Suspension upgrade for non-ST (sedan)

[Fish Freak]

.....The discussion only refers to ride height. The question is does ride height change if you use the same spring on two different dampers? B6 vs B8. I claim that B8 damper with the stock spring will have a higher ride height than the B6 damper with the same spring. You claim that it won't?

.....All other things being equal (damping, gas pressure, lower spring seat location), I'm claiming that just changing the "starting" shock shaft length by an inch will not change the ride height once the damper compressed to the operating range of its stroke.

If there *is* a difference in height between the two, there has to be some other difference between B6/B8 besides the shock shaft, or else some manufacturing variation between the dampers you have, like maybe lower gas pressure.

I was JUST going to reply with something like this DC, only less words ;-) , but you're spot on. Shock damper is parallel to the spring stack and only gas pressure can increase the height.

I'm taking a stock non-ST car with stock oil shocks and putting on ever-so-slightly lower stock ST springs on with B6 dampers, and hoping the gas pressure will keep me pretty close to my stock height S car. I don't really care about lowering it. Hoping the spring rate on the ST springs is slightly higher than the S too....

 

[Fusion Works]

There is almost no gas pressure in the B6/B8 dampers. They are Twin tube with a minor amount of gas pressure. Even my custom rear damper only uses 100 lbs of gas pressure.

 

[Fish Freak]

There is almost no gas pressure in the B6/B8 dampers. They are Twin tube with a minor amount of gas pressure. Even my custom rear damper only uses 100 lbs of gas pressure.

I just bought B6's and they CLEARLY say Monotube on them, and the fronts, I can't hand compress them, well, I didn't try real hard but they're under pressure.... Double checked, they're monotube. I would not have paid that much for twin tubes!

 

[Fusion Works]

The rears are Monotube. The fronts are not. I will cut one apart soon.

 

[Dialcaliper]

I just bought B6's and they CLEARLY say Monotube on them, and the fronts, I can't hand compress them, well, I didn't try real hard but they're under pressure.... Double checked, they're monotube. I would not have paid that much for twin tubes!

Bilstein has a smaller 36mm Monotube they use for some (most/all?) B6/B8 kits but they’re pretty much always crimped (non-rebuildable) housings. One or both front/rear may use the small monotube as they also have a 36mm piston strut design. Based on the gas force required to compress them, I suspect the fronts are also small monotubes

B4 OE replacements are twin tube

 

[akiraproject24]

Any consensus yet on whether a B6 or B8 is ideal with stock springs

And of course whether B6 or B8 is ideal with Swift springs?

Mountune uses the B8s in the clubsport suspension

 

[M-Sport fan]

So, bottom line;

Is there ANY chance at all of a Swift Spec R spring sitting any higher at static ride height on a B6 damper than on a B8 damper, all else (total sprung car weight, driver weight, ancillary installation parts/external bump stops, spring pads, etc., etc.) being equal??

Same question for total wheel travel available with that spring, and the two Bilstein variant dampers.

 

[Dialcaliper]

So, bottom line;

Is there ANY chance at all of a Swift Spec R spring sitting any higher at static ride height on a B6 damper than on a B8 damper, all else (total sprung car weight, driver weight, ancillary installation parts/external bump stops, spring pads, etc., etc.) being equal??

Same question for total wheel travel available with that spring, and the two Bilstein variant dampers.

From the sound of it, if the body length is the same, and only the shock shaft is shorter, unless the gas pressure is different (unlikely with the same valving), there is zero advantage or difference to the B8 at all on stock or any mild lowering spring. The only reason a shorter shock shaft is useful is for springs that lower the car significantly without changing the primary spring rate (Eibach/Whiteline, etc) - reducing droop is a compromise at best to get rid of some spring travel in the weak helper coils.

No wonder Swift was wishywashy on whether to use the B6 vs B8 - there’s basically no difference (except ride quality will be worse on bumpy backroads with less droop travel). The B6 seems to have more total travel (given that the compression end is restricted by the bumpstop in both cases)

The only reason a B8 would actually be desirable is if it had stiffer valving, which apparently it does not.

If you want stock ride height with stiffer spring rates, check out the 225/200 (3.0ID/2.5ID) spring solution I found - they are working quite well, not terribly expensive and I’d keep it this way if I didn’t have bigger things in mind. They also have the advantage of being linear through almost the full travel (the Swifts are not quite linear in droop because they must use soft helper coils in order for the car to sit lower)

 

[Fish Freak]

The rears are Monotube. The fronts are not. I will cut one apart soon.

I just took my front B6 struts out of the box and there's a sticker on them that says MONOTUBE. I bought them because they are monotube.

Here's what Bilstein says: Monotube Upsidedown Technology overview !

 

[M-Sport fan]

From the sound of it, if the body length is the same, and only the shock shaft is shorter, unless the gas pressure is different (unlikely with the same valving), there is zero advantage or difference to the B8 at all on stock or any mild lowering spring. The only reason a shorter shock shaft is useful is for springs that lower the car significantly without changing the primary spring rate (Eibach/Whiteline, etc) - reducing droop is a compromise at best to get rid of some spring travel in the weak helper coils.

No wonder Swift was wishywashy on whether to use the B6 vs B8 - there’s basically no difference (except ride quality will be worse on bumpy backroads with less droop travel). The B6 seems to have more total travel (given that the compression end is restricted by the bumpstop in both cases)

The only reason a B8 would actually be desirable is if it had stiffer valving, which apparently it does not.

If you want stock ride height with stiffer spring rates, check out the 225/200 (3.0ID/2.5ID) spring solution I found - they are working quite well, not terribly expensive and I’d keep it this way if I didn’t have bigger things in mind. They also have the advantage of being linear through almost the full travel (the Swifts are not quite linear in droop because they must use soft helper coils in order for the car to sit lower)

That's just it though, I can handle/accept a slight bit (0.25"-0.50") of lowering from the Swifts, I just cannot live with the full claimed 1" of lowering (on the factory dampers), or even more, which the 'slammer' types on here desire so much, for my purposes.

I trust Swift, even their decision to use those progressive-like helper/tender coils on the Spec Rs, but just am unsure about the final result when paired with the B6 Bilsteins.

Regarding the 3.0" I.D. springs you used; is there a 0.50" shorter free length option, or is that asking too much?

 

[Dialcaliper]

That's just it though, I can handle/accept a slight bit (0.25"-0.50") of lowering from the Swifts, I just cannot live with the full claimed 1" of lowering (on the factory dampers), or even more, which the 'slammer' types on here desire so much, for my purposes.

I trust Swift, even their decision to use those progressive-like helper/tender coils on the Spec Rs, but just am unsure about the final result when paired with the B6 Bilsteins.

Regarding the 3.0" I.D. springs you used; is there a 0.50" shorter free length option, or is that asking too much?

It’s not so much that Swift and every other company “chose” to use helper coils. There’s really no other way to stiffen the rate and lower a car without them except in very specific cases on certain cars.

Pop a post in the other thread here and I can fill you in on what I’ve found. Going off on a bit of a tangent from what this thread was about.

https://www.fiestastforum.com/threa...-rally-springs-for-stock-b6-suspension.30829/

 

[Dave88LX]

This has been a great read so far!

 

[Dave88LX]

Jeez I really need to do something. Haven't driven the car too much lately, been using my truck in the winter. Drove it this past week.

Couple days ago we had 20-30 MPH winds with 55 MPH gusts and it was pushing me all over the highway. I ended up getting pulled over I was drifting in my lane so badly.

Wondering if there are any other suspension components that are worn at 96K miles that I need to replace also.

 

[M-Sport fan]

^^^The cop/trooper did not give any leeway at all for it being a small, light, somewhat tall car, given those conditions??

 

[Dialcaliper]

Jeez I really need to do something. Haven't driven the car too much lately, been using my truck in the winter. Drove it this past week.

Couple days ago we had 20-30 MPH winds with 55 MPH gusts and it was pushing me all over the highway. I ended up getting pulled over I was drifting in my lane so badly.

Wondering if there are any other suspension components that are worn at 96K miles that I need to replace also.

Get underneath and check the rubber bushings in your control arms and rear trailing arms as at that kind of mileage they can start to crack especially if you have cold winters. If you are hearing any squeaking in the suspension, Upper strut mounts rubber could also be going. Ball joints usually last a while, but you can check them for dead play by shaking the wheel (just like you would for a wheel bearing). Any of those could also be worsening control difficulties in side winds that you mentioned.

 

[Dave88LX]

^^^The cop/trooper did not give any leeway at all for it being a small, light, somewhat tall car, given those conditions??

I guess the leeway was sending me on my way without a warning or ticket and telling me to be safe LOL.

 

[Dave88LX]

Get underneath and check the rubber bushings in your control arms and rear trailing arms as at that kind of mileage they can start to crack especially if you have cold winters. If you are hearing any squeaking in the suspension, Upper strut mounts rubber could also be going. Ball joints usually last a while, but you can check them for dead play by shaking the wheel (just like you would for a wheel bearing). Any of those could also be worsening control difficulties in side winds that you mentioned.

This is great info, thank you! I'll get it up in the air when the rain goes away. About time to get these X-Ice tires off and back to my 3-seasons too.

If it needs bushings and/or ball joints, probably easier, and more time/cost effective to just replace the whole arms I'd guess?

 

[Dialcaliper]

This is great info, thank you! I'll get it up in the air when the rain goes away. About time to get these X-Ice tires off and back to my 3-seasons too.

If it needs bushings and/or ball joints, probably easier, and more time/cost effective to just replace the whole arms I'd guess?

I imagine some of your crosswind issues may also be from tread squirm in those snow tires (didn’t realize you were driving on them when the incident happened). I’m not sure there’s a lot you can do about that besides switch to a different tire, but it’s a bit of a crapshoot (pretty much all snow tires have tall, soft treads). A wider snow tire might help, but will also be slightly less optimal in actual snow/ice. If your winters are mild you could consider switching to a “performance” snow tire, or even an “all weather” tire with a stiffer compound, but both of those will also sacrifice winter grip.

Control arms are super cheap ($75 for Motorcraft and as low as $35 for aftermarket on Rockauto). OEM bushings and ball joints are hard to come by these days. Sadly it’s not worth trying to DIY unless you want to go the route of installing poly bushings.

Poly bushings aren’t that hard, but annoying. Even then, there are also preassembled arms from Superpro ($300) with caster bushings, which is not that much more expensive than just poly bushings alone, but make sure you check the correct model for the base model Fiesta/Mazda2 - the FiST arms aren’t compatible with the non-ST models (one of the subframe bolts is a different size)

 

[Dave88LX]

Yeah, was on the winter tires, so that is a good point. Even with normal tires it still has that twitchy/darty/unstable feeling though (which was what prompted me to create this post originally). I'm in PA, so winters are a crapshoot on what we will have haha.

I don't think there is any reason to go with a poly bushing. It's my DD that I put 150 miles/day on. I think just standard bushings are probably fine.

SuperPro website is blocked at work but I will give it a look later on at home!

 

[Dialcaliper]

Yeah, was on the winter tires, so that is a good point. Even with normal tires it still has that twitchy/darty/unstable feeling though (which was what prompted me to create this post originally). I'm in PA, so winters are a crapshoot on what we will have haha.

I don't think there is any reason to go with a poly bushing. It's my DD that I put 150 miles/day on. I think just standard bushings are probably fine.

SuperPro website is blocked at work but I will give it a look later on at home!

Sounds like Rockauto is probably the ticket