Installed BC coils over the weekend, but found that they're impossibly low in the rear. They're as high as they can go while retaining 25mm of thread in the shock body as per BC's instructions. The fronts however are only about halfway down. The part is D17, and I don't believe they make coilovers rated differently between Zs and Gs, correct?

Aside from this, I found out after install I was shipped the incorrect spring rates (14k/12k) instead of the advertised 10k/8k which is a separate headache, but I don't believe this should alter height?

Does anyone have any experience with this on any set of coils? Pic of how the car sits with rears at max height:

 

i didnt have BC coils but mine were set about 3/4 of the way up and it looks like your. i personally like the ride height as it sits in your pic but that my opinion.

 

I like the stance as it sits, but would like to have the option to raise a bit if necessary. Just seems off that this is the absolute highest I can go

 

well some guys are getting their rims tucked under their fenders with the BC coils. so i am not surprised that is the most they will do.

 

Found the problem here - these have the shorter 180mm springs instead of the standard 200mm. I have a set of the new BC DR digressive piston coilovers with 10k/8k rates on the way, hopefully these work out better.

 

With mine I had to retain the factory upper rubber spring seat for the rear. That gave me a good 1.5 inches.

 

No spring seat anymore as this is the "true" once piece in the rear. Hopefully the issue was the shorter 180mm springs.

 

if its the true type then your spring has nothing to do with height. Your height is controlled by the sleeve in the lower mount. Your springs should be snugged up with the shock extended all the way out.

 

the attached photo is for a Subaru, but they work the same.

# 1 adjusts your height

# 2 adjusts your preload. You want your shock extended all the way out and your spring snug against the top hat (or add preload by compressing the spring from there). If set up properly you can have as short or long of a spring as you want, it wont change height.

 

That makes sense. Weird that the BRs I ordered had such a short spring on the back if those are usually reserved for additional lowering for people with OEM-style rears. Seems like true rear BCs are dumped at any height adjustment!

I'll check in after I put in the new DRs next weekend. Thanks

 

I think that's simply so you can lower it more, not raise it more. If you have 20mm less spring that means you can thread 20mm more of the shock body into the mount (20mm lower). But the maximum you can thread out doesn't change.

This concerns me as I'm saving up for the bc coils but I don't want to go that low.

 

I'm curious to see if the longer springs will work.

If you run your spring perch at the very top of the sleeve, then that will help push the entire body down farther and you'll get some more overall length out of it, but I'm concerned if you get too much out of it that you'll be running it at the limits for structural strength.

 

So after thinking about this more (actually I was drawing a paint shop photo to explain some stuff), I don't see a longer spring doing anything. The threaded sleeve that your spring perch sits on is fixed to your shock body, so all a longer spring is going to do is push your perch down farther, but you wont get any more length out of the shock itself. The only way to lake the whole assembly longer is to get a longer bottom portion that the shock body fit inside of.

I can draw a photo with my mad paint shop skills if you would like.

 

using the spring to adjust height will void your warranty with BC and could cause valve damage to the shock. BC's are meant to lower from the start, so you cant adjust them to stock height. They seem to use the same shock body ( and springs) for a wide array of vehicles and just change the mounts. You could email them and ask if they have any taller lower cups. Are the eye-bolts threaded onto the cup or are they one unit now? Mine were threaded on for my last vehicle, but the bolt was too long so I had to cut it.

 

I have Isis true rear 14/12 coils and I've been running into the same problem.

The sedans actually have 2" more travel on the springs than 350z's (which I'm assuming most parts are designed for). I found this out after a friend wanted my stock suspension for his rally z.

I also have the part shop max super angle kit and that lowers the can an additional 1" or so. Right off the bat with my set up I'm 3 inches lower in the front.

I'm hoping to speak and work with ISC suspension (as they're local) in the future to help develope a "off the shelf" option for sedan people that want a more mild drop than the current options.