First I would like to say 'hi' to everyone on this informative and informed group. Hope the sucking-up wasn't too blatant. So after years and years and years of salivating and dreaming my wife let me pull the trigger and get the car I've always dreamed about! Found a great deal on an '09 911 turbo cab which is gorgeous.

Now, I've read a lot about this concept and still don't get it: supposedly one can build boost pressure on the turbines by stepping on the brakes, hitting the gas and letting it go after a few seconds. So, after having the car a month or so I thought I'd give this a try... Put the car in Auto, sport, PSM off, slammed down the brake pedal, hit the gas and was expecting to barely be able to hold the car back (in terms of braking). Not so much. The engine just made a dull smothered sound and didn't seem to have much pull. More, the RPMs petered out at like 2000.

I've been reading about others' successes with this technique and don't get what I'm doing wrong; if anything. Did they change ecu programming in 2009 to stop this brake torquing? Should I need to hit overboost? With brakes on?

Don't get me wrong, the car takes off like a bat out of hell if I floor it after a second once the turbo kicks in around 3000rpm. I just wasn't sure if I'm missing something.

Thanks for any advice!

 

That's the technique. If you have an aftermarket stall in the tip you can brake boost higher . You are just loading the tranny and starting to spin the turbos a little. It gets you into boost faster.

 

I find the fastest launch on a tip as follows:

1. Sports on, PSM on.
2. Softer suspension setting.
3. Gear shift on manual.
4. Downshift to 1st gear.
5. Brake hard and raise RPM to around 2,500 to 3,000.
6. Once the car launches, put gear back to auto to let it shift itself.

 

Brake boosting from a dig is no problem, your software is fine; Stomp on the break and give it some throttle untill you hear turbos spool.

I recently was trying to brake boost from a roll on the highway.. While cruising, I try to do the same technique, but there is usually just a bog and my ecu/tcu does not allow it from a roll. I once spoke to Todd K. from protomotive and he said he can add brake boosting to my tune no problem..

 

The car's software is set up to shut down the motor after a couple/few seconds when the throttle and brakes are applied simultaneously. That's the dull, smothered sound you heard and it's normal. Sounds like you need to get off the brakes a bit quicker......best,

 

I've researched this topic on this forum a lot as well. You're probably not holding it long enough. This is what I do:

1) sport mode on, sport suspension on, rear spoiler up, psm off. If you do this, you'll notice all the lights are "on" on those buttons. Which actually leads me to believe that was done by design. I.e., when you're ready for maximum performance, these buttons should be pressed. anyway...
2) push the brake hard, mash the gas and don't let go until you see the actual boost meter build. The first half dozen times I tried this, I was so worried about minimzing damage, that as soon as I saw the overboost arrow, I let go of the gas--that won't do it. You have to actually see the meter build up to 4-8 psi.
3) let go of the gas. If you've done it right, you'll start to feel the car slightly give before you let go of the break. Once you do it, you'll feel acceleration like you've never felt before!!

Some people will say you're probably damaging the transmission...and I probably think that if you do it a lot and for many years, sooner or later, you'll damage it. But if you look it up online (or from a post that I put on here last year I think), there's actually a press release from Porsche from 2007 discussing the tiptronic S transmission for the turbo, and how they've designed it to allow for better brake torquing and thus, blistering 0-60 numbers. I figure if Porsche publicly announces this, then it must not be immediately destuctive to do once in a while. Basically, isn't this poor man's launch control?? Any other member's opinions or thoughts are welcom on this...

 

As a follow-up and thanks to those who replied; I can confirm the ability to gain 7+ psi boost pressure with the following brake boost protocol:

- PSM off, sport suspension on, sport mode on, spoiler up.
- Mash the brake
- Floor the gas to get into overboost
- Hold

The car will sound like it wants to stall out but keep the gas going and it will start to nudge away. HOWEVER, when I did it I almost gave myself whiplash...

Interestingly, I tried it with putting PSM back on (still could brake boost), then sport suspension off (could still do it)... Conclusion: may not need to have all the lights on after all(?)... Btw, does it seem likely that this will damage the car? I doubt it with all the built-in limiters and protect features. Hell the thing even keeps the shaft from spinning >12,000 rpm.

Again, thanks a lot for the great replies! Marc.

 

Hi guys,

Pursuant to the last post -- can the car be "launched" with PSM on?

E.g. ,
1. Turn Sports Mode ON
2. Do nothing with PSM (Default stays ON)
3. Brake to floor. Gas to floor.
4. Let off brake after a few seconds / when boost builds

Would this give a good & safe launch?

EDIT: I have a 2007 997.1 TT Tiptronic. (Realize the PDK or 6spd may be different).

 

My best launches:

1 hard hard on the brake
2 hand brake up
3 Psm off (must!!)
4 rev to about 3,000rpm
5 let both brake and hand brake off (let hand brake off a bit later than the brake)
6 manual shift to 2nd and let the car do the rest :-)

I can also brake boost while driving.