Buzzfox

12 minutes ago, daz05 said:

4.0l GTS does seem like a sweet spot all except the DPF. One of the guys did a drive past in a new gt4 before we left and the noise was pretty disappointing would go as far to say that the 3.4 was more interesting and that shouldn't be the case.

OK, time for Buzzfox's next stupid question - what is the DPF? I only know that as a diesel particulate filter but that's obviously not the case here.  

7 minutes ago, daz05 said:

You are confusing me now mate 😂

 

Rest assured I'm confusing myself far more than I'm confusing you 🤣

7 hours ago, GTSMarky said:

Nice work Daz. 

on the road my BGTS is pretty much spot on I’d say. Just back from 650 miles down into Devon with my wife for a walking, work catching up with mates trip and the car was great. Motorways and twisty Devon roads have me hitting the Sport button on and off To suit. 
At road speeds handling is very good and I’ve 20” wheels with pretty worn P Zeros on 32/33 psi.  It’s a firm ride and you know it after a while. I don’t ever use the stiffer PASM setting on the road as it’s far too hard. 
 

however on track it’s a different story and the understeer is drastic getting worse with tyre temp increasing. I keep my pressures to 32/33 and adjust as they get hotter. 
 

I think the only real fix is a geo set up and MPS4S tyres all round or Cup 2’s if they were available in the right sizes. The stiffer rear AR.bar may also help and I can see why you say what you do in the excellent summary. 
 

inside rear wheel spin on track I also get but be careful as that can also be your clutch! There isn’t really enough power to light up the rears GT3 PDK style in our boxsters and a PTV would help improve this . essentially if you push the 981 hard on track it’ll understeer badly unless you really sort the geo and even then you still have the drive/grip/PTV or nor issues which is why I have canned track days in my car now as they just ruin the car if you’re pushing on and what’s the point of a track day when you don’t push on so I ride bike track days to get my fix.  
 

I know what you mean about the understeer, mine used to understeer like crazy and it always seemed an age waiting for the front end to 'bite' before getting on the power for corner exit.

As you say the geo makes a world of difference. I took the car to Center Gravity to see if they could dial some of the understeer out but without it becoming snappy and still being great for daily driving - not much to ask eh?!!

I was sceptical that I would notice any difference but it was almost like a different car when they'd finished. Basically after initially driving it they said the rear was having too much influence in the handling leading to a fidgety front end (which I hadn't noticed until they'd fixed it!) and more understeer than necessary. 

The basic settings the car now has are: 

Front camber: -1°15'   (0°10' outside Porsche factory spec maximum tolerance)

Front total toe: 0°02'

Rear camber: -1°35' (right on the minimum Porsche factory spec)

Rear total toe: 0°12'

The car really feels great now on road and track, just need to control my right foot a bit more to stop the inside rear spinning up!

I guess with Daz's ARB change it could be even better?

18 hours ago, daz05 said:

Thanks Buzz, the purpose is to document and share experiences so glad you enjoyed. It's a great point you raise.

In answer to your question, increasing the bar stiffness should reduce traction at the rear in relation to the front. This works positively when entering a corner as the car wants to rotate quickly, and when applying power again we have less traction which again helps the car to rotate. 

However, in isolation, fitting a stiffer bar I guess in theory, is likely to make your specific problem worse.

My own experience hasn't confirmed that though, in fact, I found the stiffer bar allowed me to adjust the rear end with the throttle to get a better exit. I can turn in and dab the throttle a little to push me round moreso than before. The track guys on Rennlist suggested the X73 bar was also an improvement on track and at their X cross events they seem to enjoy over there.

To avoid the inside spinning up I would recommend you try to be smoother in applying power.

Interested to hear what the others think but I think overall you would be happy with the benefit you gain with regards to understeer.

Cheers

 

Thanks Daz, that makes sense now I think about it with less beer inside me! Would it be fair to say, very basically because I know there's a lot more science to it, that the stiffer rear bar kind of moves the balance of the car slightly more forward giving the front wheels a little more say in the handling?

Another great video @daz05which has got me thinking (which happens very rarely!).

I've just come back from a trackday. I don't do them very often so every time I do I'm amazed at epic handling of my GTS, I'm sure it gets me out of a lot more trouble than it should! The only (very tiny) fly in the ointment that I can think of is that, as I don't have an LSD, I do find the inside wheel spinning up a bit on tight corner exit. I know absolutely nothing about car set up so this might be a really stupid question but do you think a stiffer anti-roll bar would reduce the weight transfer to the outside wheel and therefore reduce the willingness of the inside to spin up resulting in better traction and acceleration out of a tight corner?

Please feel free to tell me that's a complete numpty question, I won't be offended - if you don't ask you don't know!!