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  1. #1
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    REVIEW: Alpina aerodynamics package (front + rear spoiler) / Alpina_B3_Lux

    Hello fellow Bimmerboost members,

    A few of you may know me from "the other forum" and it has been some time since I've been on this one here as well. As I'm not much in favour of the policy (the word comes from "police" I guess...) of E90post and more precisely at its way of handling conflicts (mostly by inflicting bans on members who have posted lots of useful information), I have also decided some time ago to join Bimmerboost.

    Some of you may know the reviews I've written so far, and I would like to make them available to Bimmerboost as well - together with some new ones and updates to the existing reviews. The present article is therefor one among several threads that I will be posting individually (to make them easier to find without having to wade through many posts in one thread).

    Almost all of these are performance oriented, and I will therefor post most of them in the N54 sub-section. @Sticky: If you think one or the other is better placed elsewhere, just move it there please.

    But enough of the preamble, here we go.

    ---

    Aerodynamic optimisation – ALPINA aerodynamics package

    Why?

    The faster you go, the more aerodynamic forces affect your car. Basically, until around 100 km/h that’s not so important as there are other resistances that are more noticeable. But if you approach or surpass 200 km/h, the downpressure applied to your car decreases as does the contact to the road, thus inviting instability if sudden manoeuvers are necessary or the road condition worsens. That’s by the way one of the major tricks of Ferrari’s 599 as it has a completely optimised undercarriage, which results in an almost unbelievable stability even at speeds exceeding 300 km/h; the same goes for other super cars like the Apollo Gumpert for example. Now, obviously we can’t go that far with the 335i, but ALPINA has at least brought out an aerodynamics package consisting of front and rear spoilers that helps keeping the car “sucked” to the road at higher speeds. It has been developed in their wind tunnel and optimised for the B3 S Biturbo which is more or less identical to the 335i and has an official top speed of 300 km/h. As it would be possible for me to drive at such speeds in Germany, I wanted to keep that experience as safe as possible (certainly a tad schizophrenic, but you get the idea).

    I got additional confidence from a test of the Alpina B3 Biturbo (E92) on which the German sports car magazine "sport auto" did one of their famous "supertests" in the issue 12/2008 which includes a lap on the Nürburgring, on the Hockenheimring and aerodynamic testing in a wind tunnel (among other things). You can read a summary (in German) of this test under the following link: Sport Auto: Alpina B3 Biturbo Coupé im Supertest - M3-Alternative. Although my car is not an E92 but an E90, I would assume that the two (identical) spoilers have a comparable effect on my car.

    The magazine wrote the following about the spoilers:
    "The B3 Coupé enters the test with substantially improved aerodynamics compared to the stock 335i - at least as far as lift is concerned. The lift on the front and rear axle has been minimized: On the front axle there is only 12kg and on the rear axle only 13kg of lift (i.e. the force by which the relevant axle is relieved). However, the air drag coefficient has slightly increased: 0,29 instead of 0,28 as with the stock 335i. This however has no influence on the impressive directional stability or the wind noise which is on a very low level here. The respectable maximum speed of 285 km/h is the result of a powerful engine and elaborate aerodynamics..

    • Vehicle frontal surface: 2.140 m²
    • Air drag coefficient: 0.29
    • Air resistance index: 0.63
    • Front axle: 12 kg lift
    • Rear axle: 13 kg lift


    How?

    Before picking up my car when I bought it back in 2009, I had everything painted and installed at ALPINA in Buchloe directly, also because a local BMW dealer gave me an insulting price quote – the install would have been more expensive than the price of the whole package, including installation, at ALPINA (which was around 1200 EUR). It was, as could be expected, done perfectly, everything fits just as if the car had been born like this. The rear spoiler is in fact glued onto the boot (which is why you have to wait one day for the glue to dry properly before driving again), while the front spoiler is attached with screws.

    Both spoilers can (and should) be registered with the TÜV if your car is registered in Germany, which is no problem at all as ALPINA provides you with the necessary certificate for that procedure. By the way, that certificate says that the front spoiler is only approved for up to 290 km/h…I believe that may not be enough!

    If you consider acquiring this package, go to your local ALPINA dealer or contact ALPINA directly, they are always very helpful (go to this link and contact the guys listed under “Export”). The (Alpina!) part no. for these Alpina pieces for an E90 LCI are as follows:

    • front spoiler: 41 00 420
    • rear spoiler: 41 00 364 (can only be ordered together with the front spoiler)



    Improvements?

    I do not have any way of comparing various aerodynamics kits, obviously, but I do trust in the R&D skills of the ALPINA engineers and also the above mentioned test in the German car magazine. I have since been driving at very high speeds (i.e. in excess of 250 km/h on unlimited German motorways) quite often, and it does not feel uncomfortable. As the car magazine wrote, the directional stability is very good, and at these speeds (I've gone up to 310 on the speedo) I'm far more afraid of other drivers than of what the car might do - and I do believe it’s a combination of the tires and the spoilers that at least contributes to that.

    Another advantage: The looks. OK, that’s subjective again and I know some people that don’t like spoilers at all, anywhere on their car. But I find the ALPINA ones quite discreet (see photos below) and think they give the car a more sporty look.

    ALPINA front spoiler:
    Click here to enlarge

    ALPINA rear spoiler:
    Click here to enlarge


    Problems / disadvantages?

    The only disadvantage - as with all front spoilers - is that if your car is lowered, it can make unwanted contact with a curb. This happened to me lots of times when I still had my Bilstein B16 RC coilover installed, which had the car far too low for my taste. With my current Öhlins suspension however, this does not happen.

    Alpina_B3_Lux
    Current: Audi R8 V10 2013 S-Tronic, daytona grey, carbon side blades, MTM tune, Michelin PSS tires, Capristo x-pipe
    Gone: Audi R8 V10 2010 manual, ice silver, grey side blades, MTM tune, MTM air filters, Michelin PSS tires
    Gone: BMW 335i Individual (Öhlins, PFC brakes, RB turbos etc.)

    Gone: Alpina B3 E46 3,3

  2. #2
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    Always enjoyed reading your reviews. Thanks for sharing. Much respect for purchasing aero parts that have actually been tested to provide an advantage.
    2011 E90 M3 \ Melbourne Rot Metallic

    Click here to enlarge

  3. #3
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    Moved to 3-Series E9X.

  4. #4
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    Yes Reputation No
    Click here to enlarge Originally Posted by Alpina_B3_Lux Click here to enlarge
    The magazine wrote the following about the spoilers:
    "The B3 Coupé enters the test with substantially improved aerodynamics compared to the stock 335i - at least as far as lift is concerned. The lift on the front and rear axle has been minimized: On the front axle there is only 12kg and on the rear axle only 13kg of lift (i.e. the force by which the relevant axle is relieved). However, the air drag coefficient has slightly increased: 0,29 instead of 0,28 as with the stock 335i. This however has no influence on the impressive directional stability or the wind noise which is on a very low level here. The respectable maximum speed of 285 km/h is the result of a powerful engine and elaborate aerodynamics..

    • Vehicle frontal surface: 2.140 m²
    • Air drag coefficient: 0.29
    • Air resistance index: 0.63
    • Front axle: 12 kg lift
    • Rear axle: 13 kg lift

    For 335i coupe stock e92:


    • Vehicle frontal surface: 2.120 m²
    • Air drag coefficient: 0.28
    • Air resistance index: 0.59
    • Front axle: 42 kg lift
    • Rear axle: 28 kg lift



    I don't know the sedan e90 figures.

    We are not talking about big differences in my opinion. These are measured at 200km/h, so that below that the figures are smaller, and above they are higher. In my opinion in the speed the car becomes nicely balanced into 50%-50% when it has somewhat more lift in the front. But as said, thinking about the total weights for either axle, these figures are quite small and no big deal IMO. The cd value difference looks to be 0.1, but looking at the air resistance index differences, they have just rounded the cd-figures into two decimals, but the difference might be around 0.015 or so. Again, not a big deal, but the value of lower cd could be easily as much as the value of the small difference in lift...

    I repeat, these values are for stock e92, whereas the kit should be compared against the stock 335i e90 figures, that we do not have.

  5. #5
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    I think the figures for the E90 will be almost identical.

    i disagree however with saying that the kit does not make a big difference. The figures for the lift at the front and rear axle are significantly different - 30kg less lift in the front is a substantial difference, for example.
    Current: Audi R8 V10 2013 S-Tronic, daytona grey, carbon side blades, MTM tune, Michelin PSS tires, Capristo x-pipe
    Gone: Audi R8 V10 2010 manual, ice silver, grey side blades, MTM tune, MTM air filters, Michelin PSS tires
    Gone: BMW 335i Individual (Öhlins, PFC brakes, RB turbos etc.)

    Gone: Alpina B3 E46 3,3

  6. #6
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    Click here to enlarge Originally Posted by Alpina_B3_Lux Click here to enlarge
    I think the figures for the E90 will be almost identical.

    i disagree however with saying that the kit does not make a big difference. The figures for the lift at the front and rear axle are significantly different - 30kg less lift in the front is a substantial difference, for example.
    In the big picture the front axle weight could be e.g. around 840kg and the rear axle around 800kg depending on the individual 335i. I believe that with having 30kg more lift in front, BMW has just balanced the 51%-49% stationary weight distribution into 50-50% when the car is in speed. I.e. the car in speed has around 800kg in both axles.

    When it comes to potential benefits of having more weight in the front, I believe you are thinking about lateral grip. However, the lateral grip does not increase in direct relation to the weight in a tire, instead, it has diminishing returns. 30kg in the front axle, i.e. 15kg per wheel weight is close to meaningless in lateral grip in my opinion.

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