i put my car on the scanner with my new chip tune to just see how everything looks. my wot timing is at 26.9*, then you add your base timing, mine is at 8*. so thats 34.9* total timing at wot. does this sound like enough timing..

what are most of you running at???

 

I am running 32 degrees total, which I believe is conservative.

There is a point of confusion regarding WOT total timing.

Datamaster indicate 32 degrees at WOT 5500 RPM+ for my engine. My chip spark tables also indicate 32 degrees. Intitial timing is set to 6 deg with the chip constant table also set to 6 deg. I understand that the spark table is total timing and you do not have to add initial timing as it is already factored in. My point is that I believe that that Datamaster also indicates total timing without having to add initial timing...I am not 100% positive on this.

Make sure that you are getting the total timing that you think you are getting.

 

What year vette do you have? Whats mods, what compression?

I have an '85 with about 10:1 compression and I can get away with around 35degrees total timing in good weather (sub 80F).

Heck stock GM timing is like 32degrees for the '85 vette, which only has 9-9.5:1 compression.

 

i have a 91 l98 with comp ratio 10.9-1 . heads, cam, headers, intake, rr's, mds, nos. i havnt put my miniram on yet but i will soon.

i need to see wot settings for my old chip. im pretty sure it was more.it runs a lot better now butseems to have a little less with the new chip.

the track will tell on sunday. they are having a $1000 win in the street money class.

 

Guys the chip has a reference of 6* to it. This means that the ECM will add 26.5* to that base for a total of 32.5*.

Not here is where the confusions comes in. Scanners report these values in all sorts of ways. Some will show the timing with reference to TDC, which will include the 6* and some will so it without the 6* so it will report the 26.5* in the case above. And others will show it both ways.

Now to throw more confusion ontop of all this. If you change your base timing, and do not change it in the chip. You have to mentally add whatever deviation from 6* to what is being reported, in either reporting form.

The ECM is only as smart as what you tell it. Changing the timing via the distributer, will make a global change.

If your not sure what it should be set at, your best bet is always to put it at 6*.

Hope that clears things up.

 

ski, im 99% sure that my scanner doesnt calculate timing at tdc. in my car the scanner wont even pick up the timing retard changes with msd box for nos. apparently in a 91 l98 the ecm only shows the timing that the chip asks for.

 

Here is the way the ECM usually reports the timing.

1. It looks at what is programmed into the initial timing field (typically 6*)

2. It looks at the main timing table relative to MAP and RPM. Lets say 32.5*

3. It looks at PE (power enrichement) tables: Lets say 3*


FOr the above scenerio you will have following total timing

6* (base) + 27.5 (main table since the 6* is already figured into the 32.5)+3* (power Enrichement) = 35.2* of total timing.

If that is reported as timing at TDC it will show = 35.2*
If its reported as timing with respect to reference. It will be 29.2* (6* less than your truely getting since the 6* base is already what the motor is seeing and your remainder is what the ECM is adding)

 

You guys scare me, wrong post for me to read, over my head. Think I'll go paint the bathroom

 

where did you get the figure of 3*for power enrichment. is that what you program in your chips or a universal norm.

so say my scanner is seeing 26.9 , and knowing i need to add whatever base timing that im set at, which is 8*. the 34.9* timing im coming up with may not be correct? in order to get the proper timing at wot do i need to find out if any other timing values that are being added in.

ski,
it just sunk into my thick skull

how do i know if my chip has an initial base of 6* ? i dont think it does.
26.9 is very low if it is figured in already.

so say basicly if my power enrich is 3*, and a base of 6* is figured into my 26.9 value, and my base timing is at 8*. i would come up with a total timing figure of 31.9*. a little

 

I think your thinking about it too much.

Its very simple. You need to find out how your scanner is reporting. To me if those are WOT timing numbers your quoting then its "timing with regads to reference" in otherwords its what the ECM is adding (you need to add 6* to it for the base, or 8* if that is what you have the base timing at.)

The 3* for PE was just a made up value.

You need to go to the scan section and search your scanner and see how it reports timing. That will clear it up for you.

 

my scanner does not report total timing. i took it for a ride and the wot timing was between 25* and 26*, so adding a base of 8* . 34*total timing with no knock counts. im gonna go up to 10* base and watch the knocks. i want to go as high as i can until i get sone knock and then ill pull it back some.

the only thing im worried about is my 125hp nos. if i go higher with the base timing and im pulling 3* out for the nos. should i pull the same timing im adding to the base to the nitrous retard. so if i add 4* to base should i pull and extra 4* out for nos?? i want to be safe but i dont want to choke the nos to much.

 

does anyone know if moates scanner reports the total timing for total - base timing for the 165 ecm?

 

My DFI in scan mode is showing 39* at WOT. I have to assume that is total and includes base. Is that incorrect?

 

if your at 39* it must me total. if you added you base to that it would be way to high.

im only at 34* total and i need to go up some.

 

what timing does it say your at?

 

28-29

 

Guys.

This is one of the those topics with you need to take a step back from and look at the entire picture. What I mean by that is there are MANY things that could lead to incorrect total timing. This is why I ALWAYS say to not shoot for a specific number. Let me explain more:

Your timing is based on MANY things coming together. You have to assume that your pointer is DEAD on, your crank keyway is DEAD on, your balancer is dead on, and your EYE is dead on when aligning the pointer to the balancer.

One way to make sure all these things are dead on is if you degreed in your cam yourself. You need to find ABSOLUTE TDC and see if your pointer is truely at 0*. We did my 434 and it was off 4* based on the pointer position. We just did my dads 555 CI motor, we forgot to do it when the degree wheel was on, and had to redo EVERYTHING, took over 1hr to get everything re-setup and turned out if we would have just assumed that the pointer was truely at TDC it would have been off 3*.

This is why I always say to give the motor what it wants. Do not think because your buddy has his at 10* base, yours will run its best at 10*. Your might want 3*.

Prime example. My 406 we did not do the above. Turns out my base timing needed to be at 12* which if I believed the number it was running 42* of total timing. The car would loose 4-5MPH in the 1/4 if I moved it off that spot. So I ran it there. I started at 6* and kept moving it 2* and it kept picking up. When all was said and done, and I found out I was running 42* of total timing, I knew something with either the balancer, or pointer (most likely the culpret) was off. But the car ran great there. Corky however said his was at 31*, so same exact motor, and there was 11* difference between the two. If I would have run my timing at 31* if would have been 10mph off.

Remember its just a number. Unless your absolutely SURE your pointer and all the other items are perfect, there is no telling how far off you are. And believe me, the stock pointers you can bet are off at least 2*.

This is specifically why when I do chips for people I always encourage them to start at 6* and then move it in 2* increments at the track. Keep doing it till the MPH drops off and then move it back to the best advance. Its not because I can't pick there total timing that is best, its because of the above, and I can't assume that their 6* is truely 6*. In probably 90% of the cases I would bet its off my 3* or more.

Read this a few times, and it will all make sense if it didn't the first time through. But above all, remember its just a number, and give the motor what it wants if your after performance. It it likes 42* of total timing, then run it at that.

 

ski is right.. there is no magic # to follow.

if you cant make it to the track then what i do is keep going up 2* with the timing until i start to get knock retard them go back some.

then ill go to the track and fine tune a little more.

usually the more timing you can put in the better. but you can go to far.