How is injector timing calculated?

[carlrx7]

crap,, just watched it, and he takes 20 degrees away from the ECT table. FML

[Kyne]

I think my understanding of the RPM target table is wrong, or maybe the opposite of what it does. If its boundary -ECT -RPM then the injection gets more and more advanced as the RPMs increase, I just did the math at 4k RPMs the injector would be injecting it 43*BTDC. Is that the advance it needs at that speed, or just so all of it is injected on a closed intake valve? That means it would have about 61* before it even opens.

[IDRIVEAG8GT]

Well I've added 40* to the boundary normal table and my problem is getting worse.(the smell) I think I'm going the wrong way. So you'd basically wanna chop x* of the boundary off and around the idle mark? Or carry this across the entire table?

[carlrx7]

Try taking 20 away from ect normal table

[Area47]

i added .5 to the ect makeup and various to the boundry. fuel smell has died off considerably, and picked up torque in the idle-3k range. i have the cam specs and crap, and now i see that i needed to "remove" from the boundry and make up tables? um. now im just lost. again. crap.

[DSteck]

Don't mess with the boundary.

[carlrx7]

well, i put the RPM Normal table back to stock and then removed 14.5 from the ECT Normal table, (14.5 is the duration difference between my cam and the stock cam).

Now I swear the raw fuel smell is eye burning!

these tables make no sense. time to go take a shower and burn my clothes.

-Carl

[Kyne]

well, i put the RPM Normal table back to stock and then removed 14.5 from the ECT Normal table, (14.5 is the duration difference between my cam and the stock cam).

Now I swear the raw fuel smell is eye burning!

these tables make no sense. time to go take a shower and burn my clothes.

-Carl

When does your exhaust valve close?

[carlrx7]

228/232 114

Evc 26.5 Atdc

[Kyne]

Well the stock EVC .004 is 30* ATDC so your exhaust is actually closing earlier and your timing may not need to change, and you gain 4.5. It should be less about duration and where the events occur, That's worked well for me in the past.

[carlrx7]

that was at .006

stock EVC is 30* ATDC

[Kyne]

that was at .006

stock EVC is 30* ATDC

I didnt realize that until after I posted haha.

fixed my earlier post

[Kyne]

DSteck, is it Boundary -ECT -RPM, OR Boundary -(ECT-RPM)?

Neither would effect idle since RPM is 0 there but the first one doesn't make sense in the upper RPMs where as the second one does make more sense to me in the upper (and explains to me at least why you would need 110* in ECT since the stock RPM goes up to 93*)

[Jamz]

Hi guys

I have attached Gen 4 STD HSV ls2 and STD L98 EOIT tables for reference.

I know the only different between these two motors is that the LS2 has:

• Slightly smaller injectors
• Cathedral Port Heads
• Slightly Larger Camshaft
• Roughly .5 more compression

Also note this is a HSV 6.0 LS2 tune, so it has better exhaust flow than standard.

1: I would like to know the reasoning why the LS2 has 520 across the board while the L98 tapers or (advances) at higher RPM. Is this due to head port size and velocity?? Or just for emissions. As the fuel sits on the valve longer for evaporation / Aiding in cylinder fuel distribution.

2: Why does the RPM table end at 4096. Does it continue the last value to redline or revert to 0 for any RPM over 4096 to redline??????

[IDRIVEAG8GT]

I retrarded/took away 16* on the ECT table across the board and immediately returned it to stock. Car didn't wanna start, and when it did I nearly suffocated myself

Back to square one. It was idling better with some hacked up numbers in the Boundary table.

[blkscooby]

Here's my current tables.

I used the spreadsheet that HRD posted which is essentially the same thing I developed but was cleaner.

[DSteck]

Boundary - ECT - RPM

[Kyne]

Boundary - ECT - RPM

So on a stock car it usually goes from ending 30* ATDC at idle to ending at 43* BTDC over 4k RPMs? It seems like you would want it ending later in higher RPMs.

[Area47]

so i changed the boundry back to stock. made the smell worse. obviously. added 20 degree's to the ect table. so it seems i was actually on the right track the first time guessing with it vs the other way.

[Kyne]

so i changed the boundry back to stock. made the smell worse. obviously. added 20 degree's to the ect table. so it seems i was actually on the right track the first time guessing with it vs the other way.

We already discussed this and came up with those numbers not guessing your cam is A typical though because it isn't super big. Your numbers were rpm 675, msec 3.3, boundary 530, ECT 110, EVC 27 ATDC:

530*- 110* = 420* <<<thats where the stock EOIT is at 675RPMs (60* ATDC)

3.3msec @ 675 RPM is 13.365*
27ATDC = 387*
387* + 13.4 = 400.4* <<< that's where you want your injection to end so for some reason adding 20* does make sense. DSteck correct me if I'm wrong.