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Discussion Starter · #1 ·
So over the years with the IS and playing with its suspension with various set ups and various alignment settings there are alot of things i have noticed.. I have done a couple practice autox runs but no roadcoursing yet..

Now... what i have noticed is that for autox, somewhere near stock height is beneficial. At most 1 inch lower and thats it... The dynamics of the suspension and "roll center" are optimal near stock height.. But in my opinion, for long sweeping turns light the street or roadcourse, i believe that a lower car will benefit you and keep center of gravity overal lower.

My opinion on suspension... TOO STIFF IS NO GOOD unless you got tires like Pilot Sport Cups from michelin. If your tires cant comply to your suspension, you are asking for trouble and you will find yourself in a bind once you lose traction because of the overly stiff suspension.

For example... If you have Tein RA's, dont run Hotckis sways... AT MOST use L-tuned/TRD red/eibach (all the same)

Now... if you are running springs only, for example Tein Htech, a set of stiff sways will give you the "feel" of a grippy car, but in fact its false confidence.. The sways will reduce your body roll, but the inadequate springs and dampers will make it MUCH greater to recover in case of traction loss and modulation will be alot more difficult.. A set of properly matched springs and dampers is always optimal (stock handles great for a stock car, but very floppy).

I will post up more... a discussion would be nice!!
 

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Ive been slowlying moding my suspension for autox/road course, but I feel like I still have some issues with handling.

My setup currently is:

Tanabe Sustec Pro Coilovers
TRD Yellow Sways
Falken Azenis ST-115's
Car is lowered 2.5 inches or so over stock

I feel like I have much less body roll now, and my turn in is very sharp compared to stock, but when I try to take high speed sweeping turns and moderate speed tight turns it feels like my backend is starting to float...like the rear is losing traction too early. Im having to throttle on throttle off around turns too often.

Anyone have some input on what to change, what to get etc...before my IS ive mostly just drag raced so im not very keen on proper handling attributes.
 

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Discussion Starter · #3 ·
Your tires seem to be the culprit. Also, what are your alignment settings, damper settings?? All this plays a huge. Even tire pressure makes a huge difference...

post this information up... and I can help you out a bit..
 

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Melk_IS said:
Ive been slowlying moding my suspension for autox/road course, but I feel like I still have some issues with handling.

My setup currently is:

Tanabe Sustec Pro Coilovers
TRD Yellow Sways
Falken Azenis ST-115's
Car is lowered 2.5 inches or so over stock

I feel like I have much less body roll now, and my turn in is very sharp compared to stock, but when I try to take high speed sweeping turns and moderate speed tight turns it feels like my backend is starting to float...like the rear is losing traction too early. Im having to throttle on throttle off around turns too often.

Anyone have some input on what to change, what to get etc...before my IS ive mostly just drag raced so im not very keen on proper handling attributes.
you mean the rear end is sliding out? or does it slightly bounce and feel like its floatin? how is the front end holding up? is it on track or is it understeering or oversteering? if its oversteering, sounds like you need to change the dampeners to softer. if its understeering, try to set it stiffer in the rear. but make sure its even up with the front end + 1/2.
 

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Malekreza11 said:
Now... what i have noticed is that for autox, somewhere near stock height is beneficial. At most 1 inch lower and thats it... The dynamics of the suspension and "roll center" are optimal near stock height.. But in my opinion, for long sweeping turns light the street or roadcourse, i believe that a lower car will benefit you and keep center of gravity overal lower.

My opinion on suspension... TOO STIFF IS NO GOOD unless you got tires like Pilot Sport Cups from michelin. If your tires cant comply to your suspension, you are asking for trouble and you will find yourself in a bind once you lose traction because of the overly stiff suspension.
i agree with your first statement, tho ive never killed cones myself, i can feel the benefits of the roll center at stock height around low speed turns vs now with my flt-a2's at about 2" lower, i think.. i wouldnt know really :p but i plan on raising it for that fact and just run the shocks a bit stiffer.

ive been messing with the shocks and at 10/7 (from softest) they feel stiff! a bit too stiff for the street. i dont really plan on looking to put sways in just yet, id prefer to get higher spring rates. but after i get tires, these wack-ass dunlop sp8090 are a drag :(

alignment settings are -1.7/-1.4 camber F/R toe'd out in the front .04, so very very little but it helps keep the car straight and the turn in feels better. zero toe in the back. the damn sp8090's are still lasting they are at about 3/32... for the last 1500 miles.. WTF?! hope it doesnt rain soon...
 

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The settings are going to vary slightly w/the track you happen to be running on. When I picked out the parts for my suspension I went for everything to be adjustable. How rough/smooth the surface is will make more of a differance on how compliant you want the suspension to be.

I've found the main differance between auto-x and track use for me is the shock settings. Stiffer shocks actually works better on the autocross than on most of the tracks around here.
I'm about 2" lower than stock with a very agressive alignment. (I don't put alot of street miles on w/the IS)

I agree too stiff is bad if your tires can't handle it. I run 12kg springs in front and 10kg springs in rear w/Hotchkis sways. I also run on Hoosiers. Steady state through turns I'm logging 1.16+g's. ;)

I really don't believe there is a "one setup best works for all". The track and your driving style really come into play.

Malek has the key in that your tires will determine how you want to set everything else.
 

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Malekreza11 said:
For example... If you have Tein RA's, dont run Hotckis sways... AT MOST use L-tuned/TRD red/eibach (all the same)

thank you..i have been telling people this and they never listen to me.

i for one run tein ra with eibach sways but have been contemplating many times whether i should just run stock ones.


Malekreza11 said:
Now... what i have noticed is that for autox, somewhere near stock height is beneficial. At most 1 inch lower and thats it... The dynamics of the suspension and "roll center" are optimal near stock height.. But in my opinion, for long sweeping turns light the street or roadcourse, i believe that a lower car will benefit you and keep center of gravity overal lower.
i said that near stock height is very beneficial for our car but i got a flamed. i hope more people realize this besides of having the idea that only a lower car is better for handling.
 
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my current tein ra setup:

(tein n1 style)

upgraded 20k front

upgraded 18k rear

From softest: 4 / 3

i am on a very soft setting right now.

current tire pressure: 35psi all around

i found that 35psi works very well for me even though it sounds low. the steering response feels sluggish though compare to higher psi.
 

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Yogi_TRD said:
I really don't believe there is a "one setup best works for all".
you said it, if anything you compromise what you do the most (daily/track/autoX/canyon). unless you have the means to adjust everything in a daily/weekly/monthly basis. i dont mind changing things seasonally. i dont mind changing tires and valving as the situation arises, for me; daily, track or canyon... but as far as alignment settings i'll change those according to the season.
 

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Discussion Starter · #10 ·
Hirun said:
thank you..i have been telling people this and they never listen to me.

i for one run tein ra with eibach sways but have been contemplating many times whether i should just run stock ones.




i said that near stock height is very beneficial for our car but i got a flamed. i hope more people realize this besides of having the idea that only a lower car is better for handling.

Yes i definetely agree that a combination of a stiff sway bar and very stiff suspension will result in loss of grip. Sure it FEELS like it is handling well, but in reality, if you REALLY know the limit of the car, the car will perform better with more compliant sways or even stock!

I currently have the HA's with Ltuned sways with the rear on the softest setting... Im even thinking about putting the rear stock bar back on...

Stock height... this is a major point that can be argued in my opinion and it GREATLY depends on what you are doing with the car.. When you are doing AutoX and you are doing alot of tight corner type turns, near stock height is beneficial, you will need all the dynamics the suspension can provide..
Now if you are canyon running, or wanna set up for Road Course, IMO a lower car will benefit you, but AT THE LEAST set up the alignment and such so it benefits you... If you have the ability to fabricate... well then make new arms and toe control rods to work better with the lowered ride height...
It really depends on what you are doing with the car, and as Yogi_TRD also said, no setup will be best for EVERY scenario... Sure one setup can be good or decent for any application you throw at it, but it wont be at its PEAK best or at least close to best..

So here is what i have come up with over the few years of playing with different setups... This is just a general idea..

Street-- Well anything will work here as you are not going to the limits (at least i hope you arent)
AutoX-- Keep it near stock height, at MOST .75 inches lower.. Maybe a front sway bar to dial out some of that understeer.. Toe out in the front to give SHARP turn it and 0 Toe in the rear..

Canyon-- A lowered car will help you in a large sweeping turns and keep your center of gravity lower and in turn give you a more controled car.. At most some mild sways if you have new springs and dampers OR coilovers.. If you have stock suspension, some TRD yellows or hotckis should help. Play with the settings on the hotckis and see what will be the best... alignment settings= Toe IN 1/16th of an inch so the wheel doesnt feel like a dart. Keep the rear Toed at 0 or at most Toe in 1/16th of an inch to save you a little from overstearing..

Track/Road Course-- Havent done this YET, but will this year as soon as i can drive again... If you want to be successful here.. a lowered car along with modified arms and toe control rods should help you on those high lateral force turns...

Keep the discussion goin!

-Malek
 

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What kind of camber settings up front are you all running autox ?
 

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Melk_IS said:
Ive been slowlying moding my suspension for autox/road course, but I feel like I still have some issues with handling.

My setup currently is:

Tanabe Sustec Pro Coilovers
TRD Yellow Sways
Falken Azenis ST-115's
Car is lowered 2.5 inches or so over stock

I feel like I have much less body roll now, and my turn in is very sharp compared to stock, but when I try to take high speed sweeping turns and moderate speed tight turns it feels like my backend is starting to float...like the rear is losing traction too early. Im having to throttle on throttle off around turns too often.

Anyone have some input on what to change, what to get etc...before my IS ive mostly just drag raced so im not very keen on proper handling attributes.
I have the Tanabe Sustec Pro-SS coilovers and Stillen sways, and I found that turn in is a little tricky. But it was like that stock too_Once in the turn though, the IS has some SERIOUS grip, and corner exit is nothing short of impressive. The transition is perfect going into the next straight or turn..

Oh, for all-seasons, Toyos Proxes4 are pretty damn good, only 3/4 second slower than my typical lap times
 

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since i am boosted, i have been running with traction on but that thing is killing me big time. it's always turning on right after the apex where the road becomes straight and that's where i can gun it.

should i continue to run with traction on and try to do a different throttle feed or turn it off?
 

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Discussion Starter · #15 ·
Hirun said:
since i am boosted, i have been running with traction on but that thing is killing me big time. it's always turning on right after the apex where the road becomes straight and that's where i can gun it.

should i continue to run with traction on and try to do a different throttle feed or turn it off?

learn to modulate your gas pedal and turn the trac off...

When i tune 350-450 RWHP turbo cars, even then the traction is off, i dont know how you drive with it on... Just learn to modulate your gas pedal and all will be well. Even in NA i cant use the trac.. Too intrusive
 

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Discussion Starter · #16 · (Edited)
IceCold4x4 said:
What kind of camber settings up front are you all running autox ?

I posted it, not sure if you saw it.. But for AutoX at stock height, run a camber of roughly -1.3 degree's front and rear and toe out the front 1/16th of an inch and 0 toe in the rear..
 

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Malekreza11 said:
I posted it, not sure if you saw it.. But for AutoX at stock height, run a camber of roughly -1.3 degree's front and rear and toe in the front 1/16th of an inch and 0 toe in the rear..
Huh i didn't see your camber settings up there.

I personally am runing right at -1 degree up front, and about -.5 degree's out back. think i should bump the back up more ? It feels real stable to me now when i starts to break loose in the corner, and normally it's a ever so slight drift if i auto x it. feels loose but still very controlable still need some sways i think to get rid of some body roll.
 

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good thread guys and thanks malek for posting info.

i believe sacrificial and i used to pound on these same things. I'll throw together what I feel should be the difference between autoX and road course later on and post it up that you guys haven't already said.
 

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Discussion Starter · #20 ·
What ever happened to sacrificial?? He and I would chat for a while at meets about this stuff. I dont see him or talk to him anymore..
 
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