You aren't using those numbers in Osiris are you? I noticed that you saw my thread about trying to tune with Osiris - I feel your pain.

 

no, I interpulated them for osiris.

 

You interpolated them between 10v and 14v or did you do something else?

The reason I say that is because for some reason the values for "stock" latency in the base ROM provided by Uprev are way off from what the actual latency specs are for the stock injectors (as provided by DW). Likewise, the "correct" values for DW 800's in Osiris will not be the same as what you posted above, but instead something significantly lower. Don't ask me why. It doesn't make any sense to me.

 

i interpolated them from the stock latency given by DW.

I don't have to get it perfect since i'm having it tuned this saturday. I just need to get a good base tune to get it up to chicago from st. louis. So far it's idling somewhat ok and it is stoich at highway so i'm ok i think. I'd like to get it best that i can before i go. Furthermore i would like to understand it so i can make changes to it later as things change or if i change something on the car.

 

did we ever figure out which numbers are correct? hks lists the first numbers up top as correct but that's what hal was tuning on my car and i'm still having tons of problems. also my car dips really lean if i load the engine with things like power windows, seats, and a/c so that makes me think the top dead times aren't correct.

 

Hal sent me a base map with these #s (I have 1000cc HKS) and Haltech:

9V 1.147

10V 1.092

11V 0.937

120 0.732

14V 0.450

Are they right?

 

How much does your voltage fluctuate? I notice with those same dead time values, the car goes just slightly rich when the voltage drops (like when running power windows and seats all at the same time). It's very slight for a full voltage point drop, which is fine by me. I am getting a high capacity alternator made from ExtremeAmperage.com to get better voltage at idle when the alternator is hot.

If you switch to dead times that are smaller, you will have even less correction for a voltage drop, which would mean that you would go even leaner...

 

oh wow, that's so wild because the top numbers i posted were the numbers that hal used for mine which are WAY higher than the ones you use. I wonder why hal would use 2 different values for the same engine. he used the HKS given values for mine and something a lot smaller for yours. weird

If i roll my windows up my car goes lean and bogs. so does that mean i have to increase the dead times? that makes me nervous because i think they are already too high. When i change them, should i adjust them all across the board up and down or only at certain voltages?

 

So, should I use this one instead:

HKS 1000CC

Flow LB/Hr 95

Ohm 2

10v 1.31

11v 1.14

12v 1.04

13v 0.97

14v 0.89

15V 0.79
?

 

I use the HKS spec (the higher values) and it works fine for me. The numbers you enter only apply for the voltages the ECU sees, so the only thing that really matters is cranking voltage and your running voltage - with all accessories on vs off. If your AFR is steady then you've got it dialed in. Log voltage vs AFR.

 

I will use the higher ones and see.

And my AFR isn't steady, so I hope this will help.

 

my a/f fluctuates sometimes but it's usually consistant wth a vacuum fluctuation.

I need to fix the a/f drop when i turn on accessories. When i roll both windows up it'll drop the a/f to 16:1

 

In that case you want to bump up the latencies in the <14v areas. Probably focus on 12-13V or use a multimeter to check the exact voltage when you turn everything on.

 

so a larger dead time? dang, that's a huge dead time then. I guess i have no choice.

thanks!

 

Yea you want more fuel at lower voltages basically... if my memory serves correctly a higher dead time (tuning wise) = more fuel?

 

ya, cause it's open longer. makes sense, mine are just so high already which is crazy.

 

I tried the values that is posted here (the higher values) and the car idled better but it bogged like crazy and the AFR was fluctuating (mainly rich).

Will go back to the old values, they were a lot better.

 

You cannot just change dead times without retuning your AFR tables. The dead times values are added as the last and final step to the ECU's fueling calculations. It's just a constant add on value... If you increase your dead time by 1.0 (at your running voltage - usually 13v) - you are basically adding 1 ms of fuel to every cell of the fuel table.

 

Is it ok to keep the old ones and finish the engine break in and leave it to the tuner later?

 

well, that's no big deal to retune some more stuff on the fuel map. If it fixes the lean issue when i turn accessories on then it fixes my problem.