Tune out steering angle based boost?

[ericrapp]

I was reading along and wondered if any of you folks recall way back in 07 that a couple of car magazines reviewing the Mazdaspeed 3 mentioned that boost is controlled by the EcU based on throttle position, RPMs, gear selected, wheelspin and steering angle. As for the differential theory, i am not sure about that but i also am not into the ECU, reading tables either unfortunately. I do know that with the dsc switched off, i can spin the tires to my hearts content on my car though. ireally could not take any more boost and have traction out of a tight turn with out more understeer in first or second. If this could be solved and i am sure it can, how much more boost would you folks run in the lower gears. I want all of it by 3rd gear though!

 

[COBB Tuning]

I will look deeper into this issue. One of our tuners, Tim Bailey, is out of the office this week so I will see if I can't get Christian and Tim together and see if there is some sort of solution to this.

Travis
COBB Tuning

 

[MS3Zoom24]

where is this plug you can umplug

 

[fostersafb]

double post

 

[fostersafb]

I will look deeper into this issue. One of our tuners, Tim Bailey, is out of the office this week so I will see if I can't get Christian and Tim together and see if there is some sort of solution to this.

Travis
COBB Tuning

Thanks for all the support with each new thing we discover!

 

[ericrapp]

Thanks

I will look deeper into this issue. One of our tuners, Tim Bailey, is out of the office this week so I will see if I can't get Christian and Tim together and see if there is some sort of solution to this.

Travis
COBB Tuning

Ithink you guys have Nissan GT-Rs on the brain! Haa ha. Also thanks for your support on our forum.

 

[tuckaloe]

So when do we consider the ecu to be "cracked"? Despite the phenomenal strides that Cobb has provided us, it doesn't sound like we have much of an idea about this thing.....currently, we can alter it but we don't know alot more than...we can alter it. The mystery remains.

 

[dread]

many of the tables are understood, but since cobb reverse engineers the ecu, it would take logging to figure out the tables that are not known.

 

[MS3Zoom24]

just disconnect that sensor under sterring column...just be carefull it will fully boost on the corners

sorry for 2x post earlier

now is it the white one that is about 1inch by 1/2inch.

ONly reason asking i was looking for it and only saw the sensors that went to the pedals and this white sensor that was stuffed up almost into the center column
thanks for the hlep i jsut dont want to be disconnecting stuff that i dont know what it does

 

[matsuda]

sorry for 2x post earlier

now is it the white one that is about 1inch by 1/2inch.

ONly reason asking i was looking for it and only saw the sensors that went to the pedals and this white sensor that was stuffed up almost into the center column
thanks for the hlep i jsut dont want to be disconnecting stuff that i dont know what it does

It's not a good idea.
Read the entire thread.

 

[dkswim]

looks cool

 

[MSMS3]

I was reading along and wondered if any of you folks recall way back in 07 that a couple of car magazines reviewing the Mazdaspeed 3 mentioned that boost is controlled by the EcU based on throttle position, RPMs, gear selected, wheelspin and steering angle. As for the differential theory, i am not sure about that but i also am not into the ECU, reading tables either unfortunately. I do know that with the dsc switched off, i can spin the tires to my hearts content on my car though. ireally could not take any more boost and have traction out of a tight turn with out more understeer in first or second. If this could be solved and i am sure it can, how much more boost would you folks run in the lower gears. I want all of it by 3rd gear though!

Right you are, IMHO. The system is complex. There are sensors for both wheel speed and steering angle in that plug people are talking about unplugging. Yes, you can unleash more power that way while cornering, but to do so will also completely deactive the anti-lock brakes -- not a good or safe thing.

DSC deactivate does allow unrestricted wheelspin, but does not deactivate the separate torque limiting software in the ECU which is based on gear selection. In first and second gear, regardless of DSC position, hp and torque are held back.

Given how freely these cars spin their tires, we can't actually use the extra power without much stickier tires until we get into third. But the steering angle software cuts power even more severely in the lower gears than does the torque management software. We could use a fix for the steering angle power limitation.

So, I say it is an ECU issue.

 

[ericrapp]

Thanks for helping me understand what you are up against. maybe there is a way to voltage clamp that input or loop that could be used to reduce the signal depending on whether it is a 0-5 volts from neutral steering angle to full lock. One of my concerns with your project would be related to drivetrain abuse. Coming out of slow semi rough corners even with the limits imposed, i can have some pretty nasty torque steer as the car gains traction with one wheel and then the other. It can reely pull the steering wheel and i have to pay attention with a good grip on! geez with more power available i am thinking things might break like shafts or worse like the diff. On a track car it makes sense to have all the available power all the time at the drivers discretion! if you see what i mean

 

[COBB Tuning]

After talking with Tim Bailey a bit, it seems that you could indeed tune out the "torque clamp" as there is a function in the ECU that switches maps to the "low torque" map for a given steering angle.

DO NOT unplug your steering angle sensor as this will disable other things like ABS and stability control. The trick would then be to raise the torque limits in the low torque maps. Your tuner can do this, or you can try doing this in ATR.

Travis
COBB Tuning

 

[mattj3636]

so which connector under the steering column is it?

 

[derspi]

After talking with Tim Bailey a bit, it seems that you could indeed tune out the "torque clamp" as there is a function in the ECU that switches maps to the "low torque" map for a given steering angle.

DO NOT unplug your steering angle sensor as this will disable other things like ABS and stability control. The trick would then be to raise the torque limits in the low torque maps. Your tuner can do this, or you can try doing this in ATR.

Travis
COBB Tuning

Any specific tables in ATR we should be looking at to achieve this? Any info. you can give us to get us started would be much appreciated it.

 

[dread]

I would think it is the gear specific load tables, which are for high BAT's. They have much lower load targets. The only problem is when your BAT's are high you will be ******. The other table that it might be is the throttle req load B, which has much lower load targets than A or C. Christian was not sure what this table is for but felt it was probably related to traction control.

 

[MSMS3]

so which connector under the steering column is it?

For safety sake, the correct answer is "none of the above." lol.

 

[mattj3636]

i did trial and error, its the white one. pretty sick without boost limits around turns haha..

i never slam on my brakes to cause ABS to engage in the summer anyways.. im not worried about it.

 

[matsuda]

i did trial and error, its the white one. pretty sick without boost limits around turns haha..

i never slam on my brakes to cause ABS to engage in the summer anyways.. im not worried about it.

Yeah, people that ride motorcycles don't need helmets because they aren't going to crash.