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Crx Oem Stock Spring Rate & Ride Height Shock Strut


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#1
greasemonkeyreborne 5x1g's

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    • Drives: 9 crx's: #1 228k 87si beater, #2 concours 25K, #3 108K 87si, #4 98K parts car, #5 213K 87si parts car, #6 84 straman, #7 86si 150k #8 67k parts #9 129K si for straman conversion

My 30 year old 1987 CRX DD (bought in 92-93 w 78K, now has 245K) has its original bushings, springs, rear shocks, from torsion bars.  The front struts were replaced w Honda OE due to leakage around 1996.

 

I had some highway handling and vibration problems over the recent years.  These mostly cleared up when I replaced the 12yr old set of tires and a bent panhard bar a few years ago.

 

Had alignments done every so often never considering the suspension sag over time.

 

Honda FSM measures ride height from fender wheel well apex.    Front spec is 25.35".  My front left was 23.5"  and right was 23.75".  Rear spec is 25.24".  My rear left was 23.25" and right was 23.5"

 

Basically, the car self lowered by 2 inches over time.  The rear would easily bottom out when loaded down for my annual road trips.  And the car appeared to ride lower in the back.  It just didin't look right anymore.

 

Other internet CRX posted place the progressive spring rates around 75#/"

 

I removed my springs and compared them to a set I pulled from an 86 crx w 150K serveral years ago.  I used 80# bags of concrete.  Made a jig w a 2x6 plank.  Measured spring height.

 

 

DATA TABLE 

 

80# bag   /   245K LR spring rate / 245 RR spring rate  / one 159K spring rate

 

0#  13.13" / 13.1" 13.13"(had half weight of 10' plant resting on spring, maybe 20# preload???)

80#    / 58 @ 11.75" / 61.5 @ 11.8" / 59 @ 11.78"

160#  / 59 @ 10.44"/ 59.2 @ 10.4" / 62.3 @ 10.56"

240 # / 62 " /  61.5 @ 9.2"  / 62.3 @ 9.28"

320#   / 64 @ 8.1" / 64 8.1" / 64 @ 8.125"

400# 67 @7.2" / 67 @7.1" / not recorded

 

Simple math dividing total weight by total delta in deflection.  Gives cumulative rate.

 

My CRX rides w an extra tire jack, 2 box speakers in back plus a trailer hitch. I'm guessing an extra ~80# load to the far rear of my car.  I measured best I could spring height of my car.  I got around 7 5/8" both sides.  Looking at my table above, it places me between the 320 and 400# load.  When extrapolating the 7.6" between the 8.1 and 7.2" deflections, I have an estimated static spring load of 370#.  Or 740# load on the rear spring set.  I calculated the spring rate between 8.1 and 7.2" to be 89#/".  In my case, the pregressive spring sagged into the stronger rang of the progressive spring rate range.

 

I replaced the OEM rear shocks w KYB Excel-G p/n 341050.  Not many shock options but these were made in Japan.  I called the tech support and they did not know what the dampening rate was.  This set of shocks was designed to provide OE ride dampening for the CRX, hatch and similar year integras.  Since the CRX is the lightest of these, I assume the KYB's are slightly over dampened for the CRX.

 

I wanted to restore the OEM ride height since this is a DD, Xcountry trips w back end loaded and I pull a trailer w/ it.  I added 1" spring spacers from Allstar Performance P/N ALL64195 for about $25 each.  Just an aluminum doughnut spacer inserted between the shock platform and bottom of spring.  I also inserted 1/4" Plastic doughnut I cut from PP for extra height.  The Old OEM shock bottom bushings had permenant compression set of about another 1/4".

 

After installing the new KYB shocks, aluminum spacer, plastic space and I swapped the 245K rusty springs for the 150K clean used OEM springs, it brought my rear ride height to around 24.7/8" both sides.  Or about 1.3" higher.  I"m still about .4" lower than new spec.  The service limit is 24.65".  I"m assuming to keep within the service range or you'll need to camber adjustments

 

I bottomed our the front torsion bar adjusters to near max.  Was able to raise the front about 1/4" (I raised these 15 years ago when I lived in NYC when I replaced the struts thinking I could reduce bent rims from pot holes and bottoming out struts. 

 

Right now, the front runs about 23.8" and the rear about 24.8".  I need to remove the stock torsion bars and reclock them to regain adjustibility back to 25".  I broke the bolts holding the bottom of the rear stocks to the axle due to salt corrosion.  I'll tackle the tube removal when I have a block of time.  I"m expecting to break bolts.

 

Since I broke both shock bolts on the 245K car, I used the spare southern rust-free rear axle.  I compared the bushings from the axle/trailing arm of the 245K, 150K cars.  Pulled down the same bushing from my OEM stock.  The 245K bushing were showing signs of compression set, but not bad.  Minimal cracking.  The 150K bushings looked really good.  I compared them to OEM NOS bushing.  I decided to leave the 150K bushings in place and installed to my 245K car.  This is a DD.  My goal is ride comfort and long term reliability.

 

On another note.  The drivers side rear 30yrs old OEM shock was very soft.  The bottom shock bushing was severely cracked and shot.  The passenger side was much better.  I grabbed an OEM NOS rear shock for the 86-87CRX.  I compared best I could to see if the dampening felt the same.  I really couldn't tell much difference.  Both 245K shock had no sign of leakage.  I'm assuming the internal valving just wore out.  The NOS OE shock has no leaks.  Since its never been installed, the valving should be new.  I was surprise how I had a difficult time comparing the NOS OE shock to my 30yr old OE passenger rear shock.  Then I compared the KYB and it was easily 2x the dampening.

 

I researched the MOOG rear springs which also go for the crx/hatch/integra pn CC229 (440# springs rated for 137#/").  I decided to keep the 150K rust free OE springs.  If the 245K rusty springs haven't failed yet.  I should get another 100K out of the 150K springs.  And I'm keeping the OE japanese metalurgy.

 

My conclusion is the rear springs at the static ride height of a CRX is around 75-80#/" at normal ride height when new.  I was surprised the two different sets of used OE springs were so close in spring rate.  Since my old springs have sagged so much, I"m getting a slightly higher spring rate that will help me for trailer load and heavy hatch loads during long trips.  I don't know how much the ride changes since I've lost the sensitive portion of my old springs due to sag.  I basically did not change the springs, just added riser spacers.  The KYBs reduce the bouncing quite a bit.

 

It looks so weird to see the extra space now inside the rear wheel well.

 

Hope this information helps anyone else who is trying to restore their ride to OE.  

 

Some reference:

 

2kg/mm = 112#/"

2.5kg/mm = 140#/"

3kg/mm = 168#/"

4kg/mm = 224#/"

 

Front to back axle weight distribution.  My stock 87crx si rated for 1978 plus 30# ac, 30# rear speakers, 40# rear trailer hitch and another 40# of tools/dirt, ect..  I'm guestimating the 35%/65% split ratio for rear to front for my stock car

 

RPR member APRXED posted "OEM Rear Spring Rate" 9/7/2009.  He measured his 1g CRX and a 1G teg in stock form.  Our numbers are simliar.


Keepin' it OEM

#2
greasemonkeyreborne 5x1g's

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    • Drives: 9 crx's: #1 228k 87si beater, #2 concours 25K, #3 108K 87si, #4 98K parts car, #5 213K 87si parts car, #6 84 straman, #7 86si 150k #8 67k parts #9 129K si for straman conversion

Sorry,  I"m an idiot.  i posted some of this stuff s few months ago when I was getting into it.  Sorry, but theres more info on the post above since the job is complete.

 

I searched for Apexed posting from 2009 and couldn't find it.  I printed it out.  His CRX spring rate was 70.9#/" @ 7.07"  And 75.4#/" @ 8.01" spring height.  He got 1.04.4#/" @ 7.00" and 108.8#/" @ 8" spring heights for a 1g spring.  He did not ID which teg model the spring came from.

 

I chose the 7-8" spring height b/c thats what my car was riding at when it was self (sag) lowered by about 2"


Keepin' it OEM

#3
greasemonkeyreborne 5x1g's

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    • Drives: 9 crx's: #1 228k 87si beater, #2 concours 25K, #3 108K 87si, #4 98K parts car, #5 213K 87si parts car, #6 84 straman, #7 86si 150k #8 67k parts #9 129K si for straman conversion

http://www.redpepper...l=+spring +rate

 

found it!  Apexed's data on crx and Teg


Keepin' it OEM

#4
greasemonkeyreborne 5x1g's

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    • Drives: 9 crx's: #1 228k 87si beater, #2 concours 25K, #3 108K 87si, #4 98K parts car, #5 213K 87si parts car, #6 84 straman, #7 86si 150k #8 67k parts #9 129K si for straman conversion
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Keepin' it OEM

#5
greasemonkeyreborne 5x1g's

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    • Drives: 9 crx's: #1 228k 87si beater, #2 concours 25K, #3 108K 87si, #4 98K parts car, #5 213K 87si parts car, #6 84 straman, #7 86si 150k #8 67k parts #9 129K si for straman conversion

Doing the same Shock/spacer/Spring scenario for CRX#3 (MadMax).  I had lowered his car (I mean removed the jacks and placed tires back on the concrete) a few years ago when I did CRX#1 to validate the ride height and used a tape measure to verify the spring deflection resting mostly level.  It was very close to CRX #1.  So I assume 30 plus years on OEM springs are all about the same regardless of miles????

 

This time, I was able to use a propane torch to get the lower shock bolts off.

 

52055617621_c79970ec27_z.jpg​

 

52055652603_2b6522b4cf_z.jpg​

 

I did have to cut the lower shock bolts off anyway as the bushing sleeve rusted to the bolt.  Couldn't slide the bolt out.  At least I got it unthreaded and didn't have to drill!


Keepin' it OEM

#6
CSPCRX

So what are you using for springs?  Are you changing them to lower the car?


Victor
86 K24 Powered CRX SI (SMF Solo2, HPDE-4 NASA & TA-A Time Attack

85 CRX DX totally original
07 Harley FXST Softail

2021 Tacoma Tow/Daily


#7
greasemonkeyreborne 5x1g's

  • Leadfoot
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    • Drives: 9 crx's: #1 228k 87si beater, #2 concours 25K, #3 108K 87si, #4 98K parts car, #5 213K 87si parts car, #6 84 straman, #7 86si 150k #8 67k parts #9 129K si for straman conversion

sorry,  was a little confusing...  I'm using the original 108K springs for MadMax


Keepin' it OEM

#8
na-spirit

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Besides all the torching and cutting..looks like a good time! ha. Wish I was closer to help you.



#9
Dear_Boss

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in all of your research did you ever end up finding an alternative to the KYB Excels? thats all i could find for mine

 

Nice work BTW. I thought about doing this at work because we have a large force tester that can accurately measure and record the load/deflection but i got lazy and just went with the KYB's



#10
CSPCRX

HealToe has Tiens but it’s a coil over in the rear with stiffer springs so if you are matching it to a stock front suspension it may not be the best option.  On the rear you can also use Integra Type R shocks.  They are the same as the 84-87 CRX, I actually have those on the rear of my 86.


Victor
86 K24 Powered CRX SI (SMF Solo2, HPDE-4 NASA & TA-A Time Attack

85 CRX DX totally original
07 Harley FXST Softail

2021 Tacoma Tow/Daily