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Engine braking -- good or bad ?

Discussion in 'Other Racing' started by BritBlaster, Oct 11, 2007.

  1. BritBlaster

    BritBlaster F1 Rookie
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    Jul 25, 2005
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    Paul
    I've always been given the advice by racing instructors that using the engine for braking is not a good idea. I expressed some of my opinions about this when someone mentioned that they found it essential to use engine-braking to assist in stopping (an F599 with CCBs) from high speed.

    I invite knowledgeable people to chime in with opinions in the thread here: (link to pg6 where the relevant part of the discussion commences)
    http://www.ferrarichat.com/forum/showthread.php?p=137114104#post137114104
     
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  3. 62 250 GTO

    62 250 GTO F1 Veteran

    Jan 9, 2004
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    It helps to shave time from laps and it makes a glorious sound!

    Just don't **** it up too badly, then it can get costly.
     
  4. SRT Mike

    SRT Mike Two Time F1 World Champ

    Oct 31, 2003
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    There is only one thing that slows a car down - the tires. If a car has a large amount of engine braking, it's still the tires that's stopping it. If you get (just pulling numbers from the air) 0.25g's of engine braking, and the tires can support 1g of total grip, then if you apply anything more than 0.75g's of brake pedal, you will lose traction. Many people don't think this - they think engine braking is over and above what the tires and brakes can give them, but this is not so. It's ALL the tires, no exceptions.

    I find engine braking to be not a good thing. I prefer to have complete control over how much braking is being applied and when. An engine with little engine braking usually also has a lighter rotating mass, which makes it spin easier and is easier for downshifts as well.

    So I'd agree that engine braking is always sub-optimal. Unless of course your brakes are toast and you gotta stop somehow :)

    Downshifting is what makes revving/deceleration sounds, different thing from engine braking. Regardless of whether a motor has a lot of EB effect or not, a driver should always be downshifting to maintain the power gear when driving - always.
     
  5. maxorido

    maxorido Formula 3

    Jul 6, 2006
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    Jim
    From my experience running single seaters, it's better just to threshold brake. When you engine brake, you're not stopping the car as efficiently as you could.
     
  6. Dr.T348

    Dr.T348 Formula 3

    Jan 8, 2004
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    Richard T.
    Engine braking is something for old race cars with drum brakes and large semi trucks. Any modern sports car, race car, or Ferrari has more than enough brakes to slow the car down.

    Down shifting is used to get right gear to accelerate out of the turn, not for slowing the car down.
     
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  8. EnzymaticRacer

    EnzymaticRacer F1 Veteran

    Feb 27, 2005
    5,225
    as has been said... you can only slow down as fast as the tire traction will allow.

    Also, if the clutch is engaged under braking, you are using braking power to slow the revolution of the engine, not the rotation of the tires. This means you have to use more pressure on the brakes to slow the car, putting more heat into the brakes, wearing them out more quickly, and increasing the risk of rotor warping/cracking... not to mention overheating the brake fluid and having to deal with brake fade.
     
  9. Bavarian Motorist

    Bavarian Motorist Formula Junior

    Apr 10, 2007
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    Mike
    I always thought of it this way...


    Wear on engine, or wear on brakes? You decide.


    Of course, that's for people who want to use it on the streets when approaching stop lights. I'd never.
     
  10. Remy Zero

    Remy Zero Two Time F1 World Champ

    Apr 26, 2005
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    engine braking costs more stress to the engine than normal braking costs to the brakes. which would you be willing to replace? in most car races, it's ok to do engine braking...cos the sponsors replace your engine after that :D
     
  11. Kami

    Kami Formula Junior

    Nov 28, 2006
    652
    St. Louis
    I live by the motto: Brakes are easier to replace than an engine........ And I'm sticking to that :D
     
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  13. DGS

    DGS Four Time F1 World Champ

    May 27, 2003
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    The only purpose in letting the tires push the engine, on a RWD, would be as an ad-hoc brake balance adjustment. Most stock brakes are biased toward the fronts. On pavement, this has extremely limited usefulness, as you want the engine revs matched before turning.

    On dirt, it can sometimes be useful, if you're sliding the turn anyway. (Drifting?)

    But the handbrake gives you finer control, and lets you match revs normally for exiting the turn.
     
  14. b-mak

    b-mak F1 Veteran

    Paul, your instructors are correct. You use the brakes to slow the car on the track. They more efficient and effective in slowing the car, but also less expensive to replace than engines.
     
  15. BritBlaster

    BritBlaster F1 Rookie
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    Thanks guys -- I'm always amazed by the vast wealth of knowledge on this forum, and the willingness with which it shared ... (once, of course, the wheat is separated from the chaff LOL)
     
  16. PSk

    PSk F1 World Champ

    Nov 20, 2002
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    Pete
    This is the correct answer.

    Modern brakes are powerful enough not to need the deccelation help from the engine ... or if they aren't a modification is required.
    Pete
     
  17. dretceterini

    dretceterini F1 Veteran

    Apr 28, 2004
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    Dr.Stuart Schaller
    I have been racing small displacement sedans, coupes, and spiders (750 to 1600cc) for 40 years. I have always used SOME engine braking! About 5 yards before the start of a corner, I double clutch and go down to the gear needed....usually from 4th or 5th to 2nd or 3rd; sometimes (rarely) 1st.

    I WANT to get the back end SLIGHTLY loose, and use mostly the front brakes rather than all 4 brakes to slow the car, and in essence, stand the car SLIGHTLY on it's nose. I then accelerate ALL THE WAY THROUGH THE CORNER, rather than just from the apex out.

    I am about 2-3% quicker in lap times than if I don't use some engine braking!

    How this would work in big bore, heavier cars or higher level cars such as GT2 or F2 I really have no idea nor any real experience..
     
  18. F&M racing

    F&M racing Formula Junior

    Feb 26, 2006
    665
    Michigan
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    JimF
    Race cars - minimum eng. brake meaning being in the correct gear for exiting the corner, let the brakes do the work. I drove Formula Fords for years and we now own a Formula FF2000 I retired driving and my friend drives now and this is how we do it.

    Semi Trucks yes engine brake, Street cars NO.

    Jim
     

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