Need Help With Deadtime ASAP

[TSiWarrior]

Im in the process of burning a new chip. I need help understanding/setting the injector deadtime map.

Here's some info I found

The injector deadtime map compares the deadtime of the fuel injectors to the battery voltage. The first byte of the map is 4.7 volts, the second point is 7.0 volts, then 9.34v, 11.68v, 14.0v, 16.35v, and 18.7v. The decimal value of each byte refers to the deadtime of the injectors, divided by 24 microseconds.

The stock map is "A9 58 30 23 1B 17 13"

If you wanted to add 200 microseconds of deadtime, you would add 8 to each of the values on the map, since 200 / 24 = 8.

For 550's, you want about 150-175 us more deadtime. 660's will be above 200, usually around 225 or 250. However, these settings will vary from car to car, and between different types of injectors.

My injectors need 1.13ms to open and the closing response time is .998ms.

Here's what im looking at where I change the dead time

Volts Deadtime
18.7 456
16.35 552
14.0 648
11.68 840
9.34 1152.00
7.0 2112.00
4.7 4056

I need to modify the deadtime per voltage to match the 1.13ms I need, not sure if closing deadtime applies. Im not particulary sure how to go about that. I suppose I would need to know the stock deadtime in ms? of the dsm 450's then subtract that from the 1.13ms of my 880's then divide that by 24?

Any help would be appreciated, I wanna start the car tommorow and not have to redo the chip.

Thanks!

 

[pneumo]

I saw your post on DSM-ECU and couldn't figure out what exactly you wanted. Now I see you have 880cc injectors. Why do it the hard way?


This is the list of deadtimes I have collected over the last few
months:
>Mfg. size dead time (ms)
FIC 650 210
FIC 750 315-330
FIC 850 315-330
FIC 950 315-330
Delphi 680 210
ND 660 180
RC 550 180
Hahn 625 180
Denso 660 180
Denso 720 405-450
PTE 680 288
PTE 780 300
> found a chart in a post by Thomas Dorris in mid 2002 (
> http://tinyurl.com/72ccn ). In this chart, he lists deadtime
> compensations for various injectors, as follows:
>
> Injector Dead time
> RC 550s 180 usecs
> Denso 660s 180 usecs
> Denso 720s 405 usecs
> Clinic 750s 330 usecs
> Clinic 850s 330 usecs
> Clinic 950s 330 usecs

To make it simple, just add 330usec to the stock deadtime. 330 divided by 24 = 14(rounded up). Convert 14 to hex and you get 0E. Then add 0E to the stock deadtime values and you get: B7 66 3E 31 29 25 21. use it, learn it, love it.

 

[TSiWarrior]

According to nick s, he found out that my injectors need about 410us over stock, wich is 17.xxx and according to your info it needs around 330, so I ended up adding 16 to everything. We'll see how it goes