PDA

View Full Version : excel / spring / stack



RacerX10
01-21-2023, 12:52 PM
I'm thinking somebody out there probably has an excel sheet to calculate backwards from load numbers to nut adjustment ...

anybody want to share ? would be nice if it did stacks.

thanks !

MasterSbilt_Racer
01-22-2023, 07:54 AM
I probably should have made one, but I always get out the paper and calculator.

Jking24
01-22-2023, 10:20 AM
I'm thinking somebody out there probably has an excel sheet to calculate backwards from load numbers to nut adjustment ...anybody want to share ? would be nice if it did stacks.thanks !To many variables. Not all shocks use the same thread spacing. For instance it's almost 5 turns on ohlins to get the same travel as 2 turns on a afco or Integra. Penske are kinda nice in that it's 10 turns per inch so it's easy math. You mention stacks well stacks are tough because of the staging/ timing. Not much need for a big cheat sheet its just math as long as your using quality springs that stay linear. But really hard to have some generic deal because of the variables in coilover nut travel per turn differences

RacerX10
01-22-2023, 04:47 PM
To many variables. Not all shocks use the same thread spacing. For instance it's almost 5 turns on ohlins to get the same travel as 2 turns on a afco or Integra. Penske are kinda nice in that it's 10 turns per inch so it's easy math. You mention stacks well stacks are tough because of the staging/ timing. Not much need for a big cheat sheet its just math as long as your using quality springs that stay linear. But really hard to have some generic deal because of the variables in coilover nut travel per turn differences

Don't really care about thread pitch on the shock. Just looking to do it by free height / compressed height / target load etc.

I don't think the stack part will be too much harder .. same kind of thing as a single, you're just doing serial coils (s1 X s2)/(s1 + s2) to a certain point then it's locked out and you're on the single spring.

I thought somebody would have already had this, and I'm lazy, but I guess it's on me. Will work it out and share when it's ready :)

Punisher88
01-23-2023, 05:30 AM
Spring rhythm app on play store has exactly what your looking for.

Jking24
01-23-2023, 09:09 AM
Don't really care about thread pitch on the shock. Just looking to do it by free height / compressed height / target load etc.I don't think the stack part will be too much harder .. same kind of thing as a single, you're just doing serial coils (s1 X s2)/(s1 + s2) to a certain point then it's locked out and you're on the single spring.I thought somebody would have already had this, and I'm lazy, but I guess it's on me. Will work it out and share when it's ready :)I guess I just don't see the point. Most setups be it stack or single rate now days use a bump or spring rubbers and it's impossible to have a generic cheat sheet for that. Also if you have to use a tape measure and a chart at the race track. How much more convenient if at all is it then just knowing that 1 turn = x load on your given setup. And as far as that app. Theirs alot of assumptions with it. Not all springs have the exact same free length. Most all springs do not compress at their rated value the first inch. As I stated their are to many variables but feel free to waste for time making a spreadsheet that has no real world relevance.

RacerX10
01-23-2023, 09:16 AM
Spring rhythm app on play store has exactly what your looking for.

I've seen that. Good idea but I don't like subscription based ... anything :)

RacerX10
01-23-2023, 09:24 AM
I guess I just don't see the point. Most setups be it stack or single rate now days use a bump or spring rubbers and it's impossible to have a generic cheat sheet for that. Also if you have to use a tape measure and a chart at the race track. How much more convenient if at all is it then just knowing that 1 turn = x load on your given setup. And as far as that app. Theirs alot of assumptions with it. Not all springs have the exact same free length. Most all springs do not compress at their rated value the first inch. As I stated their are to many variables but feel free to waste for time making a spreadsheet that has no real world relevance.

Respectfully disagree .. to whit :

1 ) the spring rubber just tunes in some direction from a known point. That's an "after the fact" adjustment, and is predictable when I've tested them in a spring smasher. It's going to be a pretty consistent value from the spring rate.

2 ) It's also super easy to know what a turn is worth on given spring / shock if you want to do it that way.

3 ) Free length can be known before it's mounted up. Spring compression value is also within a certain percentage of rated value. If it's not in that range, you've got a crap spring or it needs replacing. In any case, you're talking about a few pounds difference in any direction that is out of the tolerance range for any driver to know the difference. Other factors that change on the track (picking up mud / humidity changes / wind blows some other direction) are a larger issue than then a 500 lb spring being 500 or 510 lbs actual.


As far as value goes, if I can grab up my phone, plug a number in a spreadsheet and have it spit out a new load number from whatever delta in spring height (aka turns on the nut) .. that's pretty (not a nice word)(not a nice word)(not a nice word)(not a nice word) convenient.

Appreciate your comments / your opinion !

RacerX10
01-23-2023, 09:34 AM
I probably should have made one, but I always get out the paper and calculator.

I got the single spring deal working last night. Just need to confirm what it's spitting out on a smasher and make it a little more user friendly with some gfx :)

Punisher88
01-23-2023, 11:27 AM
If your only using a single spring and not having to account for a bump stop. I don't even pull the shock off to check anything. I just measure the distance between the changes I made and do the math.

RacerX10
01-24-2023, 06:30 PM
If your only using a single spring and not having to account for a bump stop. I don't even pull the shock off to check anything. I just measure the distance between the changes I made and do the math.

Entirely possible that I'm looking for a solution for a problem that doesn't exist :)

But that would also mean that the "springrithm" app is entirely useless and a bit of a scam ?

Maybe ....

MasterSbilt_Racer
01-24-2023, 06:39 PM
Entirely possible that I'm looking for a solution for a problem that doesn't exist :)

But that would also mean that the "springrithm" app is entirely useless and a bit of a scam ?

Maybe ....

The app is a PT Barnum money maker.

mab475
01-25-2023, 07:52 PM
Is there any way to add a graph system to a MLR EZ Rater?

MasterSbilt_Racer
01-26-2023, 06:23 AM
Is there any way to add a graph system to a MLR EZ Rater?

I can't remember if the linear indicator has a data port on it or not. If not, you need a new linear transducer and data acquisition cards for it and the load cell. I use my computer keyboard for the acquisition.

Jking24
01-26-2023, 08:04 AM
Is there any way to add a graph system to a MLR EZ Rater?Not exactly the first problem is the dro is not an absolute dro. Basically it can loose its zero point aswell as skip a beat if moved to fast. This can be fixed by upgrading to a absolute dro witch iguage (the brand that comes on the machine) makes a absolute model that is basically a direct replacement for what is their. They have a communication cable that can be bought separately but to my knowledge it can only transmit data statically. Basically you have to push a button to log a point. But the next issue becomes logging the load data. The load cells have a "printer" out put but I believe it's the same scenario you have to push a button to get a data point. So it makes it a little convoluted. Someone pretty tech savy could get it going but I'm not sure how user friendly it would be

MasterSbilt_Racer
01-26-2023, 09:29 AM
Not exactly the first problem is the dro is not an absolute dro. Basically it can loose its zero point aswell as skip a beat if moved to fast. This can be fixed by upgrading to a absolute dro witch iguage (the brand that comes on the machine) makes a absolute model that is basically a direct replacement for what is their. They have a communication cable that can be bought separately but to my knowledge it can only transmit data statically. Basically you have to push a button to log a point. But the next issue becomes logging the load data. The load cells have a "printer" out put but I believe it's the same scenario you have to push a button to get a data point. So it makes it a little convoluted. Someone pretty tech savy could get it going but I'm not sure how user friendly it would be

The load cell should have an analog mv/V signal, which is what the display uses. You can plot that real time by converting with the appropriate acquisition card. The load cell is just a strain gauge bridge where you excite it with a voltage and you get a mV output that is proportional to the load applied.