Diablo tyre advice and help needed | Page 2 | LamborghiniChat
News

Diablo tyre advice and help needed

Discussion in 'Lamborghini Discussion (not model specific)' started by paul328, Apr 20, 2010.

  1. Five

    Five Karting

    Jun 15, 2006
    136
    Silicon Valley, CA
    #26 Five, Apr 22, 2010
    Last edited: Apr 22, 2010
    Contact Steve at Driven Exotics via www.drivenexotics.com.

    Update: looks like my 99 Diablo Roadster has 18 inch wheels and you are looking for 17 inch tires and that might be the issue with not being able to find them (17" vs. 18") but I'm no tire expert or mechanic. I figured all Diablo Roadsters has the same wheel size but that's probably wrong.
     
  2. paul328

    paul328 Formula Junior

    May 5, 2009
    468
    Scotland UK
    Full Name:
    Paul Santoni
    Hey Guys
    thanks very much for the informed replies. I have passed these all on to my friend and he too is very gratefull for all of of your contributions.

    Nice to know that when someone needs advice that people are willing to devote their energies to helping. Lamborghini ownership is a small world, but it seems a nice one!

    Thanks again

    Paul
    Scotland
    xxx
     
  3. Five

    Five Karting

    Jun 15, 2006
    136
    Silicon Valley, CA
  4. Shamile

    Shamile Formula 3

    Dec 31, 2002
    1,522
    Lakeland FL
    Full Name:
    Shamile
    #29 Shamile, Apr 22, 2010
    Last edited by a moderator: Sep 7, 2017
    Dear Lamborghinisti,

    The issues raised by Wolfgang and the number of emails I received asking me about this had me put a call into George Evans of Evans Automotive (east coast Lambo guru) and Steve Gleaner of Driven Exotics (west coast Lambo guru )

    First the 96, 97, 97.5 VT Roadsters use 17" wheels....where the tire availably problems lie.

    The 98 and 99 VT Roadsters use 18" rims where tires are still available. If you have a 98/99...you DO NOT have this issue.

    My tires currently in use are Michelin PS'2 because I could not source Pirelli's at the time. In fact, my front PS'2's came from Driven Exotics.

    Diablo VT, 96, 97,97.5

    Front: 235/40 ZR 17

    Rear: 335/35 ZR 17

    The main issue of the VT system getting destroyed is by not using the proper tires in the matched sets. The "early" Diablo (91 -93) came with 245 size tires in front. When they went with the VT, the size was changed to 235's. You CANNOT use 245's on the VT....it will destroy the VT drive as Wolfgang indicates.

    I do not have information on the rounded sidewall vs. the straight sided sidewall of the Pirelli. I've never heard of any kind of issue from a relationship with the vehicle vs. the sidewall as it's the tire manufacturer's design style.

    As for removing the front diff, it is a completely mechanical as the viscous coupling is in the front diff...not in the transmission. ( as I have been told)

    I found the VT drive "clunky" but was willing to keep it as I drive my VT Roadster in heavy FL. rain. At the URGING of George Evans, I removed the system as HE has seen fractured bearing in the transmission and frozen front diffs. There was no talk about any ramifications to it's removal.

    I find the Diablo without the VT to be much better to match the revs, more tractable and more pleasurable to drive. BUT...you will spin the rears very easily with all the power the Diablo makes. I like to floor it and rev to redline all the time and I really have to be careful that the road surface is warm.

    I don't see how the ECU's are affected as there is NO electrical intervention in the system....it's purely mechanical with the viscous coupling sensing spinning from the rears, heating up the fluid inside the coupling and transferring progressive power to the front wheels.


    I have relayed all this to Tim at Evans automotive and is researching the issue for us. George and Mike Dillon are out till Monday.

    Steve Gleaner has not returned my call as of yet. ( ...left a detailed voice mail)

    When I find any new information....I will post it.


    Dianna (21) 6' 4" ! notices that my front tires are the proper sized 235's :D



    Shamile

    Freeze....Miami Vice !
    Image Unavailable, Please Login
     
  5. Shamile

    Shamile Formula 3

    Dec 31, 2002
    1,522
    Lakeland FL
    Full Name:
    Shamile
    Dear Lamborghinisti,

    OK....just spoke to Steve Gleaner of Driven Exotics just two minutes ago.

    He says he's never heard about the rounded sidewall vs. the squared sidewall as an ISSUE with the Diablo. We both don't like the "look" as it makes the tire look smaller.

    With the Viscous coupling....it's IN THE TRANSMISSION...not the front diff as I posted.

    BUT....Steve says the SV uses the SAME transmission as the VT except with a block off plate on the front drive shaft. The only electrical intervention in the VT system is the front diff temp sensor which goes to a warning light on the dash.....that's all.

    Steve mentioned that if you need 18" VT Roadster wheels, he has a chromed set for $5800 with tires in good condition.

    Steve has a 6.0 and has the VT system removed as well. He mentioned that he has driven thousands of miles with NO issues. He stated that he just liked the way it drove without the VT.

    Steve will look into the sidewall question...but he's scratching his head on that one.

    As Wolfgang states, it may be European law.....but I'm wondering if it may have NO technical issue on the Diablo VT system.


    Shamile

    Freeze....Miami Vice !
     
  6. Wolfgang

    Wolfgang Formula 3
    Lifetime Rossa

    Mar 8, 2003
    1,277
    Heidelberg, Germany
    Full Name:
    Wolfgang
    Hello Shamile,
    thanks for your effort.
    At least, the same result but in a fluent and understandable english :)

    I forgot to clearly point out: The problem is ONLY on VT with 17"!

    All well said and written, thanks Shamile.

    Maybe the rounded sidewalls is a european problem, but we need the approval/clearance from Lamborghini to drive another tyre beside the recommended 235/40ZR17 P Zero Asimmetrico - but we do not get this permission:
    - on tyres with rounded sidewalls
    - lower load index than 94Y on front and 106Y on the rear
    - lower speed index than +300 km/h
    - bigger sizes than 235

    Now, we try to find a tyre with exactly this specifications:
    235 / 40 ZR 17 94Y, + 300 km/h
    and at least, for a great performance, the matching tyre profile set for the rear tyres.

    We are in touch with Bridgestone.
    Bridgestone could built us a brand new set of tyres with all this specifications and could give us a permission/approval/clearance.
    Sad fact, not for this season. They will need a few months to develop, test and produce this brand new set for us.
     
  7. Five

    Five Karting

    Jun 15, 2006
    136
    Silicon Valley, CA
    You were clear in the original posts. I jumped to the conclusion it was a problem on all VTs (like mine, a '99) because I thought they all had the same wheels. Shamile had already posted that the problem could be fixed by upgrading to 18" roadster wheels but I missed that and assumed all Roadsters has the same wheels. Thanks Shamile, for the full story.
     
  8. 13MM

    13MM Rookie

    Jan 10, 2008
    23
    Thanks Shamile
    Vindicated
     
  9. Beau365

    Beau365 Rookie

    Feb 27, 2005
    3
    Congested London
    Full Name:
    Beau
  10. ONEOFEW

    ONEOFEW Karting

    Jan 19, 2006
    97
    LA
    Full Name:
    Steve
  11. Beau365

    Beau365 Rookie

    Feb 27, 2005
    3
    Congested London
    Full Name:
    Beau
    Thanks, it does indeed seem that way. God bless the French !
     
  12. Hdosanjh

    Hdosanjh Rookie

    May 15, 2019
    1
    Full Name:
    Harjit Dosanjh
    Hi guys hope someone can help please? I have a 6.0VT that has 235/35/18 tyres on front. Can I change these or does anyone know of a tyre being changed to 235/40/18 tyre instead? So 40 profile instead of 35? Thanks
     

Share This Page