Body, -Custom equal length long tube race headers, with 200cell catted over axle pipes -M&M Rear Muffler & x-pipe with tips and additional turn down tips -BMC Airfilters. - Custom Rolling Road Live Mapping - 435BHP/440ps on MAHA dyno. Other flavours of ‘Powerkit’ are available also… using different headers and/or exhaust hardware… which give slightly varying curves, but all open up the breathing up top e.g. ChrisW has gone with IPD Plenum, 82mm tb + M&M Sport Headers and Exhaust Snowy999 has gone with Dundon D4 (IPD Plenum, 82mm tb, dundon race header and catted over axle pipe and GT3 RS backbox) As i mentioned before… you don’t ‘need’ to go as far as this… a light remap alone can make a nice improvement also. Edited by TDT on Sunday 19th February 18:25

And now the RPM Technik crown wheel and pinion with lightweight flywheel and clutch .... In fact when the pinion came out the case hardening had just started to break down ... so this was very timely.

Have a read of this Chris https://rennlist.com/forums/gt4-spyder/1256913-pin... As you’ve said… is a known point that will breakdown over time… wear and tear. Maybe one way to keep on top of it is more regular transmission oil services… Porsche have a hugely long interval… so maybe with more track this needs to be revised. Same part in 718 … so probably can expect this also, although this might be the 1st most people are reading about it on this side of the pond.

Shorter gearing + breathing mods on a 981 GT4 would be perfect, guess I'll will see what yours is like soon Chris! I'd like PDK in a 981 GT4 tbh, I know I'll get flamed but considering most of my use will be track time I'd just perfer PDK, maybe cause my last track car was sequential paddle shift I just got used to it. Wonder if its an easy mod, used gearbox is about a 2.5K.

ChrisW - what do R/pM recommend for their shorter cwp in terms of service and inspection. Looking forward to hearing about the conversion. Is it coming to Oulton Pk? Snowy

Yes I'll be at Oulton. The new crown wheel and pinion came in a Capricorn box ... so I have very high hopes for it. My gearbox oil was changed at 1500 miles ... as was the engine oil, so it's had a good running-in service, but I haven't changed the transmission oil since then ... Porsche have suggested that the transaxle is the reason for torque limiting ... maybe it is their pinion that is the limiting factor ? We know that they were trying to reduce costs ... hence the splined third gear on earlier boxes becoming a welded fix to the lay-shaft on later cars ... hence replaced Gretag gearboxes with no option to repair ?? It's my experience that a little extra spend on good quality components can make a big difference to the competence of the car (if not the driver !) P.S. Service intervals on gearbox oil ? It's cheap insurance from now on ... Edited by ChrisW. on Monday 20th February 13:47

TDT said: Have a read of this Chris https://rennlist.com/forums/gt4-spyder/1256913-pin... As you’ve said… is a known point that will breakdown over time… wear and tear. Maybe one way to keep on top of it is more regular transmission oil services… Porsche have a hugely long interval… so maybe with more track this needs to be revised. Same part in 718 … so probably can expect this also, although this might be the 1st most people are reading about it on this side of the pond. It was stated that the pinion gear was not available separately from Porsche ... whilst this may still be the case RPM Technik can obviously supply the revised CWP set. This being the case, has it saved me a gearbox ? A serious question and food for thought ...

ChrisW. said: TDT said: Have a read of this Chris https://rennlist.com/forums/gt4-spyder/1256913-pin... As you’ve said… is a known point that will breakdown over time… wear and tear. Maybe one way to keep on top of it is more regular transmission oil services… Porsche have a hugely long interval… so maybe with more track this needs to be revised. Same part in 718 … so probably can expect this also, although this might be the 1st most people are reading about it on this side of the pond. It was stated that the pinion gear was not available separately from Porsche ... whilst this may still be the case RPM Technik can obviously supply the revised CWP set. This being the case, has it saved me a gearbox ? A serious question and food for thought ... As was said in the post - individual gearbox components are not available from Porsche... they'll only supply a full gearbox - and its probably down to OPC as to whether or not any goodwill would be applied. Sounded like reconditioned gearboxes are available also for not much money... so could be acquired for spares/swap. At the very least - you've paid now to find out that a problem was occurring, flushed the gearbox and replaced a wearing part with a brand new one, (Added benefit is the shorter gearing, lol), and prevented any collateral damage from a more serious in service failure? If it is the Gearbox lining that is breaking down and the small particles causing the wear - won't it reoccur in time?.. guess depends on the whether or not the replacement part is more resilient that the OEM. Potentially/probably? Later in the thread - someone with extensive racing experience of the gearboxes says... its just a wear and tear item. Something to keep an eye on and maybe up the transmission oil change intervals. Edited by TDT on Monday 20th February 14:36

Billy_Whizzzz said: TDT said: isaldiri said: Don't agree it's a gearing issue. The engine is the issue in the 981, specifically the way the power curve flat lines then falls over the last 10-15% of the rpm range. Shorter gearing would just mean one is faced with that lack of top end buzz even more often. Yep. That’s why I chose the direction to change the power curve I did with the powerkit changes on my 981, specifically boosting performance to the redline and at those higher revs, as well a power overall. You can see the difference of my 981 GT4 build vs OEM Standard 981 GT4. Shifting at near redline on track dropped me back into a rising part of the torque band, at a level that was above OEM peak and then was starting to drop off rapidly. Very emotive, really sharp at the top. Apologies if you’ve said this already: what work did you do exactly? I've had very similar engine work to P1TDT and concur that this makes the 981GT4 the car it should have always been. It races to the 8050rpm red line whereas before there was no point revving beyond 6500. The rolling road numbers show this quite clearly.

Hope it will be a good weather day for some GT4 fun next week! Lol.

TDT said: ChrisW. said: TDT said: Have a read of this Chris https://rennlist.com/forums/gt4-spyder/1256913-pin... As you’ve said… is a known point that will breakdown over time… wear and tear. Maybe one way to keep on top of it is more regular transmission oil services… Porsche have a hugely long interval… so maybe with more track this needs to be revised. Same part in 718 … so probably can expect this also, although this might be the 1st most people are reading about it on this side of the pond. It was stated that the pinion gear was not available separately from Porsche ... whilst this may still be the case RPM Technik can obviously supply the revised CWP set. This being the case, has it saved me a gearbox ? A serious question and food for thought ... As was said in the post - individual gearbox components are not available from Porsche... they'll only supply a full gearbox - and its probably down to OPC as to whether or not any goodwill would be applied. Sounded like reconditioned gearboxes are available also for not much money... so could be acquired for spares/swap. At the very least - you've paid now to find out that a problem was occurring, flushed the gearbox and replaced a wearing part with a brand new one, (Added benefit is the shorter gearing, lol), and prevented any collateral damage from a more serious in service failure? If it is the Gearbox lining that is breaking down and the small particles causing the wear - won't it reoccur in time?.. guess depends on the whether or not the replacement part is more resilient that the OEM. Potentially/probably? Later in the thread - someone with extensive racing experience of the gearboxes says... its just a wear and tear item. Something to keep an eye on and maybe up the transmission oil change intervals. Edited by TDT on Monday 20th February 14:36 Yes, I think it's certainly worth monitoring with oil changes at 6,000 mile intervals (?) and at least replacements are available

Another decent read here - https://rennlist.com/forums/gt4-spyder/1337230-gt4... Summary is that;.. changing the part isn't going to be a long term fix... but changing transmission oil weight to something heavier that OEM is going to help a lot... e.g. 75W140 ? Edited by TDT on Tuesday 21st February 11:24

I will check this out ... could be timely Tnx !