fredster2

First off I just wanted to say that I'm a long time lurker and newly contributing member (I didn't have much to add previously ) Thanks to all at CL as I've learned so much just from reading from everyone here.

I recently got my '08 IS250 AWD and I'm trying to research my options for doing a drop. My priorities are to improve the stance and that awful wheel gap in the wheel well but to maintain OEM ride quality as much as possible.

I do about 95% city driving and go over maybe 16 speed bumps M-F on my daily commute. Some of these bumps are brutal. I'm fairly careful driving but I don't want my car so low that I will scrape at all or have to go over bumps sideways or anything.

This leads me to my question.

I am still torn as to whether or not to get springs or coils but have found it very confusing given all of the different options to purchase. I have summarized what I understand the major choices to be here and would like to know whether I missed anything.

Springs (will likely need to change shocks to keep OEM ride)

F-Sport - Modest drop of about 1". Will probably like it at first and then want to go lower after 6 months.

Tein - Different springs for different drop heights. Generally chosen as a good spring depending on model.

Eibach - I honestly haven't been able to tell anything that stands out. Seems to be on par with H&R I think.

H&R - Seems to be very well regarded but currently on back order and a little bit more expensive.

Coilovers

Megan - Seems to be a very solid bang for your buck coilover. Considered slightly soft in terms of stiffness

BC Racing - Well regarded. Seems to be aimed more toward enthusiast tuners who want a racing feel. Considered stiffer than average.

KW V3 - All I know is that these are $$$$

Tein - Seems to be just as solid in terms of value for the $$.



Please note that I tried reading the suspension sticky at the top and didn't really understand the differences between spring rates and all that other jazz. Any help at all would be awesome!

ThermonMer

i had the same concerns between 95% city driving, and speedbumps...

8 speedbumps in condo, 6 at work, and 12 at gym. so figure 16+12+24 = 52 speedbumps daily.

im dropped on tein s springs - no problems.

Kurtz

iTrader: (1)

ESPECIALLY if planning to change shocks anyway, since costs will be similar, get coils.

Main reason-

All the lowering springs I'm aware of are progressive, which means it's impossible to correctly match a shock to it for both the high and low end of the rate range. This is why some folks (esp. when they keep the stock shocks) can describe aftermarket progressive springs as floaty or otherwise unpleasant over very rough bumps... and if you go the other direction with aftermarket shocks that are stiff enough for the far end of the spring rate you'll be overly dampened at lower rates.

With coilovers you can get linear spring rates, meaning not just more predictable handling, but you can match the dampening to the spring rate perfectly.

MrBBQ

iTrader: (9)

Here's a good read regarding what spring rates are.

http://www.tuninglinx.com/html/spring-rate.html

Shock dampening on adjustable shocks controls the rate at which the springs compress and decompress. With the same amount of weight or force on two identical springs and shock setups, one set to full soft and the other full full stiff. Of course the one set softer compresses faster than the one set stiffer. But after both are done compressing, the amount of spring compressed is the same. Setting it stiffer does not limit the suspension travel, it just slows it down. Spring rate ultimately determines suspension travel length. Damping controls suspension travel speed.