What kind of research has been done to know they types of "serious handling issues and maybe even longevity issues" using RCA blocks will cause?

 

Back in 2012. start on page 7 post 96
https://www.clublexus.com/forums/is-...ing-kit-7.html

 

perfect. i'll check out. thanks Figs

 

just read the thread. i guess i'll play if safe and just run stock suspension until the F isn't a DD anymore and then go coil overs. thanks for the info everyone.

 

I just feel this is like when my buddy lowered his s10. Its a very cheap way ov doing things and his s10 road like complete shiz. Steering responses was not responsive, tons of vibration and shakiness. Stock suspension wasnt meant to be lowered. I lowered my is300 on springs, and my F on coilovers. What a huge difference. You can change spring rate, lower and raise. Just a better all around setup.

On the other hand of longevity. Caster is a weird angle because it doesn't affect tire wear directly. It's greatest effect is on steering stability, steering effort and steering return. So it is often the most ignored angle. Look at how far your wheel sits back. To me thats scary and I feel your just urting yourself more then helping.

This is my opinion. Just trying to help from an outsiders stand point. Save your money and get a good setup. I promised you will be pleased.

 

hence the reason for my thread was for input/opinions. i appreciate them all and i do take them into consideration. i'm currently lowered on Tien springs. i'm going back to stock ride height, but wanted to drop the front to even out the stance. i wasn't planning on the blocks in addition to the springs though. i don't want to compromise steering response though which is why i want to go back to stock and then figures out which coil over setup to go with. all depends on cash though, but i rather pay and do it right then get something low budget and then have to do it over again.

 

Using LCA blocks is not the "budget" or "cheap" way to lower a car...it is just another method. They work perfectly fine on other vehicles, it's just that, as it's been pointed out, because the lower control arm knuckle on our car is slanted, it supposedly pushes the wheel back in the fender and you supposedly lose steering response which supposedly is bad in the long run for the vehicle. Like I have stated before...I have been running 20MM spacers for almost 3 years now with ZERO problems. I'm not saying all that other stuff is false or wrong because they're probably true...those guys are all a lot smarter than me. Maybe if you use bigger spacers like 30MM and up and you regularly drive in excess of 90 MPH you may have adverse effects from this mod, but it's a lot better than using lowered springs on the stock suspension to level the car. I drive my car daily to work and back...it's not a track car, so dropping a couple grand on coilovers just to say I did it "right" was impractical and probably would be an overkill in my situation. I'm not here to say this is the best way to do what you're intending to do...I'm just giving you a first hand account of the method that you were asking about. It's up to you how you want to proceed.

 

There are lots of ways to lower the car. They all have impact on mechanical performance. Lowering with blocks has the largest impact because it fundamentally changes the suspension in a way nothing else does. Adding height to the knuckle isn't something most suspension engineers would suggest UNLESS you have measured and modeled the suspension and you know what the outcome will be. If the factory didn't do a good job, it might make things better. Unfortunately, the IS F's factory setup isn't bad out of the box.

Lowering with springs or adjustable height shocks can be just as bad, but in a different way. There is a camber curve which is fundamental to the geometry of the suspension - the location of the mounts, the lengths of the arms, the orientation of the mounts relative to each other - all play into what happens to the wheel's alignment relative to the road as the suspension compresses or extends. There are "ideal" numbers the engineer would like to see at any given ride height, so they design the suspension to do its best to deliver those numbers. The camber curve and ride height from the factory are optimized to give mechanical performance within the design parameters Lexus chooses (read ALWAYS understeer). These numbers are also tire specific, so just changing tire brands can have positive or negative impacts on performance, and ideally you know what tires you will be running when you setup your suspension for competition. Street driving isn't nearly as critical or precise, so there is a lot of room for changing things and not really impacting the majority of street drivers.

So all this brings us back to the most basic question - what are you trying to achieve? Mechanical performance or visual performance? Blocks are a very inexpensive way to improve visual performance while sacrificing mechanical performance. Springs and adjustable shocks are a more expensive way to improve visual performance, and MAY help with mechanical performance if your goals are within the limits of acceptable for mechanical performance. If stance or a slammed look is your goal, OEM mechanical performance is not in the realm of possible.

Figure out what is important first, then pick a solution to meet those needs.

 

^^^^^ Well said. Every type of lowering has its pros and cons. I dont track so visual is my route.