TwEECer and Injector Timing calculations

Methodical

15 Year Member
Dec 1, 2003
1,192
11
59
Clinton, MD
Question. I just had EA calculate my injector timing after inputing my camshaft information. I had EA calculate injector timing using the Trailing (injector firing) and both the TDC and Exh close method (injector firing event). The numbers were difference for each range, unlike the stock settings which are set to all 300s - Is it ok to have different numbers.

Do I use the TDC or Exh close method numbers to input into the tables.
 
All of those guys who I consider to be way smarter than me are still to this very day discussin, cussin, changin their minds from time to time, and the like about this subject.

When EA first came out, I used it to figure mine and I noticed the following:

The idle was much smoother and with my cam, that was a blessing.

At idle, each pulse out the tail pipe was stronger.

Before the tweec, an idle lower than 800 rpm was too choppy and very unstable. After the tweec, I could go as low as 700 rpm and the idle was stable but still too choppy, lol.

I've not felt the need to mess with the timing since then so ...... I guess one could say this about me ....................

I don't stay on the cutting edge of self tuning :rlaugh:

btw ...... I use a value of 392 for my combo :shrug:

Grady
 
There is ALOT of talk on this subject on the tweecer forum, like said.

I did it both ways and realy not much diff. from one another...the only real issue I think you can have is if the data given in the calc. is highlighted, that means that your outside of the PW/DC range.

I did notice a good bit in smoothness to idle and some gas improvement.

Most of the debate seems to be around why ford did the whole 300 thing in such diff. areas of the table...and it gets into theory of splashing the exh. valve, to evap. more fuel to better attomize/mix with the incoming air...and some stuff that needs to be read...re-read...take a break from...re-re-read...then scratch your head and just pick a way to go....
 
final5-0 said:
All of those guys who I consider to be way smarter than me are still to this very day discussin, cussin, changin their minds from time to time, and the like about this subject.

When EA first came out, I used it to figure mine and I noticed the following:

The idle was much smoother and with my cam, that was a blessing.

At idle, each pulse out the tail pipe was stronger.

Before the tweec, an idle lower than 800 rpm was too choppy and very unstable. After the tweec, I could go as low as 700 rpm and the idle was stable but still too choppy, lol.

I've not felt the need to mess with the timing since then so ...... I guess one could say this about me ....................

I don't stay on the cutting edge of self tuning :rlaugh:

btw ...... I use a value of 392 for my combo :shrug:

Grady


Grady are you saying that you used 392 for the entire table. EA calculated different numbers from me. Thanks fellas. Peace
 
The reason there is a diff. number in the lower load areas are from lifter pump up that makes the valve action alittle less, and I think delayd' (I think because its been awhile since I last looked at the info/topic hard) from the lack of oil press. to the lifters to pump up. There is a formula on how to do this yourself for the low lift if you want to (clint added this into his table fairly early so it does it on its own in EA).

Also the top end of the load and rpm may be diff. as the speed of the motor and PW/DS can make for a diff. number being needed.

Anyway I realy doubt there is a BAD wrong way to go about this to much of an extent as long as the numbers are not highlighted as said above. I mean I doubt your motor would melt or have worse driving manners....
 
I used EA to create my Injector timing, and it gave me different degrees to use at different loads and RPMS its been like that for a year and i havent had any problems with it, like grady it seemed to smooth out my idle and make my car run overall better.
 
Methodical said:
Grady are you saying that you used 392 for the entire table. EA calculated different numbers from me. Thanks fellas. Peace

Yes, 392 was the only value that EA spit out at me, lol.

I ran the test several times over with several months in between each test and that value always came up.

Grady