1980LT1

iTrader: (7)

I just finished installing a nitrous kit(dynotune) on my LT1. I am using a 6AL, Blaster coil, and MSD 8982 timing retard box. My question is when the 8982 box is activated will Datamaster show the 4* of timing being pulled or does the ECM still think it's running at full timing(about 34-35* being shown at WOT). So will Datamaster show 30-31* at WOT with the 8982 activated?

I'm just wondering if the MSD box alters the timing after the box and that the ECM won't know that the time timing is being retarded...?

Thanks,

Guy

C_Rules

iTrader: (7)

don't know the answer but excellent question. i would like to know this myself. why don't you just retard the timing with the msd box and see what happens on data master assuming you have it already?

infinitebird

iTrader: (11)

im pretty sure it will just show what the pcm commanded timing is.

1980LT1

iTrader: (7)

I think I may have my 8982 box wired wrong. I have the gray wire going to my nitrous switch power wire. After reading the MSD instructions I think I am going to wire the gray wire to a relay so that when I use the 12V+ from the switch it will turn a relay on and remove the ground from the gray wire. The MSD instructions say that if you don't have the gray wire grounded it will activate the box and retard however much timing your pill is. I think I have been driving around with my 4* pill in and my timing has been retarded 4*. I am going to rewire it and see if can see the change on Datamaster. I will post my results as soon as I do this. I think that's why I am not seeing any change in timing.

Guy

moehorsepower

iTrader: (3)

No it will not show due to the timing box being downstream, the PCM will still command the timing where the box will retard it...

1980LT1

iTrader: (7)

Yeah I just rewired it and took it for a spin with Datamaster monitoring it. It did not show the 4* of retard. How am I supposed to know it's working properly. I assume it is because my car runs and its hooked up with the 6AL so it must be wired correctly.

Moehorsepower, do you know this for a fact or are you just guessing? That's what I was thinking but I would like a deffinent answer. I am going to call MSD tommorow and see what they say about it.

Thanks so far guys!

Guy

infinitebird

iTrader: (11)

Scan programs (datamaster et al) connecting to the under dash port tap in to the pcm datastream, so it's not going to show any modifications made to the data later on in the process.

It's really pretty obvious if you think about it.

1980LT1

iTrader: (7)

Well it may be obvious but I would still like to know for sure that my timing is being retarded as much as my pill is supposed to retard it. I don't take this stuff for granted.

infinitebird

iTrader: (11)

well to that you would have to splice in a connection to the harness after the ignition box and then sync up the output with the rest of the pcm signals somehow to read it.

96capricemgr

iTrader: (1)

I just noticed you are local, let me know if I can help.

Datamaster does not necssarily show the same as the pcm is commandinfg either, important thing is how the car runs.

1980LT1

iTrader: (7)

What if i painted a mark on the balancer at TDC for #1 and then used a timing light to see if the timing moves? I think that would be the easiest way?

1980LT1

iTrader: (7)

Where are you from?

C_Rules

iTrader: (7)

if you go to a dyno shop and ask them to hook the car up they will be able to tell if its working or not. they hook up their own timing scanner which is after the fact. you can tell them you don't want a dyno tune you just want one run to make sure your retard box is working. maybe they'll let you do it for a small fee.

infinitebird

iTrader: (11)

yes, I have usually found that it is 3-4 deg higher. Not sure why that is.

Karl Ellwein

Infinitebird:
Have you verified this with a timing light on a few LT1 engines?
I wonder about this too, (wonder if Datamaster is showing the true PCM timing).
The couple of times I have checked actual timing on an LT1 with a timing light it has seemed to show about the same timing as what Datamaster displayed, (and knowing that I make sure to put 4 deg less in TunerCat than what I'm shooting for).

But I'm not confident that I'm seeing the crank timing with the timing light with all that much accuracy.....Have only checked at an idle on the engine dyno and not while at WOT on the engine dyno. At idle timing jumps around quite a bit and you eyeball it and say....looks like about 28 deg to me (average)....what's Datamasater showing???!!!!!!! dyno operator---"About 28 deg!!!" Me, "OK".

Karl

infinitebird

iTrader: (11)

yeah, I have not verified with a timing light, I was just referring to the amount I have programmed in at certain throttle/map conditions with tunercats vs what it displayed in datamaster.

maybe datamaster's number is correct then. I've never seen any concrete data on why they are different or which is correct.

C_Rules

iTrader: (7)

your timing at idle is probably jumping around because of the idle underspeed and overspeed tables.

96capricemgr

iTrader: (1)

Currently residing in New London.


I would think that you could hear 4 degrees if you triggered it way with a momentary contact button.

buffman

iTrader: (9)

based on what is programmed in my tune vs what datamaster shows is different by about 3-4 degrees.

moehorsepower

iTrader: (3)

Yes I know this for a fact, Not guessing. Even with the timing retard box, the one where you have a **** in the car and turn it to pull out so many degrees, The only way we knew it was actually working was at idle to turn the **** all the way to pull out 15 degrees of timing and the car would almost die, we knew then for a fact it was pulling the timing out.