i thought the forum and its members could benefit from a discussion regarding brake boosting. i suspect everyone is aware of the positives associated in doing it, as having instant spool is a great advantage over someone who doesn’t and is forced to wait for the turbo etc.
the negatives however, are what i’ve always been curious about… and what usually causes me to be hesitant when i want to use the double edged sword that is brake-boosting. =p
certainly the negative impact bb’ing has on your car depends on the drivetrain, however to what extent is where the controversy begins ( for me at least ). i’ve talked to a fair amount of people with different opinions… some say that it really has no negative effect at all on the car ( other than wearing the brakes ). others say the differentials get screwed, and others say the entire drivetrain is getting burnt causing a total system meltdown! :mamoru:
I suspect in an AWD car, the negative impact of BB’ing would be the greatest, but what about doing so in a FWD or RWD?
What is everyone’s opinions on BBing? Who does it all day everyday, and who uses it sparringly?
I think we all could benefit from discussing it a bit further, if for no other reason than to clarify some technical aspects of it.
I dont know… I guess I really see no reason to do it if you have a turbo setup properly for your application. Plus, having the boost threshold makes wheelspin less of a problem off the line (in a 2wd application more so).
I guess try it at the track… see if ya get any gains from doing it.
I know that if I had a 4wd vehicle, I wouldnt do it personally… with that much traction your bound to break something in the drive train… just a matter of when.
When you are matching speeds with the other car right before you go, you might be at 20 percent throttle, and building little boost. Woudln’t you want to be closer to wot so that your turbo is really working for ya as you begin to race? It’s similar to left-foot braking, keeping your rev’s up but slowing your car down at the same time, with the brakes, so that an sti who is under full load doesn’t pull an evo starting at partial throttle by a bunch of car lengths
if you and i pace each other at 40mph for 1/8th of a mile, our turbos will no longer be spinning because they are no longer necessary to attain the speed we wanted. basically the turbo is helping the engine get to a speed faster than it could on its own. so once youve attained the speed, the turbo doesnt spool.
if you are going from a roll and pace without brake boosting, your turbo needs to spool basically from low psi. this is why its advantageous to brakeboost, because you are consistently spooling, and as soon as you let off the brake the turbo is already at 50-75% of its max psi.
i’m talking about both bb’ing from a stop and a roll btw
I brake boost all day long… every red light, everytime i need to pass someone. It is such a neccessity!
:lolham:
I would assume no one is going to brake boost unless they are racing… so the all day everyday is kind of obvious.
I really do not see how it is so damaging, it is not any different than driving up a very steep hill (aside from wear to your brake pads) in terms of wear on your drivetrain. Yea it is not the best for it, but it is not that big of a deal :shrug:
especially if u have a newer car…i cant see it hurting too much besides wearing out brakes…drivetrain damage on awd the most yes…but only if u have a LOT of power and do it often…i would assume doing it on a stock gsx/tsi wont do anything …the only stock vehicle i see it harming (if it is done often ) is an sti with pretty sticky tires…my opinion in general is…if it is a car u plan on driving everyday…dont do anything u are unsure about
No i certainly understand why it is worse for an AWD car, however I really do not think it is that bad that it is of much concern… yes it is added stress, but so is racing at a drag strip or autocross.
not that bad on the car, it’s already underway, sounds like the only things really taking a beating are pads and clutch/converter and even then it’s not a very high load in comparison to a standing launch.
There is no way that an AWD car is going to break loose from a 40 mph roll WHILE brake boosting ever, the only reason a rwd car would is because it has power to only two wheels, basically no different than power brakeing from a stop. You do that in an AWD car and the car will just slowly move forwards. pending different %'s of power to front and back wheels, which i do not know what EVO’s or STI’s %'s are… of course if it is like 30% front and 70% rear, while highly unlikely, with enough power it is possible for the rears to spin.
thanks, this is actually what i guess i am trying to say.
