Fapout

iTrader: (6)

I'm by no means an expert on spring rates and such so I wanted to get opinions on here. Long story short, I have 3 tein h-tech springs, two for up front, one for the rear. The front of my car is honestly what needs a drop and the wheel gap closed up, the rear is pretty snug as is. Can I just run the h-techs in the front and not worry about the rears?

The UPS Store

iTrader: (1)

I just recently installed Swift Springs on my ISF. I took measurements before and after. The rears actually didn't drop at all only the front. Maybe after they settle a little bit more I'll see the drop. The front feels and looks great though. I believe the Swift is 9k front and 6k rear. The handling might be affected with Htechs in front and stock in the rears though.

tenspeed

iTrader: (1)

I wouldn't try it on a road course but it might be ok on the street. Take your corners slow, there's a chance that the softer rear end might make it handle loose.

UCrazyKid

I can not recommend the use of unmatched springs in the front and back. There are too many variables involved regarding handling dynamics. I wouldn't do it myself.

GSteg

iTrader: (15)

Unless you are pushing your car to the limit (ie. tracking), then don't worry about the handling. There are many other factors that will influence handling.

ShadowISF

iTrader: (10)

I have Eibach springs on the front with stock suspension in the rear. No problems so far. But make sure you get an alignment. FIGS gave me this advice. Great guy.

Supraman16

iTrader: (5)

I had the same combo before I got the BC Coilovers...I had no problems either.

FNMUPN8

I have H-techs on the front and Eibach on the rear. I did get an alignment a few weeks after they settled at a lexus dealer. After 20k I have had no issues.

Tempest

Hey Fapout, one of the Master Certified Lexus techs at my dealership has an IS F and he put H techs up front with stocks in the rear and he has had no issues with it and he's had the car for at least a few years.

I plan on doing the same setup.

Fapout

iTrader: (6)

Awesome. This actually relieves a lot of stress. Thanks guys.

Autobacs

iTrader: (1)

No stress at all needed.

I have Eibachs in front and stock at rears and absolutely no issues.

s4play

iTrader: (2)

For street and daily driving you can run pretty much anything you want with no adverse effects....however IMO this is kinda half-a$$'d work. In the back of my mind I would always think something is mis-matched.

It's like a tire that's been repaired, I would be afraid to push the limits of the car on a mountain road for fear the tire would blow out and leave me stranded or worse.

Do it right the first time or don't do it is my philosophy but it's your car so ultimately you decide. I'm sure there are some variables that would affect something but it's probably very minor so only if you are on a track someone or a professional driver can tell the difference.

Autobacs

iTrader: (1)

The "mismatch" in spring rates is relative. From an optimum handling standpoint, I agree with you that the front and rear spring set are meant to be paired to each other.

However you gotta factor in that "handling" is not an absolute but is a range where personal preferences come into play. Some prefer more or less understeer, some prefer more or less oversteer.

The Eibach aftermarket spring in front will have only have a slightly higher spring rate coupled with a slightly lower center of gravity and increased negative camber than the stock sping and which IMO is well within the damping capabilities of the stock front shock.

The net effect of that for me from a handling standpoint is minimal and in any case I am confident that my seat of the pants feel, coupled with my feet manipulating the gas and brakes and hands turning the steering wheel is more than good enough to offset any slight "mismatch" in handling.

Fapout

iTrader: (6)

I installed the springs, been riding on them for a week now. Looks good and I feel no adverse difference. The ride is partially better. You can (kind of) see in my sig that the gap in the front matches the rear. I was on the fence of whether or not I even wanted to install the rears to begin with because I kept seeing about an inch of gap in the front and virtually none in the rear. It looked like there were a couple of fat chicks hanging out in the back seat! I will have some good pics posted soon.