Low TPS values produce no acceleration (no change in RPM)

[RRRocketMan]

As the title says, when in neutral or in gear clutched, if I gently apply throttle up to the first few percent, absolutely nothing happens. Then beyond a certain threshold which I estimate to be somewhere between 5 - 10 %, the RPM suddenly jumps and throttle response becomes more or less proportional thereafter as you might expect.

Which table do I have to modify to correct this? I don't want this electronic control feel. I want it to respond like a cable. Little bit of pedal = little bit of throttle.

Thanks.

'13 Camaro SS
Manual Transmission
Tune converted to 1.75 Bar VE

[GHuggins]

You'll want to post your current tune, but for what your wanting there is probably only one real way to get what your after and that's to "fib" some of the information in the ECM - one thing in particular..... The main issues are the desired throttle area tables, which you CAN NOT modify, so you have to "work around" them

[RRRocketMan]

You'll want to post your current tune, but for what your wanting there is probably only one real way to get what your after and that's to "fib" some of the information in the ECM - one thing in particular..... The main issues are the desired throttle area tables, which you CAN NOT modify, so you have to "work around" them

In many threads I read that would brick your PCM but 1 in particular says "modifying the throttle tables doesn't brick the E38 like it does in the GEN 3 PCMs" (paraphrased). Is that true? If it bricks the PCM then I won't do it but I hate the dead zone so would like to fix it.

BTW, what is this "work around" that you speak of?

[jtrosky]

With a 2013, I would think that it's safe to modify the Driver Demand tables to accomplish what you want - assuming the driver demand tables are currently setup in way where they're not requesting any power at low throttle positions...

Can you post a copy of your main Driver Demand table? Usually, if it's "risky", it will mention it right in the help at the bottom of the table. I've successfully modified the Driver Deamnd table on my 2012 Impala (much differernt application, but...) - makes my throttle so much more responsive...

[GHuggins]

With a 2013, I would think that it's safe to modify the Driver Demand tables to accomplish what you want - assuming the driver demand tables are currently setup in way where they're not requesting any power at low throttle positions...

Can you post a copy of your main Driver Demand table? Usually, if it's "risky", it will mention it right in the help at the bottom of the table. I've successfully modified the Driver Deamnd table on my 2012 Impala (much differernt application, but...) - makes my throttle so much more responsive...

Yours uses DD tables - completely different - but yes - does essentially the same thing...

However on gen 4 and older ecm's modifying these tables nearly "ALWAYS" puts the vehicle into REP if it doesn't brick it... I've never actually had one brick, but have heard of others experiencing this... How I achieve getting rid of this is like this - make the etc scaler 10% to 15% smaller than actual - any more than that and you have to start retuning things - it will change the fuel calibration - I HIGHLY recommend not going beyond 15% smaller...

Now, I can tell you everyone on here is going to frown on this and honestly I shouldn't even be posting it publicly, but it has other "built in" benefits besides throttle response...

[06MonteSS]

GHuggins - what etc scaler are you talking about, Idle - Airflow - General - ETC Area Scalar - 5636?? and you'd LOWER that setting by 10% ???

How does that improve throttle response and make it respond quicker??

and what are the other benefits???

and being in the idle settings, that will also affect and improve throttle response when driving??

please feel free to message me this info if you don't want to post it openly...

thanks!!

[RRRocketMan]

Yours uses DD tables - completely different - but yes - does essentially the same thing...

However on gen 4 and older ecm's modifying these tables nearly "ALWAYS" puts the vehicle into REP if it doesn't brick it... I've never actually had one brick, but have heard of others experiencing this... How I achieve getting rid of this is like this - make the etc scaler 10% to 15% smaller than actual - any more than that and you have to start retuning things - it will change the fuel calibration - I HIGHLY recommend not going beyond 15% smaller...

Now, I can tell you everyone on here is going to frown on this and honestly I shouldn't even be posting it publicly, but it has other "built in" benefits besides throttle response...

ETC Area Scalar = 5636

Is that the one? This implies the throttle throat area is 5636 mm^2?

Sorry the upload manager is hanging... unable to attach.

[GHuggins]

ETC area scaler just predefines the throttle body size - it's actually been moved to lessen confusion to the electronic throttle section on a lot of the newer tunes... AND yes it Effects everything - even wot fueling to an extent... You make it smaller so it in "essence" is working around the "unchangeable" throttle tables...

[06MonteSS]

I have a ported/polished stock gm throttle body.. what would making this value smaller essentially do? what does making this 5636 value smaller essentially tell the ecm and other settings, that there is less air flow?? even though I essentially have a little more since it's ported/polished so my openings are bigger/more open than stock??

how does making that value smaller make the throttle response faster/quicker?

[GHuggins]

Because the defined opening percents are based off of square area....

DO NOT go smaller than 15% - you can wind up with a "self opening" sensation or overly sensitive pedal / DO NOT recommend doing this on after market throttle bodies as they are all ready flowing better due to the torque steps usually being removed / May not notice much with stock TB's until 8 to 10 percent decrease.... These are the warnings and why it's typically frowned upon...

[06MonteSS]

so seeing as how I have a ported/polished (smoothed internally) throttle body (was a stock GM LS3 TB to start with), you would recommend NOT changing that scalar setting?

or do you think I would still gain some better response if I lowered the 5636 by 10% down to 5072 ??

and thank you very much for the info thus far, I greatly appreciate it man!!

[GHuggins]

You can, but probably wouldn't see as much benefit...

[06MonteSS]

ok cool... thank you.. I just may try it, reduce it by 10% down to 5072 to see if there's any difference with my Bo White ported throttle body..

also, while I have your attention and knowledge, another question for you..

Table: Torque Management - General - Tip-In Limiting - ETC Rate (ETC Tip-in Throttle Rate Limit)

stock has entire table at 0.10

description says: "Throttle rate limit - limits how fast throttle opens during tip-in"... and it can be set from 0 to 100%

so my questions are...

does setting it to 0 disable this limiting? so that there is 0% "limiting" so that it will open as fast as it can??

or - does setting it at 100% disable this limiting so it will open as fast as it can? 100% means it will open as quick/fast as possible?

OR - since it is a "limiter", does setting it to 100% mean it will LIMIT it 100% and it will open slower??? i.e. higher % means more limiting so slower opening??

[GHuggins]

Well I answered in your other posting, but this does pertain to throttle "reaction" SO, smaller number = more limiting / 100 should = no limiting... I have also been told that you have to have this set very low like the factory .1's to see any limiting at all, just for further explanation on it... 10SS can give the exacts of the settings to how low it exactly has to be set to see any benefit...

[06MonteSS]

awesome.. ok great, thank you very much man, I appreciate your help and info. . thank you...

[RRRocketMan]

awesome.. ok great, thank you very much man, I appreciate your help and info. . thank you...

While in reality the throttle plate response to air flow is sinusoidal, from a user perspective it makes sense to have the pedal behave linearly (10% pedal might be 25% change in plate angle to get 10% more air). Wonder why the engineers never did this. I hate having to push the pedal so far to get any power.

[Spawne32]

According to the post i read from chris from a while back, on the 06+ ECU's such as the E38 and E67, the way the desired throttle area works is different in the TAC module vs what the gen 3's had. He says there have been no reported issues with modifying the desired throttle area tables. I have the same problem, i have to move my pedal down to at least 1/4 throttle to get the car to move any with the larger throttle swap this issue is just worse. I may attempt to make modifications to those tables tomorrow and see how it pans out. These tables should be pretty straight forward and have no underlying connections to anything else. They are literally pedal position vs rpm = desired throttle position, they should be no more no less. But it is a wonder why GM never made them linear to make them behave like a cable system where the % pedal = the % throttle position.

[AJK13]

I'm going to piggy back a noob question. I have a 4.8 and I put a LS3 TB on. My current ETC Area Scalar is 4552.25. Should I change it to LS3 5,060?

[GHuggins]

yes, put in ls3 values

[10_SS]

I modified my LS3 Throttle tables... I also did not like the "dead zone" talked about by the OP. I shifted the values over one or two rows to the left then smoothed them from there. Worked fine. If you to agressive you will get REP... so I went less aggressive and no problems. removed most of the dead zone. It doesn't take much, you will notice a difference just by sliding the first few tables with values higher than 0 over a bit, then smooth in the 40-70% area so you dont notice it. So I moved my table to the left a bit, then I also massaged some of the values right around 30% where my Whipple boost valve would close... since for whatever reason I get a pressure spike from 105 to 115kpa with no tps blade movement (it jumps up when boost valve closed), I made the throttle blade movement pretty flat in this area using this table.

Regarding the Opening Rate Table, 100 = Full Speed. I needed to reduce my opening rate to take care of a severe over-boost spike I was getting on tip in, and found that reducing it to 10 did nothing, so asked HPT, and they said very low values should show something, so I am currently at 3, down from 100, and I see a nice reduction in the blade opening. Now my tip in looks like a non-boosted car tip in (normal). It took care of any problems I had and I cant even notice any delay (there inst really any in the pressure increase). You don't want to mess with other tables to try and speed it up as at 100 (Stock) it reacts as fast as you can mash your foot.

And yes, i HATE drive by wire. Dislike everything about it. Hate the loose feeling all the time and just the accel of the car makes your foot move, really dont like that there is no cruise control feedback from the pedal.

TPS.PNG