In reply to MrJoshua:
I see what you mean. On the front- how did you prevent the bottom from rotating? Is that welded into the lower arm? Hmmm, I suspect that's not really CSP legal, and I'll have to find a different way.
Nice and neat rear set up! Looks really good.
Are both R1 shocks? And how did drive?
In reply to alfadriver:
The front pedestal is bolted in, I added a small set screw below the shock bolt and torqued the crap out of the lower shock mounting bolt.
The car drove really well. It is the only challenge Miata I have seen corner flat enough to look like it had enough spring rate. I don't remember how it finished in '08 but it was definitely top 15 in the autocross. Home made poly bushings with all the bellcranks turned to the neutral adjustment, old 225/45/13 a3so3 hoosiers, and 2 total runs where the car made it all the way through without mechanical issues. In '10 I switched to modded rabbit illuminas on the front with the motorcycle spring and bump stop. The setup barely rode on the doubled up bump stop at ride height so the rate was likely Much higher than the 550lbs/in of the motorcycle spring. It placed 8th in the autocross with the same hoosiers from '08 and still no attempt to actually align the car. The suspension does actually have some travel despite its firmness. It was smoother than the megans on my wifes WRX at the time. 
alfadriver wrote:Teh E36 M3 wrote: I'm pretty sure the R1 springs are about 500-525lb/in. I'm only "pretty" sure because that was the big pain in the ass of my ME degree. Springs are difficult to measure properly because the inactive coil isn't always perfect. The good thing is that 7" 2.25 ID springs fit, and you can get a pretty good range from eibach or other sources. The Midget is running 350lb/in eibach's on R1 shocks.Any idea what units 1.1 would be, then? If I knew what that meant, there are other ones out there that would fit.
You mean this converted to kg/mm? It's late. I'll take a look tomorrow- but I'm not sure that's what you're asking for.
Teh E36 M3 wrote:alfadriver wrote:You mean this converted to kg/mm? It's late. I'll take a look tomorrow- but I'm not sure that's what you're asking for.Teh E36 M3 wrote: I'm pretty sure the R1 springs are about 500-525lb/in. I'm only "pretty" sure because that was the big pain in the ass of my ME degree. Springs are difficult to measure properly because the inactive coil isn't always perfect. The good thing is that 7" 2.25 ID springs fit, and you can get a pretty good range from eibach or other sources. The Midget is running 350lb/in eibach's on R1 shocks.Any idea what units 1.1 would be, then? If I knew what that meant, there are other ones out there that would fit.
Just to make sure I understand the units of MC springs. IIRC, I got a 500lb rate to be ~8kg/mm, which is a long way from 1.1.
I'm also thinking of how I can make this work in an Alfa.... 
MrJoshua wrote: It will be very hard to use any of the motorcycle shocks up front because of having very little clearance to put the spring through the upper a-arm. I think you are most likely stuck with circle track on that one. Here is a pic of the front setup I used in '08:You can't see it really well, but the clearance is less than 1/4" in several places. The vertical reservoir version doesn't work because it hits the top a-arm with minimal travel, and the horizontal reservoir one required a 1/4" wheel spacer to avoid contacting 4" backspace 13x8 diamonds with 225/45/13 hoosiers.
Couldn't you use a shock with the 90 degree reservoir and run it upside down to keep it from hitting the upper A-arm?
alfadriver wrote:Maroon92 wrote:You guys like train wrecks?92CelicaHalfTrac wrote:I also want to read it...though admittedly mostly because of the E36 M3 storm.nderwater wrote:Link? That sort of stuff interests me, and not just because of the E36 M3 storm.alfadriver wrote: The wheel size article in the recent GRM started a cost/value argument about all of the CSP mods, and that the guys who are at the front are very adamant about having to spend thousdands on each of the major go fast parts- particularly the shocks, diff, and ECU. I was arguing about cost vs improvement value, when it kind of got out of hand...You kicked up quite the E36M3 storm in that thread. When you told those autocross champions "That's a lot of money to spend... Hope those jackets you are winning are honestly worth it" I about choked.
Others piled on, not knowing what I really meant. But a few knew what I was talking about.
That thread is..... wow.
There's good info in there, and a lot of "just not getting it."
In reply to Rusnak_322:
It has been a few years since I built that, but I think any reservoir hit multiple things if you tried to mount it between the a-arms.
In reply to MrJoshua:
Sure got me thinking about it.... Say IF there is a shock that is a little more compact on the resivior end- probably shorter, too- but may be able to fab up a little taller adaptor to make it fit. hmmmmm
I may end up going through the entire spreadsheet to see what they look like!
Did you cut the bump stop? What kind of wheel travel are you getting? This is my issue with m/c shocks- I'm not sure I'm getting enough, but haven't driven the car in anger enough to really get a feel for it.
Knocking this thread back up to the front page with some links I found in my bookmarks
This link has many of the factory spring rates for bikes.
http://old.racetech.com/evalving/menu/searchstreet.asp
So if we go off the spreadsheet I posted before we can see that the 98-99 CBR900RR shock stroke length is 57mm. Racetech says the stock spring is 14.6 kg/mm And we take that number to this page
http://www.hraefn.net/projects/spring_rates.php
and get 817 in/lb. This falls right in line with what measuring the coils gives me so I am going to say I trust it.
More knowledge to arm yourselves with.
Here is a 2003 R1 Yamaha shock, note the inline reservoir. It has the 'cam' type preload aduster which is a problem, the spring has to be preloaded when everything's at rest and it doesn't have a whole lot of adjustment. The spring is approx 2.25" inside diameter and 2.5's won't work because of how close the reservoir is to the body.
Here is a R6 Yamaha shock, note the 'crossways' reservoir. It's readily available, uses an approx 2.25" ID spring and can easily hold a 2.25" spring because the reservoir is not close to the shock body. That reservoir gets in the way of a lot of things under the car, which is why I have two in my shop that I have never installed. It also has a 'cam' type preload adjuster.
Here is a Honda CBR600 shock, note the remote reservoir. And the really short travel. Not insurmountable, just have to plan ahead and use some ingenuity. The spring is approximately 2.25" ID. It has a threaded preload adjuster which is a plus. Some of these have cone shaped springs.
I like the looks of that CBR600 shock more than the CBR900's that I bought. The screw adjuster is definatley better than the cam type I wound up with.
05 GSXR 1000
74mm stroke with a 453 in/lb spring rate rate reservoir at a right angle.
wanted to bump this thread and seek if there is any new information to be added to the pool before I start deep diving over the next few months.
I am looking at using Miata subframes (front and rear) on a build that will hopefully weight about 1300lbs. There wont be a miata engine in the way.
Looking at acceptable range of motion, mounting possibilities, can I fir the unit within the F/R control arms, or will I need pushrods. For that matter, will I need pushrods/rockers to get acceptable travel?
Other topics of debate right now are what frequencies to aim for F/R on rates for a car that will see autocross and trackdays (and a trailer otherwise) I know I want over 2hz. lots to digest. I really want to use R1 shocks as this will be a budget project (not challenge budget, but well, you get it) Tires wil be American Racers or something like an R888 where DOT is required.
I'm so happy you bumped this thread!
My car weighs 1800 lbs with 55% of that on the back axle. The 5" of suspension travel is not enough so I will be pulling the motorcycle shocks and pushrods off to put some conventional shocks in. The shocks have little travel (something like 2.75") but using the motion ratio of the rocker arms, you can double or triple that if your car is light enough. If my car was lighter in the back, or if I could get stiffer springs or if I road raced or just drove on the street, the motorcycle shocks would be awesome. Race Tech http://racetech.com/ makes springs for a variety of bikes and I have the stiffest ones available for my shocks.
Just want to add that while you can use rocker arms to make up for a mc shocks limited travel you lose the ability to fine tune the handling. Without meaningful damper travel the tuning becomes almost irrelevant. This might not be a big deal in the real world but I just thought I would throw it out there.
I put '06-'09 GSXR 600 shocks up front on my hot rod.
Estimated weight: 2200 lbs (600 lbs on each front corner)
Target frequency: 2.0 Hz maybe more
Front MR: 0.62 (stock Lexus SC300 geometry)
Desired spring rate: 500 to 530 lb/in
Price: $25 to $35 shipped on fleaBay
With my MR and the short stroke of a moto shock, my travel seems pretty low. But it's also a slammed rat rod, so it'll scrape frame before it fully compresses the shock 
Here is a list of moto shocks and their rates that I found on the internet. Not sure if any of it is true, but my front end feels good to me.
Knowing nothing about this, I see you all are talking about street bike shocks. What about the rear coilover from a motocross bike? Longer stroke and heavier spring maybe.
In reply to bearmtnmartin :
I was just about to ask the same thing.
In reply to bearmtnmartin :
The dampening is all wrong for an on-road application. Might not be a problem for a street car though.
And the chart above is really cool but the newest shocks on that list are 8 years old. No new info anywhere?
Perfect range of years to be dirt cheap on ebay!
loosecannon said:My car weighs 1800 lbs with 55% of that on the back axle. The 5" of suspension travel is not enough so I will be pulling the motorcycle shocks and pushrods off to put some conventional shocks in. The shocks have little travel (something like 2.75") but using the motion ratio of the rocker arms, you can double or triple that if your car is light enough. If my car was lighter in the back, or if I could get stiffer springs or if I road raced or just drove on the street, the motorcycle shocks would be awesome. Race Tech http://racetech.com/ makes springs for a variety of bikes and I have the stiffest ones available for my shocks.
I was hopeful you would reply. I was really looking at your setup as a mental starting point.
The target weight I am looking at is likely to be 1450 with driver.
I have been working off of this to get some ideas of where I want to be http://www.fatcatmotorsports.com/FRC_TUTORIAL/FCM_MSDS_TUTORIAL.htm
Part of the joy of just grafting the whole miata suspension on is that there is so much informaiton out there on it. Thing is that I will not have the chassis side mounts to just use miata shocks, so I am looking at other solutions (and hopefully keeping costs down).
The only differences as far as that spreadsheet is concerned is that I will be taking 6.2 inches out of the wheelbase and I wont know weight distribution until I get decently along with the build.
Most of the Miatas that have worked well for me have had a frequency in the 2.3hz range for bounce frequency. Plugging my numbers through, this would indicate (if the spring motion ratios / geometry remained similar to a miata) spring rates in the 300-375 lb-in range as it affects the mounting point on the stock miata control arm I am using.
If I am reading the racetech site correctly (and converting units correctly) stock is something like 560 lb/in (for a 12-14 R1, just chucking an example), so I might be in the ballpark if damper motion is 50%ish of motion at the control arm mounting point (assuming geometry from that mount to the rocker is same as stock miata...)
Then again, reading through their product information, the springs available for that shock in their catalog range from 448 - 1400 b/in so LOTS of options...
Just need to figure out the travel I need, the motion ratio, and if it stacks together in a way that allows the damper to actually dampen...
Not to mention packaging...
Wow, if anyone else is diving into this that ride-tech site has a LOT of info to dive into.
I believe (and I could be wrong) that a damper will always be in the proper range of damping if it uses a spring rate for which it is designed. If I had a damper with valving designed for 300 lb/in springs and I installed 600 lb/in springs, there would not be enough valving to control the motion. When you use a rocker arm or some other means to get the wheel rate (different than spring rate) you are looking for, as long as you don't radically change the springs, the damping should be good. My 2007 Yamaha R1 shocks have IIRC a spring rate of 525 lb/in and with my motion ratio of .750 (.750 inch of shock travel for 1 inch of wheel travel) I had a wheel rate of 295 lb/in (or 170 cpm)-a little too soft. I upped the spring rate to 650 lb/in and now my wheel rate is 365 lb/in (189 cpm) which is exactly what I want. My shocks can still go from under damped to over damped with the stock adjustments so I feel that I don't need to get them revalved. If I could get 900 lb/in springs, I could change the motion ratio to .625 and still have the similar wheel rate of 351 lb/in and I would gain the extra wheel travel I need to keep my rear tires on the ground, but would the shocks be able to dampen 900 in/lb springs? Doubtful. Does this all make sense? I think bike shocks will work on a 1450 lb car without any issues.
(*edit, Loosecannon, I missed the bit where you said you had the stiffest springs available for your shocks... might still apply to other moto shock possibilities..., you can possibly disregard my post, but I will preserve it in case someone else is digging this way)
Thing is, looking at the Race Tech site, it looks like they do revalve dampers, which would allow them to handle different spring rates (as you said, change the range of damping).
I havent ever spoken to them, just been browsing their site, but it seems you can spec things out and they sell you parts to customize the valving of the stock units if I am reading their site correctly.
If they sell the springs for them with the really high rates, it stands to reason they may be able to revalve the shocks to accommodate that rate.
If I am reading and understanding right, http://racetech.com/page/title/Gold%20Valve%20Overview means they can basically custom valve shocks per customer.
Looking at this bit, if you drill through http://racetech.com/ChooseVehicle.aspx they may have these kits available for the shocks you are using. (leading to the next line)
It looks like they offer the parts http://racetech.com/ProductSearch/2/Yamaha/YZF-R1/2007-08 (scroll down to rear shock valving kit options).
Boils down to, if the company customizes to case/customer like I saw implied, and I am understanding this accurately... you might be able to upgrade the shocks you have to damp higher rates for $200 each if you DIY and an extra $125 if you want to farm it out to them and have it done for you.
I am at an early stage in my stuff and dont even know if I would have to go down a revalve path... Any chance I can implore you to contact them and see if I am correct in my thinking on this? (hopefully $400 is less than you were looking at in new rear shocks)
If you do, PLEASE report back... This could open a lot of possibilities I think.
My MG is running now so I can provide input on performance. I am pretty satisfied with the MC shocks on my 1800lb (with driver) car. I ended up modifying the shocks to remove preload. I initially was not getting any droop travel but after removing preload I have approximately 1" droop and 2.5" bump. I find the shocks to work, the damping adjustments make a difference and they seem to be holding up well. I am running adjustable rocker arms with pushrods so I can fine tune wheel rates. I'm sure the car would be incrementally faster with big money shocks but for the price I think the trade-off works well.
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