My 718 GT4 - geo update this morning

[Twinfan]

For anyone who's interested, I had the geo adjusted on my 718 GT4 today. It wasn't a million miles out but it's had a slight tweak.

From the factory:

front camber -1:21 and -1:37 with -0:02 and 0:04 toe
rear camber -1:29 and -1:28 and toe 0:06 and 0:11

Typical Porsche factory tolerances really, only the toe was a bit off. I've not adjusted the ride height or the ARBs as my car is not currently tracked and the best we could get without changing any parts is:

After adjustment:

front camber -1:24 and -1:37 with 0:04 total toe
rear camber -1:29 and -1:28 and 0:24 total toe

Speaking to the guys at my place, I've ordered some shims to get more camber on the front of my car but the rear will be left alone. I'm going back next Thursday morning for fitting and we're aiming for -2:15 to -2:30 on the front which should give nice sharply balanced handling for road use while retaining the stock settings for ARBs and ride height.

I think it's a bit odd that my 981 GTS could get -2:00 on the rear out of the box but the GT4 only 1:30 but there you go!

[LennyM1984]

Are there no camber adjustments on the GT4 at the top mounts/rear eccentrics (do they even have rear eccentrics on the coffin arms??)?

It looks like the only change was the toe.

[Twinfan]

Yep there are adjustments, but they were maxed out from the factory on my car...

[Twinfan]

I like a sharp handling car, hence going for more at the front.

They could have reduced the right front to match the front left but as I'm going back in a week to have the shims fitted there was no point.

[BertBert]

I don't know very much, but why does more camber give sharper handling?

[Twinfan]

Sorry, I'm not great at language! By sharper handling I mean enhancing the feel of the car in corners with regards to grip. I like the feel of a car with a decent amount of camber, I'm not looking to set the faster lap times around Silverstone.

Some info here from a quick Google:

https://www.turnology.com/tech-stories/brakes-susp...

[LennyM1984]

Porsche911R said:

My Cayman R with much softer sus then the 718 GT4 ran -1.6 degree and I did not run out of camber on the road !!

I'm putting Cayman R suspension on my 987 at some point next year (it is sat in the shed with many other "to dos" which I am currently too busy to entertain doing) and am thinking of running -1.5 (1 degree, 30 minutes) all round (i have adjustability on the front, and will get adjustable toe links for the rear). Did you try yours on track? Was -1.6 sufficient with road tyres (I do maybe 5-6 track days per year and wouldn't do stickier tyres justice even if I had some).

[Porsche911R]

LennyM1984 said:

I'm putting Cayman R suspension on my 987 at some point next year (it is sat in the shed with many other "to dos" which I am currently too busy to entertain doing) and am thinking of running -1.5 (1 degree, 30 minutes) all round (i have adjustability on the front, and will get adjustable toe links for the rear). Did you try yours on track? Was -1.6 sufficient with road tyres (I do maybe 5-6 track days per year and wouldn't do stickier tyres justice even if I had some).

no good on track, I run -2.2 front -2 rear on my Spyder for track, it's a road car now and need taking back to -1.8 ish.

Edited by Porsche911R on Thursday 2nd July 17:25

[Twinfan]

I had a chat with the place and explained how I use the car. I'm going to go with their recommendation over some random bloke on the internet

The point of this post was to explan how far the car will go as standard for those who are intereested. As I already suspected, but it was confirmed by checking Porsche part numbers, the suspension hardware is exactly the same both front and rear across both 981 and 982 GT4 versions.

[Andy OH]

I'm with 911R here. I do think 2.5 degrees (2 degrees 30 minutes) is rather aggressive for primarily road use.

Edited by Andy OH on Thursday 2nd July 17:58

[TDT]

Twinfan said:

As I already suspected, but it was confirmed by checking Porsche part numbers, the suspension hardware is exactly the same both front and rear across both 981 and 982 GT4 versions.

I’ve been saying this since launch.

My fast road geo from Centre Gravity in 2018 was around -2° 15 0” front, slight toe out, -1° 39 0” rear with 0°24’ toe in and that was with adjustable toe links fitted.. and shims.

2° 15 0” is about 2.25 decimal degrees and 1° 39 0” is about 1.65 decimal degrees

That’s based on a brief of fast road and 5 trackdays. Obviously I quickly started doing many more TDS and needed to move up after that based upon wear and chalk tests

So going to 2.5 dec degrees going to be a fair bit of compromise for what is going to be a road car only for you by your own words.

But it’s up to you.

Edited by TDT on Thursday 2nd July 19:37

[Twinfan]

It's more of a feel thing for me, plus I'm thinking of taking my car on track in the future so it's a combination of things. I can always change it back anyway Plus it's not a daily driver.

By the way, if your car is where I think it is at the moment TDT you're running -3.5 now at the front? That's punchy. Plus your engine mods should be superb

[Twinfan]

Nope. I have nothing to prove, nor am I trying to do so. Why does everything have to be a competition and an argument with you?

I'm still waiting for your apology regarding the steering column stitching by the way.

I just thought I'd try and give some information back to the forum. I won't bother in future.

[TDT]

Twinfan said:

It's more of a feel thing for me, plus I'm thinking of taking my car on track in the future so it's a combination of things. I can always change it back anyway Plus it's not a daily driver.

By the way, if your car is where I think it is at the moment TDT you're running -3.5 now at the front? That's punchy. Plus your engine mods should be superb

Around -3.2 Decimal Deg at the front at the last reading in March, with a very balanced rear.
Very good through corners on track, just bites them. Such a great platform.
Probably could, and might knock it back a bit though will see after testing.

[arcamalpha]

Twinfan said:

For anyone who's interested, I had the geo adjusted on my 718 GT4 today. It wasn't a million miles out but it's had a slight tweak.

From the factory:

front camber -1:21 and -1:37 with -0:02 and 0:04 toe
rear camber -1:29 and -1:28 and toe 0:06 and 0:11

Typical Porsche factory tolerances really, only the toe was a bit off. I've not adjusted the ride height or the ARBs as my car is not currently tracked and the best we could get without changing any parts is:

After adjustment:

front camber -1:24 and -1:37 with 0:04 total toe
rear camber -1:29 and -1:28 and 0:24 total toe

Speaking to the guys at my place, I've ordered some shims to get more camber on the front of my car but the rear will be left alone. I'm going back next Thursday morning for fitting and we're aiming for -2:15 to -2:30 on the front which should give nice sharply balanced handling for road use while retaining the stock settings for ARBs and ride height.

I think it's a bit odd that my 981 GTS could get -2:00 on the rear out of the box but the GT4 only 1:30 but there you go!

Thanks for sharing. Interesting to see (even if just to compare against others from the factory). I'll be interested to hear your feedback both now and after further camber adjustments.

[Twinfan]

TDT said:

Around -3.2 Decimal Deg at the front at the last reading in March, with a very balanced rear.
Very good through corners on track, just bites them. Such a great platform.
Probably could, and might knock it back a bit though will see after testing.

[Twinfan]

arcamalpha said:

Thanks for sharing. Interesting to see (even if just to compare against others from the factory). I'll be interested to hear your feedback both now and after further camber adjustments.

Cheers. If you're a PCGB member, Ralph has posted his settings over there on a thread he has running about his GT4

[TDT]

Twinfan said:

I’ve just twigged, btw.

[Twinfan]

TDT said:

I’ve just twigged, btw.

Thought you hadn't quite yet

[gt3rswp]

I’m booked into COG for fast road occasional track.