BC Coilovers - s14 - Rough Ride

[slevin]

Alright, this being my first s-chassis car maybe I'm expecting too much?

Quick info about my experiences with coilovers and cars. Had a 97 Miata with Tein Flex (old ones made in japan rebuildable) Rode great on full soft for the street, turned them up for trackdays and canyons rode great. Never bouncey or jarring ride.

I also own a 94 rx7, bought the same coilovers brand new for it as well. Tein Flex standard spring rates (made in japan, rebuildable ones) Set it the same from factory. I used to run 255/45/17s all around, rode like a dream. firm when tightened up, soft like stock when loosened up. Both cars never were slammed, maybe 1/2"-3/4" gap from wheel to top of fender arch. I even recently went to 18's on the FD and it rides the same it did with the 17's.

Bought this s14 from someone off offerup, came with alot of suspension components and redone rear bushings on the rear subframe, circuit sports garbage motor mounts etc etc. Replaced the circuit sport crap with Nismo motor mounts to get rid of all the unnecessary in cabin vibration.

Day i drove it back it felt like it beat the shit out of it, every bridge on the freeway would buck me out of the seat. Once I got home i softened all the settings on all 4 corners to see if it would change anything, same thing. beats the shit out of me, jarring uncomfortable ride.

I looked into the actually coilover itself. It's just a standard BC coilover with 8kg/6kg spring rates.

I got the car on stands and added about 1/2" of preload all around as well as raised the ride height up about another 3/4" just to see if it would change anything... messed with the dampers again and took it out for a drive. Still bone jarring ride.

Am I expecting too much from these coilovers ? or the car itself? Short drives it isn't bad, but anything longer then 45minutes and on the freeway just beats the shit out of me.

Should I just sell them and get something better, or maybe swap in Swift replacement springs?

[S14rebuild]

Run 0 preload and back the dampening to soft and see....more then likey just how those coilovers ride.

[samotage]

Mine has always been firm, and my new MCA coilovers are firm and precise, but not bone jarring. With all the suspension work I?ve done, there is a raw harshness, but it?s not uncomfortable at all.

And I get why that engine mount is no fun.


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[Krusty_s13]

The coilovers don't NEED that much preload for a street car. If I recall correctly, BC ships them with roughly 5mm (less than a 1/4 inch) of preload and thats basically just to keep the spring from bounching around.

I typically run my coils with 2-3mm of preload and keep the dampers on the soft side.

Back out the springs until they are loose, snug them up and add a little preload. adjust the dampers a bit softer and see if that helps. If it doesn't, there should be a sticker on the bottom (threaded side) of the damper with the build month and year. Check that out.

[FaLKoN240]

Too much preload.

Macpherson strut front, multilink IRS rear.

These cars don't run high spring rate coils for the most part and are pretty compliant with minimal preload.

Like the other poster said, I loosen the springs all the way then tighten them up a tad so they don't move around when there's no load on them.

Try that.

[mechanicalmoron]

240 stuff is often pretty much geared towards being too stiff, for drifting and people who actually and fanatically believe suspension shouldn't comply. I believe I've read things about BC coilovers being excessively bouncy. It's probably got solid or stiffer subframe bushings, and everything else.

Modified, they're not dainty or subtle cars.

Maybe you're expecting too little?

[slevin]

I?ll back the preload back off to the BC recommended 5mm this weekend and see if it makes a difference.

Maybe dual wishbone suspensions from Miatas and rx7 spoiled me and I?m expecting too much. Previous owner also replaced all the rear subframe bushings with solid ones, but that should just affect transmission shifting and lsd clunking etc

[mechanicalmoron]

I?ll back the preload back off to the BC recommended 5mm this weekend and see if it makes a difference.

Maybe dual wishbone suspensions from Miatas and rx7 spoiled me and I?m expecting too much. Previous owner also replaced all the rear subframe bushings with solid ones, but that should just affect transmission shifting and lsd clunking etc

Why wouldn't the solid stuff in the rear matter? It makes the whole car seem a lot louder and bouncier and less comfortable.

It's not a miata, get over your miata - they're very different cars, ride very differently, handle very differently, etc.

It's a bouncy car, that you have bouncy coils on, that are set bouncier than the manufacturer even suggests, that's full of solid bushings.

What's your actual question here, if you expected too much? YES, you expected too much, sell the car and go somewhere else...

[slevin]

Backed the preload off to the recommended 5mm from BC and didn’t notice a difference, but dived into the web more about spring rates etc. Ended up ordering a set of Swift springs from BC, 6kg front 4kg rear. Will install this weekend and report back.

[[240sx]]

Went through the same sh*t with stance xr-1s. Thought about going swift, but really.. it's all about the dampening. Hope it works out for you, interested to hear what swift upgrade does.

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[Krusty_s13]

Backed the preload off to the recommended 5mm from BC and didn?t notice a difference, but dived into the web more about spring rates etc. Ended up ordering a set of Swift springs from BC, 6kg front 4kg rear. Will install this weekend and report back.

It may ride a bit better with the lower rates, but it is all relative to suspension compliance and your tires. ride quality is also very subjective. best of luck!

[samotage]

Should be sweet at these rates, soft springs, stiff bars. Get some nice 27mm stiff front sway bars front, 20mm rear and it will be awesome.


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[mechanicalmoron]

Backed the preload off to the recommended 5mm from BC and didn?t notice a difference, but dived into the web more about spring rates etc. Ended up ordering a set of Swift springs from BC, 6kg front 4kg rear. Will install this weekend and report back.

I expect that you will like it a lot better that way, both in terms of comfort and handling.

[slevin]

welp, I think that was the golden ticket. swapped to the 6kg/4kg springs saturday night and drove it around all weekend, obstacles that would normally jar me out of the seat or make me hold my breath and clench my muscles I no longer have to do.

Springs were a bit shorter then the BC ones that came with it though, so I had to bring the spring perch up quite a bit so that the spring wasn't loose. left the springs with zero pre-load. On full soft for the dampening the car drive a little stiffer than stock, with the dampening turned up handles spirited driving well.

[samotage]

Good to hear! Now get some stiff bars, and you will be rocking the corners in no time.


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