TQ RED. < Driver Demand

[c0ke]

Running into some throttle limiting, here's the file and a log if anyone could take a look on a GT350 supercharged



gt350r throttle log.hpl

gt350r-.hpt

[blackbolt22]

Make sure you aren't running into any limits. For example: Low Range Limit under Trans>Torque Management>General Tab = 738lb ft. Try raising this. Look for other limits as well..

[c0ke]

Thanks I also noticed the map combustion limit was kinda low so I raise that also but neither of these have solved the problem yet

[barkingspud]

Have you tried raising your Driver Demand tables? I had a similar issue at the track last Friday. I raised the DD table 10% from 44% on up and it made a difference. See attached logs. I have a different car/setup but it should translate to yours. Ignore the Spark Cut. That's another issue.

[c0ke]

Yes I have done that already, I tried lower loads like you suggested and that didn't solve it either

[LastPlace]

try this and see if you can get your maf tuned a little better at high rpm

[c0ke]

Thanks also didnt work

[LastPlace]

try Raising driver demand to 950 on the entire row.

your engine see what it is told is actual torque is higher then what’s requested.

Raising dd is a bandaid.

your torque to load tables need work.

[LastPlace]

Also Getting your maf fueling perfect will lower your load and reduce the torque the engine thinks it’s making.

yours is not off by much so it’s not gonna do a ton but still needs to be correct.

[c0ke]

try Raising driver demand to 950 on the entire row.

your engine see what it is told is actual torque is higher then what’s requested.

Raising dd is a bandaid.

your torque to load tables need work.

Thanks I'll look into that. The maf was off because the intake pipe collapsed a little bit and was sucking in some unmetered air. plastic pipe unfortunately

[Thatwhite5.0]

There are two ways you can fix this.

The correct fix, the airflow model in your torque tables are calculated incorrectly and scaled about twice as they should be. You would need to rescale, repopulate the cell values and recalculate torque/inverse. That would get your tune running the the way it's supposed to instead of against itself.

One pid that doesn't get credit is desired airload and youre logging It. Air load Is calculated using indicated torque tables. Desired load is calculated using the inverse torque table. Theres also Desire torque. The torque/inverse tables need an equal inverse relationship. One table has 500 ft lbs at 1.1 load and the other table has 1.1 load at 500 ft lbs.


The easy fix, your dd is too high, you're requesting too much torque. Lower your driver demand so torque request stays less than 15 ft lbs more than engine brake torque

[barkingspud]

There are two ways you can fix this.

The correct fix, the airflow model in your torque tables are calculated incorrectly and scaled about twice as they should be. You would need to rescale, repopulate the cell values and recalculate torque/inverse. That would get your tune running the the way it's supposed to instead of against itself.

One pid that doesn't get credit is desired airload and youre logging It. Air load Is calculated using indicated torque tables. Desired load is calculated using the inverse torque table. Theres also Desire torque. The torque/inverse tables need an equal inverse relationship. One table has 500 ft lbs at 1.1 load and the other table has 1.1 load at 500 ft lbs.


The easy fix, your dd is too high, you're requesting too much torque. Lower your driver demand so torque request stays less than 15 ft lbs more than engine brake torque

I see in the logs that the ETC Torque Request is well over what Brake Torque is logged at. The request is 738 lb-ft and the Brake Torque is at 580ish. If I am requesting too much torque, why would I have a TQ Reduction? I mean, wouldn't I attempt to meet that demand rather than limit it?

I'm not challenging your answer, just trying to learn here. Thank you.

[Thatwhite5.0]

Driver demand is your torque request, the ECM is trying to achieve the requested ft lbs.. If you don't request enough tq, and your request is less than engine brake torque. The throttlebody can close as many degrees necessary to restrict/reduce engine brake torque down to your requested torque.

Increasing driver demand a few ft lbs in the tables can actually increase engine brake torque.

So you're requesting around 140 ft lbs more than engine brake torque. See if you were logging fuel source or driver demand limit source. One of those would be in "insufficient fuel flow". So that is your torque reduction. The ecm is not receiving proper fuel to achieve requested torque so it reduces power.

Also driver demand on the s550s have a limit and you said it. 738 ft lbs is as high youll be be able pull from torque request.

There's also a limit or a distance, I think between engine brake torque and indicated torque or desired , both channels are almost twice engine brake torque. Like I said, Decreasing DD is a patch. If you want a noticeably better running tune. Your torque tables need to be a little more realistic. The highest values on your axis is 2.0 load and 1200 ft lbs. Should be scaled around 700.

The last Whipple I tuned, I ran only 6 mapped points. PD blowers require more work and tuning than a centri or turbo because a PD blowers power increased through the entire rpm range. I do not know why they scale their tables like that. I'm guessing the use the same tune for all their set ups.


You can also try setting clip/add torque to adaptive to see if that helps at all with current torque tables.

Set realistic limiters too. I've had fueling issues and torque reduction from limiters set too high. I never max out any limiters other than the tables already maxed out.