Just got my eibach prokit springs installed last week (w/Work SC1 19x9 +35 & 19x10.5 +45).

Issues #1: Knocking noise near the rear of the car while going over bumps today (I had a fully loaded car (4 total) & two people were kind of big so that may be it). Any one have any idea what it could be?

Issue #2: The ride seems kind of soft. Not overly soft but more than stock. Will the stock shocks/struts hold up or will I need aftermarket shocks/struts?

Will any of these issues be solved once the springs settle in a few weeks?

Thanks

 

I'd hazard a guess that the first issue might be from bottoming out your car if you went over a bump too fast.

The springs are a bit firmer than stock, so I would say that they might put a little bit more stress on stock shocks.

 

Eibach springs are progressive rate springs which means they start off somewhat softer than stock, then firm up to stiffer than stock as the springs are compressed. They are designed this way to provide a compliant ride quality on the smaller initial bumps, but ramp up to a firmer suspension on larger bumps and when you are in a turn to reduce body roll.

Given that Eibachs eventually firm up to stiffer than stock, yes, your stock shocks will wear out faster than w/ OEM springs. However, I'd say you're probably good for a good 30K to 50K+ miles depending on how aggressively you drive and how bumpy your roads are in your area.

 

Thanks for the info.

Man, these springs are a lot softer than stock. I even get a slight front dive when breaking and a squt when taking off hard (more so than stock springs). I'll probably lstart looking into aftermarket shocks. Any suggestions?

Thanks

 

Sorry, I have to ask the obvious question ... are you sure you got the right part number? Maybe you got springs for the previous generation.

 

Terrycs: Yes, that was my first thought. Part# 6383.140 = '08 G35 Sedan

 

With a 10.5" wide wheel and a +45 offset you would be real close to a rub depending on the tire you used. I would pull the rear tires off and look for contact on the radius rod/suspension and the wheel wells of the car. You will see it right away if there is tire contact anywhere. Did you install the rear camber/toe kit when you did the install?

 

OK I think I figured part of this out. It has to due with part #s. The part # for the prokit for my car is 6383.140. The part # on the box that my springs came in is 6383.140, however, the part # on the springs is 6363.002. Wrong springs!!! I got them along with my wheels & tires at the shop. That's probably why the ride is extra soft & rubbing at times.

 

Yeah the 6363 line is for the 03-06...sounds like they just put the wrong springs in the box.

The rubbing probably wouldn't do much with the spring rates though...you're probably still going to rub.

 

My Bad!!!!!

Just called eibach. They stated that the 6363.002 is the part # for the rear springs for 07-08 G35 Sedan. They stated that it's be changed and that's the correct part #. 6383.140 is the part # for the front.