Tyre pressures

[Carrera2RS]

Anyone run different to standard. My tank cap says 2.6Bar, just under 38psi. This seems a lot, I noticed that my wheels are currently 32 all round, so I will add a few more psi, but they do already feel a little 'hard' I was kind of hoping I might be able to lose a few psi.

My car is a Pirelli with 8x18 TD's fitted.

[stealthwolf]

The tyre pressures can and should be varied to suit the conditions.

I when I took my car in for its first service, I had them set at 37psi. When I drove home, the steering felt very heavy and the car wasn't as nimble. The dealers had dropped them down to 32psi. I promptly stuck them back up to 37psi and the car was fine.

Use trial and error to find what suits you but remember tyre wear will vary according to the pressures.

[Richn83]

Whats your tyre width, if your running 8" wide wheels I assume it might be wider than the standard 225 tyres on all the GTI's and this will affect the pressure you need to run.

I run 2.65 on my fronts and full load pressure on the rears 2.9 bar its possibly a little hard but I prefer that to soft and wobbly and can feel when one of the rears gets low.  Before anyone asks I run the full load pressure even when the boots empty saves having to change it when I load the boot up or take on extra passengers and I would rather run higher pressure than too low a pressure.

[the bruce]

The pressure you need depends on:

- load index: '88' needs more than '92'
- weight of the car front + rear
- speed: Vmax needs more than country
- camber: extreme camber > more pressure needed
- driving style/preferences: GTI > more lively rear > same pressure front + rear

Have a look at the recommended pressure of A3/Golf 2.0 TDI. These have the
same weight as GTI.
Recommendations are lower !! One reason ist the lower speed. Then these
recommendations are different front + rear. I guess 2.2 and 2.0 bar.

The pressures will be a good fit for a GTI as well. But then you should not
run 250 km/h.
Now you know why VW recommends higher pressures for the ED30, which
is not heavier but just faster.

I'm not a friend of rising pressures to make the car feel stiffer. This reduces
the contact area and so reduces grip.
So it's clear that a GTI is faster in corners than a ED30. 

It's a main mistake to put too much pressure on the tyres. 

[keano]

Will 35psi be okay front and rear?

The only extra weight in the car is a slightly chubby driver 

[the bruce]

32 - 34 psi cold will be best for street use.
If on track with stiffer tyres some use 30 psi warm.

[Carrera2RS]

I am running 36 F&R warm, I will try dropping a PSI. This was better than 32 cold.

My set up is Nuespeed 25mmF and R bars, soft front, hard rear. Ride heights 335F 320R with Bilstein PSS9 3F, 4R, WALK, TD 8x18's I am still experimenting, this is good but not great. I want better turn in and it still feels slightly front heavy, good balance in corner. Good compliance but a little fidgety. I am a fussy bugger with suspension settings and feel.

Wondering about camber plates. I am running 0.5 degree neg camber at the front, probably need 1-1.5 ? its 1.5 neg at the rear.

[the bruce]

Just 0.5° (= 0°30'), are you sure ???
With a height of 335 mm front a Golf normaly has about 1° negative.

If 0.5° - hat's less than good. First try setting the FARB on 'hard' as well.
I know the often told advice, but I made some experiences against the
''old rules''.
Even much better you fit TT lower arms for more camber.
You'll get 1°30 - 2°00' with them.


ps:
320 mm rear is quite low. Be careful when cornering hard if you hit a bump
- some oversteer may occur (when the damper touches the bump stop).

[Carrera2RS]

Bruce, I do agree with the camber.

The four wheel alignment figs suggest -0.5 deg. the front is down some 25mm, the back 40mm. I am thinking of running 340/325, the 15mm difference puts the sill closer to flat and less nose down. I prefer the balance and feel with a full tank which is some 3-4mm lower at the rear. Drive out of a filling station after putting 50L in and it feel more planted and neutral (I know there is some 40kg added in the right place !).

WIth prior cars I have found more feel with toe at 0 deg, or less toe in than stock (This is for rear wheel drive through) and 1.5 deg of neg. 2+ and it becomes too camber sensitive and you get the impressiont that the contact patch is wandering over surfaces. I am unfamiliar with front wheel drive.

I also feel that the car is off on the corners (it hasnt been corner weighted), it 'feels' like the front right and rear left is taking more of the weight with how it folds into corners.

I was also wondering what the target caster might be with a WALK and if fitting top mounts and adding a little more positive might help feel and weight to the steering.

I think you are right with the front ARB it feels as though the chassis has to pick up a little slack as it turnsn and loads up at the front, if it dials in a little more understeer when loaded I get the impression on the road the better turn and placement will outweigh any ultimate balance issues and improve the feel and drive.

Are TT bottom arms expensive new ? Or easy to find secondhand ?

I am also thinking that a big brake kit to improve the braking and unsprung weight could be a worthwhile investment. Are the TT arms more about camber and less about unsprung or both ?

[the bruce]

TT arms are about 3 kg each, so same as (non adjustable) S3 arms and similar to the steel tin ones the smaller Golfs have.
Cast steel arms of most GTI and R32 are double the weight. The swivels do even more in weight.

TT and S3 arms are forged aluminium alloy. TT and S3 swivels are aluminum as well, but made in an innovative processs called ''Cobapress''.

One more advantage of the TT- and S3 arms is the stiffer rear bush (no matter if you swap for a WALK instead).
But the big difference of the TT arms is camber adjustability !!

Similar camber front and rear is absolutely necessary to get neutral cornering.

[Carrera2RS]

Are these the ones ?