Breaking news! J30 Front Lowering Springs

Post by **swimshark** » Sun Sep 13, 2009 8:17 pm

I have a friend with a Z31 300zx and he took a look at the J30 suspension and said ti looked very similar. Well since they make lowering springs for the 300zx and his is current on jack stands being worked on, he let me take his springs off to see if they fit and see how it looks on my car. I only put it on the passenger side and left the drivers side stock.

I will update with more info for sure once I get a set of my own and see how it rides.

300zx strut on left and J30 on the right

Modified by swimshark at 4:20 AM 9/14/2009
Modified by swimshark at 6:07 AM 10/7/2009

Post by **S133P3R** » Sun Sep 13, 2009 8:45 pm

bump for this, you may be on to someting junior!

Post by **AZhitman** » Sun Sep 13, 2009 10:09 pm

They share a lot of suspension components. This is known.

Post by **swimshark** » Mon Sep 14, 2009 2:44 am

Well in my 2 years of searching I have only seen people either wanting to but cant because they cant find a good way (besides cutting springs) or they drop a couple grand to swap out suspension just to lower their J30. I am going to be looking into the rear soon also. With the front, if it all works and rides great, people can spend less than $200 to lower their J30 in the front.

I never really knew they had same suspension as the Z31 300zx until the past few weeks and looking at my friends Z31 300zx. Ive been looking into this for quite some time as I said before.

I also machined my own solid tension rod bushings. I will post those pics in another thread if anyone is interested. It stiffened the suspension a lot and eliminated a lot of the body roll and it has a better feel now going through turns.

Post by **kbflip02** » Mon Sep 14, 2009 1:10 pm

freaking sweet

Post by **swimshark** » Mon Sep 21, 2009 2:59 am

Well it has been done now. For the most part it rides really good and seems to handle well. Haven't been able to test it since I'm in the heart of GA where it is flooding currently. Have to watch for some bumps or quick transitions over bridges or it will bounce and almost bottom out if going really fast. Otherwise the J looks pretty sick and my friends like it.

Modified by swimshark at 6:05 AM 9/21/2009

Website · Post by **diamondj30** » Thu Oct 01, 2009 8:20 am

look's cool.I spent 110.00 a coil at gitt's spring in kent wa.the bounce can be controlled with good struts.Heatgun the inner fender wall so you dont rub the tire.How' the clearance.2 finger?i ran good aftermarket struts just in front for a while before my read struts were made and it was no problem at all.not even!!

Post by **swimshark** » Thu Oct 01, 2009 8:32 am

i was just looking to get some better stiffer shocks along with the stiffer springs. know of anywhere i could get a set for the front? as for clearance i have to put my fingers in at an angle to get it to go between tire and fender.

here are some more pics

http://img9.imageshack.us/img9/4379/dsc1081y.jpg

Website · Post by **diamondj30** » Thu Oct 01, 2009 9:41 am

i have no idea.i havnt bought anything in years.Or kept track.sorry.Are you going to bring the back down a bit too?You didnt hear me say this.Id cut them in back.heavy rake you got there.

Post by **yodawill2000** » Thu Oct 01, 2009 9:43 am

Yup and that puts a lot of stress on the front end.Learned that back in the 60's.

Post by **swimshark** » Thu Oct 01, 2009 9:53 am

im looking to see if the suspension is the same on the rear as a z32 300zx and buy some lowering springs for the rear or i may just cut them.

what can happen if i leave it with too much rake in the front for too long?

Post by **swimshark** » Thu Oct 01, 2009 9:59 am

im already still getting used to going over bumps at certain speeds and havent bottomed out. this weekend i am making my own debris shield. it hangs too low and scrapes over certain bumps.

speed bumps can either be good or bad. depends on how big they are. currently i am trying to find ways to avoid areas i know there are the small tall bumps vs the long gradual bumps. small tall i hate cuz the debris shield scrapes big time.

as for the front tires they seem to be doing fine. havent noticed any unusual wear.

Website · Post by **diamondj30** » Thu Oct 01, 2009 11:04 am

your front tires will wear hard most likely.But then your camber look's better than mine.By alot,lol.So i may eat my word's.Not versed in your deal,sorry.I been through 5 sets of firestone sz50's.my wife always ask why i corner so hard like a slot car..Well,Because i can,lol.I have 120,000 on my odometer,lol.The front camber setting on the J sucks bigtime.little adjustment.Now if this were my 58 chevy id get some extended top a arm's.Do you have more camber adjustment with this units?Heck,the way your working on your maybe you know someone who can do that.heavily reinforce it.How low is the car actually.mines 4 inch's off the ground,plenty high.Easy to get around.negative camber may help you handle better though.its all about the rubba,lol.i applaud you tackling this.Taking the bull by the horn's.Good on you!!!Those z spring's look the same leangth as mine but thinner strand.Mine are tied in cause so short.Never have a problem.Used a lighter wind in mine for that reason."being short"there normal wind would put me way over.

Modified by diamondj30 at 2:10 PM 10/1/2009
Modified by diamondj30 at 2:14 PM 10/1/2009

Post by **SuicidnS13** » Sat Oct 03, 2009 6:19 am

For your rears I am about 99% s13 or s14 rear coilovers will work as long as they have adjustable shock bodies. Later today we are going to mount s14 tokicos with tein s techs just to verify it bolts up. I just read a thread about some guy bolting up stock s13 rears and it lowered his car buy 3 inches. Im assuming due to valving and spring rates for a much lighter car. So we are going to try an s14 shock and spring setup for giggles. If it works I will be ordering s13 coilovers from like megan or something.

Another person on here also just used s13 rear coils on his car but wouldnt give me the parts needed to complete it. I will come up with them on my own and give you guys the updates.

Awesome work with swapping out springs and finally lowering a j30. Please resize your pics down to 640 x 480...lol

Post by **SuicidnS13** » Sat Oct 03, 2009 6:33 am

This is actually the route I am going with my setup-

http://www.redz31.net/pages/coilovers.html

Post by **yodawill2000** » Sat Oct 03, 2009 8:26 am

Not sure I would put those on a 3850 Lb sedan.

Post by **yodawill2000** » Sat Oct 03, 2009 8:33 am

I wonder if that is the setup that killer J from Canada has ??

http://photos-d.ak.fbcdn.net/h...n.jpg

Post by **brettsdad** » Sat Oct 03, 2009 1:40 pm

where did you get the 3850 lbs from? i weigh 160 and have about 80 pounds of stereo in my 96 and i tipped the scales at 3740 lbs. i dont recall how much gas i had.

Post by **swimshark** » Sat Oct 03, 2009 8:09 pm

with 3/4 tank and amp in car i weighed my J at 3535 at Silver Dollar Raceway without me in the car.

I made my new debris shield and measured how low the J sits. at the lowest point which is either the debris shield or tow hooks the J sits about 2.5" above the ground. bottom of front bumper is about 3.5" or so.

im going to see if the z32 suspension is the same in the rear. dont wanna drop the rear a whole lot. only an inch or so and want stiffer springs.

even with my crazy rake i was able to keep up with my friends 300zxTT through turns (except for the exit cuz i lack power).

where do you get those adjustable top hats for the J? those would be great to have to adjust the camber.

Website · Post by **diamondj30** » Sun Oct 04, 2009 8:01 am

Ah yes.I like that i dea.I dont think ive seen an adjustable top hat before,sounds cool.

Post by **J30TPI** » Mon Oct 05, 2009 4:23 pm

So the J30 has a front end of a Z31 and possibly a rear of a Z32? interesting, please let us know!

Post by **swimshark** » Tue Oct 06, 2009 5:40 am

ill will find out either wed or thurs. i have a friend with the 300zxTT and ill take off rear wheel of both and compare.

btw i got the springs from z31parts.com

http://z31parts.com/suspensionparts.html

$170 for the front springs and you can either go with -1" or -1.5" drop. its really about almost 2.5" drop or so on the J30.
Modified by swimshark at 9:02 AM 10/6/2009

Post by **SuicidnS13** » Tue Oct 06, 2009 5:51 am

swimshark wrote:ill possibly find out either wed or thurs. i have a friend with the 300zxTT and ill take off rear wheel of both and compare.

btw i got the springs from z31parts.com

http://z31parts.com/suspensionparts.html

$170 for the front springs and you can either go with -1" or -1.5" drop. its really about almost 2.5" drop or so on the J30.

Actually according to my measurement it has the same springs as s13's in the rear with obviously a stiffer spring rate than typical s13's. I am going to be going with stance coilovers with custom spring rates. On a 2600lb car they are way to stiff. But on a 3500lb car with 10/8 springs or heck even the box 8/6k springs I bet they would be tollerable. For example Ksport and Megan sells the same exact strut valving for most cars and simply changes the spring rates over. Lexus IS350's run a 12k/8k spring setup for example.

Post by **swimshark** » Tue Oct 06, 2009 6:11 am

you want stiffer springs in the rear of the J30. its already loose as it. put them on and see if they are any stiffer and how much does it change the ride height. only 2 things i am concerned with. it may be stiff for a 2600 lb car but loose for a 3500 lb car. also big question is how much of a drop would it create.

like i said the -1.5" springs for the z31 dropped my J30 between 2.5"-3"

Post by **J30TPI** » Wed Oct 07, 2009 2:47 am

http://www.zcciv.com/darren/Z31_S14_Front_Coil.pdf This might help you out with coilovers for the J's

Post by **swimshark** » Wed Oct 07, 2009 2:57 am

swimshark wrote:Well in my 2 years of searching I have only seen people either wanting to but cant because they cant find a good way (besides cutting springs) or they drop a couple grand to swap out suspension just to lower their J30. I am going to be looking into the rear soon also. With the front, if it all works and rides great, people can spend less than $200 to lower their J30 in the front.

doing it for a reasonable cost is the whole point of my thread and reason for doing this research. i am a college student and dont have a couple thousand dollars to buy new s14 suspension and lower my car.

last line in the first paragraph states to be mindful that this isnt super cheap to do, and you then have to BUY a list of nine items just to put coilovers on. list of 9 items or 1 set of springs. let it be your pick.

Post by **mels95j30** » Mon Oct 12, 2009 3:51 pm

Hey i have TEIN S.TECH springs off my old 240 will they work or no ?

Post by **swimshark** » Thu Oct 22, 2009 4:05 am

I got the shocks and struts from my friend that he took off his NA 300zx. Springs might not be the right size, but I havent had the time to pull a wheel off and check. I am also trying to find a friend who has the rear springs off the 240 and compare those also. Will post updates once I test these out.

Post by **Outkast** » Sun Oct 25, 2009 3:45 am

I meet you at Z Nats this year.

The only differance in the rear suspension is the upper link. On a Z32 it's round and the shock/spring assy goes through it but on the J30 it is hook shaped. The only other part I'm not sure about is the geometery. All the componants may be shifted differently. I'm going to do a little engineering cause I want to put the complete front suspension from a Z32 parts car I have over. And just for giggles the springs all around as well. If it works it should look like a stock Z32 wheel gap instead for the 4x4 it's at now.

FYI the brake calipers are direct blot ons so I have 4 wheel fixed piston calipers and once I find me some decent 17" rims I will put my spare big brake Z32 kit on it.

Post by **swimshark** » Mon Nov 16, 2009 6:18 am

This weekend I will be putting the rear struts off a s13 onto the J and if not test the springs off a z32 strut to see how much of a diff it makes in the ride height. the s13 strut it a direct bolt on. it has the bolt through on the bottom of the strut like the J30, the z32 however has a wishbone mount.

also i am getting a TT rear sway bar from a friend and seeing if that is a direct bolt up. will be much better on roll with that.

fun weekend because i get to replace valve cover gaskets, test sway bar and dropping possibly the rear too.

will post more with pics

Breaking news! J30 Front Lowering Springs

Breaking news! J30 Front Lowering Springs

Re: Breaking news! J30 Front Lowering Springs (swimshark)

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Re: Breaking news! J30 Front Lowering Springs (swimshark)

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Re: Breaking news! J30 Front Lowering Springs (swimshark)

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Re: Breaking news! J30 Front Lowering Springs (Outkast)

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