How is boost limited in 1st and 2nd on these cars?

[MSMS3]

And as implied above if not explicitly stated, disabling DSC does NOT disable the torque limiting in first and second gear. It does disable the circuits that control wheelspin when going straight ahead. To disable torque limiting in first and second gear, you have to reprogram the ECU.

 

[Darth Vader]

Reality is, you can easily overwhelm the TC on this car if you stomp it hard in low gears, particularly in the wet. It doesn't paralyse the car like BMW's DSC does so, by extension, turning off the DSC part by pushing the button later there's no real diff than doing the pre-push.

 

[alexspeed3]

phantom6294, man you sure know your stuff!!!

Can you please chime in on my vid. If you see at around 22 sec the boost needle starts to move up and down even though I am holding constant pressure on the gas pedal. Is this normal?

I spoke to so tuners and they said that it's something related to the duty cycle and as long as it's happening in vacum then I should be fine?

http://www.youtube.com/watch?v=hkHDufXq_cw

 

[destrux]

Interesting..

So if I shut off the DSC, installed a boost controller and a "map clamp" with the intention of forcing the car to run a constant (as in, in all gears and steering angle conditions) boost limit of 15.9psi, the ECU would still limit the throttle to achieve the target torque value? Assuming it does, I would imagine that it would end up with snappier boost response as a result of the wastegate being held closed by the boost controller... but the throttle plate would have the "last say" determining the maximum torque output by means of closing it till it was achieved. That could result in a jerky, abrubt tug-of-war... or it could be the ticket for better 1st and 2nd boost response at low RPM (my dsm with a ported 14B had better low RPM response than this car), without eliminating the torque limiter completely. It is good for tire wear and torque steer, after all. Hmm. Too bad we can't just eliminate the e-throttle. I hate those things.

With an AP, you could also slightly raise the torque value to accommodate racing tires or wider tires with more traction.... even drag slicks.

 

[destrux]

After reading the thread about the low RPM torque being a probable cause for all the snapped rods in stock motors, maybe better boost response at low RPM isn't a great idea after all, at least on a stock motor. A boost controller should still improve the consistency of the power delivery under all conditions, which is something that bothers me severely. It seems like every time I step on the gas in 1st and 2nd, the car has a different amount of power, and different power delivery. I like consistency.

 

[oaklandopen]

It seems like every time I step on the gas in 1st and 2nd, the car has a different amount of power, and different power delivery. I like consistency.

probably cuz everytime you do that the car is going crazy to try to prevent your wheels from spinning. don't go WOT in 1st or 2nd cuz it does nothing but put extra wear on your tires and doesn't make you go any faster. if i go WOT it's really only in 3rd or 4th, and if i do it in 4th it's only after 3k rpm. i never do it in 5th or 6th because i never go fast enough to be able to do it without lugging the engine. and i consider "lugging" to be trying to gain speed substantially but giving it too much throttle under 3k rpms, which is where the meat of the motor lies.