Is just a Cobb Tune worth the effort on a 981 GT4 - Page 2 - Boxster/Cayman - PistonHeads UK

Quick question. I did a search on modifying a 981 GT4 and was surprised how little there was on PH Most threads on this matter have had little or no posts or progress since 2016 So my question is is a COBB tune worth the hassle and cost on a GT4 without any other mods My thinking is the 981 GT4 uses a detuned 991 Carrera engine so is it possible to get a bit more power out if it by just an ECU remap? Or is the detuning done by the exhausts ? Any thoughts appreciated

You'll need to ask TDT or ChrisW, but I believe the intake is a major restriction on the 981 GT4. A re-tune or exhaust swap won't do much on its own, you need to do more.

From the £70k 981 GT4 or £85k 718 GT4? thread a couple weeks ago. Engine is an air pump... intake and exhaust are the ways in which Porsche have controlled the performance of the Cayster in general and this applies to GT4 also. Headers with Sport cats are in the region of 3k. Headers are probably biggest bang for buck for HP. But there are various options... You can go for a package based on custom tune and 82mm Throttle body (IPD plenum is commonly used to facilitate the fitting of the larger TB) The standard 74mm Cayman throttle body is replaced with the 82mm unit from the 911. This helps with intake ingestion at higher revs... This can be done for c£3k fitted. So for around £6k, put headers, the 82mm TB + IPD plenum and the tune together and you can get really nice gains c40hp over stock and really nice torque pick up... which is an overall amplification and smoothing of the 981 GT4 OEM power profile. Then there are more extreme options with even larger intake manifold components... picking up in the region of 55hp over stock The power delivery with these options have a different profile signature to OEM style, and crucially now builds power with revs all the way to redline. Strong and very linear. But key point... I wouldn’t just buy an OTS map... Definitely worth while speaking to a reputable shop who can advise best for your requirements and ideally will customise the tune for your car and hardware. This give the best result. Edited by TDT on Tuesday 6th April 11:58

Agreed ... I think it was David who mentioned the Cobb map option ? But all it can do is vary the fuelling and ignition if the air-pump is the same ... and there are rolling roads that will tell you whatever they are told to ... This is why the tuners love turbo's ... just turn up the pressure with an appropriate re-map and away you go ... but then lag and linearity can become issues, to mention nothing of heat soak.

TDT said: From the £70k 981 GT4 or £85k 718 GT4? thread a couple weeks ago. Engine is an air pump... intake and exhaust are the ways in which Porsche have controlled the performance of the Cayster in general and this applies to GT4 also. Headers with Sport cats are in the region of 3k. Headers are probably biggest bang for buck for HP. But there are various options... You can go for a package based on custom tune and 82mm Throttle body (IPD plenum is commonly used to facilitate the fitting of the larger TB) The standard 74mm Cayman throttle body is replaced with the 82mm unit from the 911. This helps with intake ingestion at higher revs... This can be done for c£3k fitted. So for around £6k, put headers, the 82mm TB + IPD plenum and the tune together and you can get really nice gains c40hp over stock and really nice torque pick up... which is an overall amplification and smoothing of the 981 GT4 OEM power profile. Then there are more extreme options with even larger intake manifold components... picking up in the region of 55hp over stock The power delivery with these options have a different profile signature to OEM style, and crucially now builds power with revs all the way to redline. Strong and very linear. But key point... I wouldn’t just buy an OTS map... Definitely worth while speaking to a reputable shop who can advise best for your requirements and ideally will customise the tune for your car and hardware. This give the best result. Edited by TDT on Tuesday 6th April 11:58 TDT thanks so much for taking the time and effort to write up a detailed plan of action and associated costs I think I might have to leave it standard as it still has Porsche Warranty till Jan 2023. I was hoping a simple remap would unlock maybe 20-30 HP which would be enough to change the way it drives Maybe been spoilt with turbo cars for the last 20 years as they respond so well to a good remap both for performance and drivability Instead I think I will take it to a track and invest in some professional tuition and just enjoy the thing until I can really through it around and still handle it safely. So far after owning it for 3 months I have managed to do 1000 plus pretty amazing driving miles. Last Saturday when temps hit 16 degrees plus I finally got the hang of the cup 2 tyres and I think we are becoming friends as long as you can get the heat into them as without decent temp they are quite skittery. But it could do with more power but I guess then it would be a threat to the GT3 and Porsche would not allow that Thanks to all who have helped guide me again , cheers guys

EvoSid said: TDT thanks so much for taking the time and effort to write up a detailed plan of action and associated costs No worries EvoSid said: I think I might have to leave it standard as it still has Porsche Warranty till Jan 2023. Instead I think I will take it to a track and invest in some professional tuition and just enjoy the thing until I can really through it around and still handle it safely. Absolutely do this...

Back in 2017 I fitted COBB , IPD, TBD and filters to my 981 spyder. In short it does make a difference but it isnt the way forward imo. Knowing what I do now I would fit the filters again (K&N style) with cargraphic 200cell headers and leave it at that. This will give a nice improvement with no CEL,s or downsides. I should add that the COBB on its own did make a small difference but the fuelling is off (rich) so needs further mapping and is not as driveable as stock (theres a surprise) , its not a fit and forget. Fuel trim was fighting with it. I particularly dont rate the alloy IPD or larger tbd vs the lightweight plastic original. Edited by kilarney on Wednesday 7th April 17:55

kilarney said: Back in 2017 I fitted COBB , IPD, TBD and filters to my 981 spyder. In short it does make a difference but it isnt the way forward imo. Knowing what I do now I would fit the filters again (K&N style) with cargraphic 200cell headers and leave it at that. This will give a nice improvement with no CEL,s or downsides. I should add that the COBB on its own did make a small difference but the fuelling is off (rich) so needs further mapping and is not as driveable as stock (theres a surprise) , its not a fit and forget. Fuel trim was fighting with it. I particularly dont rate the alloy IPD or larger tbd vs the lightweight plastic original. Edited by kilarney on Wednesday 7th April 17:55 Thanks for the input. Funny say about the fuelling as that was one of the issues I want to tackle via a tune. You can smell it runs way to rich When you say Headers do you mean Manifold (to us Brits) plus 200 Cell catalytic convertors ? If that is the case then maybe that coul d be avery cost effective upgrade

Yep… exhaust headers = exhaust Manifolds. Swapping out from OEM to after market will make the biggest bang for buck difference. OEM cats are 600cell i think. Pretty much solid substrate lol. Aftermaket will be 200cell and release a good chunk of power whilst still being MOT compliant once up to temp.

EvoSid said: Thanks for the input. Funny say about the fuelling as that was one of the issues I want to tackle via a tune. You can smell it runs way to rich When you say Headers do you mean Manifold (to us Brits) plus 200 Cell catalytic convertors ? If that is the case then maybe that coul d be avery cost effective upgrade Yes manifolds. Definitely the best upgrade is to fit high flow manifolds with cats and the intake filters. Leave the rest. Just watch the USA hype , lots of bull around including claims on manifolds.

Would a new manifold (Soul/Fabspeed 200 cell cat) require an ECU tune?

Royal Jelly said: Would a new manifold (Soul/Fabspeed 200 cell cat) require an ECU tune? You don’t have to... you can install this kind of sport header and should not trigger a CEL, and the car will be fine. A tune would then obviously ensure that all A/F ratios etc are correct... but if you’re adding hardware over time.. then you can just add the hardware step by step (depending on what it is) and then get a tune at the end to optimise it all together.

Royal Jelly said: Would a new manifold (Soul/Fabspeed 200 cell cat) require an ECU tune? The self learning will dial it in as non of the inputs have changed like tbd size the ECU is quite happy. Changing the tbd for a GT3 for instance confuses the ECU and it throws a code for definite, I know as I tried it. The engine really doesnt flow enough air to need a GT3 tbd which are aimed at 500 bhp, stock is fine. Factory mapping is good imo unless you mess with the inputs. Headers and filters are the easy no pain mod apart from the cost of course. More warranty friendly as no evidence you have been there unlike a flash. I know filters is normally bull but in this instance it actually made a small difference, fit in the stock housings

Thanks for taking the time to answer, both of you.. I’m considering upgrading the air filter and manifolds just to unleash some of the deliberately restricted potential. It doesn’t really need it for my use, I just think it’s going to waste. Mine is a 981CS. I’d probably take it to a tuner to be honest - just to get the mixture just so. I don’t have the appetite to do much more - radiators, plenum, throttle body etc. But by all accounts there are a few great products for the manifolds and BMC filters seem favoured. On top I may get the thicker sway bars (is it worth front & rear or just rear?) then I’ll be done.

Royal Jelly said: Thanks for taking the time to answer, both of you.. I’m considering upgrading the air filter and manifolds just to unleash some of the deliberately restricted potential. It doesn’t really need it for my use, I just think it’s going to waste. Mine is a 981CS. I’d probably take it to a tuner to be honest - just to get the mixture just so. I don’t have the appetite to do much more - radiators, plenum, throttle body etc. But by all accounts there are a few great products for the manifolds and BMC filters seem favoured. On top I may get the thicker sway bars (is it worth front & rear or just rear?) then I’ll be done. If you do go to a tuner for a map - always the best option IMO - you could give AC Speedtech in Warrington a shout (https://www.acspeedtech.com/). They're well known in the GT-R^ and Evo tuning world (obviously, tuning of these types of car is massive compared to Porkers) but used to do some great things with the 987 Caysters and I am sure have things for 981 & 718 variants too. Andy is one of the best mappers you will find, too - he can do rolling road mapping but also always does road mapping to ensure that the car runs nicely and not just all about pushing the extremes, as a RR map can - and can map the car how you want it. ^ACS built a forged engine and a hybrid-built gearbox, and installed KW V3 hybrid coilovers, exhaust system (plus other incidentals, like filters and injectors etc.) and mapping for my GT-R and I cannot recommend them highly enough. If you do contact them, tell them that Daz from Switzerland recommended you.

EvoSid said: Quick question. I did a search on modifying a 981 GT4 and was surprised how little there was on PH Most threads on this matter have had little or no posts or progress since 2016 So my question is is a COBB tune worth the hassle and cost on a GT4 without any other mods My thinking is the 981 GT4 uses a detuned 991 Carrera engine so is it possible to get a bit more power out if it by just an ECU remap? Or is the detuning done by the exhausts ? Any thoughts appreciated Fabspeeds Tune witll gain you 30+ WHP - https://www.fabspeed.com/porsche-981-cayman-gt4-ex...

EvoSid said: Quick question. I did a search on modifying a 981 GT4 and was surprised how little there was on PH Most threads on this matter have had little or no posts or progress since 2016 So my question is is a COBB tune worth the hassle and cost on a GT4 without any other mods My thinking is the 981 GT4 uses a detuned 991 Carrera engine so is it possible to get a bit more power out if it by just an ECU remap? Or is the detuning done by the exhausts ? Any thoughts appreciated Fabspeeds Tune will gain you 30+ WHP - https://www.fabspeed.com/porsche-981-cayman-gt4-ex...

Fabspeed John said: Fabspeeds Tune will gain you 30+ WHP - https://www.fabspeed.com/porsche-981-cayman-gt4-ex... Cheers is the map a generic single map or can you change between maps for fuel etc. I think the USA has a large range of RON whilst in the uk is is quite close between 95ron min to 99ron max at norma pumps, SO a map to suit the fuel would make sense

Evo9lution said: If you do go to a tuner for a map - always the best option IMO - you could give AC Speedtech in Warrington a shout (https://www.acspeedtech.com/). They're well known in the GT-R^ and Evo tuning world (obviously, tuning of these types of car is massive compared to Porkers) but used to do some great things with the 987 Caysters and I am sure have things for 981 & 718 variants too. Andy is one of the best mappers you will find, too - he can do rolling road mapping but also always does road mapping to ensure that the car runs nicely and not just all about pushing the extremes, as a RR map can - and can map the car how you want it. ^ACS built a forged engine and a hybrid-built gearbox, and installed KW V3 hybrid coilovers, exhaust system (plus other incidentals, like filters and injectors etc.) and mapping for my GT-R and I cannot recommend them highly enough. If you do contact them, tell them that Daz from Switzerland recommended you. Thanks for the heads up as I did not realise they also did Porsche mapping. I have heard good things about their EVO maps and the fact they map for the road makes the cars very drivable. I would like to map it for a certain grade of fuel and have it no so rich as it stinks

EvoSid said: Evo9lution said: If you do go to a tuner for a map - always the best option IMO - you could give AC Speedtech in Warrington a shout (https://www.acspeedtech.com/). They're well known in the GT-R^ and Evo tuning world (obviously, tuning of these types of car is massive compared to Porkers) but used to do some great things with the 987 Caysters and I am sure have things for 981 & 718 variants too. Andy is one of the best mappers you will find, too - he can do rolling road mapping but also always does road mapping to ensure that the car runs nicely and not just all about pushing the extremes, as a RR map can - and can map the car how you want it. ^ACS built a forged engine and a hybrid-built gearbox, and installed KW V3 hybrid coilovers, exhaust system (plus other incidentals, like filters and injectors etc.) and mapping for my GT-R and I cannot recommend them highly enough. If you do contact them, tell them that Daz from Switzerland recommended you. Thanks for the heads up as I did not realise they also did Porsche mapping. I have heard good things about their EVO maps and the fact they map for the road makes the cars very drivable. I would like to map it for a certain grade of fuel and have it no so rich as it stinks I'm not sure if the OEM ECU can hold multiple maps or not but if it can I am sure that you will be able to have a 99 and 95 (or 97) map without many issues. I have 102, 99, 97 & a special 99 map (which I never use) on the GT-R and that still uses the OEM ECU (mapped via ECUTek).

EvoSid said: Cheers is the map a generic single map or can you change between maps for fuel etc. I think the USA has a large range of RON whilst in the uk is is quite close between 95ron min to 99ron max at norma pumps, SO a map to suit the fuel would make sense All of our Maps are fully customizable to suit your needs! Shoot me an email for our Piston Head discount. [email removed]

Hi, Do the 200cel headers make a big difference to noise? I'd like to get the bhp gain but want to break the noise limits at UK tracks which this car is already perilously close too?

Yes. I have read that std 981 often fails sound at Brands and Bedford for example. 200 cel headers will be louder. My set up is 106-110dB static and so I run down turn pipes at UK hill climbs. Not likely to be a problem at Spa and Silverstone (my experience). I would still do it and FabSpeed or Soul sell some noise reducing tips for the GT4 to help.