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View Full Version : Serious AutoX setup discussion



Mafix
07-01-2012, 03:08 AM
i just wanted to get a serious suspension/tire/weight discussion going based on autox only. so i suppose i'll get started.
currently i'm running nt01 2254515 tires on 7 inch rims, megan street coilovers with 450f and 200r springs. stock front sway bar (which stays so i can rarely have a nice weekend drive) and i have a 7/8ths rear bar that will arrive in a couple days. other than that she is stripped down to nearly 2500lbs in FP class. autopower cage, frame connectors, front and rear strut braces, corbeau forza drivers seat hard mounted (no other seats), poly bushings everywhere possible, as much caster as i can get in a 4th gen. i think that's it.

Mafix
07-01-2012, 03:11 AM
i'm planning on changing the entire rear arm setup to heim next year. i'll probabily get some hoosier bias slicks next year as well.

KoreanJoey
07-03-2012, 12:57 AM
So... what's up?

Mafix
07-03-2012, 02:45 AM
just discussing ideas to better the celica chassis. and a list of who has done what and so forth. this way we can see if there are common things between everyone.

KoreanJoey
07-03-2012, 07:23 AM
I would take a look at the goodyears and the avons. We run the Goodyears on the CP car and they are just awesome.

Swapping to heims is the way to go man.

How are the megans working for you? I've been unimpressed in the past. But then again, they're not any worse than Teins or JIC or any JDM shock for that matter.

METDeath
07-03-2012, 11:39 AM
What exactly are you talking about when you say change the rear arms to Heim?

underscore
07-03-2012, 07:38 PM
^ +1 I'm curious on this as well.

Mafix
07-05-2012, 04:04 AM
removing all 6 stock rear control arms. literally make 6 new ones, all adjustable with heim joints on both ends (except the rear of the trailing arms, cause you can't)

i looked at the goodyear tires, they don't make anything in a size i can practically use. the best tire i have found here recently is a cantilever bias hoosier. but that is going to have to wait a while. 1K in tires is out of the range with a little one on the way.

Mafix
07-05-2012, 04:09 AM
k.beaty setup:
http://i426.photobucket.com/albums/pp343/kbeaty47/Hamilton2-20120407-00038.jpg

underscore
07-05-2012, 08:53 PM
That looks spiffy as hell, what are the benefits from adjustable arms? (noob questions)

k.beaty
07-05-2012, 09:25 PM
k.beaty setup:
http://i426.photobucket.com/albums/pp343/kbeaty47/Hamilton2-20120407-00038.jpg


Make sure you use good quality rod ends. Mine were about $30.00 each, but well worth it in my opinion.


Also, making the trailing arm adjustable makes you able to adjust rear caster, and there's something to adding rear caster. I've spent enough time with the car on scales, moving weight around, adjusting caster and camber to have it pretty well figured out. The best thing you can do is adjust something, run some laps and see how the car feels, as well as how the lap time was affected.

Everyone will have different opinions on alignment setup, you have to figure out what is going to work best for your driving style, and maximize it.

Mafix
07-06-2012, 01:50 AM
thanks for the tips kyle. are you increasing or decreasing the rear caster? my thoughts are that you are simply changing the wheelbase and spring rate by doing that on a wheel that doesn't turn.

Luni
07-06-2012, 05:00 AM
Why would you be changing the springrate? The wheelbase does change, but how would the springrate change just by strut angle?

k.beaty
07-06-2012, 03:12 PM
thanks for the tips kyle. are you increasing or decreasing the rear caster? my thoughts are that you are simply changing the wheelbase and spring rate by doing that on a wheel that doesn't turn.

Spring rate is not affected by a change in caster, but you're right about the wheelbase being changed. Personally, I do some silly things when playing with my alignment that most people laugh at. Maybe thats why I'm able to beat 220hp Honda's with my 5SFE celica...

For auto-x, I think you'd want your cross caster to be exactly the same. I dont know if having adjustable rear caster would necessarily help on at auto-x course. I race on road courses, so I'm not sure how helpfull my advice will be....

KoreanJoey
07-08-2012, 07:57 AM
The caster in the back is really a non-issue as the rear spindles don't turn. Focus on the camber and the toe. What might be more of a factor is the wheelbase/camber gain vs compression.

Mafix
07-08-2012, 10:08 PM
spring rate was more of my brain thinking at extremes. at any rate, interesting stuffs. i actually use negative toe in the rear to help with rotation

METDeath
07-09-2012, 11:02 AM
Really? I found that 0 toe in the rear helped more... or maybe I just thought it did...

Unless you're talking toe out?

Mafix
07-09-2012, 02:31 PM
yes toe out not toe in. i'm trying to force the car to rotate rather than let it push.

METDeath
07-09-2012, 02:32 PM
How much Toe out do you run? Like I said, I currently run 0 when I go to meets and then set it back to stock for daily driving.

Mafix
07-09-2012, 02:35 PM
.15 degrees out on both sides. it make the 3 digit numbers most interesting.

METDeath
07-09-2012, 05:51 PM
.15 degrees out on both sides. it make the 3 digit numbers most interesting.

Last time I saw three digit numbers was down hill with a tailwind on the skyway...

KoreanJoey
07-09-2012, 09:29 PM
That's a lot...

I would rather play with camber and spring rate in the back than that much toe out.

emicen
07-09-2012, 11:49 PM
Are these tyres you're using cut slicks rather than full slicks?

Wouldn't run that much rear toe, increases tyre scrub way too much in a straight line for me. Run more camber and jack the rear pressures up.

Mafix
07-12-2012, 05:49 PM
.15 degrees? that is hardly nothing. stock is .2 degrees positive.

hey guys don't forget what this whole thread is about. it's not for street cars. it's for autocross.

KoreanJoey
07-14-2012, 04:08 PM
Exactly, I think it's the wrong way to go. It'll always rotate (which means when you oversteer the car will take longer to reign back).

Like I said, I'd play with the spring rate or swaybars before adding that much toe out.

PS: .2 in with stock bushings would probably bring them close to 0.0 at freeway speeds.

Mafix
07-16-2012, 01:25 AM
rofl...good chance of that!

well 1st again this weekend. the rear sway bar is a huge help but not enough. i still had to run with 38psi in the rear tires and i still have freaking understeer. so hoosier cantilever tires are the next upgrade after i finish getting the weight down. if my thoughts add up correctly the car will weight about 2450 fully loaded.

Car_Barn_Bandit
07-17-2012, 02:43 AM
Still running the front sway bar?

KoreanJoey
07-17-2012, 06:04 AM
rofl...good chance of that!

well 1st again this weekend. the rear sway bar is a huge help but not enough. i still had to run with 38psi in the rear tires and i still have freaking understeer. so hoosier cantilever tires are the next upgrade after i finish getting the weight down. if my thoughts add up correctly the car will weight about 2450 fully loaded.

More rear spring!

Or more compression dampening.

I'd try the Goodyear Eagles over the Hoosier cantilevers. I have a set of 23x9.5x15s and I was just never that happy with them.

KoreanJoey
07-17-2012, 06:04 AM
PS: what are your tire temps looking like?

Mafix
07-18-2012, 10:04 PM
i haven't temp gunned the tires but they are not getting hot enough. perks of using road race tires. nittos at that.
i looked at the goodyear and hoosier line ups. there is 1 tire that will fit my build. it just happens to be a cantilever. i'm undecided at the moment. it won't be until next year anyways.

i might try and get my hands on some used 225 tires in a slick.

KoreanJoey
07-19-2012, 01:21 AM
Want my hoosier cantilevers? R35A never ran.

Mafix
07-19-2012, 01:23 PM
sure. i'd love to give them a try.

KoreanJoey
07-19-2012, 03:19 PM
They're for a 15x7.

Mafix
08-10-2012, 02:58 PM
215/580r15 r80 hoosiers for this weekend. i will report back. hopefully i can actually get the car to spin out.

KoreanJoey
08-10-2012, 05:28 PM
Skinny...

Mafix
08-11-2012, 11:40 PM
one would assume that until you actually measure the tires. they have a nearly 9 inch contact patch. don't let the 215 part fool you.
at any rate...
sucess. the car finally "spun out". now to dial everything down a touch in the back. i'm finally happy with my setup. now i can concentrate on modding the driver.

KoreanJoey
08-12-2012, 12:04 PM
Loose is fast.

Mafix
08-15-2012, 08:11 PM
so to speak. but it was far too loose. but an easy thing to repair.

KoreanJoey
08-16-2012, 05:27 AM
What's the alignment spec you're running? Maybe too much toe out? I generally run 0 toe in the back with very little toe out in the front (.05-.1*). You play with shock settings at all?

I honestly don't know what you're whole setup is.

Mafix
08-16-2012, 11:56 PM
it's very close to where i want. i need to run my test models more. i think i need less rear camber. currently it's at -1.2 which i know is a bit much. but corner balance first. then re-align the whole car....for the like 6th time in 3 months.

KoreanJoey
08-17-2012, 02:15 PM
http://sphotos-a.xx.fbcdn.net/hphotos-snc6/217639_10151023639423801_1746962883_n.jpg

Mafix
08-18-2012, 01:44 AM
fuck yes!
(but it's a damn good thing i have sponsors and a shop and a great group of friends)

donteatbugs
08-23-2012, 10:03 PM
Joey, What are you doing with those hoosiers? I have a set of 15x7 wheels for my 7th gen...

KoreanJoey
08-24-2012, 03:34 PM
The shipping would be killer. I might have someone interested locally, otherwise I'll save them for a Time Trial.

91Atrac
08-24-2012, 03:39 PM
fuck yes!
(but it's a damn good thing i have sponsors and a shop and a great group of friends)

Pretty important to have those factors. Got a friend with a shop and a pit for us to work with.


Sent from Qbabys Tapatalk.

Mafix
09-22-2012, 01:10 AM
http://i13.photobucket.com/albums/a262/mafixcelica/A2/imagejpeg_2_90_zps9570e7d0.jpg

hard to believe these are off the shelf megans. that's easily 30mph in that hard left (uphill)

KoreanJoey
09-22-2012, 02:57 AM
Too far from the cone!

:)

Mafix
09-23-2012, 09:53 PM
a bit of understeer into that corner. it also is the worlds most misleading pic.

KoreanJoey
09-24-2012, 05:16 AM
A single apex cone by itself really doesn't give me a location.

Mafix
09-24-2012, 08:49 PM
that's the thing. very very misleading pic. that was from a friends cell phone. my gopro guy never showed up (though i should stop being cheap and go buy one)

Mafix
10-05-2012, 06:48 PM
so 8.8 width race slicks in the back and 10.4 inch width slicks in the front. i'll see how it goes (unless it's baby time, then i'll be watching a completely different race)

KoreanJoey
10-05-2012, 09:17 PM
I've never been a fan of the staggered tire sizes. But if it works, it works.

Mafix
10-09-2012, 06:31 PM
fwd man. not much choice when i have to make the car rotate.

KoreanJoey
10-09-2012, 06:49 PM
More rear bar/spring?

Mafix
10-11-2012, 05:58 PM
already there. but now i need more rear grip and more front grip. i was running the 215 r80 hoosiers on the front and the nitto 2254515 nt01 (street tire) on the back. now i'll have the 215 hoosiers in the back and the goodyear 23x9 in the front. should be interesting to say the least.
next year i'll have the 215 hoosiers in the back with the 245 hoosiers in the front. i'm planning on running regionals next year.

KoreanJoey
10-11-2012, 06:57 PM
*scratches head*

Your tire choices confuse me...

Mafix
10-12-2012, 02:43 PM
rofl!!! fwd man. i've been battling with tires for too long. i've found that offsetting the size works the easiest.

KoreanJoey
10-12-2012, 08:39 PM
I'm of the mindset that it's nice to be able to rotate the tires. I've never been a fan of the staggered setup. If I could tune around the need I would.

Mafix
10-15-2012, 07:19 PM
my street tires are all the same size. for the race tires (which i now get at a great price), i'm not too worried about it. i can always dismount them and flip them.

KoreanJoey
10-16-2012, 09:07 AM
I'm too lazy for that shit.

KoreanJoey
10-16-2012, 09:08 AM
On a related note, I just killed it on a set of Kumho W710s:

http://www.ebay.com/itm/290700464675?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Mafix
10-16-2012, 06:30 PM
nice price for wets. i just run my street tires in the rain.

KoreanJoey
10-17-2012, 07:12 AM
I would but my "streets" are Hankook RS3s... Not really choice rain tires.

Not that I drive it aside from to and from the track.

Mafix
10-20-2012, 04:08 AM
lol yeah. i'm enjoying that i do NOT have to use dot tires. makes such a difference, but it's a very loaded car on the way to the track.
4 wheels and tires, a jack, tools, air pump, ect.
good thing it's a stripped car.

Mafix
11-04-2012, 06:31 PM
fucking hell man, i just reviewed all the rules regaurding FP and i've been running an illegal intake. i need a 46mm restrictor plate. damnit. (my turbo is a 58mm)
well never a dull moment.

KoreanJoey
11-04-2012, 07:31 PM
Doh.

I think my corolla will play in XP after the V8 swap... and I'll have to add weight. :(

Mafix
11-04-2012, 11:08 PM
i'm trying to aviod xp.

KoreanJoey
11-05-2012, 01:10 AM
Sadly, it's just where it looks like a V8 corolla falls.

Mafix
11-07-2012, 03:05 AM
i'm honestly just going to see how it runs next year and then i may run xp. i'm currently undecided. but i think i can be competitive in fp, which is where i'm having a crisis.

KoreanJoey
11-07-2012, 08:50 AM
Yeah... My crisis is more about engine options/ minimum weights.

Mafix
11-07-2012, 11:34 PM
yeah...not running xp. there is no way in hell to get my car to a competitive level there.

KoreanJoey
11-08-2012, 07:39 AM
I'm probably placing an order for Formula Atlantic tires for the Corolla. :)

Mafix
11-08-2012, 04:53 PM
i looked at those and the hoosier rep explained that it would be a bad idea. the FA tires require a lot of downforce. autox cars don't make anything near that much. just an fyi for ya

KoreanJoey
11-08-2012, 10:20 PM
I talked with Jeff Keisel about it, he runs Goodyear FA tires on his EM Sprite. Ensuring the use of the qualifying compounds seems to work fairly well in the light EM car.

Of course, I'm not sure that the hoosiers will work the same or not. If not then I'll swap to the GYs instead.

Mafix
05-19-2013, 02:17 AM
so after many adjustments and driving/driver adjustments...
i now have a huge rear wing and canards and a front splitter. hopefully i can add some false weight and improve further. the only thing left is the rear diffuser. i'll get to that.

Grot
05-22-2013, 07:06 AM
PICS or GTFO

Mafix
05-28-2013, 03:02 AM
no. neither will happen until i repaint the car (in 3 weeks). then i'll do a pic dump in my ride thread and you can see it there.

KoreanJoey
05-29-2013, 07:33 AM
Sweet deal. I need to work on some aero at some point. Right now I'm looking at revising the suspension design on the rear axle. Looking at converting to a 3-link design with a watts link instead of a panhard. We'll see if I ever get around to any of this development this year or not.

Mafix
06-11-2013, 02:56 AM
i've always found the watts style interesting and confusing. comes on the 2nd gen durangos.

i'm almost done with aero "rough" work. and the diffuser will just have to wait until later on. i'm going to the Dragon in september. it'll be fun to use there (since i'll be at higher than autox speeds, idealy)
also i've tweeked the rear sway bar some more and remapped my ecu. hopefully it'll be warm enough to get some grip in a couple weeks.

KoreanJoey
06-11-2013, 08:04 AM
Switch to Avons dude, we're making grip at 55*! 50* surface temps.

Mafix
06-17-2013, 07:09 PM
the last autox was freezing. it was about 40 out. no race tires doing good in that

KoreanJoey
06-17-2013, 09:56 PM
Mafix, seriously dude, grip on the first run on 50* temps. They do work at 40*, no shit.

Mafix
06-20-2013, 06:53 PM
interesting. well i'll give it a look

KoreanJoey
06-20-2013, 07:36 PM
And this is with the A11 compound. They make a softer A15 as well.

KoreanJoey
06-20-2013, 07:36 PM
If you're looking for some inexpensive tires for testing check out:

http://www.jbracingtires.net/

Mafix
08-04-2013, 02:04 AM
so i changed the wheels and the alignment. wheels...good. alignment...bad. -2 degrees of camber is rubbish in my car. i'm going back to -1.5 all around. i can't drive the car in a straight line. and accelerating in a straight line is asking for an accident.

so hopefully tomorrow or later in the week i'll get the car in the shop and redo the alignment. i'm curious if the new wheel center line offset is affecting the camber settings. on a truely flat ground i can visibly see the outer edge of the tire is not contacting the ground.

i'm also thinking of reverse mounting the front pillow ball mounts so i can get more caster in the car. that or slotting the holes out...might do that first. i'll follow through with more later guys.

Mafix
08-04-2013, 06:15 PM
alignment success.
-1.6 on all 4
0.0 front toe
0.20 rear toe
+4 front caster (i don't believe you can have more with the stock lower control arms)

KoreanJoey
08-04-2013, 09:23 PM
Are you on radials or bias plys?

I run -1* on the front of my car and that seems about perfect with the Avon bias plies.

Mafix
08-05-2013, 12:59 AM
radial. the bias just feel funny to me.

KoreanJoey
08-05-2013, 02:04 AM
They do, primarily they have a slower response and like lower pressures than the radials (I run 25 psi front and 22 psi rear).

Also, they seem to be happy with less camber than the radials (I ran 1.5* and the outside of the tire wasn't being used at all).

Additionally, they are fastest with a pretty big slip angle (seems like the radials like more precision vs the bias plys).

Definitely takes a bit to get used to, but, when you're comfortable with them, they're amazing.

Mafix
08-05-2013, 11:29 AM
i don't have any complaints about radials.
as i understand it, no clue whether its true or not, the radials hold temp longer than the bias as well.

KoreanJoey
08-06-2013, 08:22 AM
They also, typically, need the heat more than the bias plys. Like I said, since you're wanting less camber, you might want to think about swapping to Avon (plus they're just better).

Mafix
09-02-2013, 11:06 PM
you do love those avons. i see why but i really like my hoosiers. so we will agree to disagree?
now rolling on 15x9.5 on all 4 corners and 10.5 wide slicks. life is good.
street tires however need to catch up to my awesomeness. 225/45r15 rivals are not enough. i need like 245/40r15

KoreanJoey
09-03-2013, 09:33 PM
225... that's cute.

KoreanJoey
09-03-2013, 09:34 PM
I wish they made some nice wide 15" street tires.

Mafix
09-06-2013, 09:10 PM
no lie there. at least they make nice slicks.
i'd love a 245/40 or 35/r15.

KoreanJoey
09-09-2013, 07:14 AM
Well, if I put street tires on my corolla it would just be to drift it anyways. Guess I don't really need wide tires for that.