What are some common suspension mods for the 3IS? The one I test drove seems to have good dampening but I noticed quite a lot of understeer and front end push when cornered hard. I suspect its mostly due to the conservative stock alignment. I know this car has double wishbone suspension but what sort of mods would be useful?

I'm thinking camber plates, sway bars and an LSD for a start.

 

Coilovers, sqaure wheel and tire setup, RR USRS, Strut tower bar, BBK for lighter weight.


It seems to be my understanding that sway bars are a MAJOR pita and not worth the small benefit over stock? That's what I've heard but that is just my opinion.

 

Im not sure how good the stock sway bars are, but they tend to offer a profound upgrade over stock by controlling body motions which improves handling as well as ride quality.

 

Not sure how much info is actually in here, but maybe try this sub-forum: https://www.clublexus.com/forums/sus...nd-brakes-250/

 

I totally agree. What ive read here on the forum is telling me that the stock sway bars are actually pretty good and that an aftermarket replacement isnt super super beneficial, especially because of installation difficulty.

 

Body control does feel quite great on this car, so I can see what you mean about the stock sway bars.

I'm not sure camber plates are necessary on a car with double wishbone suspension, but to me the most glaring issue with this car seems to be the alignment and inability to fully turn of VSC off. It is clearly setup for safety understeer.

 

What do u mean you can’t disable VSC?
in my 2015 350 AWD I press and hold the traction button for about 3-4 seconds while the vehicle is completely stopped and that’s it. You’ll see “TRAC OFF” appear on the dash and a the traction off light will come on the dash also.
I turn it off in snow and I can spin the tires all i want, I can drift the car no system intervention of any kind.

Just pushing the traction button quickly only disables it partially and only up to a certain speed.

I think the cars understeer because their front end heavy with narrow front tires. Apparently there is an installation technique where they can swap the sway bar (from an RC 350 for example in 2-3 hours time. The thread is on here, search “rc350 sway bar on 3is” or “Lexus IS sway bar swap”

 

Really? I tried holding the button when I drove one and I was under the impression that the VSC system was still intervening. I assume I just got it mixed up with the 2IS I sampled. That cars suspension is overdamped. Looks like Lexus got the dampening right with the next generation.

A car with a front biased weight distribution can still easily get tail happy, if the manufacturer is willing to allow the driver to fully exploit their vehicles potential. I looked it up and the weight distribution is pretty good @ 52% percent front. Obviously if it was closer to 50/50 and had wider tires it would help, but ultimately, tweaking the alignment should completely change handling balance at the limit.

 

Yup just press and hold the TRAC button for 3-4 seconds while at a COMPLETE stop and the traction light and “trac off” message appear on the dash. traction control and VSC is now disabled.

are you RWD? I’m AWD and I think it’s 56% front 44% rear weight distribution. You have to push the car pretty hard to get to the point of understeer though.

Read post #17 in this thread. This guy claims to have a way to install a rear swat bar in a few hours without touching the sub frame. He says he uploaded the instructions to his social media, apparently you remove the rear something and you can slide the bar into place.

https://www.clublexus.com/forums/is-...ay-bars-2.html

 

I think a new set of wheels and coilovers will you get where you want. Of course stuff like USRS and strut tower bars and sway bars are great, but I think that a good set of coils and a squared wheel and tire setup are going to be more than enough for most people.

My buddy who has a track prepped s550 is letting me try out his set of 18x10 Apex wheels. Squared setup. We'll see if the fronts fit haha.

 

You have to come to a complete stop.

Or you could do the pedal dance routine, but of course, doing so locks you out of turning VSC back on again until restart after 5 minutes of driving.

 

What is said pedal dance?

 

Here you go: https://www.clublexus.com/forums/is-...l#post10281364

It's not really necessary. Holding the TC OFF button while stopped seems to have the same effects.