So I'm guessing one of three things is going on here: (1) You forgot to post this discussion on April 1, (2) Recreational cannabis just became legal in Mauritius, or (3) One of your fellow islanders just crashed a 718 2.5 and you are circling it like a hungry vulture. Sorry, this was meant in good humor so please don't ban me from your beautiful country, I'd love to visit someday. 😀

Unfortunately I can't really offer any helpful comments other than to ask the question of "why?" If you are really unhappy with the (very adequate) power of your base Boxster, would't it be easier, safer and less expensive just to swap the entire car for a Boxster S? I don't know what the Porsche market is like in Mauritius, but in the US, the price difference difference between similar age, equipped and condition base and S models is generally in the $6,000 $9,000 range, as confirmed by a quick look at the classifieds in the latest issue of Panorama magazine.

Completely on the other end of the spectrum, I just met a veteran Porsche driver/instructor whose engine in his 991.1 GT3 blew up at 9+ years. Porsche had extended the warranty on that motor to 10 years because of design issues/problems. He got a brand new 991.2 GT3 4.0 liter engine (newer design) installed for free under warranty. The total cost of parts and labor by the dealer would have been $117,000.

Regardless of what you decide, I wish you the best in your quest. Me, I'd probably be happy tooling around with the top down at 20 mph, given scenery like this..... 👍

 

thank you for your comment, even when it's not very helpful, but still made me lough

the reason why i'm looking for a 2.5 liter engine is that i need an engine rebuild on my 2.0 liter engine, which is veeeeeeery costy on a small isolated island in the indian ocean because of crazy spare part prices.

my thoughts are, that i just buy a 2nd hand engine in europe, let it ship to here and swap it before rebuilding the old one - and by this the idea of let's go for the bigger one was born, because 2nd hand prices are equal for both engines

i'm still needing any advice on how to swap those two powerplants...

ps: and 4 sure you are still welcome in mauritius

 

For the reasons stated by Ed, I very much doubt if anyone has done this conversion-it doesn't make economic sense. Pretty substantial power gains can be realized on the 2 litre engine - check out some of the products from the forum's vendor section.

 

The S version, as well as the 2.5L engine has different front brakes, cooling system and electronic changes above and beyond the ecu: I think the PDK box software is also different.

I'd suggest importing an 2.0L engine from Europe, then rebuild your damaged engine at an even higher state of tune and then sell the imported one.

Good luck!

 

The S version, as well as the 2.5L engine has different front brakes, cooling system and electronic changes above and beyond the ecu: I think the PDK box software is also different.

I'd suggest importing an 2.0L engine from Europe, then rebuild your damaged engine at an even higher state of tune and then sell the imported one.

Good luck!

Sir, what is different on cooling? I am not disagreeing with you, simply asking what the difference in cooling system is?

I understand that if you got the GTS 2.5 or 4.0 which came standard with the Sports Design package you got a 3rd radiator but you can get that same package on 2 and 2.5 cars.

I have heard Matt Farah say that the 2.5 has more "thermal capacity" but I think he was confused by the aforementioned 2.5 GTS which comes standard with Sports Design and third radiator.

Regular Base, T and S don't come with the 3rd radiator except in you live in extremely hot climates where it is added standard.

You could make a case that running less boost would give generate less heat but that is not really thermal capacity, simply generating less heat and not really a cooling system difference.

I have downloaded lots of technical documents and don't see where there is any significant increase in cooling. Could you share what the difference in cooling system is?

Thank you sir.

Meanwhile, I did some quick checking, both cars share the same radiators, water pump and intercoolers.

These are the same Porsche OE radiators for both 2L and 2.5L motors

Porsche Radiator Kit - Genuine Porsche 9P1121251KT

Porsche Radiator Kit - Genuine Porsche 9P1121251KT

www.fcpeuro.com

This is the same Porsche OE water pump for both 2L and 2.5L motors

Porsche Engine Water Pump - Genuine Porsche 9A210604004

Porsche Engine Water Pump - Genuine Porsche 9A210604004

www.fcpeuro.com

This is the same intercooler for both 2L and 2.5 cars

2021 Porsche 718 Cayman Intercooler - 982145621B | Porsche Atlanta Perimeter - Monday-Friday 9am-5pm, Atlanta GA

Intercooler. 2021 Porsche 718 Cayman. Genuine Porsche Part - 982145621B (00004321049, 982-145-621-B, 982145621A). Ships from Porsche Atlanta Perimeter - Monday-Friday 9am-5pm, Atlanta GA

www.porscheatlantaperimeterparts.com

These are the same auto and manual transmission oil coolers for 2L and 2.5L and same as the 4.0L

2021 Porsche 718 Cayman Cooler. Oil - 9G230701700 | Porsche Atlanta Perimeter - Monday-Friday 9am-5pm, Atlanta GA

Cooler. Oil. 2021 Porsche 718 Cayman. Genuine Porsche Part - 9G230701700 (9G2-307-017-00). Ships from Porsche Atlanta Perimeter - Monday-Friday 9am-5pm, Atlanta GA

www.porscheatlantaperimeterparts.com

These are the the auxiliary radiators on the right and left sides with fans, assorted hoses and coolant reservoir, all the same for 2L and 2.5L

Porsche COOLING SYSTEM. COOLING FAN. RADIATOR. WATER PUMP.

Diagram of OEM COOLING SYSTEM. COOLING FAN. RADIATOR. WATER PUMP. Contains Radiator for COOLING SYSTEM. COOLING FAN. RADIATOR. WATER PUMP. Fits Porsche.

www.porscheatlantaperimeterparts.com

Here is a Porsche press release of similarities and differences between 2L and 2.5
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://newsroom.porsche.com/dam/jcr:86a2a46d-fa29-42ef-8480-5d50a8d9974d/PCNA18_0111_us.pdf

 

My understanding is that in some (tropical?) markets the 2.5L cars have the central radiator fitted as standard.
There is a link to a pdf document of the dealer technician training book that details amongst everything, the air, water and oil cooling systems.
I can't find it, but im. sure someone will remind us of the link.

 

My understanding is that in some (tropical?) markets the 2.5L cars have the central radiator fitted as standard.
There is a link to a pdf document of the dealer technician training book that details amongst everything, the air, water and oil cooling systems.
I can't find it, but im. sure someone will remind us of the link.

Yes I mentioned that but in those cases the 2L also gets the extra radiator as well. I have seen those in the Middle East cars. Not sure if you saw my post about that above.

Here is screenshot of 2L base Cayman from United Arab Emirates Porsche site. Both 2L and 2.5 get a standard center radiator.

Model Start | Porsche Car Configurator

cc.porsche.com

 

UPDATE:
i made a thread for the damage itself - find it here:

https://www.718forum.com/threads/718-2-0-liter-blown-engine.30660/

because people asked about my issue with the 2.0 liter engine - here my story:

engine about 35k km, tuned to stage 2 (cobb, intercooler, 3rd cooler, bigger turbo with max 2bar, exhaust manifold and exhaust etc) since about 10k km, with about 500hp on the dyno. did oil change every 2 to 3k km,

lastly (before the incident) the engine was going too rich in terms of black smoke under load / shift, but lambda was good at 0.82 and no knock when analyzing the logs. i changed the spark plugs and checked the valves, exhaust valves and plugs were all too black = rich. so i lowered the amount of fuel for ignition slightly and also cam timing.

operating in a tropical country with temperature average above 30 degree celcius and high humidity. intake manifold temperature always about 40 to 45 degrees celcius.
we have poor fuel quality with max 95 ron / 91 octane, so i always added a bottle of octane booster

incident occured going quick over hills and corners wot with full boost. after releasing the throttle there was suddenly a engine noise and the the engine felt very strange like missfires at 3k rpm after re-opening the throttle. stopped it immediate and let it get towed to the workshop.
there the guys checked the oil from the filter (see photo) and the sump. in the filter oil there are small (less than 0,5mm) metallic non magnetic particles inside. no magnetic particles in the oilsump.
the sound was mostly on the right bank (cyl 1 or 2) from the impression.
the workshop changed the oil and said that the sound is gone...
going to get further dismantled the next days to see the cause, maybe i am struggling with this longer than just the last ride. the 'missfire' issue/feeling i had some times in middle rev since months because of a non optimal tuning under certain conditions.

any comments / ideas / suggestions on the issue also very welcome

 

i have the third cooler installed, living in mauritius, tropical country with temperature average above 30 degrees, but it didn't got delivered with it

because people asked about my issue with the 2.0 liter engine - here my story:

engine about 35k km, tuned to stage 2 (cobb, intercooler, 3rd cooler, bigger turbo with max 2bar, exhaust manifold and exhaust etc) since about 10k km, with about 500hp on the dyno. did oil change every 2 to 3k km,

lastly (before the incident) the engine was going too rich in terms of black smoke under load / shift, but lambda was good at 0.82 and no knock when analyzing the logs. i changed the spark plugs and checked the valves, exhaust valves and plugs were all too black = rich. so i lowered the amount of fuel for ignition slightly and also cam timing.

operating in a tropical country with temperature average above 30 degree celcius and high humidity. intake manifold temperature always about 40 to 45 degrees celcius.
we have poor fuel quality with max 95 ron / 91 octane, so i always added a bottle of octane booster

incident occured going quick over hills and corners wot with full boost. after releasing the throttle there was suddenly a engine noise and the the engine felt very strange like missfires at 3k rpm after re-opening the throttle. stopped it immediate and let it get towed to the workshop.
there the guys checked the oil from the filter (see photo) and the sump. in the filter oil there are small (less than 0,5mm) metallic non magnetic particles inside. no magnetic particles in the oilsump.
the sound was mostly on the right bank (cyl 1 or 2) from the impression.
the workshop changed the oil and said that the sound is gone...
going to get further dismantled the next days to see the cause, maybe i am struggling with this longer than just the last ride. the 'missfire' issue/feeling i had some times in middle rev since months because of a non optimal tuning under certain conditions.

any comments / ideas / suggestions on the issue also very welcome

View attachment 71646

I think if you go to the effort of rebuilding it I agree with you, you should try to go with the 2.5. You are already playing with Tunes and mods, you might as well go for the real thing...displacement. The compression ratios are the same according to the press release. Unless I am wrong, you already have the same cooling and oiling system as the S. The standard turbo and wastegate can go up to 20lbs of boost vs 14.5 in the S. This is one concern. Porsche must have done it for a reason but if you through all of this work, you could turn the boost down a bit too. With bigger displacement, you might end up with more lag though, especially down low since the engine can take more air in but the turbo hasn't changed. On the other hand the larger displacement from the exhaust would help drive the unit sooner? That is the benefit of the variable vane unit. I still think if doing all the work of rebuilding or swapping, I think it would be an awesome mod.

 

dear all,
finally it has been done, works well and now i have time to tell the story.

first part of the story:
i blew my 2021 stock 2.0 engine in my modified 718 boxster - finally it was my fault, not respecting the requirements and making much too much boost pressure - more details about the blow engine can be found here:
blown engine details

initial, when i ordered my car, i ordered a 718 boxster gts (2.5L version) during the covid period.
after down-payment and three months awaiting, porsche UAE (responsible for the mauritius market), told me that porsche had canceled my order because of 'semiconductor shortage' without any delay or replacement available. they told me, there will be no more 718 for mauritius in the future and i can choose a stock car or buy another model, which will come.
the stock cars were all 2.0 Base Models, so i had no alternate when i wanted to stick to the 718. thanks to porsche mauritius i could find a good deal on one of the two stock vehicles, that's how i got my base model.

because it was 'base' and i wanted to have a gts, i started to look for some more power, which than ended finally in the above blow-up.

so this year in may, it became time to look for a new engine or fix the existing engine.
after short investigation after the damage, it was clear that here in mauritius nobody will be able to fix the broken engine in a serious way - there is just no workshop having tools and machines which are necessary to fix the cylinders. sending it on a round trip to europe and back costs more than a 2nd hand engine, not thinking about labor- and spare-part costs.

so i asked google, what 2nd hand engines are available. from the pricing there was almost no difference on 2nd hand engines (from wrecked cars) between the 2.0Liter and the 2.5Liter engines in europe.

after checking about the compatibility and requirements, i decided to go the GTS way - and finally make my own real GTS.

it was clear that nobody had experience with this, replacing a 2.0 by a 2.5 and keeping everything else 2.0 (no vtg, same ECU, tricky tune, PDK torque values).

luckily i had a bigger turbo (TTE465), which should be able to deliver the 25% more airvolume, which the 2.5 Engine needs over the 2.0 Engine. The only 'external' difference of the 2.5 is the bigger throttle body, everything else just fits perfect - even the cable harness is completely identical. so just bolt it to the intercooler with the bigger 2.5 Hose and the rest fit's 1:1 - many thanks for Porsches 'Baukasten'.

So after intensifying my search on 2nd hand engines, i found a dealer in poland, with whom i negotiated on a 'proper' engine with acceptable specs and also warranty.
I made the payment and got scammed immediately. He sent me an engine, but not the one i ordered - just a crap part with value of 7k EUR below the paid one

Really long wired storry, where i made a full documentary about it, but not sure if i'm allowed to link it here.

However, i was able to make the 'bad' engine run by myself and decided that i will use this engine to tune the ecu proper and buy another proper engine, which than i don't have to 'misstreat' for tuning purposes.

to be continued...

 

i checked all the faq on this forum and didn't found anything that it's not allowed to place an link to an external site. so i'm linking now my documentation of my first buy at the polish dealer, who didn't send me what i ordered or paid for - the full story of my fail of this 'first' new engine can be found here:

burz sp porsche engine deal gone wrong

 

so i had to tune the 2.0 ecu to be able to deal with the 2.5L Engine.

with the cobb accessport you are able to tune many parameters, but not all are fully understood as well as the documentation is not complete. so finally it's a lot of try and error, when you are leaving the 'simple tune' pathes.

the ecu is based on SDI21 (Siemens/Conti) architecture which is fairly similar to the VW MQB control structure, where you can find more generic information than for the Porsche.

following are the main differences for the engine ecu:

• 25% more air volume per stroke (the ecu has a volumetric model, so that's the most important part)
• different exhaust camshaft and different valve timings
• different injectors
• different knock sensitivity
• different ignition timing
• bigger throttle body so different intake-flow-rate
• different torque references
• different boost level

following the main differences compared to a standard 2.5L setup:

• non vtg turbo which is wastegate controlled in my setup
• 2.0L borgwarner k04 turbo has smaller diameter than the 2.5 vtg, so different airflow and intake-flow-rate

so it was clear, that i have to start from almost zero with all those tables necessary to make the engine run with my ecu.
this means also to 'adapt' all the reference tables of airflow, torque etc from zero.

those tables go developed by porsche engineers in for sure hundreds of hours on pure engine development setups. i just had the possibility to do it theoretically with live test than afterwards on the road.

i decided to keep it simple and use existing 'knowledge' as far as possible. so i went trough all the stock different 2.5L reference maps and looked which was 'most' compatible with my previous 2.0 maps. this than i took, to blend the reference tables between the 2.5 and the 2.0 engines together. i couldn't use the 2.5 tables 'pure', because my turbo had a different airflow than the 2.5 turbo. that's why i had to blend them together.

those tables to blend where three groups: airflow reference, torque reference and torque airflow. each of this group has sub-groups per cam/valve state (all valve lift, exhaust valve lift, intake valve lift and standard valve lift). in each of those valve subgroups you have than 16 tables for each cam angle. each table than has than 2d tables 12 x 16 with values for airflow mg/stk or nm in relation to rpm.

so it's total 3 * 4 * 16 Tables = 192 Tables per engine model, each with 12 * 16 values = 192 values = total 36,864 values per engine to blend with each other.

excel is your friend.

after this was theoretical done, the other things were simple. just use the injection parameters and the camshaft & timing from the 2.5, because there is no blending necessary - just another hardware with other parameters.

for the turbo i had no idea, because i don't have a compressor map for the borgwarner K04 nor from the modified TTE465 (which is based on the stock K04). so for the first try, i just limited the max boost level to 1.1 bar via the wastegate, that nothing can go very wrong.

first start went pretty wrong. the engine reved up at idle uncontrolled. after investigating, we found out, that burz sp (see above post) sold me an engine, which was missing a gasket for the 'stock mounted' intake manifold on one bank. this just took us one day to find and fix (not that easy in our car to remove the intake manifold when the engine is in the car).

after that it was time for first diagnosis. by this we found out, that some hydraulic valve pushers in the engine were bad as well as some compression levels and one high-pressure injector were not good with the engine.

at this time i decided to not fix this engine in deep and will just use it for the 'tune' only. fixation of the hydraulic pushers costs more than a good second hand engine - so i said to myself, just use it for tune, you got ripped of and make the best out of it.

a screenshot of one of 64 blended tables for airflow:

 

finally, today is the day, where i say, my project is finished and the car is fully operating as it should be, again.

the hardware side was easy, after i got ripped off with the wrong engine as described above, i bought a 2020 GTS wreck with very low mileage and used the engine from there. the 'bad' 2.5S engine i keep stored for 'bad' times

the software side took me really a lot of work, for sure about 200 hours of try & error till it got perfect.

the main problem was, that the accessport doesn't fully support all tables nor that all 'implemented' tables are fully understood in terms of logic flow and dependencies.

so i trapped from the beginning into the tricky DME dtc P061B which always occurred together with a PDK dtc's P1990 & P199A.
When this happened, the car immediately went into limp mode and was almost undriveable, even after restarting it.

Luckily this happened only on some specific 'race' conditions, so the car was usable, but not in every condition:
The car had to be in Sport-Plus Mode, you have had to rev above 5500 rpm with more than 25% of throttle, resulting in turbo boost, which is defined in sport-plus-mode not via the map, but with the compressor ratio, even when there is currently no overboost condition for the manifold. than releasing the throttle full to 0% Pedal value. After 0,5 to 1,5 seconds the car tried to remove the overboost in the manifold via the wastegate to make a fuel cut off. this always went wrong, without any significant reason. and exactly in this condition it shifted itself into 7th gear, rev-limited to 1500rpm and no more shift possible = undriveable.

in normal mode (=eco mode) and in sport-mode (NOT the sport-plus-mode) this problem never occurred.

i have the cobb pdk tune too, but it was not possible to change anything in the cobb torque maps on this platform, which seemed to be the reason of the error - because of different live data between engine and pdk.

by filtering the DME dtc, i could make the error 'on-the-fly' resetable, which made testing much easier without clearing all dtc's. but the PDK error still occurred, but able to reset it with a turnkey.

after about 50 different software versions and hundreds of logs, comparisons of different ecu's, analysis of thousands lines of logs etc i could solve it. it was a very complicated combination of parameters of airflow mg/stk, negative torque for the pdk, fuel-flow quantity (which is not controllable via cobb anymore, thanks to EPA regulations), intake-airflow and exhaust-airflow and some spikes in the stock 2.5 tables on the wrong place.

i managed to have a lambda 1.0 for the normal mode with a flat torque of 330nm from about 2000rpm to 7500rpm. for the sport, sport-plus and boost mode, i have up to 571nm, but also pretty flat curve, which makes the driveability great. in the stronger modes, i dropped lambda regular down to 0.84 for keeping combustion fat, cool and knock free. for the boost button, i have a torque reserve of 20nm for the sport and the normal mode. in sport-plus mode the boost button has no effect, because the plus mode is like a permanent 'boost mode'.

in sport-plus-mode i made the throttle pedal also linear, and not exponential like in the other modes. so it's really a pure form of quick and controlled driving in sport-plus-mode.

in normal mode, the car doesn't feel agile, but is very nice to cruise relaxed and needs very little fuel of about 8L per 100 km.

when you want to show off, put it in sport-mode and it immediately changes to pops & bangs and an aggressive throttle map as well as additional up to 240Nm.

when you want to go really quick, put it in sport-plus-mode and you can keep up with the big toys easily

key features:

• based on stage 1 2.5gts map
• timinig & knock tuned for 91 octane / 95 ron fuel
• vmax 310km/h (277 stock)
• eco torque limit 330nm
• sport/sport+ torque limit 571.59nm from 3500-4000 rpm
• exhaust pops only in sport (from stage 0 stock 2.5gts), none in eco & sport+
• throttle in sport+ linear, other throttles like stage 1 2.5gts
• turbo/wastegate limits: wastegate max 1.35 bar, map setpoint 1.41 bar, overpressure 1.71 bar (results in 1.45 to 1.51 bar max boost)
• knock detection from stage 0 stock 2.5gts

to reflect this also on the instrument cluster, i adapted it to my current torque-curve, too.

 

This is super impressive work! I learned a lot.

I am sure you considered using a 2.5 ecu and a VTG turbo. Why did you instead do all the tuning work to mix the components you chose?

 

Приветствую всех,

Я думаю о замене своего 2,0-литрового двигателя на 2,5-литровый.

Я думаю, что основные различия (кроме разной кубатуры) с точки зрения «деталей» и «датчиков» заключаются в турбонаддуве (у 2.5 турбонаддув с VTG) и в том, что оба распредвала управляются.

Моя идея заключалась в том, чтобы продолжать использовать мой турбокомпрессор без VTG (который уже является модернизированным), но не было никаких идей относительно управления/датчиков кулачка...

возможно, мне придется сменить ecu/dme на версию 2.5 из-за кулачков (я уже однажды менял свой ecu, чтобы он заработал с cobb accessport)...

Кто-нибудь делал что-то подобное или у кого есть идеи/предложения?


большое спасибо, любой полезный комментарий будет очень ценен
[/ЦИТИРОВАТЬ]
Привет.

 

I don't think this is great idea.
Better to trade your car in for a 2.5.

 

Why not? It's got a blown engine so its value is minimal? It sounds to me like it was a great experiment with a sh1tload of learning.
MOO & FWIW

 

Wow, that is great work. Congrats.

Mike