Learn me: Front suspension and rallyX

wvumtnbkr wrote: The nice thing about the FC is that the cheap chinese ebay coilovers work. Then you just need springs. You can get used springs pretty cheap. The adjustability means that you can run the springs on the front or rear if you get them short enough (7" works okay for front or rear).

10" springs are almost too short for an FC front suspension. 7" would definitely be a no go because there's 6" or so of travel already. The only problem is the longer the spring, the thicker the wire has to be for the same rate, so you don't gain travel quickly. I have 14" springs up front right now and they barely have enough travel - there's evidence of the coils going solid ever so gently.

Don't get "cheap chinese ebay coilovers", get Allstar threaded sleeves and lower collars. They may be cheap but they are a known quantity. Support circle track companies instead of riceware!

Yup, Allstar is good stuff. Or go to a roundy-round racer swap meet.

There is absolutely no way to get longer then an 8 inch spring in the front with a over stock springrate and be anywhere near stock ride height.

I bought the ground control setup and it came with 6" front springs.

Yeah I'm not sure how you're cramming 14" of spring on the front end.

Mazda comp catalog lists eibach ers 2.5" springs in rated from 175 to 500 in 7" 8" or 10".

Pete, Evan posted part number already

wvumtnbkr wrote: There is absolutely no way to get longer then an 8 inch spring in the front with a over stock springrate and be anywhere near stock ride height.

Here you go:

That's a 10" QA1 250lb spring with the ground-flat section of bottom coil cut off, and an upper seat made out of a piece of 3/16" plate and three washers, one on the bottom to locate the spring and two on top to work with a ZX2 strut mount/bearing. Upper washers not necessary with an FC strut mount/bearing.

Ride height was just about the same as stock FB ride height. Zero spring preload but much higher rate.

I dunno about how it'd fly in an FC but you can tweak ride height with different strut mounts.

DaveEstey wrote: Yeah I'm not sure how you're cramming 14" of spring on the front end.

Here you go:

Stock on top, new strut on bottom.

That's a GC rear strut housing with another set of GC strut ears grafted to the top, Allstar threaded sleeves/perch, QA1 175lb 14" spring that I used to use on my FB struts years back, and rear WRX Koni Yellows. Lots more travel than the FC struts. Too much travel, really - I can't run negative camber because the ball joint runs out of travel at full droop. So one of this winter's projects after my wagon is finished is to cut the strut towers and relocate them higher and further inboard - basically rotating the suspension around the control arm axis. Then I'm thinking of doubling some shorter 300-400lb springs, basically make it springs all the way down.

I like to fab suspension parts...

See i dont know/understand this suspension stuff at this level. So its hard to justify spending several hundred on stuff i dont understand.

Tire Rack has Bilsteins for an 87 FC listed if you search by Turbo model, and you can use the GRM link to kick some bucks their way, I think.

I had Racing Beat Springs on my car and they raised it about 1/2" from the worn stock Turbo springs.

Your chart does show the same part numbers for Turbo (couple with LSD) and Convertible, those look like part numbers for 89 and later cars.

I show these stock part numbers for 87-88 Turbo Suspension:

Rear Springs: FB01-28-011A

Front Springs:

(right) FB44-34-011 pink mark (NOT 011B)

(left) FB44-34-021 gray mark (NOT 021B)

Mazdaspeed has an old parts catalog for suspension here, with some trick aftermarket stuff that is most likely NLA:

http://www.mazdamotorsports.com/pdfs/catalog/09_Suspension.pdf

Stock parts index for 86-88 cars: http://www.mazdamotorsports.com/pdfs/rx/8688rx7/0191_1.PDF

Stock Parts for '89 and later cars: http://www.mazdamotorsports.com/pdfs/rx/8990RX7/0230_2.PDF

fidelity101 wrote: See i dont know/understand this suspension stuff at this level. So its hard to justify spending several hundred on stuff i dont understand.

You could do what I should have done.

Accept that struts are a wear item and get AGXs every couple of years. Done.

I think the fronts are the same for every application, and the rough rule of thumb is the setting to use is the spring rate divided by 100. 200-250lb springs like setting 2, 400lb springs like 4.

I would always rallycross on setting 2 with 250lb springs, and I'd drag race on 1 because it seemed to help the launch a little. Not enough damping on 1 to rallycross and waaaaay too much on 3. The adjustment is rather chunky, but at least you can tell what it's doing, unlike some other adjustables.

All the front FC Bilsteins are inserts. One of my winter projects is to cut up my spare set of front struts and get the Bilsteins I have here installed on my FC Rallyx car.

I am keeping an eye on this thread about the spring choices since I have just been running stock springs.

moxnix wrote: All the front FC Bilsteins are inserts. One of my winter projects is to cut up my spare set of front struts and get the Bilsteins I have here installed on my FC Rallyx car. I am keeping an eye on this thread about the spring choices since I have just been running stock springs.

I'm not convinced that you've been running any front springs or shocks at all this season, personally. And neither is your skidplate

Racing Beat springs on an '87 TII (my old one). It does look low, but it was sitting even lower before that on stock springs. I imagine if you stripped out most of the interior it would ride higher. An N/A car might also ride a bit higher due to less weight as well.

In reply to Brett_Murphy:

Yeah I have been going off of the S5 chassis because they were heavier so in theory they would have stiffer spring rates to compensate.

I may just accept that the struts are wear item and get a lifetime warranty through local parts store and just replace them every time they blow out. Because if I get the bilsteins from wherever and then order from mazda the coil over conversion strut w/ two 2.5" springs and camber plate it comes to be about a grand...

However I don't want to replace a shock every event or two.

the car is much lighter than a turbo, it is gutted and there isn't much under the hood. More diet is soon to follow too within the next year.

EDIT: STOCK COUPE (source, mazdatrix):

1.front spring rate is 95 lb

1. rear spring rate is 90 lb

RACING BEAT COUPE (1" drop, 20% stiffer than stock, source RB):

1. front spring rate is 156 lb

2. rear spring rate is 128 lb

RACING BEAT CONVERTIBLE(.5" drop, 20% stiffer than stock, source RB):

1. front spring rate is 139 lb

2. rear spring rate is 134 lb

SUSPENSION TECHNIQUES (.8" drop, source mazdatrix):

1. front spring rate is 120 lb

2. rear spring rate is 120 lb

Maybe the drop in the front isn't all that bad, it already sits pretty high in the front with the weight loss as is it is so a minor drop may not bad because under accel it will pick up anyways.

Middle of the road idea is run bilstein inserts (300 for the pair) new springs (260-300 for all 4) new mazda comp upper strut mount (150) or moog (100) + the cost of having strut modified for insert ($$$$$?)

is about 800 dollars still, with no camber adjustment and limited to springs that fit stock mounting.

but for 900-1000 dollars I can have a mazdaspeed coilover converstion setup in the front and when it comes to suspension tuning it is 100 dollars for a pair of 2.5" springs with new rates with a variety of spring manufacturers.

Coilovers are worth it.

100 dollar difference between coilovers and non coilovers make it worthwhile too(when already spending 800). I'm curious to see if I can shove a 10" spring in there though...

So the spring length depicts travel, correct?

Okay well then mr smarty pants now which one do I try? Obviously I can get 2.5" from virtually anywhere but for the 1st go around I would just get my stuff all from one place. Future build idea is turn into stage rally but right now rallyX is far more budget friendly. Yet somehow this doesn't feel like it.

I'm sure you could get a 10" spring on there. That is what I am planning for the Miata when I get the Bilsteins rebuilt and converted to coilovers this winter.

Suspension checklist:

KYB AGX - RockAuto.com = $210

QA1 springs = $90

QA1 coilover kit = $50

AWR camber plates = $290

Total = $640

EvanB wrote: I'm sure you could get a 10" spring on there. That is what I am planning for the Miata when I get the Bilsteins rebuilt and converted to coilovers this winter.

I Blame you guys for this! I don't want to upgrade my suspension because I'm cheap and I love to flog the vehicle but you guys have all stepped up your game...

I guess I hope my engine makes it through 1 more season...

DaveEstey wrote: Suspension checklist: KYB AGX - RockAuto.com = $210 QA1 springs = $90 QA1 coilover kit = $50 AWR camber plates = $290 Total = $640

You can save almost $300 by not using camber plates. Just stock uppers. They fail frequently enough, aftermarket probably wouldn't last two events.

In reply to Knurled:

but can I run 2.5" springs on stock upper mounts?

It doesn't look like I can.

In reply to Knurled:

This is why I don't rallyx.

Stuff that will last for years doing hillclimbs and roadcourse work won't last a season of rallyX.

I have stock type strut housings (tokiko blues). I am running ground control coilover sleeves. I am running stock upper strut mounts (you just need the spring keeper and a washer to use the stock strut mounts).

I have a 200# front spring that is 7" long. The car is sitting with the front suspension arms level. This is with the adjuster the entire way down.

I realize that if you run not stock suspension parts that you can cram anything you want under there.

If you are running stock type struts (or even bilstein inserts) and you are running over 150# front spring AND you are running some type of coilover sleeve AND you are running a stock strut mount OR a camber plate designed for an RX7 THEN you can't fit much more than a 7" spring in the front.

Rob R.

BTW, I recommend getting KYB GR-2 struts all around. Then get some allstar threaded collars. Then get some 7" or 8" springs of whatever springrate you want. Make sure you get the upper spring mount with the collars. Make sure you don't bind up your strutmount bearing (use a washer between it and the upper spring perch if you have to).

fidelity101 wrote: In reply to Knurled: but can I run 2.5" springs on stock upper mounts? It doesn't look like I can.

The parts car I bought had 2.5" coils just sort of sitting against the stock uppers.

My uppers, again, are just some plate with a big washer welded to the underside to locate the spring. It doesn't locate to the bearing in the strut top, but then it doesn't really have to. The strut shaft is hardened and the plate isn't. In practice, wear is not an issue.

So what your saying is theres a chance...

SO, new middle of road idea:

1. Mazda competition upper strut mount/bearings

2. bilstein inserts

3. some sort of coilover sleeves (allstar or mazda comp)

4. 10" (or 8") 175lb springs

I realize there are other spring rates/suppliers but how do I know which one will suit me? Also now don't I have to mess with the rear since it will be a stock 90-95lb spring rate in the rear, now wont the car just understeer heavily being too stiff in the front?

My brain hurts.