416" on the dyno

[B3422w5]

That is the correct answer. And sadly, you’d be in the majority of racers today. None of them have any idea what their timing is at any point in the curve except where they set it and check it.


Im betting (guessing actually) that you are using an MSD 6 box. Probably analog, not that the digital boxes are any better and that somewhere between 3500 and 4500 rpm the timing starts retarding.

How many degrees and how much more it retards is also a guess unless you bench test it.

You can see it for yourself with a timing light, but ALL timing lights also have a slew rate and they don’t all have the same slew rate.

So even if I set the timing curve on my bench I know the actual timing numbers will be slightly different at the crank on the engine because the timing light is slower than the electronics on my test bench.

Generally, the better the timing light the closer it is to my machine. I’ve seen timing lights off 4 degrees at 1k rpm.

As long as you know it and you always use the same timing light you can tune with it.

One thing that drives me crazy is guys show up to dyno their engine and they don’t bring their timing light. It just makes **** all the harder once it’s in the car.

Or worse yet, you get to the track and they want to make a timing change (which Im all for if the conditions call for it) and they borrow a timing light.

Yes the 6 analog box with built in two step( that I have yet to use) as I footbrake this car.

 

[Newbomb Turk]

OK, how is that even possible? I create my own timing tables in the Holley software and unless I am missing something I don’t see how you would accomplish that. I would genuinely like to know.

Regardless, how much different could the individual curves be? You’re only dropping a few hundred rpm between them.

On the dyno we checked the timing at 3,000rpm and it was 34. The Holley EFI software has a check sequence to verify the timing at any RPM you want.

With a programmable ignition you can do it.

I’m not sure about the EFI software but I’d be surprised if you can’t set a curve for every gear.

Load is a huge factor in timing. Low gear sees a lot less load so you can add some timing and add some power IF you can hook it up.

Of course you can go the other way too. If you are traction limited you can pull timing to kill a little power at the hit and make it hook up better.

 

[Newbomb Turk]

OK, how is that even possible? I create my own timing tables in the Holley software and unless I am missing something I don’t see how you would accomplish that. I would genuinely like to know.

Regardless, how much different could the individual curves be? You’re only dropping a few hundred rpm between them.

On the dyno we checked the timing at 3,000rpm and it was 34. The Holley EFI software has a check sequence to verify the timing at any RPM you want.

https://documents.holley.com/c2e90a8b8240134f4cb1209aeaf9715d1e610941.pdf

Here are the instructions for the Grid. You can put the grid over several different ignition systems and you can do individual cylinder timing AND do curves for every gear.

Im going to tell you that I don’t have the experience to even start to do cylinder to cylinder timing. Thats pretty complicated IMO and you’d need some data acquisition tools on the dyno I don’t have and at my age Im just not going to spend the money to buy that gear and learn how to use when 99.99999999% of the people I know would never even consider individual cylinder timing, let alone sorting out timing curves for every gear.

But the software is out there. And I believe it has merit IF you want to spend the money and time to learn it and then use it.

If I was younger I’d be on that like stink on poop. But I’m not. Im still trying to convince guys that the internal combustion engine as we use them need less timing at peak torque and more timing at peak power.

Thats pretty complicated means the needed timing for any given engine is a curve. How in the hell would I convince anyone that each GEAR can use its own curve and each CYLINDER can use its own timing curve?

 

[TT5.9mag]

https://documents.holley.com/c2e90a8b8240134f4cb1209aeaf9715d1e610941.pdf

Here are the instructions for the Grid. You can put the grid over several different ignition systems and you can do individual cylinder timing AND do curves for every gear.

Im going to tell you that I don’t have the experience to even start to do cylinder to cylinder timing. Thats pretty complicated IMO and you’d need some data acquisition tools on the dyno I don’t have and at my age Im just not going to spend the money to buy that gear and learn how to use when 99.99999999% of the people I know would never even consider individual cylinder timing, let alone sorting out timing curves for every gear.

But the software is out there. And I believe it has merit IF you want to spend the money and time to learn it and then use it.

If I was younger I’d be on that like stink on poop. But I’m not. Im still trying to convince guys that the internal combustion engine as we use them need less timing at peak torque and more timing at peak power.

Thats pretty complicated means the needed timing for any given engine is a curve. How in the hell would I convince anyone that each GEAR can use its own curve and each CYLINDER can use its own timing curve?

The grid uses a very basic 5step retard and it’ll pull timing from a set “locked” amount working backwards. It’s very 2D for lack of a better description. All you’d have to do is trigger each step with a gear indicator and you’d have a 2d programmable curve for each gear. On most quality ECUs with a gear indicator you can set timing (and fuel) table modifiers or completely separate 3d timing maps for each gear. I do boost by gear on my falcon with the AEM infinity ecu on a simple 2d map. 1st gear is 10psi, 2nd is 15, 3rd is 25, 4th,5th,6th is 30psi. It works wonderfully.

 

[rmchrgr]

Cool, thanks for the explanations. I hadn’t messed with anything like that before. I would have to look into how to set up a gear change trigger.

Don’t think I need to get that deep into it for now. My main goal is to get the car going down the track regularly then I can get into stuff like that.

 

[92b]

And I’m saying never once have I seen locked out timing not kill torque all around peak torque and peak power.

Not once.

And I used to lock everything out.

Plus, I’ll say it again for those who might not have heard of it before, the chances of you having 34 degrees of timing at max rpm is near zero. Unless you are setting your total at max rpm you don’t have any idea of what it is anywhere but where you set it.

Thats unless you have tested your ignition on a test bench just like it is in the car and your box has little to no retard. That would be very rare.

You can rev the motor to max rpm on the dyno while setting timing. Then you know what timing is there. You can see the whole curve that way. You can see if a motor is going to want significantly different timing at low RPM and high rpm by looking at the power curve when doing your timing sweeps. Some motors do ,some don't. Some ignitions lose alot of timing, some don't.

 

[rmchrgr]

The dyno shop owner and I discussed it and he agreed the timing was pretty much optimal. I appreciate the info and I get the idea of the on-track performance aspect of having individual curves but in reality, I'm not a serious racer (at least not right now) so learning how facilitate timing curves for individual gear changes is not on my priority list. Sadly, the car is still apart and hasn't been down a drag strip for over 10 years. I need to accomplish that first and then get some seat time before I go down any more tuning rabbit holes.

For clarity, the image below is what you're trying to do with a Holley timing table.

I don't know anything about other types of software or ECU programming. The above image is a screenshot of the 2D view that someone put text over to illustrate what the areas represent. The 3D view is a multicolored graph that illustrates the peaks and valleys of the cell values over the entire x y plot.

Again, I have not looked into gear triggers or overlays or what have you. There is probably a way to set that up but I'm not sure what it would be. Most likely you'd wire a switch into the shifter or use data from a driveshaft sensor going into an I/O to trigger something in the software. It's fairly involved if you're not familiar with any of that.

I know I could figure it out, I have other things set up like that - trans cooler fan, radiator fan, low oil pressure shut off etc. Again though, the car needs to be running for me to even consider any of this stuff so it's 20º initial and 34º total for the foreseeable future.

 

[Newbomb Turk]

You can rev the motor to max rpm on the dyno while setting timing. Then you know what timing is there. You can see the whole curve that way. You can see if a motor is going to want significantly different timing at low RPM and high rpm by looking at the power curve when doing your timing sweeps. Some motors do ,some don't. Some ignitions lose alot of timing, some don't.

I’ve only had one box that had so little retard so late it didn’t matter.

You can not determine what the engine wants for timing making power sweeps.

If that was the case you could use a wheel dyno to do it.

You can rev the engine e to death with no load on it and you can keep adding timing.

 

[Newbomb Turk]

The dyno shop owner and I discussed it and he agreed the timing was pretty much optimal. I appreciate the info and I get the idea of the on-track performance aspect of having individual curves but in reality, I'm not a serious racer (at least not right now) so learning how facilitate timing curves for individual gear changes is not on my priority list. Sadly, the car is still apart and hasn't been down a drag strip for over 10 years. I need to accomplish that first and then get some seat time before I go down any more tuning rabbit holes.

For clarity, the image below is what you're trying to do with a Holley timing table.

I don't know anything about other types of software or ECU programming. The above image is a screenshot of the 2D view that someone put text over to illustrate what the areas represent. The 3D view is a multicolored graph that illustrates the peaks and valleys of the cell values over the entire x y plot.

Again, I have not looked into gear triggers or overlays or what have you. There is probably a way to set that up but I'm not sure what it would be. Most likely you'd wire a switch into the shifter or use data from a driveshaft sensor going into an I/O to trigger something in the software. It's fairly involved if you're not familiar with any of that.

I know I could figure it out, I have other things set up like that - trans cooler fan, radiator fan, low oil pressure shut off etc. Again though, the car needs to be running for me to even consider any of this stuff so it's 20º initial and 34º total for the foreseeable future.

I wasn’t saying you need to do curves for each gear and/or cylinder to cylinder timing.

I was simply pointing out the capability is out there and guys use it.

I’ll say it again. If you set your timing just by doing sweeps you’ll end up with the wrong curve.

34 at below peak torque sounds very high to me.

If your dyno operator didn’t steady state the engine at multiple rpm and move the timing at that rpm and load then your curve is off.

Also note that in the car the timing numbers will probably be LOW, meaning you can add 2-4 degrees to whatever made the best power on the dyno.

But the SHAPE of the curve will be the same.

I start at 2500 and go up in 1k increments to max rpm and steady state the engine at each rpm to find the timing that makes the most torque and then move on.

When you are done, you can see the curve and its shape.

Then you go to the distributor test bench and figure out how to get that curve in it.

Or, you use keystrokes to get there.

Just doing sweeps will never show you what the curve needs to look like.

This is why it’s a minimum of two days on the dyno IF we have to break in a cam and install inner springs, retorque the heads (that should be done before the engine goes in the car if it’s not done on the dyno) break in the pistons (if they are coated because you can do the cam and the pistons at the same time) and then make some easy, short pulls on the engine before you start testing for a timing curve.

Most guys don’t want to do two days and they get what they get.

 

[B3422w5]

Newbomb Turk

On a motor like the OP has, what would you expect to see on a time slip dialing in the curve like you posted about above, compared to doing what he is doing now?
Just curious.

 

[Newbomb Turk]

Newbomb Turk

On a motor like the OP has, what would you expect to see on a time slip dialing in the curve like you posted about above, compared to doing what he is doing now?
Just curious.

Who knows? I don’t know his chassis, converter, gearing and a host of other things.

But here is what is not only frustrating it’s ignorant.

What if his engine made 20 more foot pounds of torque at peak and 20 at peak power and averaged 10 each from the start of the pull to the end of the pull?

What does that tell YOU? Not as a shoe polish tuner. But as a thinker.

I know what it tells me but I’m curious to know what that tells you.

Answer that and I’ll give you my answer.

 

[rmchrgr]

‘71 Duster, let’s say 3,150lbs. with driver at the staring line
904 with good internal parts, not rollerized (usually good for 1/10 v. 727)
9 1/2” 4,500 converter
4.10 gear, 28” drag radial
Holley Terminator X ECU and ignition hopefully optimized as much as possible and running open loop so the ECU is not commanding any changes
shift at say 6,600

I say easy low 10s and possibly into the 9s without too much effort.

Dyno shop guy said he had a similar combo years back that made 625 and went 9.70s in a Duster. Same car won Pinks All Out at ETown. Might have even been a member here at one point.

I’m jumping for joy if it goes 10.20s!

 

[B3422w5]

‘71 Duster, let’s say 3,150lbs. with driver at the staring line
904 with good internal parts, not rollerized (usually good for 1/10 v. 727)
9 1/2” 4,500 converter
4.10 gear, 28” drag radial
Holley Terminator X ECU and ignition hopefully optimized as much as possible and running open loop so the ECU is not commanding any changes
shift at say 6,600

I say easy low 10s and possibly into the 9s without too much effort.

Dyno shop guy said he had a similar combo years back that made 625 and went 9.70s in a Duster. Same car won Pinks All Out at ETown. Might have even been a member here at one point.

I’m jumping for joy if it goes 10.20s!

It will run better than 10.20’s. That’s mine in good air at 3350.
I just have a 260/264 flat tappet that has 565 gross lift. I am giving up a ton running that cam compared to bigger duration 650 ish lift rollers I have seen others guys run with similar combo’s. Those heads are proven to continue to make more power to at least that lift.
I didn’t want more cage, a license( been there done that) and currently my nodular moser 875 center section lives footbraking it.
Only thing different with mine is I had the heads shaved to 61cc to up compression a point for the little extra crispness and to run 110, which is available to me here locally at the pump. I don’t mind running it because I don’t drive it enough to where it negatively affects my wallet enough to be a party pooper. Although now that I am retired, it does matter a little more.
I think your convertor will prove to be less than optimal, but it will still fly.

 

[B3422w5]

Who knows? I don’t know his chassis, converter, gearing and a host of other things.

But here is what is not only frustrating it’s ignorant.

What if his engine made 20 more foot pounds of torque at peak and 20 at peak power and averaged 10 each from the start of the pull to the end of the pull?

What does that tell YOU? Not as a shoe polish tuner. But as a thinker.

I know what it tells me but I’m curious to know what that tells you.

Answer that and I’ll give you my answer.

That extra torque and horsepower where it matters going down the track could probably result in 12 or maybe even 15 numbers. It’s gonna he,p at the hit, and so will help carry better numbers down track.

Btw… you keep making this shoe polish tuner comment.
You do realize guys like me who typically dial tight and don’t consider myself a great finish line racer run my car flat out every single lap, except when I feel confident I can chop my margin down if I have the other guy covered.
So it’s actually more about knowing what your car will run flat out, and that you can consistently do everything right to make that happen

 

[B3422w5]

Talked to a buddy who runs an NHRA stocker. He maps his runs.
Gen3, fuel injected, zero timing change throughout his runs.
Also has a trick low 9 sec nostalgia super stocker. Carbs, MSD, locked dizzy. Said he has never heard anybody have timing changing significantly enough( if at all) to show on a slip.
Called MSD and ran this stuff past them. They said timing won’t change enough to concern yourself( if at all) with with locked dizzy an MSD box.
I sent Charlie Westcott( a friend) a message asking him about all this.
Will post what he says when he gets a chance to respond.
So far, this appears to be trolling or something like it

 

[Dart Frog]

Very impressive output on your build congratulations. It is definitely great results for The supporting cast. Always A lot of advice from a lot of people who have never or probably never will achieve your numbers with a stock push rod location La small block. My question is do you have any concerns of the integrity of the block at that power level.

 

[rmchrgr]

Very impressive output on your build congratulations. It is definitely great results for The supporting cast. Always A lot of advice from a lot of people who have never or probably never will achieve your numbers with a stock push rod location La small block. My question is do you have any concerns of the integrity of the block at that power level.

Thanks.

The block will be fine.

 

[Newbomb Turk]

Talked to a buddy who runs an NHRA stocker. He maps his runs.
Gen3, fuel injected, zero timing change throughout his runs.
Also has a trick low 9 sec nostalgia super stocker. Carbs, MSD, locked dizzy. Said he has never heard anybody have timing changing significantly enough( if at all) to show on a slip.
Called MSD and ran this stuff past them. They said timing won’t change enough to concern yourself( if at all) with with locked dizzy an MSD box.
I sent Charlie Westcott( a friend) a message asking him about all this.
Will post what he says when he gets a chance to respond.
So far, this appears to be trolling or something like it

lol ok.

I’ll ask you this and BTW I don’t care how you dial in.

If you are on the dyno and you change oil and pick up 10 hp average, what does that tell you and by you I mean you specifically?

If you are on the dyno and you put a curve in your distributor and it picks up power across the rpm range, what does that tell you specifically?

If you are on the dyno and you change primary tube length on your header, not the whole header and it picks up power across the rpm range what does that tell you?

What does it tell you when you put a complete ignition system on a test bench and the timing retards with rpm, what does that tell you? Ive posted at least two videos Ive done myself here on FABO, and the professional arguing class will jump in the thread and tell everyone how it can’t be because they’ve tested it and it’s not true.

But I have my testing on video.

Im not trolling because I can prove what I’m saying.

What I will say is I have three very experienced mentors who I can get on the phone any time I need help who have done as much dyno testing as anyone, with the possible exception of the David Vizard legend which I do not believe.

One of them ran a complete slew of dyno’s and controlled the testing protocols and everything else.

So I don’t bullshit.

Again, if you put a curve set up for your engine and it makes 20 more hp, what does that tell you?

 

[rmchrgr]

Dude, this is my thread so if you don’t have anything practical to add just stop. You’re just creating drama I detest drama especially when there is no reason for it.

I don’t care who your mentor is or what facts you purport to know but the stuff you’re spouting here is not relevant to what I do. You may think it is but trust me, I’m good.

I try to be respectful to everyone but you are so pedantic about what you claim to know that I can’t take you seriously. Not everyone needs to get so deep into this stuff, it takes the fun out of it. I will never need multiple timing curves for anything. I’m just a guy trying to enjoy the hobby and hopefully get my car down the track.

I am absolutely a shoe polish racer and there is no shame in that. I have a family, a business and whatever else that prevents me from living at a racetrack. If I can race the car more than three times a year I’m doing OK.

So maybe I’m leaving power on the table because my ignition timing is not perfect. Who cares? I’m actually a perfectionist myself but I’m not obnoxiously anal about it. Well, maybe sometimes…

Regardless, I did a good job building my engine. I sweated the details, worked hard at it and it surpassed my expectations. I could care less about anything else.

 

[Newbomb Turk]

Dude, this is my thread so if you don’t have anything practical to add just stop. You’re just creating drama I detest drama especially when there is no reason for it.

I don’t care who your mentor is or what facts you purport to know but the stuff you’re spouting here is not relevant to what I do. You may think it is but trust me, I’m good.

I try to be respectful to everyone but you are so pedantic about what you claim to know that I can’t take you seriously. Not everyone needs to get so deep into this stuff, it takes the fun out of it. I will never need multiple timing curves for anything. I’m just a guy trying to enjoy the hobby and hopefully get my car down the track.

I am absolutely a shoe polish racer and there is no shame in that. I have a family, a business and whatever else that prevents me from living at a racetrack. If I can race the car more than three times a year I’m doing OK.

So maybe I’m leaving power on the table because my ignition timing is not perfect. Who cares? I’m actually a perfectionist myself but I’m not obnoxiously anal about it. Well, maybe sometimes…

Regardless, I did a good job building my engine. I sweated the details, worked hard at it and it surpassed my expectations. I could care less about anything else.

Carry on then. It doesn’t matter to me what you do, but when I see that timing number at that rpm I get nervous. You should too.

 

[TT5.9mag]

but when I see that timing number at that rpm I get nervous. You should too.

Especially so when the converter is 4500 and peak torque is only a few hundred more than that. It (likely) carries max ve for that few hundred and in good air I could see it knocking a ring land off. Hopefully it will only nip the plug and it can be caught early.

 

[B3422w5]

Especially so when the converter is 4500 and peak torque is only a few hundred less than that. It (likely) carries max ve for that few hundred and in good air I could see it knocking a ring land off. Hopefully it will only nip the plug and it can be caught early.

Huh?
Having the convertor hit a few hundred over peak torque is where its at. I try to do exactly that. And in 50 odd years of racing( with a few gaps here and there), never wacked a ring or a plug.

 

[Newbomb Turk]

Especially so when the converter is 4500 and peak torque is only a few hundred less than that. It (likely) carries max ve for that few hundred and in good air I could see it knocking a ring land off. Hopefully it will only nip the plug and it can be caught early.

You can’t say that. Because everyone locks out their timing. So everyone is always right.

I get tired of trying to help people and then guys with virtually zero experience jump in and run their mouth.

They don’t test. They aren’t tuners. Most of them aren’t even engine builder and even less of those are actual machinists but they know. And they argue to the point I call them out and Im the bad guy.

It gets old. Most guys don’t want to learn they maybe left something on the table. Even less so want to learn that what they are doing could be detrimental to their expensive engine.

I had to learn it myself. After years, decades of actually doing it wrong and teaching others to do it wrong.

But it doesn’t matter because it’s all good.

 

[Newbomb Turk]

Huh?
Having the convertor hit a few hundred over peak torque is where its at. I try to do exactly that. And in 50 odd years of racing( with a few gaps here and there), never wacked a ring or a plug.

Could it be that you don’t know exactly what your timing is at peak torque?

Naw, that can’t be it. I’d be willing to test your ignition for free because I can prove what you don’t know.

Thats up to you.

 

[TT5.9mag]

You can’t say that. Because everyone locks out their timing. So everyone is always right.

I get tired of trying to help people and then guys with virtually zero experience jump in and run their mouth.

They don’t test. They aren’t tuners. Most of them aren’t even engine builder and even less of those are actual machinists but they know. And they argue to the point I call them out and Im the bad guy.

It gets old. Most guys don’t want to learn they maybe left something on the table. Even less so want to learn that what they are doing could be detrimental to their expensive engine.

I had to learn it myself. After years, decades of actually doing it wrong and teaching others to do it wrong.

But it doesn’t matter because it’s all good.

Usually guys with race cars have more octane than they need. And if they lock their distributor and set the timing at idle they’re a few degrees short at 6500. That’s why their engines live. Once you start to tune on stuff with a very narrow tuning window (big boost on gasoline for example) you learn very quickly that too much timing at peak torque can and will destroy stuff. What’s crazy is backing stuff down makes the car faster, but it’s hard to get people to do that. I learned by blowing crap up. Then asked the guys making a bunch more power than me. Then went to the dyno and questioned Brule till I was blue in the face (and he was mad at me). It matters. Just because stuff doesn’t blow up doesn’t mean it’s right.