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upgrading to 18" rs4's but what tyre pressure

Discussion in 'A3/S3 Forum (8L Chassis)' started by jediknight, Apr 11, 2005.

  1. jediknight
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    jediknight Member

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    I have worn the tyres on my avus wheels as low as i dare and now with 3pts per bald tyre i dare not risk it anymore.

    So i am buying a set of 18" rs4 reps from Leigh tyres with 225/40/18 toyo tyres

    but what tyre pressure should i run on these??

    glen.... if you still browse the forum your input would be apreciated.
    #1
  2. Ess_Three
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    Ess_Three Active Member

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    I used to run 32F and 36R...IIRC.
    No uneven wear, much better grip, much better feel...and all with aggressive suspension angles.

    I don't know why people don't actually play with their tyre pressures...just because Audi say so, it doesn't make it great...we all play with suspension, so why not tyre pressures?
    It's free, for goodness sake!

    Bear in mind that tyre make, construction and compound affect tyre pressures, as do road surfaces, suspension set up etc...
    For example, Toyo T1-Rs like higher tyre pressures than the previous T1-Ss did
    #2
  3. nervus
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    nervus Well-Known Member

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    @ Ess_Three,

    Are Toyo T1-S' a noisy tyre at motorway speeds c.f. Michelin's etc?
    #3
  4. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]
    @ Ess_Three,

    Are Toyo T1-S' a noisy tyre at motorway speeds c.f. Michelin's etc?

    [/ QUOTE ]

    I have never found the T1-S or T1-R noisy...
    Apparently, the newer T1-R is quieter than the T1-S...but I can't tell.
    Neither is noisy to me.

    But there again, Michelin Pilot Sports aren't noisy either.
    #4
  5. PaulRS3
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    PaulRS3 Well-Known Member

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    Glen, i did dabble,, but my car didnt like less air in fronts.


    on cotswold blats (much the same as Scottish back roads i guess)

    ,coupled with 10mm Spacers/quattro GmbH suspension, it was quite easy to scuff the inner arches on the bumpy stuff.
    #5
  6. Pontio
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    Pontio Member

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    the only time my toyos seem noiser than my michelins is around corners when driving hard, they hold the road much better but are abit noisier..
    #6
  7. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]
    Glen, i did dabble,, but my car didnt like less air in fronts.


    [/ QUOTE ]

    I could believe this, depending on tyre make.
    What tyres are you running?


    [ QUOTE ]

    on cotswold blats (much the same as Scottish back roads i guess) ,coupled with 10mm Spacers/quattro GmbH suspension, it was quite easy to scuff the inner arches on the bumpy stuff.

    [/ QUOTE ]

    Odd...what offset are your wheels?
    I ran 16mm spacers, ET32 wheels (8" wide) and 25mm lowered and had no rubbing issues.

    What's your rear negative camber set at?
    Sounds like you could do with a bit more rear negative camber...

    I have never scuffed a tyre...front or rear.
    #7
  8. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]

    What's your rear negative camber set at?
    Sounds like you could do with a bit more rear negative camber...

    I have never scuffed a tyre...front or rear.

    [/ QUOTE ]

    Unless you were referring to scuffing the front inner arches?

    Again, I ran 16mm front spacers, ET32 wheels (8" wide) and lowered 25mm and NEVER scuffed a tyre...this most definately is because of the large amount of negative camber I was running...-1.55 per side approx.

    With the adjustable rear tie bars fitted to my S3, the rears WOULD have scrubbed at anything less than -0.5 rear nergative camber per side.
    #8
  9. Ess_Three
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    Ess_Three Active Member

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    Another thought Paul,
    Are you still running standard dampers?
    If so, that could explain the scuffing...it could be tyre hitting well inside the arches..again, mine didn't do this as the Bilstein dampers were stiff enough to control body movement well before any scuffing could take place.

    I can't honestly remember any scuffing before the Bilsteins were fitted though...


    Just another thought...if it turns out that the scuffing was high up in the front inner arches...I'd be wary of your sump!
    mine has no engine undertray left...and a nice chamfer on the rib around the sump plug!


    ...anyway, I digress!
    #9
  10. nervus
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    nervus Well-Known Member

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    I changed my pressures last night as suggested by Glen and felt an immediate differance. Steering has more resistance and the car reacts quicker to change especially through the slow down, speed chicanes. The car also seems to tram-line less than before but maybe all this is the product of driving GT4 for 4 hours before i went out for petrol.

    Anyway 32psi front and 36 rear works for me and the Toyo's.

    What do you rekon for the 911 Glen? i know ours are different but have the same track width ride height etc, but prob different weights.
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  11. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]
    I changed my pressures last night as suggested by Glen and felt an immediate differance. Steering has more resistance and the car reacts quicker to change especially through the slow down, speed chicanes. The car also seems to tram-line less than before but maybe all this is the product of driving GT4 for 4 hours before i went out for petrol.

    Anyway 32psi front and 36 rear works for me and the Toyo's.


    [/ QUOTE ]

    That's exactly what I'd have expected...especially on Toyos.

    It should turn in far sharper, feel more planted, with more feel...and the rear should seem to 'rotate' more on turn in.

    Pleased it works for you...

    If it's T1-Rs you are using...try going up by 2psi all round, try 34F, 38R...T1-Rs seem to like slightly higher pressures than T1-Ss did. Might be worth a go...



    [ QUOTE ]

    What do you rekon for the 911 Glen? i know ours are different but have the same track width ride height etc, but prob different weights.

    [/ QUOTE ]

    Yeah, different weights...mine's probably lower too (I have the X73 chassis pack on...20mm lower than a 'normal' C4S / Turbo) and has the lightweight wheels, which affect handling...

    None the less...I've found nothing better than standard Porsche settings just yet...but this has been on wet, winter roads, so I guess it's not surprising.

    What I did find, is that the OPC insists in pumping the tyres up too high...I let them back down to what it says on the sticker, according to my gauge and things are much better...the front pitter-patter's less, the steering has more feel, and the ride is more forgiving.

    I'll play some more in summer.
    #11
  12. jediknight
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    jediknight Member

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    glad to hear your having success with the tyre pressures on the Toyos.

    I getting my 18"s with toyos (T1-S) on friday and will try those.
    #12
  13. nervus
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    nervus Well-Known Member

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    Yeah they are T1-S's and the car feels much, much better.

    I didnt realise till i got the porsche that the OEM turbo alloys are different to the OEM turbo 'look' alloys fitted to standard C4S's. Did you know that Glen? Is that why you opted for the lightweight GT3's? It suprised me, seems like a lot of hassle to make 2 types.

    On the turbo wheels, the spokes are hollow as evident when you look at the back of the spokes, they are flat and the C4S wheels are solid and are dog legged/ re-inforced on the inside of the spoke. Didnt get a chance to weigh them as had no overlap with ownership but interesting!
    #13
  14. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]
    Yeah they are T1-S's and the car feels much, much better.


    [/ QUOTE ]

    Great stuff!!


    [ QUOTE ]

    I didnt realise till i got the porsche that the OEM turbo alloys are different to the OEM turbo 'look' alloys fitted to standard C4S's. Did you know that Glen?


    [/ QUOTE ]

    That is the case on the 993 Turbo.

    I'm sure the part numbers for 996 TT and 4S were the same once the C4S got the 11" wide rears.
    I will check though...

    Definately the case for 993 though...

    As far as I am aware, the only hollow spoke 18" wheels available for the 996 are the 'Sport Techno' (I think that's what they are called) - the ones with the geometric swept back spokes - available as a £1322 option on Turbo or C4S.

    The fact that the upgrade price is the same for TT or C4S adds weight to this...

    As does the fact that the upgrade price to go to GT3 type wheels is the same for TT and C4S.

    ...all this despite what one of this months magazines has printed!

    I may be wrong though...


    [ QUOTE ]

    Is that why you opted for the lightweight GT3's? It suprised me, seems like a lot of hassle to make 2 types.


    [/ QUOTE ]

    I wanted GT3 wheels as they are the lightest available from Porsche, and I prefer the design.


    [ QUOTE ]

    On the turbo wheels, the spokes are hollow as evident when you look at the back of the spokes, they are flat and the C4S wheels are solid and are dog legged/ re-inforced on the inside of the spoke. Didnt get a chance to weigh them as had no overlap with ownership but interesting!

    [/ QUOTE ]

    As above...I thought this was for 993 TT and C4S...
    I'll check PET though...
    #14
  15. nervus
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    nervus Well-Known Member

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    Glen, they are definately different between my 4S and TT, ill post a pic to show you.

    My 4S was an 02 and im sure they were 11" ??? maybe not. maybe they were 10's and thats why they differ, but the tyres are same size???. Ill be interested to see what you find out as im thinking the TT hollow ones have got to be lighter than the solid design ones.

    One thing's for sure, those 3pc kahns are going, im checking into bling re-hab.
    #15
  16. PaulRS3
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    PaulRS3 Well-Known Member

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    [ QUOTE ]
    [ QUOTE ]
    Glen, i did dabble,, but my car didnt like less air in fronts.


    [/ QUOTE ]

    tyre make.
    What tyres are you running?

    I could believe this, depending on
    [ QUOTE ]

    on cotswold blats (much the same as Scottish back roads i guess) ,coupled with 10mm Spacers/quattro GmbH suspension, it was quite easy to scuff the inner arches on the bumpy stuff.

    [/ QUOTE ]

    Odd...what offset are your wheels?
    I ran 16mm spacers, ET32 wheels (8" wide) and 25mm lowered and had no rubbing issues.

    What's your rear negative camber set at?
    Sounds like you could do with a bit more rear negative camber...

    I have never scuffed a tyre...front or rear.

    [/ QUOTE ]


    sorry just catching up. so ill try and answer in short...

    Was referring to occasional catching of inner arch liners on the front only on bumpy stuff, when running 32 PSI (by accident not intentional in fronts)

    solved by returning to 36 PSI.

    Offset OEM RSTT's ET33

    + 10mm spacers to clear porkers.

    Tyres were Ver.1 Mitchelin Pilot Sports, now GY Eagle F1

    Cambers as it left factory. never set it.


    Dampers same as Factory fitted Optional Quattro Gmbh kit.
    #16
  17. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]
    Glen, they are definately different between my 4S and TT, ill post a pic to show you.


    [/ QUOTE ]

    Lets put this to bed, even though it is well off topic!

    The article in this months PCGB magazine - 'Post'- is regarding the 993 'Turbo Look' wheels...and the differences between the hollow spoke 'Turbo' wheels and the non hollow spoke C4S versions.
    This is 993 specific, and is printed in the 993 Register section.


    I spent some time reading through the official Porsche parts system (PET) disc last night, which is current for 2005 (includes 997 etc)

    On the 996, the Turbo wheels are referred to as 'Turbo Look 2' in order to differentiate them from the 993 style 'Turbo Look' wheels.

    2004 996 Turbo wheels have a bright silver finish (Arctic Silver) and have option code 416.
    They are:
    Front - 8" x 18", ET50, P/No 996 362 136 02
    Rear - 11" x 18", ET45, P/No 996 362 142 02

    2004 C4S wheels have a bright silver finish (Arctic Silver) and also have option code 416.
    They are also:
    Front - 8" x 18", ET50, P/No 996 362 136 02
    Rear - 11" x 18", ET45, P/No 996 362 142 02

    Same wheels....

    Earlier C4S wheels (up to 2004) had the same front wheels, but a 10" wide rear. These appear to be option code 415.
    These were 10" x 18", ET47.

    The Turbo rears have always been 11" wide (from what I can see)...but the finish (and hence the last two digits of the part number) have changed.


    To add weight to this:
    Listed under the 'Wheel Sets' section is this:
    Wheel Set for 2004 Turbo/C4S
    000 044 600 88

    Again...both cars share the same front and rear wheels...on 2004 and later cars.



    Then there's these from the Tequipment range:
    2004- GT3 Style wheels for Turbo/C4S
    Bright silver finish (Arctic Silver)
    Front - 8" x 18", ET50
    Rear - 11" x 18", ET63
    ...there's also a 'Spacer Kit' listed for use on the rear of this wheel kit. Presumably, this is the GT3 Style set I have...I'll have to check for spacers!



    The difference between your current 'Turbo Look 2's and your previous 'Turbo Look 2's must have been the difference between 10" wide and 11" wider rears...and possibly the silver finish.


    ...I know...I'm sad. I can live with that! /ubbthreads/images/graemlins/grin.gif
    #17
  18. jojo
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    jojo S3 Drift King! Staff Member Moderator

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    I think I've been driving FWD cars for waaaaaaay too long, I've got the illusion that the rear tyre pressures have to be lower than the fronts for some stupid reason or another!? Just tried 36F and 38R on my 19s, can't believe the amount of understeer that's been reduced, can push the car through a series of turns with much higher speed - amazing - gonna give 34F and 36R a try on another night /ubbthreads/images/graemlins/grin.gif
    I can only dream how Ess-Three's ex-S3 can take corners!, thanks for the insight Glen /ubbthreads/images/graemlins/beerchug.gif
    #18
  19. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]
    Just tried 36F and 38R on my 19s, can't believe the amount of understeer that's been reduced, can push the car through a series of turns with much higher speed - amazing


    [/ QUOTE ]

    I'm pleased it works for you...
    You'll get at least the same gain by pulling the bottom balljoints outward to add some negative camber! (not as cheap as playing with tyre pressures though!)


    [ QUOTE ]

    gonna give 34F and 36R a try on another night /ubbthreads/images/graemlins/grin.gif


    [/ QUOTE ]

    Try also 34F, 38R...
    That would be my starting point on 19s.

    On 19" wheels, 34F may prove to be a little too soft...so you may also want to try 36F and 39R, or maybe 40R.

    Set the pressures cold...try to use the same roads for testing, try to keep weather conditions similar...and don't be afraid to experiment.
    Just make a note of what 'feels' best...and keep returning to that.

    With tyre pressures, this is one of the few instances where the 'feel' IS the major factor...if it 'feels' right, you will have more confidence, and hence will carry more corner speed.

    After establishing a set of good baseline settings, the next step, should you decide to go onwards, is to optimise camber, castor, toe etc and juggle the tyre pressures to get even tyre temperatures accross the tread...but this takes time...



    [ QUOTE ]

    I can only dream how Ess-Three's ex-S3 can take corners!, thanks for the insight Glen /ubbthreads/images/graemlins/beerchug.gif

    [/ QUOTE ]

    My pleasure...

    The S3 went well...and generated massive corner grip....just ask Imola S3!
    #19
  20. nervus
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    nervus Well-Known Member

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    [ QUOTE ]
    [ QUOTE ]
    Glen, they are definately different between my 4S and TT, ill post a pic to show you.


    [/ QUOTE ]

    Lets put this to bed, even though it is well off topic!

    The article in this months PCGB magazine - 'Post'- is regarding the 993 'Turbo Look' wheels...and the differences between the hollow spoke 'Turbo' wheels and the non hollow spoke C4S versions.
    This is 993 specific, and is printed in the 993 Register section.


    I spent some time reading through the official Porsche parts system (PET) disc last night, which is current for 2005 (includes 997 etc)

    On the 996, the Turbo wheels are referred to as 'Turbo Look 2' in order to differentiate them from the 993 style 'Turbo Look' wheels.

    2004 996 Turbo wheels have a bright silver finish (Arctic Silver) and have option code 416.
    They are:
    Front - 8" x 18", ET50, P/No 996 362 136 02
    Rear - 11" x 18", ET45, P/No 996 362 142 02

    2004 C4S wheels have a bright silver finish (Arctic Silver) and also have option code 416.
    They are also:
    Front - 8" x 18", ET50, P/No 996 362 136 02
    Rear - 11" x 18", ET45, P/No 996 362 142 02

    Same wheels....

    Earlier C4S wheels (up to 2004) had the same front wheels, but a 10" wide rear. These appear to be option code 415.
    These were 10" x 18", ET47.

    The Turbo rears have always been 11" wide (from what I can see)...but the finish (and hence the last two digits of the part number) have changed.


    To add weight to this:
    Listed under the 'Wheel Sets' section is this:
    Wheel Set for 2004 Turbo/C4S
    000 044 600 88

    Again...both cars share the same front and rear wheels...on 2004 and later cars.



    Then there's these from the Tequipment range:
    2004- GT3 Style wheels for Turbo/C4S
    Bright silver finish (Arctic Silver)
    Front - 8" x 18", ET50
    Rear - 11" x 18", ET63
    ...there's also a 'Spacer Kit' listed for use on the rear of this wheel kit. Presumably, this is the GT3 Style set I have...I'll have to check for spacers!



    The difference between your current 'Turbo Look 2's and your previous 'Turbo Look 2's must have been the difference between 10" wide and 11" wider rears...and possibly the silver finish.


    ...I know...I'm sad. I can live with that! /ubbthreads/images/graemlins/grin.gif

    [/ QUOTE ]


    Thats not sad, spending 6 hours washing a car then trying to go the long way home to possibly avoid the rain is sad! /ubbthreads/images/graemlins/grin.gif

    My rear wheels on the 4S must have been 10's then. What threw me was that the rear tyres are the same size on the TT and my ex 4S.

    I haven't seen the magazine artile on the 993's, i think ill have a look anyway.

    Back on topic,
    Glad you seen the benefit too jojo, id just always assumed tyre pressures would not make much difference.
    #20
  21. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]

    Thats not sad, spending 6 hours washing a car then trying to go the long way home to possibly avoid the rain is sad! /ubbthreads/images/graemlins/grin.gif


    [/ QUOTE ]

    This is true...

    ...it also takes you longer to wash your car...I can do mine in 4 hours!


    [ QUOTE ]

    My rear wheels on the 4S must have been 10's then. What threw me was that the rear tyres are the same size on the TT and my ex 4S.


    [/ QUOTE ]

    Yup, that's confirmed by PET...same rears for all year C4Ss.
    #21
  22. jediknight
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    jediknight Member

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    do tyres need a few days to wear in before they start giving good grip??

    got my T1-S tyres on my and got 32F and 36R psi but feels a little 'fluid' in some corners?? would feel too happy pushing it hard just yet ..... or maybe i just need to adjust to the feel now i have bigger wheels??
    #22
  23. nervus
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    nervus Well-Known Member

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    Yeah, i think so jedi. It takes a few miles to knock the corners off a bit.

    Do you find an annoying ressonance noise bang on 70mph? Just like a low frequenc drone?

    I find this with my new toyos, which isn't there with the michelins. i've swapped back and forth and is defo only present with new wheels/tyres.
    #23
  24. jediknight
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    jediknight Member

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    no there just as quiet as my old pilot sports.

    i'll take it for a proper spin at the weekend see if they are any better by then
    #24
  25. dickys3
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    dickys3 Moderator Staff Member Moderator

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    couple of hundred miles should do it!
    #25
  26. solihul
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    solihul Member

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    Hi, I'm new to the forum, I've got an Audi S3 facelift model and have recently fitted a set of 18" RS4 wheels with 225/40/18 Continental conatct sport 2 tyres. Originally i put all 4 tyres on 36 psi but found the ride really hard. I've put the fronts on 34 and the ride has become softer but the rear still seems very hard. Does anyone else have conti's on their car who can suggest some trye pressures for me.

    I haven't used any spacers, when the wheels are on full lock they are very close to the inner arches. will I need spacers or will the wheels be fine.

    Best Regards
    #26
  27. imported_velcrobix
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    imported_velcrobix Guest

    You don't have to have spacers with 18" alloys and 40 profile tyres. It will be fine without them.

    As for ride quality - it will be more harsh with 18's on than with 17's.
    I run 34 at the front and 36 at the rear.
    #27
  28. dickys3
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    dickys3 Moderator Staff Member Moderator

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    Hi Solihul, its Richard - we spoke the other day on the phone!

    Glad you found your way here!

    As said above, you don't need spacers. The 18's will make the ride slightly harder as you have lowered the profile of the tyre and stiffened the side walls.
    #28

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