Hey everyone

Got a bit of an interesting one today.

7 weeks ago I injured my back at the gym. Not sure 100% what I've done but could be a bulging disc or a strained back etc not 100% sure at this point. Anyway, I'm wondering if the 350z contributed to it and the reason I ask is I recently remebered I had some aftermarket springs on the car (on it when I bought it) which are the H&R Sport Springs (SKU 53050). Anyway, only the rear springs were ever on the vehicle and I don't have the front springs. I never thought anything of it until recently. I have not been driving the 350z as it is harsh and uncomfortable now and I am starting to wonder if the 350z contributed to it.

I had a few questions:

1. Are those H&R springs quite a harsh spring or softer? I'd feel a bit better if they were not much different than OEM springs. From what I can tell, I have the 427ib rear OEM springs as mine is a JDM 05 350z. I can't seem to find much info on the H&R spring rates and a few threads say that this is a worry and they might be bad quality springs? I did find I think at peak they are 400ibs which would make them softer than the OEM right? Especially since the intial softer part would be even softer?

2. Is it bad that I had a mixed aftermarket and oem set up. Front were OEM and rear are the H&R. I'm not worried if it was bad for the car but rather would it have caused any issues that could have contributed to my back injury?

3. Struts are OEM as far as I am aware. I assume those springs are ok to fit on OEM Struts?

I am selling the 350z now but I just feel a bit of regret wondering if MAYBE it contributed to my back injury and MAYBE the set-up was bad too.

I have not really done lots of driving in it. It was a daily but apart from the first 3 months where I drove 30 minutes to and from work it has really only been used for 10 minute drives to work and drives around town, nothing long distance except a few 1 hour trips in it.

 

1. Interestingly, a quick Google doesn't really reveal much about the spring rates of the H&R springs. Since they're progressive rate lowering springs, they will likely be firmer than OEM, but just a guess. No firsthand experience with them.

2. Whether driving contributed to your back injury is a medical question for your doctor. My guess is their opinion, at best, would be maybe. Any significant past medical history of back issues?

3. You can put lowering springs on OEM struts, but you shouldn't.

My guess is that the struts are toast. If they're original, I bet they have quite a bit of miles on them and likely exceeded their lifespan. Really need more details on the "harsh and uncomfortable" ride quality. If it's bouncy, then that's probably your struts, but there are so many suspension components making it hard to diagnose.

 

The H&R springs are/were stiffer than OE.

Did they do back damage? I doubt it BUT.... as heel said, the shocks are likely toast (if you have >50k miles, they're pretty much done). In which case, bad/dead shocks are offering little/no spring control so essentially you're riding on the springs alone, unmitigated.

If you were keeping the car, I'd say do new shocks and see how the ride is. But since you're selling, no need. Let the new owner know it needs new shocks.

 

Never ever had back issues my whole life. Used to play Tennis for 10 years, BJJ for 4 and now do latin/ballroom dancing. My Osteo said I overdid it as I was competing and I trained 5 days in a row then hit gym straight after training and hurt it there.

Bugger I didn't put the springs on wish I had changed it. I've had the car in serviced and WoF and struts have never been brought up so I assume they were replaced at some point so I don't think they are original ones.

 

In our country we have yearly Warrant of Fitnesses and they check things like struts etc and I had a WoF done 4 months ago so I assume they are either fine or had been replaced at some point.

I really hope they didn't damage my back I am worried

 

As mentioned, doubt the car is to blame for injury unless you're WRC rallying the car. There aren't any streetable springs that will cause the kind of damage you describe. Maybe a lifted 4x4 used as it should be but a Z on normal suspension, nope.

Exacerbate an existing issue, maybe.