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Steffen_Leitgeb-LSWGmbh

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Posts posted by Steffen_Leitgeb-LSWGmbh

  1. Thanks for the concerns:

    tires:
    Michelin PS4s on the Leitspeeds (2017)
    Pirelli Corsas Lotus Original (2015)
    So basically the Pirelli as a Semislick should have more grip … in theory. Was stored well, never overheated on track, road use only.

    tire grip:
    tire grip was taken out of the calculation by the driving profile chosen - accel. from 2.500 rpm IPS car in 2nd gear. Because it was not needed to show impressive values, it was necessary to drive like a dyno run. 
    This produced only low acceleration and repeatable g figures, I posted them as average in the graph.
    Max 0.44 g longtitudinal peak accel. is really very low today and every tire can cope with that to my experience in vehicle testing business
    The biggest G increase was when applying full throttle at 2.500 rpm where the rate of change was 0,29 g / 0,5s - which is low too.
    Can´t be seen in the graph, sorry.
    Please check the g-long graph and you can see a very linear power supply which is typical for a supercharged engine and perfect for tires.  
    (I supply Racelogic VBOX Motorsports products to German industry, racing and automotive media, so I have some insight in these testing procedures).

    road grip:
    At the same place where I am measuring regularly private cars I can reach a negative g-force of -1.1 g with the Evora and then ABS kicks in.
    Road was clean as I had checked before.

    warming and rear tire pressures according to the Lotus manual:
    Pirelli: 2.6 bars rear
    Michelin: 2.2 bars rear

    I drove the car before measuring both times approx. 7 km country road to warm engine, gearbox and tires evenly.

    Testruns:
    each wheel set was driven 4 times, incl. changing direction 2 times to even out track influences or wind influences, track is 100% flat
    the runs were averaged and the delta of 0.14 is the also averaged delta

    Later this day I will give you the total weight of Lotus Forged Original with Pirellis and the Leitspeeds with the Michelin PS4s.


    Is such a small difference really important?:
    On a winding road or track day or even on an Autobahn competition with a Porsche or Audi RS this small advantage adds up massively.
    So it no longer stays a single 0.1 s. 

    Lightweight wheels make you quicker everywhere (except Vmax) without big technical changes or a change of drivestyle and you save tires, shocks and bushings too. 
    The Evora gets simply more alive. Makes much more fun to drive.
    Looks are a different point of view. Not the topic here.


     

     

    • Like 1
  2. 1 hour ago, KAS-118 said:

    Hmmm...to be fair I think @mik solution looks reasonable - albeit not as nice as your Diamond Cut ones @Steffen_Leitgeb-LSWGmbh 

    I would agree that if the cost isn't a concern then yours are certainly the way to go - not least because of the massive weight saving 🙂

    Big weight saving is always heavy on the budget. Just check Lotus` spec lists for the Exige V6 410 or Evora 410 f.ex.
    And wheel weight reduction really works perfectly well.
    So first it is performance. Second is fashion.

     

     

    • Like 1
  3. That lightweight wheels have a big effect for the speed and safety of race cars is well known - that´s why in most racing there is a reglement which limits materials and forces a minimum weight.
    It is not known to many that the reduction of rotational mass means basically more hp at the wheel if it comes to positive acceleration.
    This is what I wanted to show here:

     

    Acceleration test shootout today 🙂
    Leitspeed LSL01 vs Lotus Original Forged of Lotus Evora S.
    delta in kg: 9,6 in favour of the LSL01

    Testing result averaged over 4 test runs each:
    LSL01: 5,07 s
    Lotus Original: 5,21 s
    delta: 0,14 s 50 - 120 km/h 
    same outside conditions

    Procedure:
    Lotus Evora S IPS, standard engine, Komo Tec headers, K&N filter
    run start in 2nd gear @2.500 full throttle, 50-120 km/h (no aero involved, starting from very low rpm just like on the dyno, staying in one single gear)
    4 testing samples each to minimise driver and measuring errors but there were none in the files.

    See the screenshot of the data analysis graph.
    Measuring tool Racelogic VBOX Sport 20 Hz GPS

    The delta in acceleration performance will be there on every acceleration area (positive and negative) on track and road. So lightweight wheels do make a difference even on straight line performance.

    Testergebnis_1 Kopie.jpg

    IMG_7303.jpg

    IMG_7325.jpg

    • Like 1
  4. HRE is a US wheel manufacturer. The machine only. It means they must buy the forged material because they can not forge themselves.
    HRE is famous for cool design. No racing products. It is mainly bling bling but some designs are very lightweight too.
    Laptime is just one of their German dealers which normally concentrates on BMW tuning.
    Any HRE dealer in UK should be able to sell these wheels too. 

    Set price of these HREs for the Exige V6 is above 8.000.- EUR incl. tax. to my knowledge. 
    I think this is slightly out of the normal Exige V6 club, right?

    What do you think of my suggestion above? Are lightweight wheels interesting for the Exige V6 cars at all?

    If yes, what is more appreciated?

    Slighly less weight, same price, better looks
    or
    much less weight, better looks, but higher price
    than the Lotus forged original?

    The HRE performance can be done of course by us too - but just not at a small budget. 


    In general I have the feeling the big performance improvement of lightweight wheels is not fully understood in the Lotus world yet because in the past there was no realistic offer for Evora and V6 Exiges but I might be wrong … 

     

  5. Hi,

    after having finished the Evora wheels I am checking the Exige V6 now. (check www.leitspeed-wheels.de)
    What would you consider a good deal for forged alloys for the Exige V6 models?

    A) Same size (17"/18") and slightly less weight (- 3 kg per set) like Lotus factory forged but optically different and more classy looks - at the same price like Lotus factory forged as an upgrade mostly for Exiges with casted wheels

    or

    B) Same size but less weight (- 6 kg per set) and more modern racing looks - at a price of approx. 1.000 EUR more than factory forged for an upgrade for all kinds of V6 Exiges

    Remember lightweight wheels (rotational mass and unsprung weight) are a major improvement for any sports car.
    The Lotus factory wheels are really good but there is still potential left for those who are really into lightweight technology and who want to get the best out of their cars.

    Any thoughts on that? 

    • Like 2
  6. The first reason why I ever looked into making a wheel for the Evora was the unsatisfying surface of my Evora S forged wheels. Both sets 18/19 for winter use and 19/20 for summer were no longer acceptable after 4 years of use.
    For two reasons: a) by design of the wheel, it has sharp edges where the coating thickness was not okay and b) the base coating was wrong or too thin or simply missing (!) so at my 19/20 the wheel colouring simply peeled of and fell off.
    For the same design reasons the 19/20 of Evora S are not really "stable" on the final colouring of the DC wheel and the DC seemed to be a design afterthought here too.
    These wheels are really fine when getting a professional powder coating. 

    Just after being disappointed with the wheels surface I was checking weight and found also big improvement possible.
    My focus was weight reduction and surface improvement over the basic Lotus wheels. 

    The surface of DC wheels is down to the forging pressure, raw material and wheel design.
    Our wheels for all Evora types are designed that DC can work longer because it was not an afterthought.
    If you use 8.000 ton forging the material is normally so packed that a material corrosion is not so big like with casted wheels. 
    If the clear coating material and the spoke design are alright the clear coating does not allow that salt or humidity gets underneath at the edges unless the surface is damaged by impact(s).

    Our surface treatments in my partners factory:

    - inspection and hand cleaning of the raw machined wheel to round off sharp edges 
    - pea shooting whole wheel to make the right surface for further coloring
    - powder base coating 
    - first colouring layer
    (optional DC treatment with slow processing speeds, in case of of the LS01 the wheel has a thicker design to have it cut off more material)
    - final coating

    This treatment is a little different to classic (forged) racing wheels which are not protected so well because they are consumables anyway.

    As we would be able to also do forged magnesium wheels with German TÜV license (already a prototype was corrosion tested out of curiosity and the test was passed successfully) this surface treatment looks alright to me.

    In general in Germany (for German cars Mercedes, BMW, Audi, Porsche) DC is a basic design for many many casted and forged wheels. There is no huge quality problem known to me at the moment even with casted wheels which are indeed not so good for DC like forged alloys.

     
    But in any case the DC wheel is not a wheel for track use and it should be driven more carefully than non DC wheels.
    And corrosion level after a damage is also influenced of the area driven - coastal areas with a lot of salt in humid air are always more critical than others. 
    I would expect in UK DC is more critical than in Arizona for example. But of course I keep fingers crossed that DC customers do not run on very bad roads where stones or gravel will impact the last clear coat layer heavily 😉




     
     
     

    • Like 1

  7. I would never do a DC treatment of none DC designed wheels.
    But I suspect the beefy original forged Lotus wheels can be okay 😉 

    Upper class forged wheels which will get a DC treatment are normally milled thicker first so that they do not get "under measured" after the additional DC milling … at least this is how I have decided to have produced my Leitspeed wheels for the Evora. With that technique you can cut off slightly more material and get a nice mirrored surface and the static of the wheel is fully unchanged which is most important for lightweight wheels.
    Check Infos here: www.leitspeed-wheels.de

     

    IMG_5568.JPG

    • Like 2
  8. As I know normally all professional press cars are prepared in very detail to meet sport auto testing procedure - if they are not prepared they fail badly or are outperformed by those who do. 
    I expect Lotus simply did not do it, or took it not really seriously or the car was even simply borrowed from a dealer who was not up to the task and hoped for good results against the other cars.
    All prepared press cars use special camber settings to work at the difficult Hockenheim short circuit. 

    Lotus should invest in a special preparation for their press cars and that is all and they are set at the front if the driver can handle it.

    F.ex. the German press cars are selected from the factory, rebuild and adjusted for the special test of magazine or TV.
    If it is for speed: Tire sets may be selected or prepared even. Geo is for grip and not life time or safety. Car is made more lightweight. Engines are slightly more powerful, auto gearboxes shift quicker, brakes are bedded in perfectly and the test was run at the factories testing areas secretly beforehand to know the potential results.
    I have worked with German press car divisions and I know the huge efforts which are taken here.
    I even came across a German sports sedan once having an aluminium roof instead of a steel version which was used in serial production 😉 
    The car manufacturers are giving their best - including smallest cheating and as all are doing this it is really no problem.
    But Lotus might not be able due to cost savings?

    Apart of that: if the magazine´s lap time on a track is your only "currency" of sports cars to find the right performance/price relation you must rely more on a journalists information than your own feeling inside a car.
    I learned long ago this is like watching porn, fake boobs and all - just second hand, you are not in it yourself and this not your personal reality. And forget about objective press judgements. I am in the automotive business far too long … 


     

    • Like 2
  9. Evora 430 is "GT country". High performance and small quantity production.
    I simply guessed approx. 4.800 GBP price inc. VAT.
    Glad that I am not bad with such guessings.
    Compared to the new sales price for the car it is okay even.

    What is the delta to 410/400 discs?

    If you really want to cry go to Porsche for a serious 911 parts shopping and service or repair costs outside warranty. Don`t even think about the 911 Turbo S or PCCB brakes which are basically crap and ruinious when driving on track 😉
    BMW M4 or Audi S4 steel brakes are not really cheap too and they are produced in real big quantities compared to any Evora part.
     

  10. On ‎28‎/‎07‎/‎2018 at 11:56, Bravo73 said:

    These are the only sizes that Avon make their ZZR tyres in. (ie the same setup as the Lotus Cup cars). 

    These are my track/winter wheels. 

    I see. Good info.

    Is the wheel in the Lotus cup regulated somehow? Would it be possible to use a different and more lightweight racing wheel in 18" for the Evora?

    I understand the Evora race cars in the Cup are not fully identical with the GT4 cars. In GT4 there is a strict wheel regulation (minimum weight) and only the special wheels which have been homologated by Lotus at the FIA are allowed. 

  11. Good addition. Interesting.

    But why did you go for 18" front and rear?
    Clearly the rotational mass is better as the rim is more centered.
    But according to magazine tests and also Michelin statements grooved tires (even Cup 2) do need a stiff wheel system (tire+wheel) for best handling and traction.
    That is why I never took 18/19 into consideration while development after the Michelin discussions.
    It is completely different with slick tires, here the whole system can use more flexibility to put more rubber on the road under dynamic pressure.

    Does anyone else drive BC Forged? 19/20? 

     

  12. 16 hours ago, AK70 said:

    @Steffen_Leitgeb-LSWGmbh Well done! That is an achievement in weight reduction.

    I have an 2012 S, so roughly calculated the reduction is (4.4+5.2)*6 = 57.6KG felt reduction... if you estimate  a 1:6 factor to be applied when the car is moving and that weight becomes mass...  Think one can feel a difference 😉

     

     

    Yes. Exactly. Thank you. Perfect. My old car has changed really. The Evora S is now really quick and steers even better. 

    If has one has an Evora 400 and compares a full titanium exhaust with lightweight wheels (approx same cost of 5k and approx the same reduction of 5,5 kg) the wheels are the more clever investment because the weight reduction counts several times: it is reduction of 
    - unsprung mass -> better comfort, better tire grip, less wear
    - rotational mass -> better acceleration and deceleration, better cornering
    - total mass -> better of everything according to Chapman

    Wheel weight reduction is the most easy and best solution to optimise even a Lotus.
    Not really cheap but highly effective.

    The exhaust´s weight reduction f. ex. counts once into total mass and as it is also located near the center of gravity of the total car you don´t feel a real difference in handling. 
    But even if lightweight wheels are technically sound … they still do not sound as good as a titanium exhaust! 😉

    Now there is a new opportunity für Evora drivers to decide here.
    Why don´t take both and have a much better car afterwards?





     

  13. I have all the basic wheel weights - just this special 410 is missing.
    The 430 is not of big interest for me as it is a simple design and very cost effective on the production and therefore not ideally lightweight.
    Front and rear and size is 19x8 and 20x10,5 rear which makes the rear really heavy compared to standard.

    wheel/rim weights in kg:
    Evora (S) Lotus original forged 19x8 and 20x9,5
    Front 10,15 measured
    Rear 12,1 measured

    Evora 400 original forged 19x8 and 20x9,5
    Front 9,5 said, 9,5 measured 
    Rear 10,5 said, 11,1 measured

    Evora 410 Lotus super lite forged 19x8 and 20x9,5
    Front ???
    Rear ???
    These do not accept all Evora max loads, Lotus will sell only to certified owners of Evora 410 two seater I was told by Lotus in 2017.

    Our Leitspeeds are 19x8 and 20x9,5
    Front 7,95 @ 380 kg max load homologated*
    Rear 9,5 @ 600 kg max load homologated*

    *German TÜV tested and homologated for use on German streets
    TÜV accepts the wheel for all Evora S, 400, 410 Sport, 430 GTS, 410GT max loads with downforce
    - except the 430 two seater in Germany only - but the wheel withstands higher loads so outside of Germany the GT 430 can use the Leitspeeds too - and there it is a huge difference in handling.
    The max downforce is in area wich you might reach on the German Autobahn but not on a racetrack. Not even the Nordschleife long straight.
     

     

    As I have all the exact weights for the Michelin different tires  and TPMS valves I am happy if someone can simple measure a Evora 410 front and rear wheel.
     


     

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