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I increasingly only use the Cobb stage 1 (370bhp) in my 718 CS or even stock map in inclement weather, even though I’ve a custom tune (390 bhp). The issue is any more power than Cobb s1 and it’s hard to put down- accelerate hard and I get wheelspin, PSM light and if it’s slippery some back end fishtailing. It’s not a problem in that PSM sorts it out and avoided by being more gentle with throttle but it raises the question of what’s the point in having more power if you can’t readily deploy it.
The 911s I’ve driven don’t seem to have this issue, I guess due to more weight over the rear axle.
I don’t know the best solution. I’m considering changing Pzero N1s to Michelin PS4S (although no N rated in 19” in the UK) which might be stickier, or getting a CGTS- although unsure if that’d be any better (PTV perhaps). Maybe a heavy suitcase in the rear boot would help! Anyone else experience similar with power increases? Cheers
 

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I increasingly only use the Cobb stage 1 (370bhp) in my 718 CS or even stock map in inclement weather, even though I’ve a custom tune (390 bhp). The issue is any more power than Cobb s1 and it’s hard to put down- accelerate hard and I get wheelspin, PSM light and if it’s slippery some back end fishtailing. It’s not a problem in that PSM sorts it out and avoided by being more gentle with throttle but it raises the question of what’s the point in having more power if you can’t readily deploy it.
The 911s I’ve driven don’t seem to have this issue, I guess due to more weight over the rear axle.
I don’t know the best solution. I’m considering changing Pzero N1s to Michelin PS4S (although no N rated in 19” in the UK) which might be stickier, or getting a CGTS- although unsure if that’d be any better (PTV perhaps). Maybe a heavy suitcase in the rear boot would help! Anyone else experience similar with power increases? Cheers
I’m not a big fan of the Pzeros. Just not as confident with them
 

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Pzeros not good if you are trying to maximize performance. The grip is poor compared to other tires. Not near the same traction as say the PS4S... That is the tire I would put on your car, no question about it.

To give you an idea about traction, when going from the factory Pzero on my 718 Cayman S to Yokohama A052, there was a roughly 4-5 second difference between them on a 50 second course. Yes, the A052 is a 200 treadwear tire made for track and autocross, but 5 seconds is an eternity and the A052 are still a 200 tw tire.
 

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Thanks for your suggestions. I think I‘ll will go with tyre change.
On another note, does anyone know if the Cobb maps work with GPF equipped 718s, in the UK this is post September 2018 models
 

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Safety and HP output don't always go hand in hand. Here's what went into the Porsche program from APR, and how we're able to tune to the levels we do, knowing we're not risking the life of the engine as we may if we guessed:

 

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Thanks for your suggestions. I think I‘ll will go with tyre change.
On another note, does anyone know if the Cobb maps work with GPF equipped 718s, in the UK this is post September 2018 models
The only tuner I know offering a tune for GPF equipped 718’s is FVD Brombacher.
 

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i've had previous experience with cobb on my sleeper subaru sti that i owned some time ago for about 5 years with no issues whatsoever. i found the solution to be pretty solid for those who like to be more hands-on with modding their vehicle. the data logging was also a very cool feature and it helps in understanding what's going on with the engine a little better especially when adding or removing a part. while not the most technically advanced device, it is an easy interface to use for most people. it allows the user to see what codes come up when a CEL comes on, allows ecu resets, and (at least in the subaru's case) gave the ability to ignore some DTC codes when a mod caused a CEL. it didnt allow me skate through smog checks, but the CEL was not on all the time! i had a positive experience with cobb and would recommend it as a reliable and safe way to get most of what the engine was capable of. if you wanted to squeeze out every last drop of performance along with other mods, then pro-tuning was always an option which is nice to have. lastly, when i sold the cobb along with all the different OTS map versions, i got back about 75% of what i paid, so i dont think a return of half is the case, for this kind of mod especially, if it was kept in good to like-new condition like mine was complete with original box and all documentation.
 

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I think COBB really failed in their marketing for the Porsche products. Most folks have no idea what the potential advantages of the AccessPort over a canned tune are.

Even if you aren't custom tuning the logging is a great feature for gathering data at track days, etc..

I'll talk to COBB and see if they'll split the cost with us.. :D

Josh
I just got a Cobb with the 10% sale on thanksgiving....hoping to use that 10% towards a custom tune!

Do you have before and after a on a custom tune for a stock GTS?


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I just got a Cobb with the 10% sale on thanksgiving....hoping to use that 10% towards a custom tune!

Do you have before and after a on a custom tune for a stock GTS?


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There is a dyno chart in this thread:


It seems to be for a GTS on 91 fuel and has a dyno chart with stock, Cobb OTS and EQT Stage 1 tune. Results for the EQT tune look great and should be similar to the the APR tune. But the OTS Cobb map looks pretty ordinary with a very mild improvement IMHO.
 

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There is a dyno chart in this thread:


It seems to be for a GTS on 91 fuel and has a dyno chart with stock, Cobb OTS and EQT Stage 1 tune. Results for the EQT tune look great and should be similar to the the APR tune. But the OTS Cobb map looks pretty ordinary with a very mild improvement IMHO.
Yeah looking at that and also tracking the APR page, seems like Cobb base tune leaves alot on the table.

I may protune it after I add the mods....thinking Soul Cat replacement as a starter.

I'll post back butt Dyno once I get it....


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I’ve recently changed my custom tuned 718CS for a 718 CGTS, added Cobb S1 and switched the Pirellis to Michelin PS4Ss. I’ve not put this on the dyno yet but assuming similar gains to the last one it’s likely to have about 380bhp and 360lbft (+20 bhp and +40lbft over stock). In my eyes the car is now more or less perfect; I’ve enough power to better exploit the chassis but without running in traction issues. The car still feels absolutely glued to the road, even in the wet, whereas my custom tuned CS would start to get a bit twitchy under hard acceleration. For the time being I‘m planning to leave it alone and just enjoy!
 

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I twitch on the highway and in 1st gear....wet roads and essentially first 4 gears are useless.

Cobb base for the win!

When I get the Soul DP I'm ready for custom tuneathon.


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I had a Boxster GTS as a courtesy car yesterday, virtually identical spec to my cayman but on Pirellis and a 2020 car so has the petrol particulate filter/GPF. It was interesting to drive the two back to back. The grip of the Michelins is noticeably better, much more twitchy on Pirellis. As an aside the GPF quite dramatically strangles the exhaust- it is a lot quieter.
 

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I've recently had my 718 GTS 2.5 Cobb custom tuned and have a couple of observations that may be of interest to those considering tuning. Previously I had a 718 Cayman S which was also custom tuned with dynos posted on this forum.
First, the GTS with its larger turbo does make more power than the S when tuned. Some tuners, FVD included, are quoting the same max power for both cars though. APR cite +60 bhp over measured stock for the GTS which seems about right.
Second, whereas I had traction issues on my S, this isn't the case with the GTS. I can put the power down with impunity now. Some of this might be down to the Michelins (I had Pirellis on the S), but the rest must be the chassis- PASM, PADM, PTV etc.
My conclusions is if you want to custom tune, the GTS is the model to go for the get the most out of it. Plus has 3rd inter-cooler so shouldn't overheat or limp etc.
 

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If talking about straight line traction, I would bet the difference between the two cars is 90% +(if not 100%) the tires. The Pirellis have zero game compared to the Michelins.
 

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Plus has 3rd inter-cooler so shouldn't overheat or limp etc.
Just clarifying that the turbo intercooling on the GTS is identical to every other model, but it has a 3rd radiator which is for engine coolant cooling. As fas as I know this only makes a difference at the track. I have yet to see anyone experiencing cooling issues in road driving.... so definately worth having if tracking. If it did have better turbo intercooling, that would be fantastic as a source of extra power.

I agree with the poster above that the traction difference is most likely tyres for straight line traction. Do you have dynos of the GTS like you had for your S?
 

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We've been having some great results with custom tuning via Cobb. Especially impressive with ethanol mixes!

-- Ed
Just received Ed’s stage 2 tune.
Boost target is much higher than stage 1+ and is bonkers fun.
Ed can you share with us what the boost target is for the stage 2 tunes on GTS?


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