Cool early Father's Day gift

[Old60Driver]

So, I've been trying to figure the timing curve out on my 83 K20 SBC for a bit. I was in a bind a few years ago and needed a dizzy, and picked up an Amazon special out of desperation. And, while the truck runs, I couldn't effectively tune the curve. My wife, awesome as she is, comes out while I'm tinkering and asks what I'm tinkering on, and I'll explain what I'm doing. She's not mechanically minded at all, but she's pretty cool like that. Let's me vent or ramble, or both. Anyway, yesterday, I was just rambling and told her about this new distributor I read about from Progression Ignition. Evidently, she was really paying attention, because she went and ordered it for an early Father's Day gift for me! Should be here in a few days.

Not sure how I feel about having a 'computer' in the truck, but the fine tuning that can be done on the fly, without adjusting the dizzy itself looks pretty amazing. Plus, it can be set up to give an extra bit of timing when the RPM drops (putting in gear or A/C), that'll ramp the RPM back up a touch.

Anyway, I'm pretty stoked to try it out, and just let y'all know I'm a lucky man to have a woman like this.

And yes, she's reading this as I type it! LOL

 

[dsteelejr]

That’s awesome she did that for you! I use those in two of my squares and I love them. You won’t be disappointed.

 

[Strick]

You are fortunately blessed to have a woman that pays attention & listens. She's a keeper for certain!

HS

 

[Old60Driver]

That’s awesome she did that for you! I use those in two of my squares and I love them. You won’t be disappointed.

Yeah, she's pretty amazing! Quick question. How much tinkering did you have to do with the timing map after it generated one? I don't mind tinkering at all, just curious. Thanks!

 

[Old60Driver]

You are fortunately blessed to have a woman that pays attention & listens. She's a keeper for certain!

HS

Agreed. I'm punching WAY outside my weight class.

 

[idahovette]

^^^^^^^^I know EXACTLY what you mean!!!!!^^^^^^^^

 

[dsteelejr]

Yeah, she's pretty amazing! Quick question. How much tinkering did you have to do with the timing map after it generated one? I don't mind tinkering at all, just curious. Thanks!

I didn’t have to do much to get it going. Right off the bat it will generate a base timing table for you with a conservative advance, a ‘safe’ table. You can generate as many new tables as you want and for each one you’ll be able to input your own specs. See the attached pic.

I played with the max RPM based timing to see how much advance I could give it. 36° for max works well for my 454. I pushed it to 38° without it pinging, but I didn’t feel any gains so left it at 36°. I also played with the ‘all in’ RPM. Stock distributors have to reach about 3000 RPM before all your timing is ‘all in’. I set my Progression distributor to be all in at 2000 RPM so it starts advancing much faster as soon as you come off idle, but still maxs out at 36° total. That really woke up the engine and gave me a lot of power that was being left on the table with a stock distributor. Stock ones are very conservative.

 

[Old60Driver]

I didn’t have to do much to get it going. Right off the bat it will generate a base timing table for you with a conservative advance, a ‘safe’ table. You can generate as many new tables as you want and for each one you’ll be able to input your own specs. See the attached pic.

I played with the max RPM based timing to see how much advance I could give it. 36° for max works well for my 454. I pushed it to 38° without it pinging, but I didn’t feel any gains so left it at 36°. I also played with the ‘all in’ RPM. Stock distributors have to reach about 3000 RPM before all your timing is ‘all in’. I set my Progression distributor to be all in at 2000 RPM so it starts advancing much faster as soon as you come off idle, but still maxs out at 36° total. That really woke up the engine and gave me a lot of power that was being left on the table with a stock distributor. Stock ones are very conservative.

Thanks for the insight! So, just so I understand it correctly, you have it set for 36° max RPM based, and max vacuum @ 8°. So at all in (2000 RPM), are you at 36° or 44°?

 

[dsteelejr]

Thanks for the insight! So, just so I understand it correctly, you have it set for 36° max RPM based, and max vacuum @ 8°. So at all in (2000 RPM), are you at 36° or 44°?

Yes. It only hits 44° when vacuum is extremely high, which is on deceleration. Once you give it throttle and the vacuum decreases the timing drops and returns to 36°.

The red highlighted row near the bottom is idle vacuum. The very bottom row is higher vacuum than idle and you can see it only hits 44° at high vacuum high RPM on the bottom right. Top row highlighted in blue is atmospheric pressure, zero vacuum WOT. As you go from bottom to top you can see the advance back off as it gradually goes back to 36° the more you get on the throttle.

 

[JamesSam]

So, I've been trying to figure the timing curve out on my 83 K20 SBC for a bit. I was in a bind a few years ago and needed a dizzy, and picked up an Amazon special out of desperation. And, while the truck runs, I couldn't effectively tune the curve. My wife, awesome as she is, comes out while I'm tinkering and asks what I'm tinkering on, and I'll explain what I'm doing. She's not mechanically minded at all, but she's pretty cool like that. Let's me vent or ramble, or both. Anyway, yesterday, I was just rambling and told her about this new distributor I read about from Progression Ignition. Evidently, she was really paying attention, because she went and ordered it for an early Father's Day gift for me! Should be here in a few days.

Not sure how I feel about having a 'computer' in the truck, but the fine tuning that can be done on the fly, without adjusting the dizzy itself looks pretty amazing. Plus, it can be set up to give an extra bit of timing when the RPM drops (putting in gear or A/C), that'll ramp the RPM back up a touch.

Anyway, I'm pretty stoked to try it out, and just let y'all know I'm a lucky man to have a woman like this.

And yes, she's reading this as I type it! LOL

Very cool. Great wife. She obviously loves you!

 

[Old60Driver]

Very cool. Great wife. She obviously loves you!

Yes she does, and it's very mutual!

 

[Old60Driver]

Yes. It only hits 44° when vacuum is extremely high, which is on deceleration. Once you give it throttle and the vacuum decreases the timing drops and returns to 36°.

The red highlighted row near the bottom is idle vacuum. The very bottom row is higher vacuum than idle and you can see it only hits 44° at high vacuum high RPM on the bottom right. Top row highlighted in blue is atmospheric pressure, zero vacuum WOT. As you go from bottom to top you can see the advance back off as it gradually goes back to 36° the more you get on the throttle.

Awesome. I'm actually going to use the it like it appears that you have it set as well. I don't have an A/C idle solenoid, but after talking to Ted at PI, he said that a lot of folks do what you did, and add timing at 500 rpm to bring the idle back up. Pretty excited to start this project. In the meantime, I'm going to be modifying my qjet to square bore adapter to be an actual dual plane, so it matches my intake. Fun times!

 

[Old60Driver]

Okay y'all, just finished putting the new dizzy in. Literally took me twenty minutes. Maybe 21. lol This ol' girl has never run better. Made a couple of adjustments on the fly on the test drive. Damned cool!!! AND, I was able to add some timing when a load comes on at low RPM (A/C or putting in gear), and it works perfectly!! Heck, I almost feel as cool as Cleetus fine tuning his runs in Mullet!

 

[dsteelejr]

Okay y'all, just finished putting the new dizzy in. Literally took me twenty minutes. Maybe 21. lol This ol' girl has never run better. Made a couple of adjustments on the fly on the test drive. Damned cool!!! AND, I was able to add some timing when a load comes on at low RPM (A/C or putting in gear), and it works perfectly!! Heck, I almost feel as cool as Cleetus fine tuning his runs in Mullet!

Told you you wouldn’t be disappointed! I’ve messed with MSD boxes years ago and didn’t notice much improvement, but the PI distributor works so much better than anything else I’ve tried without the hassle of wiring up the extra brain box.

 

[Ricko1966]

For best mpg you want to find minimum best torque which means you are running the minimum timing that gives you the best power. The way I find it is accelerate a measured distance and check MPH trap speed keep adding timing until trap speed quits increasing,then go back to minimum timing that gave best MPH. That way the engine isn't. Fighting ignition an extra 2,4,6 degrees on the pistons way up. On the highway at cruise with working EGR you want high 40s to low 50s timing, no EGR, low to mid 40s