Evening.

Since I bought the car approx 2 years ago, I've experienced an issue that just about made me want to pass on buying the car. That being a horrible shudder on the smallest bumps, probably bad enough to eventually break plastic interior pieces.

I've replaced all bushings w/exception of the DTSS ones and subframe ones. I've been through 2 suspension setups coils/springs and the problem remained.

Upon ordering my K-sport coilovers a few days ago, I started digging. What could cause this general structural instability. First thought, rear subframe. Well, I put that back together a few months ago when doing my bushings back there.

Next idea, engine crossmember. Bingo. None of the bolts (8 or 10) were even hand tight. I torqued them down, and when I put the new coilovers on, I'll report back (Friday).

 

That'll do it. The steering rack bolts to the crossmember. If you were experiencing a suspension shake, then the first thing you should have done was jack the car up and shaken the wheels side to side. Funny though, I don't even think that I'd have caught it if I were working on it. I use jack stands, and I'd have placed them right on the subframe. If it were on a lift (which I'm sure NAS Jax has a hobby shop with a lift) you could have easily seen it with a shake of the front wheels. If all else fails, you could always try the steering wheel shake with the wheels on the ground. (Need a buddy to watch under the car for any suspension play).

 

Car is up in the air now, though at home, on jackstands (and will be till the K-Sports get here).

Funny though, I thought blown suspension from day one. I guess I got lucky because when I pulled the stock springs/shocks, 2 shocks were actually blown. I was ecstatic when I found that cause I thought the shaking would go away.

Then I thought the strut tops might be bad (retained for use with the KYBs and Teins), so I went with HKS coilovers w/pillowball camber plates. No luck there either.

Now I've completely ruled out the BIG suspension parts.

 

Update!

After 2 years, its gone! The f*cking shaking is GONE! It was those friggin' bolts on the crossmember/subframe!

Oh, and the K-Sport coilovers ride like a dream too!

 

well yeah... the whole underside of the front end of the car is walking around and shuddering violently when hitting a bump. as mentioned, the whole bottom side of your front suspension mounts to that cradle.

but why anyone would feel the need to remove it in the first place is the better question. in my time with these cars i have never once removed an FC front subframe. FD, yes, FC, no. there's no need to ever remove it unless it or the frame is rotting away, or it was damaged in an accident, hint hint.

 

Nah, no accidents... unless they did a REALLY good job straightening everything.

Probably had something to do with the turbo swap, not that removing those pieces needed to happen though :/ In any case, I didn't do it. Just glad its done with!

When are you gonna fly over here and tune my car? What do you want? Airfare/hotel?

 

if there's enough interest then could get a few people together for a session, figured there was already enough options in FL but it seems only on the very southern edge and Gaby is too busy most of the time.

once i finish the shop i will probably have more free time to schedule sessions.

 

Convertible and coupe subframes are different. Are you sure yours didn't get the lighter (not as strong) coupe one swapped in?

 

I dont know what the difference looks like... sounds reasonable though.

Hopefully there's a picture of the difference if I search, but I doubt it. For some reason, I think I remember seeing two different subframe/crossmembers up front... with one aft of the engine one, but forward of the tranny crossmember.

 

Does your car still have the k-member? Non-vert subframes dont have the mounting points on the rear of the subframe for the front of the k-member.