What is your injector pulse offset with Roe SC ?

[Schulmann]

I have done some fine tuning on my injector pulse offset over this week-end.
The result is interesting and after the fine tuning my car runs much better.
Car has 5lb Roe SC, 1 3/4 headers, 3'' head back.
Here is what I did.
After a short trip of 50mi of cruising at 1750rpm I stopped and removed my spark plugs. According to what I saw, I modified my offset. Espetially the rear plugs were in bad shape. I repeated this several times. Finally all plugs look "good" but there is still place to make adjustments. Here are my offset:

#1 0.08 #2 0.03
#3 0.08 #4 0.03
#5 0.18 #6 0.08 ( These two values #5 and #6 are special and I might #7 -0.05 #8 -0.28 changed them.)
#9 -0.46 #10 -0.97

I would be interested in comments on my offset and see other settings.

 

[J DAWG]

I dont have a s/c on my car, but when I set my inj. pulse offsets, I just made sure I set them to whatever it took to get my long term adaptives to 0%. Used the Ease scan tool(enhanced version).


to me it doesn't seem that 0.03 or 0.08 mls would make much difference when the injectors are open for over 20 mls at the higher rpms(stock injectors) since that is <1% change, but if it helped then that is what matters. Boosted cars may respond differently to changes than n/a cars.


with my heads/cam car I had to take out nearly 2mls on each bank because it was so rich. Once the adaptives were inline then I had to add quite a bit back(load and rpm tables) to get the a/f where it needed to be.


John

 

[Schulmann]

My trouble is espetially on cylinder #10. Today I removed even more fuel now its offset is at 1.2ms.

 

[J DAWG]

8 and 10 are normally the trouble makers. I have just trimmed mine the same even though trimming them individually is best like you are doing.


wonder if there is a percentage most use as they trim fuel going from the front to back of engine???


probably just have to do it like you are doing it and read the plugs unless there are certain individual cells that a scan tool can show that would give some input on each individual cylinder

 

[Cudaman]

J DAWG is normally the trouble maker.

Cudaman


What is this:

12/21/04 - 3/11/05 R.I.P. Jackson

 

[Schulmann]

My point is that a 1.2ms offset on cylinder #10 will harm at wide open throttle or not.

Until now nobody gave a valuable feedback on a SC Viper.

 

[GTSnake]

How are you determining how much to take out? Do you go by how the plug looks if it's too black or not? I have adjusted my #10 injector leaner as well but don't know at point do I stop.

 

[Schulmann]

Actually I try to read my plugs. Every time I stop to refuel I check my rear and front plugs. At this point it is not difficult because the plug #10 is black like coal. I managed to fix plug #9 with 0.60ms offset. Now my offset at plug #10 is 1.3ms. However I got light detonations at 5000rpm and I had to remove timing. I thing removing too much fuel isn't good for racing. Sean told me that this plug trouble only occures at cruising at low rpms. So for racing plug #10 is not an issue. At this point my idea is to write a card for Highway cruising with rev limitation at 5000rpm and removing more timing. Then I will write a card for racing where offset will be minimal (like 0.40ms at cylinder #10).

GTSnake what is your present offset at cylinder #10 ?

 

[GTSnake]

I can't believe you pull the plugs every time you refuel. Don't you remove the HVAC cover too?

My #10 is also black as coal so I've set it at -1.1. I'm not experienced enough to do anything too drastic.

I had the timing ******** to 9-deg because I was getting detonation. But I found that I had a MAP sensor issue. I'm planning on going up to a 6-D card and the colder plugs after I fix the MAP sensor. When I first had the SC installed I could run the 3-D card without any problems using 94 octane.