I know these are pretty rare cars for you guys over in the US, but does anyone know the factory spring rates for either of these models?

 

I have my ch1 springs laying down and can´t find that as well!!

I´m running the pro-kit but was looking for something stiffer since it seems to me it´s almost identical...only thing is if part number matches the usdm 4door 4cyl. accord, is it possible that a neuspeed race or h&r race spring for the same car will fit in the Ch1? The Koni have a different part number so i don´t know if the bottom plate is different but still the pro kit for the 4 cylinder usdm version fits...

 

Have you got the springs off the car? Measuring the I.D, wire thickness and length we could calculate it, better than relying on second hand internet information for certain!

 

Yeah i can check it this week! ID, OD, wire thickness and length of the wire...something else?

 

Just had a look, the inputs required are:

Free height
Wire diameter
Outside diameter
Number of active coils

I guess all of these are simply used to calculate the length of active wire, and the rate is simply the torsional rate of that length of wire with that diameter.

Just to clarify, these are CH1, EDM Accord Type R springs yes? :D

 

Yep as it´s coming from my pre-facelift ch1!

As for coil pitch in front it´s not a problem since is linear coil, but in the back since its progressive spring it could be harder to calculate it, no?

 

That's not a problem, we can try and work out the rate for each section if we know the number of coils in each section.

 

Do you have the compressed length? i found that site that can help:

http://www.pontiacracing.net/js_coil_spring_rate.htm

 

That was the exact one I was looking at! I don't think the compressed length is required to know the spring rate, only the force exerted by the compressed spring.

Infact it doesn't look like the free length is a factor either, it's just O.D, wire diameter and number of active coils.

 

Ok then! Stay tuned...

I wish to know the spring rates for the neuspeed, h&r and eibach coils for accord, that would help to choose, since Ground Control kits are a little difficult to pass on MOT inspections!

 

Ok it came out like this:

Front:
Total length: 14", 6 coils@ 3.875OD, 0.5coil@ 3.75OD, 1coil@ 3.5OD, Wire thickness 0.5OD
Only for the 6coils portion i get 380lbs/in, but if you make a average OD it comes down to 355lbs/in

Rear:
Total length: 13.5, 5.5coils active(6.5 but 0.5 on top and 0.5 on bottom are pretty much a seat and don´t move so they don´t count)@ 4.5OD, wire thickness 15/32 aka 0.46875
It came out around 190lbs/in

I can try to check the eibach for some values aswell!

 

Wow, good work! Those rates are not what I would have expected at all really, very front biased for a Type R especially with the 27mm and 16mm ARBs, although the motion ratios could change those into more familiar natural frequencies...

 

You've noted the difference between the total and active coils on the rear, are the front counts just the active ones?

I make the average of the front to be 323lbs:

((6 x 3.875)+(.5 x 3.75)+(1 x 3.5))/7.5 = 3.81" average O.D, over 7.5 coils.

 

Just checked out the rear damper mounting location and it's almost like a MacPherson strut with the damper mounting directly to the hub/upright/knuckle. I expect a rear motion ratio of about .9 with a front around .7, should put the frequencies at about 1.4hz front and 1.7hz rear, which sounds spot on!

 

In my measurements i only count the active ones, 1 coil been the tip of wire+360º to next position, first 1 in top not counted(sliced wire to fit top-plate) and i start there since it becomes a normal coil pitch and the end about 0.5 non-active!

In the back is like i stated 0.5 in both ends non-active!

Also find this:

- Accord CL7 - Spoon progressive springs
High Reduction (mm): -40
Spring Rate (kg/mm):
- Front: 6.3 (OEM 6.2)
- Rear: 3.9 (OEM 2.8)

If on a CL9 OEM
Front: 6.2*55.8= 345.96lbs/in
Rear: 2.8*55.8= 156.24lbs/in

So i think it´s pretty much close to reality!

 

Nice! Do you know if CL7/9 springs fit our cars? I had Spoon progressives on my EK4 and they were brilliant for road use!

 

If i go with part numbers, no it´s not...but you know this chassis is a mix of parts, i know that a Progress Rear sway bar for Acura cl-tl 2004+ fits...it´s why i´m looking to see if the neuspeed and h&r race springs (for 98-02 4door 4 or 6 cylinder) fit our cars!

 

Cross checked spring rates from Tein Springs...

6cyl. 4 door 98-02 Accord have the most rate! But is lower than we calculated!! Probably because usdm accord are softer since they were not type R intended aka track frendly car like dc2 vs usdm integra gsr!

Found the S-TECH for CL1 bro!

6.5*55.8= 362.7lbs/in
4.1*55.8= 228.78lbs/in