Custom Rough Road / Winter Duty Suspension.

[ZeroDrift]

Hello all,

I'm looking for some opinions for my next suspension setup. Where I live the roads are in piss poor shape and I plan to keep my car as the 'winter duty' vehicle. -A bit of background info: I used to be an avid auto-crosser and I enjoy having the rear end step out some on the track, however I am thinking a fairly neutral handling setup may be best for winter duty. Thoughts here?

I'm looking into 2004 STi struts (which will be re-valved for the specific spring rates). Please don't suggest KYB AGX's or D-Specs. I already have Group N top hats front and rear. Rear sway bar is a Cusco bar (I can't recall the size right now).

For springs, I'm leaning towards Ground Control springs as I can choose the rates and have some flexibility to control ride height and to have the car corner balanced. The smaller springs should allow less snow to pack in the suspension and cause some binding (which has happened to me in the past w/ traditional springs).

This leads me to my question as far as the spring rates and spring heights:
Spring Rates I'm leaning towards: 250 FR and 225 RR or perhaps 225 FR and 200 RR. Not looking for the most plush ride, but something more taught yet livable. Although, honestly I'm unsure of how this setup will be, so any advice is more than welcome.

Regarding the spring height, I'd like to have the car lowered about ~1" or so. I should be getting a set of 15" rally gravel rims to mount a dedicated set of snow tires to as well.


Thank you for your constructive feedback! :)

[Gancherov]

For snow driving I would not want the car lowered at all. You will end up being limited by your ride height all the time. I would at least keep stock height if not a little taller. If you are higher up there is less chance that you will get stuck on top of a "pillow" of snow.

Ideally you would want lots of clearance with tall skinny winter tires so that your tires will cut through the snow rather than ending up on top of it. Skinny tires concentrate your weight more than wider ones so you will get more grip in slippery conditions.

04 sti struts and springs will lower the car ~1cm from stock WRX stuff. I wouldn't go lower than that, in fact I put in a 1/2 inch saggy butt spacer to keep WRX height in the rear. The springs are already conveniently 225FR/200RR which gives you a good neutral handling and fairly comfortable car.

Make or buy some spring (or coilover) blankets. They go on over the springs and you can just tie them to the strut body. This will keep snow as well as gravel and dirt away from your springs 99% of the time. Super cheap as well.
http://www.gearheadsonline.ca/shop/image.php?type=D&id=296

Why buy gravel rally wheels for snow duty? Get snow rally wheels. These are designed to keep snow out so you don't have to clean it out every time it gets packed with snow. Which it will.
http://www.teamilluminata.com/Shop/Braid/winraceN.gif

[ZeroDrift]

Thank you for the response. I forgot to add my car's information to my profile/sig on this forum.

I've got a '99 Impreza 2.5RS so the STi stuff should keep the car the same height, or if using the stock springs raise it up some. I'm partially looking into the Ground Control setup so that I could change the ride height depending upon the conditions.

I'm planning to get the 15' rally rims to clear my 4 pot brakes, and hopefully a set of SpeedLine Course 2118 wheels. I'd be making a 'snow scraper' to assist in the cleaning of the snow from the rims.

The cover idea is actually a great idea, and I'll be sure to make some before I install the new suspension setup.

[ZeroDrift]

Any comment or suggestions on the spring rates?

I'm more worried with the FR to RR bias and how it will effect handling on snow.

[ZeroDrift]

Figure I would update this thread:

I have since purchased some STi struts and have since been serviced/re-valved for the new spring rates.

Struts have had all spring perches ground off and are about ready for the heavy duty threaded bodies. The struts will have a steel collar welded towards the mounting tab with a key-way so that the aluminum threaded body has something flat to rest against and won't turn when making adjustments.

New Swift springs were purchased as well.
Rates: 250# front, and 225# rear.

Springs are standard sized 2.5" ID front and rear. Spring length is 8" front and 10" rear.



http://img193.imageshack.us/img193/6629/dsc0643br.jpg

Machine shop started working on the threaded lower spring perch and the locking collar. I need to contact the anodizing shop to find out expected thickness buildup of the process so that tolerances can be compensated for at this stage. These things are going to be VERY heavy duty! Locking perches/collars are going to be roughly 1" thick, which will do a very good job of keeping the threads alive under the abuse.

Machining aluminum stock (6061 alloy): :D

http://img153.imageshack.us/img153/3682/imag0026k.jpg

http://img600.imageshack.us/img600/4162/imag0030.jpg

[lino]

:headbang:

[Gancherov]

Looking great! any more progress?

[ZeroDrift]

There is more done now, but no pictures just yet. Perhaps next week I'll do another update.

Rims/tires came in a while ago. Old suspension setup still pictured, and the engine is out. Ride height will be around there I believe once everything is back together.

http://img17.imageshack.us/img17/6948/dsc0637d.jpg



Oh yes: Happy Thanksgiving!

[careercadaver]

^^Looking good!

I have a set of lowering springs coming for my GC. How bad will lowering the car 25mm in the front and 30mm in the rear really affect my handling in the snow? I have new tires but is it that the wheel well fills up and causes issues?

[ZeroDrift]

I found that my last setup caused some issues with snow and really cold temperatures. Snow compacted at the top of the wheel well and froze. Normally this isn't much of an issue as most will fall, but I had ice form between the spring perches which locked up the suspension.

http://img26.imageshack.us/img26/1628/sam0291u.jpg

[ZeroDrift]

Nearing completion!

Whats left:


Weld lower collar to strut body.
Make upper spring perches from steel
Test fit whole assembly
Uninstall, and send parts to get anodized and powder coated.
Make coilover 'bags'.
Install!


http://img27.imageshack.us/img27/3097/imag0052k.jpg

http://img94.imageshack.us/img94/4170/imag0056l.jpg

http://img12.imageshack.us/img12/4845/imag0055fm.jpg

http://img684.imageshack.us/img684/7026/imag00530.jpg

http://img258.imageshack.us/img258/5153/imag0054a0.jpg

[phoenix1112]

Nice, where can I get some of those? Seriously, if you kept the specs, people would buy them.

[ZeroDrift]

Nice, where can I get some of those? Seriously, if you kept the specs, people would buy them.


For the price currently I doubt people would buy these. Perhaps I can outsource these to another company who could mass produce em? In either case I would have to have more interest in these to even consider it. If you are very interested send me a PM, and I can contact the machine shop that is currently making these.

[Jard]

That's a really cool setup. Kudos on going out and getting it done.

[Ruh Roh 1]

Very Nice!

[ZeroDrift]

Anyone know of a dust boot that will fit under the 4" OD diameter barrel spring? Preferably something quality that can cope with the cold weather. I will be using an outer protective skin as well.

[ZeroDrift]

Quick update. Going to test fit these Monday!

Steel upper spring perch. This is designed to fit snugly within Group n tophats.
http://img209.imageshack.us/img209/3369/imag0079o.jpg

Grease fitting protected nicely! I should have little trouble with access!
http://img196.imageshack.us/img196/4016/imag0075zq.jpg

http://img576.imageshack.us/img576/4307/imag0072o.jpg

Few more:

http://img821.imageshack.us/img821/9426/imag0077zg.jpg

http://img834.imageshack.us/img834/2650/imag0076ol.jpg

http://img811.imageshack.us/img811/112/imag0074tl.jpg

[Gancherov]

Looking great! Don't forget to snap some shots of the test fit for us.

[lorenkb]

Those are turning out very nicely!

Have you made sure you aren't going to run into coil bind with those 8/10" springs?

[ZeroDrift]

Those are turning out very nicely!

Have you made sure you aren't going to run into coil bind with those 8/10" springs?

For what ever reason I kept posting the wrong information for a while. The coils are actually 10" front, and 12" rear. The usable travel is more than the damper can provide. :)

[lorenkb]

:rofl:

For what ever reason I kept posting the wrong information for a while. The coils are actually 10" front, and 12" rear. The usable travel is more than the damper can provide. :)

It's not as simple as just making sure that the usable travel is more than max damper travel. Keep in mind that whatever preload distance you require to set the rideheight as desired will subtract from that usable spring travel.

I have a feeling that with your lighter GC and higher spring rates you'll be OK, but when I looked into doing the same thing for my WRX wagon, I required 12/14" springs.

[ZeroDrift]

I'll have to go over my calculations some more to verify things. When I do the test fit I will take some pictures and measurements, but I currently have no engine in the car, so things will change with the extra weight. Worse case scenario, I will buy additional springs.

Thanks for the heads up though!

[ZeroDrift]

Well time was short today, so only got front driver side tested.

Bolted up:
http://img259.imageshack.us/img259/9506/dsc0692yp.jpg

Clearance with my 15" x 7" +50 Enkei rims.
http://img842.imageshack.us/img842/6789/dsc0698i.jpg


Clearance with Advan 17" x 7.5" +47 rim.
http://img218.imageshack.us/img218/4387/dsc0708j.jpg


So far so good. Hopefully tomorrow or the day after and I'll have time to test the rear setup. I'm guessing it will be a tight fit at this point.

[ZeroDrift]

Quick update on the top hats. I've picked up the tophats today and wanted some opinions.... The rear spring perch is looking a little scrawny compared to the front perch. The spring perches are steel, and I don't know the alloy.

http://img253.imageshack.us/img253/2564/dsc0710f.jpg

http://img130.imageshack.us/img130/3163/dsc0711o.jpg

http://img408.imageshack.us/img408/3541/dsc0712mk.jpg

http://img703.imageshack.us/img703/9409/dsc0715t.jpg

http://img256.imageshack.us/img256/1280/dsc0717j.jpg

[lorenkb]

I think your spring perches will be fine. Considering how the stock stamped steel perches survive just fine, your much thicker machined steel parts should be overkill.

[ZeroDrift]

Reworked the top hats since the last test fitment. Hopefully I can test fit the rears today.
http://img80.imageshack.us/img80/7964/dsc0719f.jpg

[ZeroDrift]

Progress:

http://img195.imageshack.us/img195/3099/20110110124336299.jpg

http://img709.imageshack.us/img709/3470/20110110124328588.jpg

http://img132.imageshack.us/img132/9990/20110110124320109.jpg

[ZeroDrift]

Progress:

http://img824.imageshack.us/img824/6862/dsc0735v.jpg

http://img443.imageshack.us/img443/1376/dsc0734a.jpg

http://img534.imageshack.us/img534/5439/dsc0731q.jpg

http://img577.imageshack.us/img577/9318/dsc0732i.jpg

[bc5scooby]

wow, those are beautiful

[ZeroDrift]

wow, those are beautiful


Thanks! I can't wait to test em out! :)

[Ioku]

Nice work, I actually just finished building something very similar to your set up STI struts with 250 Front and 225 Rear springs only I used 12 inch springs front and rear. The spring I got are Eibach 2.5 in id coils. The problem Im having is the car sits too low in the front and way high in the rear I and I have almost no preload in the rear and a good 1.5 inches in the front. heres some pics of my set up I still need to get some full pics of the car.

http://i272.photobucket.com/albums/jj199/Ioku7/Linked%20Images/DSCF0088.jpg

http://i272.photobucket.com/albums/jj199/Ioku7/Linked%20Images/DSCF0089.jpg

http://i272.photobucket.com/albums/jj199/Ioku7/Linked%20Images/DSCF0092.jpg

http://i272.photobucket.com/albums/jj199/Ioku7/Linked%20Images/DSCF0096.jpg

http://i272.photobucket.com/albums/jj199/Ioku7/Linked%20Images/DSCF0097.jpg

[greaser]

wow awesome work guys. I wish i had that kind of mill work skills.

[flyguyeddy]

most of that was done on a lathe. the slot cutting for the adjustment nuts is probably the easiest part of all that.

[ZeroDrift]

Nice work, I actually just finished building something very similar to your set up STI struts with 250 Front and 225 Rear springs only I used 12 inch springs front and rear. The spring I got are Eibach 2.5 in id coils. The problem I'm having is the car sits too low in the front and way high in the rear I and I have almost no preload in the rear and a good 1.5 inches in the front. here is some pics of my set up I still need to get some full pics of the car.



Looks good! Look into Swift Springs. Their springs have more usable compression per any given length compared to the Eibachs. Also what dust boot are you using?

[Ioku]

The dust boots are procomps, there made for regular shocks like you'd find on a truck. I got them on summit racing, they just barely fit between the springs and big sti strut tubes.

[ZeroDrift]

Car is finally back on the ground. I'm still finishing up the engine and interior so I can't drive it yet, but here are a few quick pictures:


http://i409.photobucket.com/albums/pp174/ZeroDrift_album/1999%20Impreza/Itlives.jpg

http://i409.photobucket.com/albums/pp174/ZeroDrift_album/1999%20Impreza/DynamicDuo.jpg

http://i409.photobucket.com/albums/pp174/ZeroDrift_album/1999%20Impreza/DSC_0129And8more_fused.jpg

[pope_face]

That suspension looks great... I love the gold on black paint scheme to match the car. Very nice...

As for the stance... looks good, but it seems your a bit low in the front, not to mention your engine will drop it down even further. But, I'm a fan of a level height. Did you just toss these in and test them out, or did you try adjusting the ride height before you put it in? I like the height in the rear, but again, that's personal preference.

Awesome little setup though...

[Two5RS]

Very nice!!!!!

[ZeroDrift]

I have yet to adjust anything. Once things settle down I will add some pre-load to the fronts to help level things off some. I do plan to have the front slightly lower than the rear most likely though.

Thanks for the kind words though! :)

[ZeroDrift]

I finally tinkered with the suspension height some and had an alignment recently:


http://i409.photobucket.com/albums/pp174/ZeroDrift_album/1999%20Impreza/DSC_0202And7more_fused.jpg

http://i409.photobucket.com/albums/pp174/ZeroDrift_album/1999%20Impreza/DSC_0236_37_38_39_40_41_tonemapped.jpg

http://i409.photobucket.com/albums/pp174/ZeroDrift_album/1999%20Impreza/DSC_0231_2_3_4_5_fused.jpg


All in all, I am very pleased with the setup! Goes over rough patches at speed very well. Still a somewhat harsh ride when going slow over some washboard but only some noise when going at speed. All that is left is to sort out a few rattles. :)

[Ioku]

did you ever get your car to sit perfectly level, I had to add quite a bit of preload to the front and have just enough in the rear to keep the springs in place but it still sit too high in the rear.

[ZeroDrift]

did you ever get your car to sit perfectly level, I had to add quite a bit of preload to the front and have just enough in the rear to keep the springs in place but it still sit too high in the rear.


I had to add some pre-load to the front, but it wasn't much. Perhaps ~1/2" or so. Have any pictures of how your car sits? Also, are you 100% positive that you have the higher rate springs up front? The only other thing that comes to mind is upper spring perches, or possibly tophats. I did use some Bakemono rear camber plates which may have effectively brought the rear end down some.

[Ioku]

I know I have the lower rate springs in the rear, there labeled and the coil diameter looks smaller. heres a pic of the car

http://i272.photobucket.com/albums/jj199/Ioku7/Linked%20Images/content___media_external_images_media_12.jpg

I think I might just need some rear camber plates to lower it a bit, I just bought some Noltec front plates so that might help to lift the front a little too and even it out.

[Super2.2]

Zero, I'm very interested in doing a similar setup. How much would that machine shop do another set for?

[cantpee]

I know I have the lower rate springs in the rear, there labeled and the coil diameter looks smaller. heres a pic of the car

http://i272.photobucket.com/albums/jj199/Ioku7/Linked%20Images/content___media_external_images_media_12.jpg

I think I might just need some rear camber plates to lower it a bit, I just bought some Noltec front plates so that might help to lift the front a little too and even it out.

That's really beautiful fitment at the front for street usage.

[RS MN]

Awesome setup!

Wish I had the resources to do something like this.