GM Module timing curves

[chevmasta]

So we don't completely hijack the other thread.


So you're saying that 24 degrees commanded might not necessarily = 24 degrees? Is this why all these timing curves look weak on the "mechanical" side?

My 90kpa @2800RPM is 20 degrees in the tune, with no adders active, but it could actually be higher (or lower?)

FWIW, my current tune has 22* at the same load and RPM.....but I'm waaaay less efficient than your engine. lol

Yup! Never know... even the spark latency settings in all stock GM bins are not accurate. I think the engineers used it as a cheat? Some engines with same distributor have different settings, although same parts.

If you want a information overload then read where it was found and some testing done back in 2008 at ThirdGen.org

http://www.thirdgen.org/techboard/di...ncy-table.html

I have the DUI setup....full distributor and coil. I remember at some point reading that the DUI modules were extremely good. Similar to the 369 modules I believe.

[EagleMark]

I have the DUI setup....full distributor and coil. I remember at some point reading that the DUI modules were extremely good. Similar to the 369 modules I believe.

Well if you read it on the internet then it must be true?

But as shown above here the same engine etc... has different latency's! So GM must have used this as an adjustment? Most of them are really close, say at 2000 RPM but they do move timing around a few degrees, but that same number in Usec at say 5500 RPM can be off by 11*so if you really need say 22 at a certain RPM for cruise and MPG or towing then the only way to be sure is some testing with a timing light on the balancer.

[chevmasta]

Well if you read it on the internet then it must be true?

But as shown above here the same engine etc... has different latency's! So GM must have used this as an adjustment? Most of them are really close, say at 2000 RPM but they do move timing around a few degrees, but that same number in Usec at say 5500 RPM can be off by 11*so if you really need say 22 at a certain RPM for cruise and MPG or towing then the only way to be sure is some testing with a timing light on the balancer.

Haha I know! Gotta love the net! I thought I remembered reading a comparison of oscilloscopes from the dui and Delco modules. Don't remember where.

I definitely learned something today on these modules. But it's not gonna change the way I tune.

[Nasty-Z]

Haha I know! Gotta love the net! I thought I remembered reading a comparison of oscilloscopes from the dui and Delco modules. Don't remember where.

I definitely learned something today on these modules. But it's not gonna change the way I tune.

THe DUI Dynamod for the GM distributor is one of the best . I always try to use the 369 module but my NOS stock is fading fast , the new modules you get from GM with the new part might or might not be the genuine 369 like before , there are no markings on the ones I have ordered , just the new part # .

Only way to know for sure is to install it and try it I suppose .

TOM

[chevmasta]

THe DUI Dynamod for the GM distributor is one of the best . I always try to use the 369 module but my NOS stock is fading fast , the new modules you get from GM with the new part might or might not be the genuine 369 like before , there are no markings on the ones I have ordered , just the new part # .

Only way to know for sure is to install it and try it I suppose .

TOM

Maybe we should collectively, on this forum, purchase the new delco module part number and have it tested to see where the values are set in the unmarked delco module?
Just a thought.

I'm getting ready to test my new moates hardware. If it turns out as I hope....I owe Mark $100 anyway. LOL

[chevmasta]

THe DUI Dynamod for the GM distributor is one of the best . I always try to use the 369 module but my NOS stock is fading fast , the new modules you get from GM with the new part might or might not be the genuine 369 like before , there are no markings on the ones I have ordered , just the new part # .

Only way to know for sure is to install it and try it I suppose .

TOM

Because of this thread, I decided to email Performance Distributors and ask them about the "curve" built into their DUI ignition module. This is what they responded with:

Ryan,

The only difference in our module over stock is the increased dwell
time. There is about a 3° retard in the higher rpm's that is inherent to
the module. Thank you.


Performance Distributors (DUI)
2699 Barris Drive
Memphis, TN 38132
www.performancedistributors.com
901-396-5782

[Nasty-Z]

Because of this thread, I decided to email Performance Distributors and ask them about the "curve" built into their DUI ignition module. This is what they responded with:

Well that's weird , contrary to that reply , the one I have in the 434 in my S10 actually acts more like a 369 , IIRC it advanced about 2 degrees or so after 3500 or so RPM.

Dunno.....

TOM

[Fast355]

Well that's weird , contrary to that reply , the one I have in the 434 in my S10 actually acts more like a 369 , IIRC it advanced about 2 degrees or so after 3500 or so RPM.

Dunno.....

TOM

The one in my TPI G20 did the same.