Torque request and boost

FK2 Civic Type R 2015-2017, FK8 Civic Type R 2017-2021, FL5 Civic Type R 2023+ and Integra Type S 2024+
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Piv
Posts: 40
Joined: Sat Apr 03, 2010 4:20 am

Torque request and boost

Post by Piv »

Hello,

New to this platform, I've been very careful to read thoroughly the overall Tuning guide on the FK but I'm still not quite sure on how boost control and torque demand work or are related.

As far as I understand, if Torque demand was remaining the same across the rev range, the boost should go up with rpm to try and keep the torque at that flat level but what seems to happen is that when the torque request goes up, the boost goes up in the mid range but top end still falls regardless of what I do, and it seems to be the same on all the logs that I've seen on this forum.

Power is very similar with a torque demand of 425, 460 or 460 climbing to 530, only the boost goes up in mid range but remains the same top end
Air charge Limit is not reached, and not sure on Turbo Ratio as it's unitless and can't be logged but changing it up or down did not make any difference either.

Current car as a Eventuri Intake, downpipe and catback, OEM intercooler

Cal and logs attached, car is making 360 Flywheel hp, torque is higher in R-mode but power same between the 2 as boost top end is near the same

I may miss something obvious here

Thanks,

Piv
Attachments
Euro FK8 3in CB, Eventuri, Intercooler Downpipe RL01.fpcal
(15.62 KiB) Downloaded 229 times
Comfort RL01.fpdl
(30.55 KiB) Downloaded 190 times
R Mode RL01.fpdl
(14.45 KiB) Downloaded 219 times
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Spunkster
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Re: Torque request and boost

Post by Spunkster »

We are working on a video to better explain the FK8 tuning and how it all works together. As you know it is very complicated and I myself who have an FK8 still do not understand it all, but I am also not a tuner.

The reason you cannot make more top end power is that the turbo is just maxed out. We have found that more boost does not mean more power as the added boost just increases heat and causes the ignition to have to be retarded. You can actually make more power many times by reducing the boost and increasing the timing slightly.
Piv
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Joined: Sat Apr 03, 2010 4:20 am

Re: Torque request and boost

Post by Piv »

Hi Spunker,

Thanks for the quick reply

I'd be surprised if the turbo is maxed out, the ECU isn't even trying to make more boost as the boost is 1.3bar top end and same as the target the ECU wants. I would understand if ECU was requesting 1.6bar but wastegate was fully closed and actual boost pressure at 1.2bar but that's not the case, the boost target and actual boost are identical.

It looks like the torque request is going down with RPM, car is pretty much making OEM power as the OEM boost target at the top end is near enough the same

I know those turbo can make and hold 1.6-1.7bar top end as I've mapped them on Standalone ECUs as well but it's obviously completely different from the Bosch ECUs and I feel I or the software is missing something
Piv
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Joined: Sat Apr 03, 2010 4:20 am

Re: Torque request and boost

Post by Piv »

Hi guys,

Any news on this?

If it's just a matter of having to wait for an update and new tables that's fine but I just need to know so I can plan what we need to do with that car, I have mapped stock FK2s and FK8s on Standalone ECU and can easily make 1.6-1.7bar up top and would like to be able to have more control on the boost target

Being able to log the actual torque request from ECU or torque limitation for whatever reason would be a great bonus too
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Hondata
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Re: Torque request and boost

Post by Hondata »

If the boost cmd is much higher than the actual boost then the limitation is the turbo. At that point be careful since the turbo can overspeed at which point the shaft bends and then things go wrong very quickly.
If the boost cmd is low then the ECU is limiting boost based on pressure ratio, intake temperature, discharge temperature, exhaust temperature, catalyst temperature or one of many other things the ECU looks at.
Hondata
Piv
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Re: Torque request and boost

Post by Piv »

Hondata wrote: Tue Mar 26, 2019 4:39 pm If the boost cmd is much higher than the actual boost then the limitation is the turbo. At that point be careful since the turbo can overspeed at which point the shaft bends and then things go wrong very quickly.
If the boost cmd is low then the ECU is limiting boost based on pressure ratio, intake temperature, discharge temperature, exhaust temperature, catalyst temperature or one of many other things the ECU looks at.
Oki that's fair enough but pressure ratio is way higher than base and I don't think it reaches it as boost is too low, intake temperature is ok ish on log I've attached, catalyst is no present anymore so I wouldn't like the ECU to limit the boost based on that as the temp will be much higher than when cat is present and there is no table or option to prevent that as far as I can see

Did you have a look at the map and the logs I've attached?
sirgrumble
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Re: Torque request and boost

Post by sirgrumble »

Spunkster wrote: Wed Mar 20, 2019 5:14 pm We are working on a video to better explain the FK8 tuning and how it all works together. As you know it is very complicated and I myself who have an FK8 still do not understand it all, but I am also not a tuner.
Can you provide an update on this video? Is it available? Can you give an idea when it might be available?
touge tom
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Joined: Fri Aug 29, 2014 7:16 am

Re: Torque request and boost

Post by touge tom »

How much of a difference does the boost cmd vs the actual boost to be a concern? On average I see a 1psi difference. I'm assuming that's due to a pressure drop in the system? Or am I wrong?
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Spunkster
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Re: Torque request and boost

Post by Spunkster »

We have created a tuning guide which may help: https://www.hondata.com/tech-tuning-the ... vic-type-r
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