arghx

iTrader: (3)

First, this is on a 94 with stock sequential twins, 550/1300, already with a pretty good idle and off-idle tune in the fuel maps. I have not gotten a chance to try this on my 2nd gen with series 4 narrow range TPS yet as I am in the process of putting the motor together.

Anyway, I'm writing to report some success with using the Settings 2 INJ vs TPS table to improve tip-in, especially when the car is already moving (2nd and 3rd gear at lower speeds, like when in heavy traffic on an interstate). Chuck has made some brief mention about this table before but nobody has done much testing it seems. I have found that, on this particular car anyway, the INJ vs TPS table can noticeably reduce lean spikes and stumbles, but without requiring changes to the INJ/basemap , the Accelerate Injector Map, or Inj vs Accel TPS1 to keep the motor from running too rich.

Normally if you fiddle too much with those other tables you will find the car dumping in fuel off a stoplight if you're not careful, or dumping in fuel from slight throttle movements on the highway. I had already added fuel to the bottom row of INJ vs Accel TPS1 and richened up Accelerate Injector as well, but there were still some stumbles that were tricky to tune out without having rich spots in my fuel maps.

When tuning INJ vs TPS, the first thing I did was change the bottom two TPS % bins to ~10% and ~30%, so that the extra fuel would kick in earlier and more progressively. Because we never know exactly which TPS % bin the car is running in at any given time (no map trace function for this), I tuned INJ vs TPS mostly by feel, usually at 20-30 mph in 2nd or 3rd with no traffic around. I do really small throttle movements, and if I feel a stumble, I add fuel to the lower bin. Then I do quicker "medium" and "heavy" throttle movements, sorry I can't quantify. I just kept adding fuel from the lowest TPS % bin up. It appears that the higher TPS numbers need more fuel.

Now, here is my table:

INJ vs TPS
TPS % - Setting

89.8 - 1.055
79.7 - 1.047
69.9 - 1.039
59.8 - 1.039
30.1 - 1.039
10.2 - 1.023

For reference, here are my other tip-in settings:

Inj vs Accel TPS1
Input - Setting

103 - 256
37 - 230
20 - 50

Accelerate Injector
RPM - Amount - Decay

5000 - 7.80 - 1.00
4000 - 7.80 - 1.00
3000 - 7.80 - 1.50
2000 - 8.40 - 1.80
1000 - 6.30 - 2.00

So in conclusion, from my test on this one FD I believe that the INJ vs TPS may offer improved throttle response with less of the compromises we have all been making with the other tip-in tables.

Somebody else give this a shot and let me know how it goes.

Dudemaaanownsanrx7

iTrader: (23)

did you have to lower your base map settings at all in order to get afrs back to where they were?

arghx

iTrader: (3)

I didn't touch them.

Aeka GSR

iTrader: (4)

I just wanted to bump this thread to see if anyone has tried this. I've been having these issues with my stock FD and it has been frustrating.

arghx

iTrader: (3)

here is the latest table I am running:

89.8 - 1.063
79.7 - 1.055
69.9 - 1.047
59.8 - 1.047
30.1 - 1.039
10.2 - 1.023

Save a copy of your current map and then you can certainly give it a shot. if it doesn't work for you, put it back to your old settings or adjust that table however you want. you can't damage anything by fiddling with this table. you obviously need a datalogit and a PFC, and your TPS should be in spec according to the FSM voltages.

Aeka GSR

iTrader: (4)

thanks, I'll check this out this weekend when I have some time.

Aeka GSR

iTrader: (4)

well it didnt seem to do anything for me.

AchillesGr

iTrader: (1)

arghx,
i seems that i have the oposite problem. when i hit the pedal i get lean and not rich spots.
here is the story:

My programming skils are not very good . I have a lc1 wideband . ..

I was in 3 gear with about 2300rpms with almost 0psi. I floor it and in a few seconds bang.the engine did not hit over 8psi.also if I open progressively the throttle the fuel is at 11.5afr until redline. So I assume that it is not from inadequate injector size.the engine did not reved over 6000rpms. As I saw at the wideband there was a lean situation imedietely as I step on the pedal for a few sec and then bang(afr about 14-15). I assume that it is the “inj vs acel tps” settings witch I have:
103-256,
37-256 ,
20-35 .

the inj vs tps are all set to 1.00

arghx

iTrader: (3)

Just for the heck of it try these:



that's off an FD with 550/1300, street ported motor with sequential twins

milano maroon

iTrader: (1)

arghx:

Somewhere I have a one page document which I think was in a post on this forum that talks about setting the Injec vs TPS1 lower values. The suggestion was Input = 5 and Setting = 175 for the lowest row. I have looked at a fair amount of maps and never seen values like that. Any ideas?

What I thought I remembered was that a slight throttle movement would put more fuel in. I think I'm running 15 and 80 but nothing as radical as the 5/175.

arghx

iTrader: (3)

What I will say to that is: whatever works. Let me post some maps for you to look at:





Those are pre loaded maps from Apex'i. One of them is the default map for the AP Engineering s5 Rx-7 Power FC. The other is the default map for the s14 Sylvia D Jetro map (Speed density like Rx-7). I know two people who are using those default settings for their respective vehicles and have not expressed any dissatisfaction with throttle response.

Here's another map for a JDM JZA80 Supra, which were all speed density:

AchillesGr

iTrader: (1)

arghx,
here is the map witch blow the engine.
since i have pulled the engine out i cannot try your setings.
do you see if something is wrong with my map?can these setings lead to a teribly lean condition with disaster?


I will try to describe my setup and give you more info the better I can.
removed: precat , (and fited a strait pipe about 3.5in diameter) ,air pump, egr , acv
stock injectors and entire fuel rail (rceng cleaned and balanced)
Apexi Pfc
Datalogit
Innovate lc1 wideband with xd-16
aeromotive fuel regulator at 38psi
stock porting
bonez main cat
new enlarged fm intercooler
turbosmart wastgate,
Greddy exaust
Greddy Type-RS BOV
Greddy elbow
hks air filter
garret turbo (T4/62-2 with: turbine 0.82A/R 64mm , compressor 0.60 A/R 66mm)


also,
1)what is the use of the inj vs tps table? will i have the same results if i increase the base map cells?i am asking this because i think it will be more easy to read the base map only and have an idea of the fuell than taking a look at the base map AND the % increase from this table.
if the afrs are where they sould be with the settings at this table at 1.00 should i decrease the base and increase the setting numbers?parhaps i am mising the whole point of existing this inj vs tps table....

2)the accelarate injector (ms) table:
the "amount" is in milliseconds that the setting from the inj vs accel tps1 table aply?
what the "decay" is?



3)the inj vs accel tps 1 table:
my settings are
103-256
37-256
20-35

if i understand corectly the first and the second rows are seted at the maximum amount (256)100% and the third row gives 35/256=13.67% more fuel for 20/256=7.8% tps movement

so if the tps moves 7.8% the base fuell will go up 13.67% for 8.000 milliseconds(8 seconds???)
stil dont understand what the "decay" is....

can you please clear this??

if my setting are so increased why the lean at suden pedal movement?
thanks!!

AchillesGr

iTrader: (1)

the last row of ap engineering default map is 20-135 ???
i assume it is beter dump fuel at the bigining and then lowering it as tuning goes on than blow an engine trying the oposite: starting from lean tip in and increasing the setings like i did....

arghx

iTrader: (3)

You're asking some difficult questions, questions I myself have asked. I don't know for sure how any of this stuff is calculated. All I have to offer are clues and speculation.

Some people say it's extra fuel based on TPS voltage alone (not change of TPS voltage). So at 2 volts/40% TPS you add a particular amount of fuel. It's kind of a crude way to improve tip-in but in my experience so far it seems to help. Will you have the same result as increasing the base map cells? I don't think so. I say that because the base map cells do not directly take into account the throttle opening angle or how fast the throttle is opening. The reason why I use it is because it works in my experience. It makes the engine stumble less when you open the throttle, without kicking in so much extra fuel that you go super rich. I won't claim to completely understand it, but I can claim some positive results.

The decay has to do with how the maximum accelerate injection value tapers off. Lowering the value increases fuel iirc. In my experience so far all I've managed to do with the decay value is dump in more fuel without solving any stumbling or hesitations. Now I'm not completely clear on the exact decay calculation, but here is what I can offer. This is a page out of the Evo Power FC manual:



And here is a log of injector pulsewidth from my FC as tip-in fuel is being engaged:



It appears that "Accelerate injector" and the "Decay" are used to calculate the MAXIMUM tip-in value. That max value will be applied if "setting" under Inj vs Accel TPS1 is "256" . Maybe. The "Input" value is some unit corresponding to the rate of change of TPS voltage. 1st derivative. It's how fast the throttle is opening, not its actual position. When you lower the "input" value in Inj vs Accel TPS1 you are making tip-in fuel kick in earlier. But you still have to be careful with this. When you start playing with this table you can end up dumping in more fuel but still having a hesitation.

What happened was that I started playing with the Inj vs Accel TPS1 and Accelerate injector Amount settings for a while. I got as far as I could but it still was stumbling more than I was willing to put up with. So I started messing with the INJ vs TPS table and that seemed to improve things.



I am pretty sure that the PFC does not calculate tip-in fuel like the stock ECU. The stock ECU is a lot smarter. It uses an additional, completely separate burst of fuel, instead of just adding more fuel on top of the regular calculation. Mazda developed this system for the series 5:

AchillesGr

iTrader: (1)

thanks arghx,
i will try to find out more about this from the datalogit guys and i will inform you.

Wo:Deep

Hi arghx,
I want to chime in here due to the experiences I made the last time tuning my FD.

As you kn ow I´m driving 850s primary and so I had to make a few trick getting the car as I want it to be.

So negative lag-time on injector setting. >> Recalc base map
negative Split on leading >> trailling for nicely lean cruise.

Everything worked fine.
But, as you can imagine the lean condition PLUS the with intense wrong lag-time parameters made the tip in really worse.

So I tested the above mentioned parameters.
From my perspective your good Tip-in results are coming from your Accelerate Injector settings.

Most time in those cruise / drinving conditions you are around the 2000rpm range.

So putting a higher "Amount" value will help to increase the AMOUNT of fuel in a shorter time.

Inj vs. Accel TPS1 also helped in my case. But to high values tend to an overly rich condition after the tipin for a second or so (in my case I realized it because the car misfiered when putting to high values in here!)

So I cannot say something about your personal results.
But In my case it was different.

btw. if someone has problems understanding the "amount" and "decay" values.
Maybe someone knows something about music production or other things with synthesizers or effect gadgets.

Amount is called "Attack" and decay is decay...
So attack is the value which indicates the "angle of attack" in the reaction to a demand.
Decay is the value which indicates the speed of the parameter fading out. So high decay >>> slow fading out
low decay >>
fast fading out

regards

Marc

arghx

iTrader: (3)

I was just messing with the INJ vs TPS settings actually, on a bridgeported car with 1000cc primaries. They didn't seem to do a whole lot of good on that application. So far I've had the best luck with street ported engines running 550 or 720cc top feed injectors.