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Discussion Starter #1
OK, I got the race alignment free from the Lexus dealer as part of the 1K service. I complained that the car was trammlining on a level at freeway speed. They reset the alignment to (as found on this site, thanks!):

-Zero toe front
-1/8 toe in rear
-1 deg negative camber all around

NOTE: These settings are much different than what the alignment was before. Rear toe was zero left, +1 right. Camber was zero front and rear. Trammlining disappeared after alignment, steering response quickened slightly.

Question about the tires. I'll be running the stock Potenzas with TRD Race Swaybars. I'm running 40psi ff/rr for the street, have tried up to 43psi ff/rr but didn't try anything close to auto-x maneuvers to test during break-in. What would you start with for race day tp's? I'm thinking 43-45 and adjust from there.

I'm still undecided about race class. If it's raining, I'll replace the stock rear sway and go D Stock. If dry, I'll take my chances in STX.
 

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Discussion Starter #3
Trammlining is longitudinal instability on smooth, level surfaces at moderate speed. Sort of like the tires are catching big-truck created freeway grooves where there aren't any.

The factory front camber was -0.5, so I reset to 0.0 to increase turn-in, making directonal changes quicker. I did the opposite in the rear to keep it planted better when exiting tight turns under WOT. It worked really well with my MR2 Spyder in B Stock. Then I read in another thread that those were the same settings Derek Butts used on his IS last year. Good enough for me, I figured! You'd think the "looser" front would tend to increase trammlining, but the opposite happened making me think that the negative rear toe has more of an effect on that. The car tracks better now, and really digs into a turn. Much improved.

Thanks for the tp's, especially the ff/rr differential that works best. Info like that can take the better part of a day to figure out.
 

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Toe out in front ussually increases turn in, toe in makes a car more stable at speeds, Toe in in rear make it more stable a speed, I can not remember what toe out in rear does. Ussually the more negative camber you have the better, however if you are driving the car every day, you will kill the inside of you tires with this set up, so it like everything, you have to come up with a comprimise.
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On 2002-02-22 12:33, Carcrazd wrote:
Trammlining is longitudinal instability on smooth, level surfaces at moderate speed. Sort of like the tires are catching big-truck created freeway grooves where there aren't any.

The factory front camber was -0.5, so I reset to 0.0 to increase turn-in, making directonal changes quicker. I did the opposite in the rear to keep it planted better when exiting tight turns under WOT. It worked really well with my MR2 Spyder in B Stock. Then I read in another thread that those were the same settings Derek Butts used on his IS last year. Good enough for me, I figured! You'd think the "looser" front would tend to increase trammlining, but the opposite happened making me think that the negative rear toe has more of an effect on that. The car tracks better now, and really digs into a turn. Much improved.

Thanks for the tp's, especially the ff/rr differential that works best. Info like that can take the better part of a day to figure out.

</FONT></TD></TR><TR><TD COLSPAN=2><HR></TD></TR></TABLE>
 

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Mr. Negative
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I have the Potenza's and with them at temperature I run 49-51 in the Front and ~43 in the rear. My steering is more precise and quicker when I go above 47-48 on these tires.

That's what I've found. I suggest that everyone try this out if they are running the Potenza's. I was getting too much sidewall flex with these tires at lower pressure ranges.

Thankfully I just ordered a new set of wheels with some Kuhmo Ecsta V700 wrapped around them to keep 'em warm.
 

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I was running 41 all around. I've totally trashed the sides of my tires. Even after I went up to 50 on the Potanzas I will still wearing the outside edge of the tires. The inside edge of the tires are in perfect condition. I think that I've got a bad camber setup on my tires. Anyway be really careful with that setup. I'll have to see if I can get someone to do the "race" setup... maybe for free too.
 

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Mr. Negative
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Sorry to revive such an old topic but I wanted to add to it.

I just had my alignment done. Dude it was so messed up.

The original settings were screwed. front left had -.8 the right had 0 and the rear had 0 left and -1.3 right. I'm amazed it went straight.

I set it up with:
Front: .9deg neg camber, max castor(6.3), and 0deg toe
Rear: 1.3deg neg camber, and 0deg toe.

I'm not sure about the 1.3 deg neg camber in the back yet but we'll see. Any comments about the rear camber? Or anything else?
 

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I have my camber set at -1.5 front and -1.75 rear. I would max out the camber front and rear keeping it even. The only reason not to max out the camber is tire wear, and the outside of my tires end of wearing a lot more than the inside :smile:
 

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TP's vary but based on surface I would run about a 4 psi differential front to rear (higher front). No matter what pressure you run you will have severe shoulder wear on the fronts with stock springs. High 40's in front sounds about right. I run 52 front/ 48 rear on Hoosiers/concrete. You generally want to run a couple of pounds higher on grippy concrete than asphalt.

Everyone's camber sounds consistent with these cars. Toe out in front will help turn in greatly but will chew up tires on the street. Good, solid braking will reduce the need for toe out in front. Rear toe in will keep the tail behind you (especially with LSD) as this car has a fair amount of power on oversteer.

Toe out in the rear is mostly for front drivers who have difficulty getting the cars to rotate in sweepers and slaloms. Keeps the rear end loose.

-Derek

'02 Sportcross Grocery Getter
 

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Mr. Negative
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Thanks for the advise.

Croddy. Wow that's a lot of camber. I bet it's great on the course though. It sounds good.

Derek. I went with 0deg rear camber because of the high speed push that I'm expecting to get w/ the TRD front race sway. I feel I can compensate for the on power loose feeling w/ throttle control and luck. We'll see though.


I always read that people have so much push in high speed corners and nearly everyone has rear toe. **shrugs shoulder** I thought I just give it a shot in the dark and see if it works.

I have a race Sunday so I'll let you guys know. Of course I've changed so many things since the last time I raced so who knows what I'll be able to tell. exhaust,dropin filter,alignment,front sway..... :grin:
 

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I thought you said 0 degrees of camber. With the small amount of camber available I would recommend dialing in as much as possible.

Croddy has lowering spring on his car which allows more camber.

-Derek
 

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Mr. Negative
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Oooops I meant toe. I have -.9deg front and -1.3deg rear camber. I'll quote it and fix it.

Fixed statment I made
<TABLE BORDER=0 CELLPADDING=0 CELLSPACING=0 ALIGN=CENTER WIDTH=85%><TR><TD COLSPAN=2><font size=-1>Quote:</font><HR></TD></TR><TR><TD> </TD><TD><FONT SIZE=-1>I went with 0deg toe in the rear because of the high speed push that I'm expecting to get w/ the TRD front race sway. I feel I can compensate for the on power loose feeling w/ throttle control and luck. We'll see though. </FONT></TD></TR><TR><TD COLSPAN=2><HR></TD></TR></TABLE>

Have you thought about going w/ 0deg rear toe? What do you think about it? I definately think it's worth a try.

<font size=-1>[ This Message was edited by: IS_Dude on 2002-05-14 23:01 ]</font>
 

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Cone Killer
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Ok, I am bringing this topic back. On the last three events, I suffered from really bad oversteer, and I am attributing mostly to the alignment being out of whack. I noticed that my front tires, the outer edge is wearing out in steps. Leads me to believe the toe is off.
I also think that the Azenis do not like being driven everyday, they got really slippery. I actually did a 360 one of these days going to work. Luckily, nobody was around.
I'll have a new set next year

Anyhow, I am looking for alignment setting for a stock shocks and springs. I may add a front roll bar for next season.

From reading the posts, it looks like:
-0.9 camber all around (guess it is the max).
0.0 toe in the front
-0.8 toe in the rear

is that about right?

I was thinking more negative camber in the front than the rear, i was thinking of -1.2 in the front, and -0.8 in the rear, but i guess that is not possible.
 

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Test Mule/Parts Breaker
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METEORO said:
I also think that the Azenis do not like being driven everyday, they got really slippery. I actually did a 360 one of these days going to work. Luckily, nobody was around.
I'll have a new set next year
Good to hear you're OK.


I have some friends that run Azenis and from what I've seen they don't handle heat cycling too well. They get very hard (i.e. slippery) when this happens. A new set of tires would be a good idea. Until then I'd use the traction control. ;)
 

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Cone Killer
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Yogi_TRD said:
Good to hear you're OK.


I have some friends that run Azenis and from what I've seen they don't handle heat cycling too well. They get very hard (i.e. slippery) when this happens. A new set of tires would be a good idea. Until then I'd use the traction control. ;)
Thanks, yes for the most part I have the traction control on. See there is a shortcut I take every mornig to get to the highway from my house, it is thru an industrial/corporate park. I know this road like the back of my hand. I call it my morning coffee. I always take the traction control off to go thru here, tons of fun. The road has this chicane, well more like switchbacks. So I make a right from the main road, put the pedal to the metal, let the car slide and go flat out thru the "S'", but the time the road straightens out, i'm going about 90-100.
So anyway, this morning, it was like any other mornig, but when i stepped on the car, the tail just bit me and the car spun. I had not chance of even trying to recover it. Never has the car done that, it is always so progressive when it begins to slide.

Yes the tires are a big factor, but the alignment has to be way off too. And these cars are very sensitive to alignment changes.
 

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my set up on 245 azenis( the old ones)

zero toe all around - max negative up front max positive in the rear which is about -1.5 and -.9

operating temp on the old azenis is around 98 and they usually need to be cooled after the second or third run even when it's below 80 degrees outside, so bring a spray bottle. 43psi up front and 37-38 rear gives a good temp gradient for asphalt.

edit- .1 deg toe in upfront .1 deg toe out in rear.. this helped dial out some mid corner/corner exit understeer
 

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cone killer
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FWIW heres my set up for DS
2002 IS 300 5 Speed with LSD
traction control OFF (DUH)

custom valved konis
set to 1 turn in the front (out of 2)
1.5 turns in the rear (out of 2)

TRD yellow front bar (30mm solid)

Kosei K1-TS 17x7 50mm offset (14 lbs each)

Hoosier 225/45/17
50-52 front 46-48 rear
(i ran the lower pressure with out passengers)

-1.25 camber front
-1.00 camber rear

0 toe all around

i ran this set up on smooth concrete
approx 50 degrees low humidity LOTS of wind and a mile up

GREAT balance AWSOME slaloms just a hint of oversteer under power but VERY predictable
10th on index out of 189
first time out with brand new (still stickered) hoosier SO4's
with only 3 runs
theres more to come!!!!


Donnie
 

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Donnie said:
i ran this set up on smooth concrete
approx 50 degrees low humidity LOTS of wind and a mile up

GREAT balance AWSOME slaloms just a hint of oversteer under power but VERY predictable
10th on index out of 189
first time out with brand new (still stickered) hoosier SO4's
with only 3 runs
I drove Donnie's car at the 04/16/06 Autocross here in Denver...and these are my post-event notes...

* I'm still a Novice - I've been to 8 Events and 1 school.
* Because I was Donnie's Co-Driver, I ran with him in the local X (Experts) class. Having a car marked "179X(N)" isn't all that common... :)
* Had I not tagged one cone on my second run, I would have placed "not Dead Effin' Last" in X, which is my goal for the season.
* Even with my tagged cone, I bested the D-Stock cars by a full 5 seconds - and a full 7 and a quarter seconds if my fastest run were clean...
* My runs were a full 10-12 seconds faster than what I can manage in my dedicated autocross MR2, which is a light, nimble vehicle...
* Even in my noobness I was only about 3 seconds back from Donnie...
* I've seen the light and...
* I'm selling my '03 Vibe GT (DD) *and* '85 MR2 (Dedicated Autocrosser) and buying an '02 IS300, and modding to match what Donnie's done thus far...

Sometimes it *is* the car... :)
 

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Just to share my test & tunes...

2001 IS300 e-shift, LSD.
removed spare tire.
Traction off, Power buttom On.
K&N drop-in.
EBC green-stuff brake pads (too dusty, not recommended)
TRD yellow sway, f/r.
Tein H-tech springs, stock shocks.
16x8 FD RX7 wheels all around
Sumitomo HTR-Z 225/45/16 front, 245/45/16 rear (to have the rear higher)
16 to 20-degree Celcius dry day (not hot, just normal vancouver weather), i have 42 front, 37 rear.
Zero toe all around.
front -1.1 camber, rear -0.6 camber.

Competing in STX w/ vcmc & ubcscc under CACC/SCCA solo II.

Good front grip turn-in. Have the option to exit with full power.
 
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