Could you add a target boost table?

FlashPro questions & answers specific to the 2006-2011 Americas Civic Si
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ajpturbopittsburgh
Posts: 145
Joined: Wed May 26, 2010 10:58 am

Could you add a target boost table?

Post by ajpturbopittsburgh »

Is it possible to create a target boost table? I did opensource tuning via the tactrix cable on my subaru WRX and it has tables for target boost in addition to wastegate duty cycles by throttle position and rpm.

It is really nice because if you don't have your Wastegate duty cyles for your boost solenoide dialed in you still run the DESIRED boost level because the ECU adjust the wastegate duty cycles. Not only that but when datalogging it tells you what wastegate duty cycle you need to hit the target boost so you can change the WDC to correspond with target boost. And it helps when the climate changes because if your temp compensation tables for WDC are poorly setup you still will be close to the target boost.

It would be awsome for those that are boosted and use the hondata boost control solenoid.

I run about 6 psi on wastegate spring pressure and I don't understand why I can make my boost control duty cycle about 27 and I still get 6 psi and then making it only 30 I hit 10 psi and 35 gets me to 17psi. It's so touchy.

I don't like how such little inputs in duty cycle yields large swings in boost. 6psi gives me about 320whp and 11psi is 400whp and 18psi is 500whp so I have to be careful with it. So I just wish 80 duty cycle gave me 17psi and not 35 dutycycle. Target boost would be sweet.

Thanks for reading.
soxfan143
Posts: 216
Joined: Mon Nov 12, 2007 5:09 pm
Location: lynnfield MA

Re: Could you add a target boost table?

Post by soxfan143 »

ajpturbopittsburgh wrote:Is it possible to create a target boost table? I did opensource tuning via the tactrix cable on my subaru WRX and it has tables for target boost in addition to wastegate duty cycles by throttle position and rpm.

It is really nice because if you don't have your Wastegate duty cyles for your boost solenoide dialed in you still run the DESIRED boost level because the ECU adjust the wastegate duty cycles. Not only that but when datalogging it tells you what wastegate duty cycle you need to hit the target boost so you can change the WDC to correspond with target boost. And it helps when the climate changes because if your temp compensation tables for WDC are poorly setup you still will be close to the target boost.

It would be awsome for those that are boosted and use the hondata boost control solenoid.

I run about 6 psi on wastegate spring pressure and I don't understand why I can make my boost control duty cycle about 27 and I still get 6 psi and then making it only 30 I hit 10 psi and 35 gets me to 17psi. It's so touchy.

I don't like how such little inputs in duty cycle yields large swings in boost. 6psi gives me about 320whp and 11psi is 400whp and 18psi is 500whp so I have to be careful with it. So I just wish 80 duty cycle gave me 17psi and not 35 dutycycle. Target boost would be sweet.

Thanks for reading.
Lower the boost control frequency and you will have much more control. I run 20Hz and it works perfectly.
locash
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Post by locash »

It sounds like you are asking for closed loop boost control, perhaps a PID based setup.. None of the other Hondata products have this, so I am doubting it is going to happen anytime soon..
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ajpturbopittsburgh
Posts: 145
Joined: Wed May 26, 2010 10:58 am

Re: Could you add a target boost table?

Post by ajpturbopittsburgh »

soxfan143 wrote:
ajpturbopittsburgh wrote:.
Lower the boost control frequency and you will have much more control. I run 20Hz and it works perfectly.
I am running 50 hz. I thought a higher frequency would give more resolution since it's cycling more times per second. I will try it though thanks sox
Last edited by ajpturbopittsburgh on Sun Oct 03, 2010 10:26 pm, edited 1 time in total.
ajpturbopittsburgh
Posts: 145
Joined: Wed May 26, 2010 10:58 am

Post by ajpturbopittsburgh »

locash wrote:It sounds like you are asking for closed loop boost control, perhaps a PID based setup.. None of the other Hondata products have this, so I am doubting it is going to happen anytime soon..
What is PID based? But yeah I guess closed loop boost control is what would be nice.

Would it be that hard to implement that into the software though? The ECU could make changes to the boost control duty cycle based on tables and from what the MAP sensor is seeing.
mucter
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Post by mucter »

The current logic works well enough once you get the frequency dialed. The frequency is like a gain control. It amplifies how much boost you'll get per % of duty.

Like Mike said, lower it down to like 20hz or so and you'll have a much easier time getting it dialed in. 20hz works great for anything under 18psi on an external wastegate.

I run 28hz on my internal wastegate setup, boosting between 13-19 psi. Attached is how my boost table looks currently. I have to run way more duty in 3rd gear to hold boost at high rpm (thanks to my awesome log manifold and internal wastegate.)
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boost-table.PNG
boost-table.PNG (84.69 KiB) Viewed 4886 times
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