Dose's Sometimes DIY and Pay Someone Home & Boat Improvement Thread

[joshuaho96]

On 7/15/2022 at 5:03 PM, Dose Pipe Sutututu said:

Once you go DBW, you don't look back. Great idle quality, AC doesn't cause idle quality to degrade.

The factory air leak valves are so slow to react, with bigger cams your motor is very inefficient at lower RPMs the compressor engaging is enough to stall the motor.

Nissan should have used stepper motors like JZs or 4Gs, instead they installed a two slow reacting air leak valves lol.

Have you seen the rats nest of hoses under the intake manifold of an RB26? Stepper motors for idle control is far too elegant. On the bright side at least the power steering idle up on these motors isn't a physical valve that can start leaking power steering fluid into the intake with age.

[RBW49N]

On 15/7/2022 at 11:12 PM, Dose Pipe Sutututu said:

Used up everyone single DPI, AVI. Even sacrificed the power steering input lol.

DBW uses up 4x inputs.

How many extra i/o’s does if use. 

[r32-25t]

On 16/7/2022 at 10:03 AM, Dose Pipe Sutututu said:

Once you go DBW, you don't look back. Great idle quality, AC doesn't cause idle quality to degrade.

The factory air leak valves are so slow to react, with bigger cams your motor is very inefficient at lower RPMs the compressor engaging is enough to stall the motor.

Nissan should have used stepper motors like JZs or 4Gs, instead they installed a two slow reacting air leak valves lol.

The fact they fitted 2 of them always confused me 

[r32-25t]

On 16/7/2022 at 12:03 PM, RBW49N said:

How many extra i/o’s does if use. 

Drive by wire uses 4 AVIs and the 2 dbw driver wires 

brake and clutch pedal use one each 

[r32-25t]

Did you not already fit a brake pedal input when going to dbw as fail safe if something goes to shit? 

[RBW49N]

On 16/7/2022 at 12:55 PM, r32-25t said:

Drive by wire uses 4 AVIs and the 2 dbw driver wires 

brake and clutch pedal use one each 

Thanks Looks like I’ll need an i/o expander. May as well get a can button panel as well. No clutch pedal on mine. So I saved one there

[r32-25t]

To free up some AVIs you can cheat with the temperature sensors and use them on SPIs and change the scaling of the sensor to suit 

the drive by wire AVIs must be on the ecu and can’t be in the i/o box 

[Ben C34]

On 7/16/2022 at 12:27 PM, r32-25t said:

Did you not already fit a brake pedal input when going to dbw as fail safe if something goes to shit? 

Is that even a thing?

[RBW49N]

On 16/7/2022 at 1:01 PM, r32-25t said:

To free up some AVIs you can cheat with the temperature sensors and use them on SPIs and change the scaling of the sensor to suit 

the drive by wire AVIs must be on the ecu and can’t be in the i/o box 

I’ll have to move some other stuff to the I/o box then. Probably auto controls

[RBW49N]

On 16/7/2022 at 1:12 PM, Ben C34 said:

Is that even a thing?

Try doing a brake job in a modern car with a factory ecu 

[Ben C34]

On 7/16/2022 at 1:05 PM, RBW49N said:

Try doing a brake job in a modern car with a factory ecu 

That's a different story.

In relation to aftermarket ecus with dbw I have never seen them need a brake pedal input as part of the safety system.

[r32-25t]

On 16/7/2022 at 1:12 PM, Ben C34 said:

Is that even a thing?

Yes

[r32-25t]

On 16/7/2022 at 2:16 PM, Ben C34 said:

That's a different story.

In relation to aftermarket ecus with dbw I have never seen them need a brake pedal input as part of the safety system.

When you select drive by wire in the haltech ecu it pushes you to set up a brake pedal input so that if the pedal says be closed and the brake pedal is saying you want to stop but the throttle isn’t closed it will put it straight into limp mode 

[Ben C34]

On 7/16/2022 at 3:42 PM, r32-25t said:

When you select drive by wire in the haltech ecu it pushes you to set up a brake pedal input so that if the pedal says be closed and the brake pedal is saying you want to stop but the throttle isn’t closed it will put it straight into limp mode 

Interesting. Link ecus definitely dont do that, nor do motec from my experience.

 

 

it deosnt make sense, because all that matters is the pedal and the throttle relationship. If the pedal is lifted and the throttle is still open it should go to safety conditions straight away, regardless if you push the brake or not. Can't see how it helps at all. 

 

Also I am assuming you mean  a mismatch between the pedal and throttle and foot on the brake makes it go into safety mode, otherwise you wouldn't be able to do burnouts and that would be dumb!

 

 

[Ben C34]

Anyway I looked it up and it is optional to have the brake pedal as part of dbw safety with Haltech, and it doesnt relate to a failsafe function really anyway compared to having to have a primary and secondary position sensor on both Pedal and throttle.

 

Brake Pedal Check  Enable if a Brake Pedal Switch has been wired and configured. Enabling this function will enable the Max Brake TPS Setting. This setting will override all other commanded throttle values.

 

 

 

 

From

https://support.haltech.com/portal/en/kb/articles/drive-by-wire-elite

can't see why anyone would actually do it.

 

 

 

 

[Dose Pipe Sutututu]

The brake input is optional on the Haltech, I personally don't use the brake input.

I'll post up my IO assignment tonight, unfortunately using SPI for temperature sensors are not recommended as you lose resolution. 

[r32-25t]

I hooked up both my brake and clutch pedals into the ecu all my temp sensors are on AVI except fuel 

[Duncan]

using a brake pedal override seems like a nightmare for left foot braking/trail braking, and burnouts for that matter

[Ben C34]

On 7/16/2022 at 4:36 PM, r32-25t said:

I hooked up both my brake and clutch pedals into the ecu all my temp sensors are on AVI except fuel 

So are you using a lower throttle plate max opening with brake pressed?

[RBW49N]

On 16/7/2022 at 5:25 PM, Duncan said:

using a brake pedal override seems like a nightmare for left foot braking/trail braking, and burnouts for that matter

Sounds like a great excuse to have a “hoon” “race” button on the CAN keypad