How to brake boost?
Oooh street racing on the freeways I see!!
People still do that?
EDIT: The tennessee video is BOSS.. and that's the stock e-brake?!? Also You say its OK to do that with the car but what happens with the AWD system when you do? In the STi when you pull the E-brake it disengages the lock on the center diff which is why it is safe to do on it instead of the WRX which is a basic viscous center that fries easily.
People still do that?

EDIT: The tennessee video is BOSS.. and that's the stock e-brake?!? Also You say its OK to do that with the car but what happens with the AWD system when you do? In the STi when you pull the E-brake it disengages the lock on the center diff which is why it is safe to do on it instead of the WRX which is a basic viscous center that fries easily.
This is out of the owners guide under the ACD section.
Note: If the parking brake lever is pulled up while the vehicle is moving, the center differential is designed to switch to a free state condition which will allow the rear wheel to lock easier.
Seems a waste to me for a straight line, I agree with Rob, get in the right gear. Trail braking is a bit different though, feather the brake while on the gas on a sweeping exit to bring the rear around can help keep you on the cam (and boost) while managing grip through track out. It's an a necessary art if you want to be competitive and staying in boost is just one of the benefits.
I can promise you, unequivocally, that this never happens when on a road racetrack when driving in a straight line. Not on the racetrack? Who cares? They can have it, there's nothing to win.

Brake boosting comes from the Rally world, when the cars had a big turbo allowed to race, and they had a big lag which comes with it. The one of the main reason for Left Foot Braking started, to try to keep the boost up when the RPM dropped when you were better of to not down shift, and up shift at some turn combinations. So in other words you don't need or not beneficial in time wise for a turn combination a head to down shift before the turn and up shift when you come out.
But with LFB ( knowingly the first user of this technique was Walter Rohl ) you also kept the car in better power state, and let you go at the Apex to exit without shifting also but faster then others. Keep in mind this happens out of the optimal HP /RPM range. In 10-20 mile stages , this technique actually can add up for seconds vs the none LFB. at end of the stage. Never mind the end of the entire rally. That was before the ECU got advanced to over come the turbo lag .
Today ECU's can have an Anti Lag System in the car to help prevent that issue. And it is funny how the ALS doesn't help in rolling start... I know I had both set up in my car.

The ALS effect starts fading out over 4800-5000 rpm in my car and the HP /RPM effect starts ruling.
Also other good effect were to keep the car balanced and planted, which is not a subject of this conversation. But worth to mention how the LFB beneficial in more segments in the racing .
When you argue on this , take out your Dyno sheet and see which RPM your engine has more TQ and more HP. If you are in the range there the TQ is a king when you getting ready to jump that is the ONLY range you need a boost really. The other half where the HP rules you don't need a turbo peak boost, never mind a fact on stock turbo your peak boost is at a lower rpm anyway. so when you start racing against someone at a rolling speed and he is at a healthy range on his HP rpm vs yours boosted (let say he is willing to wait for you to boost up) power at low rpm, he will be quicker in my experience.
But I can be wrong of course. Everybody has a different approach for racing idea and has a different racing mentality. That is why we have winners and losers.
Last edited by Robevo RS; Nov 25, 2012 at 06:19 AM.
Again like I said to each his own. You can keep blathering about racing history and ALS which both have nothing to do with the OPs original question. It's simple common sense that you guys are nuking the hell out of. 2 cars, same turbos, same rpm, same mph start: one brake boosting and one not. The turbo already pushing out peak boost will benefit over the turbo that is just sitting in vacuum land. I don't understand what's so difficult to understand about that...
Yeah 11+ the ECU sees more than 1-2psi and goes into limp mode until the load clears .
Just to be clear, the OP had his answer covered. The use of this isn't for the means of this board. And before this thread copies a billion others on the same topic, the reason why it doesn't work on the 11+ is likely because Mitsu knows what's up and why people do it, but they did it under the guise of of the run-away prius' with stuck throttles.
Retuning my car did not correct this either, but I don't care, because I don't have a use for it.
Just to be clear, the OP had his answer covered. The use of this isn't for the means of this board. And before this thread copies a billion others on the same topic, the reason why it doesn't work on the 11+ is likely because Mitsu knows what's up and why people do it, but they did it under the guise of of the run-away prius' with stuck throttles.
Retuning my car did not correct this either, but I don't care, because I don't have a use for it.
So this is my first turbo car and I've always wondered how to brake boost, I tried looking it up on YouTube but couldn't really find anything. I am aware it wears your brakes down but a few times won't hurt
if anyone knows and would like to tell me that would be great thanks
if anyone knows and would like to tell me that would be great thanks





