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      11-15-2020, 04:17 PM   #111
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We run with a private group when we do lapping days with the car. A friend of ours and another member of this group happens to be a photographer (and a good one at that). Here are a few shots of the M3 from this past season from these open lapping days:












He also had some pictures of our old E36 M3 race car. My dad built this car back in the winter of 2008 and began racing it in 2009. He won many regional championships in Western Canada in the ITGT and later the STO class with car, and held track records at the late Race City Motorsports Park for those respective classes. This is also the car I first drove and learned to drive on track and starting seriously working on cars with, so it holds a special place in my heart as well






Last edited by tsk94; 11-18-2020 at 11:16 PM..
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      11-30-2020, 04:54 PM   #112
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Further to the previous suspension talk and from recent discussion in dogbone's thread, here is a spreadsheet for calculating wheel rates and wheel frequencies:
If you have a google account, use this link and click yes on create a copy. You will have access to the spreadsheet and can edit it as you please: https://docs.google.com/spreadsheets...p-FDeDMek/copy

If you do not have a google account or want to use the spreadsheet in excel use this link:https://docs.google.com/spreadsheets...it?usp=sharing
Go to file, download and choose Excel.

I put steps/explanations in the spreadsheet itself so it should be fairly straightforward to use.

I will upload/post a more detailed spreadsheet at a later date that can be used to calculate wheel rates, wheel frequencies AND front roll couple distribution.

Last edited by tsk94; 11-30-2020 at 05:17 PM..
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      11-30-2020, 06:53 PM   #113
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Quote:
Originally Posted by tsk94 View Post
We run with a private group when we do lapping days with the car. A friend of ours and another member of this group happens to be a photographer (and a good one at that). Here are a few shots of the M3 from this past season from these open lapping days:












He also had some pictures of our old E36 M3 race car. My dad built this car back in the winter of 2008 and began racing it in 2009. He won many regional championships in Western Canada in the ITGT and later the STO class with car, and held track records at the late Race City Motorsports Park for those respective classes. This is also the car I first drove and learned to drive on track and starting seriously working on cars with, so it holds a special place in my heart as well





I recognize that car now. You sold that to Colin Spencer correct?
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      11-30-2020, 07:08 PM   #114
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Originally Posted by FMLYSDN View Post
I recognize that car now. You sold that to Colin Spencer correct?
Yes, that's correct!
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      12-03-2020, 10:38 AM   #115
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Quote:
Originally Posted by tsk94 View Post
Further to the previous suspension talk and from recent discussion in dogbone's thread, here is a spreadsheet for calculating wheel rates and wheel frequencies:
If you have a google account, use this link and click yes on create a copy. You will have access to the spreadsheet and can edit it as you please: https://docs.google.com/spreadsheets...p-FDeDMek/copy

If you do not have a google account or want to use the spreadsheet in excel use this link:https://docs.google.com/spreadsheets...it?usp=sharing
Go to file, download and choose Excel.

I put steps/explanations in the spreadsheet itself so it should be fairly straightforward to use.

I will upload/post a more detailed spreadsheet at a later date that can be used to calculate wheel rates, wheel frequencies AND front roll couple distribution.
For your motion ratios, it looks like the values in J5/K5 is for coilovers and J6/K6 is for divorced. If so, the comments in F5/F6 and I5/I6 need to be updated (and possibly the cell reference in C6 if you're using a rear coilover).
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      12-03-2020, 10:45 AM   #116
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Originally Posted by 135 View Post
For your motion ratios, it looks like the values in J5/K5 is for coilovers and J6/K6 is for divorced. If so, the comments in F5/F6 need to be updated (and possibly the reference in C6 if you're using a rear coilover).
I just checked the sheet, not exactly sure what you you mean? The motion ratios in cells J5/K5 are correct for a divorced spring and J6/K6 are correct for a coilover. That also matches the comments I had of what to enter for each.

Can you elaborate a bit on what you think the problem is? Are you just thinking I mixed them up?

0.576 is the correct MR for a divorced spring setup and 0.819 is the MR for a rear coilover - everything seems to match up to my eyes.
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      12-03-2020, 11:11 AM   #117
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It just seemed strange that 0.576 was the divorced MR on an M3 (and 0.819 was the coilover MR).
The M3 rear subframe suspension components can be interchanged onto a 135i so I was thinking it would have had the same rear MR. The 135i has a coilover setup with an MR of 0.563, which is quite close to your M3 divorced MR of 0.576, which is why I was confused. The 135i front MR is quite similar at 0.96.
Interesting.
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      12-03-2020, 11:30 AM   #118
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Quote:
Originally Posted by 135 View Post
It just seemed strange that 0.576 was the divorced MR on an M3 (and 0.819 was the coilover MR).
The M3 rear subframe suspension components can be interchanged onto a 135i so I was thinking it would have had the same rear MR. The 135i has a coilover setup with an MR of 0.563, which is quite close to your M3 divorced MR of 0.576, which is why I was confused. The 135i front MR is quite similar at 0.96.
Interesting.
The E8X chassis is very similar. Here are some numbers from a 1 series:
https://www.1addicts.com/forums/show...42&postcount=2

Notice the rear spring MR is ~0.56 and the rear shock (coilover) is ~.81. Compared to the M3 values of .576 and .819 they are very close!

Slightly different, but different wheel+tire setups will vary the numbers ever so slightly. I suspect you had your numbers mixed up!
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      12-08-2020, 01:10 AM   #119
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How embarrassing, I mixed up my terminology, seeing Rear Coilover and thinking it related to a "set of coilovers" (which actually includes a rear divorced setup).
That's what happens when I reply to posts at 2am (my time). I was just excited to have another suspension spreadsheet!
I've updated my copy to say "Rear Divorced (OE):" so no chance of confusion in the future.

btw, I used those same MRs from that 1addicts post when I did my suspension calculations five years ago.
In addition to the wheel rate (which is calculated based on spring rate, as in your spreadsheet), I also used the bushing rate and tyre rate to calculate the static wheel/bushing deflection and static tyre deflection, respectively, and subsequently the total static wheel deflection, which was used to calculate the undamped ride natural frequency for each corner and averages for each axle. The results from this can differ (relatively) considerably compared to using just a spring-based wheel rate, e.g. my calculations resulted in a front axle frequency of 1.98 Hz +/-0.3 vs 2.15 Hz +/-0.5 in the spreadsheet.
I'll be keen to see the next iterations of your spreadsheet.
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      12-08-2020, 10:47 AM   #120
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Quote:
Originally Posted by 135 View Post
How embarrassing, I mixed up my terminology, seeing Rear Coilover and thinking it related to a "set of coilovers" (which actually includes a rear divorced setup).
That's what happens when I reply to posts at 2am (my time). I was just excited to have another suspension spreadsheet!
I've updated my copy to say "Rear Divorced (OE):" so no chance of confusion in the future.

btw, I used those same MRs from that 1addicts post when I did my suspension calculations five years ago.
In addition to the wheel rate (which is calculated based on spring rate, as in your spreadsheet), I also used the bushing rate and tyre rate to calculate the static wheel/bushing deflection and static tyre deflection, respectively, and subsequently the total static wheel deflection, which was used to calculate the undamped ride natural frequency for each corner and averages for each axle. The results from this can differ (relatively) considerably compared to using just a spring-based wheel rate, e.g. my calculations resulted in a front axle frequency of 1.98 Hz +/-0.3 vs 2.15 Hz +/-0.5 in the spreadsheet.
I'll be keen to see the next iterations of your spreadsheet.
Not a problem, I figured it was a simple mix-up/confusion we were having.

I really like your idea of going beyond and including the bushing and tyre deflection into the equation. Much more accurate approach for an individual car. However, I'm not sure how I could incorporate that (easily) into a spreadsheet intended for many people to use. Tyre deflection will vary per tire setup and bushing deflection will vary depending on bushing and control arm setup. For some running stock arms and bushings it will result in much different values than those who have replaced most, or all, of the stock bushing with solid ones and spherical control arms.

My FRC spreadsheet doesn't go further in-depth for frequencies, it still uses spring based for the final value. I don't know of a simple way to incorporate bushing and tyre deflection into the equation for a possible infinite amount of variation depending on a persons tire and bushing setup. If you have any insight on how it could be easily (relatively) incorporated please let me know and perhaps with your help it could be added in.

I think the spring-based frequency at least provides a good (albeit rough) starting point. I'm still on the fence of the relative importance of wheel frequencies when sorting out an initial setup or tweaking an existing one. Despite a few individuals and brands that advocate a 'flat-ride' or rear biased frequency approach/'neutral' spring setup based on frequencies, almost all examples of professional race cars (factory GT4, GT3 Cup cars, etc.) seem to run higher front then rear frequencies. Despite my research, while I have learned more, it's almost made things more unclear. There is nothing remotely close to a definitive 'right approach' that I've come across, perhaps because varying approaches to suspension setup can be made to work.

Last edited by tsk94; 12-08-2020 at 11:39 AM..
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      12-10-2020, 09:31 PM   #121
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I really appreciate you creating this thread. I am in the process of gutting my e92 m3 and was wondering if you could provide some information as to what computers (electronics) you removed and or what is critical and must be left alone. Thanks.
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      12-11-2020, 11:09 AM   #122
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I really appreciate you creating this thread. I am in the process of gutting my e92 m3 and was wondering if you could provide some information as to what computers (electronics) you removed and or what is critical and must be left alone. Thanks.
In general there will be a few you need to leave. The Fuel pump module will obviously need to stay. The DSC module under the driver seat must stay, otherwise ABS doesn't function properly. And I believe 2 modules under the dash must stay, one being the CAS. These allow the dash and push button start to work, one other one is needed for things like lights and brake lights to keep working. When you're in the process of taking things out, look up the part numbers and it should be fairly easy to figure out which modules do what. Most can be removed but you will need to keep a few for sure.

Hope that helps!
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      12-11-2020, 06:55 PM   #123
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Thank you, that does help.
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      12-11-2020, 08:22 PM   #124
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I think I also read somewhere about the Aircon module in the dash being needed to keep the radiator fan from operating normally. Otherwise it just runs full speed all the time.
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      12-11-2020, 09:52 PM   #125
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I think I also read somewhere about the Aircon module in the dash being needed to keep the radiator fan from operating normally. Otherwise it just runs full speed all the time.
There's an electric relay for the radiator fan. I can't remember exactly where it's located from the factory (somewhere up front on the passenger side), but you'll need to retain that. Not sure if that's the one you're talking about but you'll definitely want the fan to operate normally. Thanks for bringing that up.
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