LehmanZ06

Joe250, are you aware that when you turn off all traction nannies in a non GT car…….then when you trigger ABS and you’ll be doing that a lot on the track……the nannie gets reactivated somewhat.

The original poster was asking about power difference I know. But power difference on the Track. Track GT4 is a better, faster drive even if at 6,000 feet IMO.

Joe250

You make a good point. Page 190 of the 718 (non GT4/Spyder) Owner's Manual states:
"When braking in the ABS control range, the vehicle is stabilized when PSM is switched off. One-sided spinning of the wheels is prevented even when PSM is switched off."

What do those statements mean exactly?
Statement 1: "When braking in the ABS control range, the vehicle is stabilized when PSM is switched off." = When PSM is fully off, triggering ABS allows for yaw control thru different brake pressures at each wheel? So one can achieve high yaw angles (even spin out) as long as ABS hasn't been tripped, but not under hard braking?
Statement 2: "One-sided spinning of the wheels is prevented even when PSM is switched off." = When PSM is fully off, Automatic Brake Differential (ABD) and/or Anti-Slip Regulation (ASR) never really turns off? Is statement 2 only true when ABS has been tripped or is this statement not contingent on ABS engagement and is not a dependent clause for Statement 1?
And then there is Statement 3 (on page 189): "When PSM is switched off, the support provided by PSM is absent in critical driving situations outside the ABS control range." If statement 2 is referring to acceleration events, then ABS would not be triggered so does this mean Statement 2 is referring to "spinning of the wheels" as locking up one wheel under braking events only?

I think we all know at this point that Porsche is not big on really explaining what all their system actually do. Watch their PVT video clip and you'll be more ignorant than when you started. So no surprise that the manual is ambiguous/confusing. All that said, you are correct and my earlier statement was wrong. GT4's separate out PSM vs TC whereas GTS 4.0's do not. Further, "PSM Off" is actually "PSM Off unless you cross the line and then PSM is back on to some extent until things are somewhat back under control". I wish I really knew what these statements in the manual mean. If you know, please share.

And the "journalist" I was referring to was the Throttle House YT video where he turns PSM Off but then acts like PSM is fighting him. However, he doesn't say what the car is preventing. He corners hard a few times and stabs the throttle a bit without the car power oversteering. Does he just expect the car to instantly drift but PSM is preventing it? It just seems like he's too half-hearted and there's too much grip. PSM won't prevent power-on oversteer a.k.a. drifting, as there are plenty of non-GT4 718's doing just that:

or this guy: or this girl: or this guy:
So I just don't understand what his actual complaint is. More importantly, will PSM on non-GT4s hold any decent driver back on a race course? Will OP find the GT4 fantastic fun but a GTS would be a major disappointment simply due to PSM:Off vs PSM:Off*?

As for OP's original question, you (Lehman) clearly have made up your mind, but I think it is not as clear-cut. Both the GTS 2.5 or GT4 would make great track cars. On paper, the GT4 is "better" but if the budget is fixed, one could have a very similar experience in the 2.5 and have money left over for upgrades, more track days, tires and other consumables, etc. OP asked for any potential issues. With the GT4 it is the initial cost of the car. With the 2.5 it could be the heat issue/limp mode. Paying hundreds to attend and prep for a track day and then have your car go into limp mode two laps into your session is no one's idea of fun. But there are workarounds. In the end everything is a compromise so OP is going to have to consider his budget and start plugging in all the numbers in a spreadsheet until he has a car that he thinks will work better for him than the other.

Joe250

Just to throw more information into the mix, here is what Porsche says about PSM:

"...The “PSM Off” mode is activated by pressing and holding the PSM button. This is in keeping with the Porsche philosophy of allowing drivers to deactivate the control system entirely when desired. However, in “PSM Off” and “PSM Sport” mode, powerful braking in the ABS control range re-activates the full stabilising effect of the PSM system, but only until the brake is released again." (Emphasis mine)

https://presskit.porsche.de/specials...ndstrecke.html

So in PSM Off mode, while braking AND only after triggering ABS, PSM reactivates either some or all features (ASR, ABD, Steering Torque Pulse, EDC) until the brake is released. Again, since this is only during braking events I wouldn't think ASR or ABD would come into play. Sounds like this is all about yaw control while panic braking.

Sorry OP. I probably should have started a new thread with this tangent, but to bring it back to your original question and Lehman's point - will non-GT4 PSM behavior make track driving suck compared to a GT4? Although I still cannot say I fully understand exactly what PSM OFF overrides do, it doesn't seem like a deal killer to me.

pjmcgnns

I too have had both the 2.5 and 4.0 CGTS and agree 100% the 2.5 is the best value and ride especially when chipped. I had close to 480 hp in the 2.5.

ldamelio

And again - the limp mode (mostly limited to 2017 and 2018 S cars) has been definitively and inexpensively fixed.
Should not be part of the conversation in 2024.

manifold danger

I knew it. I've thought for a while now that both Thomas and James have to inject their very weirdly personal opinions on things, and there is not a small amount of bias that goes into their "reviews" as a result. It's become part of their schtick now and at times it can be charming, but I think especially recently, it's been an actual turn off for me. I think it was this traction control thing with the 718 that was the straw that broke the camel's back. He went on and on about this particular issue that I've literally never noticed in many miles of hard driving in these cars, and thought for whatever reason because he likes oversteer or whatever it was a legitimate issue. To see that actually disproven and with such a minimal effort, is a true disappointment. Possibly worthy of unsubscribe because I haven't enjoyed a TH video for quite some time, actually... and this- let's just call a spade a spade- lack of journalistic integrity genuinely irks me.

Good find. Thanks for sharing- also thanks for sharing the bit from the previous poster about his lack of clarity around his statement around ABS turning all the nannies back on again or whatever. I figured that was probably a similar story; sure it turns PSM back on during hard braking but why tf would Porsche decide to leave it on? Good to see someone actually did the due diligence to flesh out actual research with sources cited without me having to go google-diving to figure it out myself. I love when that happens.

mikedee

Ive had both. Currently in a 4.0. The Tuned 2.5 wins in my book when all comparison are not track related.