Alltrac Handling FAQ

Suspension and other discussion

Alltrac Handling FAQ

Postby CMS-GT4 » Sun Sep 11, 2005 11:12 pm

I wanted to make a thread for the suspension setups of the alltrac.
Post your track alignment settings. Maybe we can use this thread to come up with solutions for suspension for track and rally use.

Here is an article on the stock handling of the st185.
Goes into alignment settings as well.
http://www.whiteline.com.au/articles/RH ... aGT4_a.htm

Thread on seting up a serious course car. More on hows and whys to setup your alltracs handling.
http://alltrac.net/phpBB2/viewtopic.php?p=187915#187915

Also here is a link that explains alignment better.
http://www.familycar.com/alignment.htm

Here is a tech on doing your own alignment.
http://corner-carvers.com/forums/showth ... ge=1&pp=40

The whiteline article claims that the st185 could use more + caster.
I would like to post up the 185 suspension workings and look at how other mcpherson strut type cars adjust the caster. We may be able to develop a solution to get everything worked out right.

Here are the Whiteline sugested track settings for the 185.

Camber: (F) -1.5 / (R) -1.0
Toe (F) 0 / (R) 1mm out

They later updated from camber to-2.0 for racing. Some board members that autox run up to -3 camber.

I plan on trying out these settings when I get the car running again.

Parts that seemed to help:
Cusco front underbrace. (Helped firm up steering)
Whiteline rear sway bar. (Excellent)
Whiteline bushings. (Made the car feel more planted and controlled)
Adjustable sway bar links.
Aluminum rear diff mount.

Parts I will test and install:
Strut tower bars.
J-speed chasis mounts. (http://bulletproofautomotive.com/catalo ... hp?ID=1242)

On a note of handling. No matter how much $$ you throw at your suspension, unless you upgrade to a wider gripier tire, your throwing money away.

Another note, lsd is another important aspect to this cars handling, but we will cover the suspension chasis part of it in this thread and touch on the handling aspect of lsd some.

Here is a link to the lsd thread.
http://alltrac.net/phpBB2/viewtopic.php?t=5570

Here is a link to the wheel/tire size thread to help in choosing a wide enough wheel/ tire for you budget or needs.
http://alltrac.net/phpBB2/viewtopic.php?t=1327

Weight reduction thread.
http://www.alltrac.net/phpBB2/viewtopic.php?t=863

Good artilce on brakes. A very important apsect to handling. And braking parts.
http://www.stoptech.com/tech_info/wp_wa ... disk.shtml
http://alltrac.net/tuning/brake.html
http://www.rocketeerperformance.com/cat ... 637616491b
Threads on braking:
http://alltrac.net/phpBB2/viewtopic.php ... re&start=0

http://alltrac.net/phpBB2/viewtopic.php ... brake+bore

Link to many alltrac related suspension parts.
http://alltrac.net/tuning/suspension.html

Discuss... :?
Members don't see the above ad. Register now - it's free!
Last edited by CMS-GT4 on Wed Apr 11, 2007 2:38 pm, edited 8 times in total.
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
User avatar
CMS-GT4
GTSilver Member
 
Posts: 10342
Images: 7
Joined: Mon Aug 09, 2004 9:12 pm
Location: St Louis Area (IL)

1992 Toyota Celica

Postby furpo » Wed Sep 14, 2005 4:36 am

interesting...

just a few questions, what is the cusco front underbrace? dont we have an underbrace front and rear as standard?

how did the aluminum rear diff mount help? i thought the diff was completly independent of the rear suspension. i have a stuffed rear diff mount at the moment, whould you recommend i fabricate an aluminum one?

i got rid of a large amount of rear toe which has helped quite a bit. i run 1.5 deg total now (so .75deg eaach side). i have -.5 deg camber as well and i still wear the outside of the tyre which would suggest i still need a bit more.

i have yet to stuff around with the rear track, i am also going to try brace the suspension tops back to the bottom of the a piller to see if this helps.

here are a couple of other points to help.

- lighter front end
- stiffer rear roll bar
- stiffer rear shocks
- reducing front scrub radius
- having big balls
- using a tyre pyrometer to set your suspension geometery
- get your corner weights right
- get a good allignment. the factory tolerances on our cars are huge. if the allignment guy does not allign it to within say .25 deg all round dont pay him and go somewhere else.

roger
don't mind me, i always need help
furpo
Club Member
 
Posts: 897
Joined: Mon Sep 13, 2004 12:45 am
Location: new zealand

Postby mtbgael » Thu Sep 15, 2005 1:14 pm

I have an ST165.

F: -2.5 camber
1.5 caster (seems too low, but I haven't ventured to adjust it yet)
0 Toe

R: -1 camber
.2 toe (.4 total)

195/60/14 Hankook RS-2 (Similar to Falken Azenis)

The car is for autocross. My only suspension mod is a set of lowering springs on fresh stock struts...awaiting struts until I can afford them. The car power oversteers! It feels okay overall. The soft spring/strut combo mean it doesn't transition very well, and lateral grip is still to be desired. However, since the first part of the thread was about alignments, I feel mine is getting pretty close. I think I should add another -.5 to the rear and see how it does.

*edit* camber was adjusted by slotting my upper bolt hole in the strut.
Last edited by mtbgael on Thu Sep 15, 2005 2:23 pm, edited 1 time in total.
Restoring an '88...
Image
mtbgael
Club Member
 
Posts: 217
Joined: Mon Aug 09, 2004 3:07 am
Location: Virginia Tech

Postby CMS-GT4 » Mon Sep 19, 2005 5:33 pm

furpo wrote:just a few questions, what is the cusco front underbrace? dont we have an underbrace front and rear as standard?


It is an additional brace. Just to make it even stiffer.
Here is an explination I found from a WRX site.

Not a "large" difference, but certainly a difference. This is a critrical area to have reinforced (the v8 STi's actually have a similar setup right out of the factory)- sits right between the two front control arms (transverse links). This reinforcement will allow less deflection, which translates to less camber changes in turns (going positive), which results in more grip.


furpo wrote:how did the aluminum rear diff mount help? i thought the diff was completly independent of the rear suspension. i have a stuffed rear diff mount at the moment, whould you recommend i fabricate an aluminum one?


It seemed to cancel any delay or slop the rearend had, as far as the diff reacting. Seemed to make the rear more direct and work more. I think combined with rear lsd, will make more of a difference on the rear lsd affecting the handling characteristics.

b00staholic wrote:What are you guys using to adjust your alignment?

Camber bolts? Camber plates? If so, which brands?


Not a lot of options.

Cusco makes a seperate set of pillow mounts, but it will also be a much hardsher ride. Camber bolts are cheaper and get the job done.
My tein HA suspension came with camber plates.
Whiteline makes camber bolts. I know there is a company on ebay making camber bolts for st18x models. Not sure if they will work on an alltrac. They are cheap. Best bet is to find a set of gt camber bolts to compare your alltrac ones to.

Here is another link on handling. This one is for the gtfour, and goes a little into strut selection/adjustment.

http://gtfour.supras.org.nz/chassis%20dynamics.htm
Last edited by CMS-GT4 on Mon Sep 19, 2005 6:54 pm, edited 1 time in total.
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
User avatar
CMS-GT4
GTSilver Member
 
Posts: 10342
Images: 7
Joined: Mon Aug 09, 2004 9:12 pm
Location: St Louis Area (IL)

1992 Toyota Celica

Postby CMS-GT4 » Mon Sep 19, 2005 5:38 pm

Here is a good link to a do-it-yourself alighnment tech.
I am going to research this more, so I can do my own alignment to save money, and set it up properly so I can take it to track and autox.

http://corner-carvers.com/forums/showth ... ge=1&pp=40

I also updated some of the handling forum links for reference in the first post.
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
User avatar
CMS-GT4
GTSilver Member
 
Posts: 10342
Images: 7
Joined: Mon Aug 09, 2004 9:12 pm
Location: St Louis Area (IL)

1992 Toyota Celica

Postby CMS-GT4 » Mon Sep 26, 2005 5:59 pm

Another note of suspesnion is it is very important to maintain certain items. Steering can be numbed by worn out tie rod ends. I am not sure what it is about them, but I tend to have to replace mine every 1.5 years.
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
User avatar
CMS-GT4
GTSilver Member
 
Posts: 10342
Images: 7
Joined: Mon Aug 09, 2004 9:12 pm
Location: St Louis Area (IL)

1992 Toyota Celica

Postby CMS-GT4 » Mon Oct 03, 2005 9:06 pm

Some links for handling in other awd cars that may apply to our car. I would like to go to a test and tune autox and try out some of these items.

http://forums.nasioc.com/forums/showthr ... did=203801

I will update this if I find more links.
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
User avatar
CMS-GT4
GTSilver Member
 
Posts: 10342
Images: 7
Joined: Mon Aug 09, 2004 9:12 pm
Location: St Louis Area (IL)

1992 Toyota Celica

Postby jprine01 » Mon Oct 03, 2005 11:18 pm

I have a solid rear end (aluminum end, and nylon in the 2 side mounts). It was hard to tell because I did other mods at the same time, but the car feels allot more solid in the rear overall and shifts better.
I think it helps solidify the rear subframe too... but the rear subframe is pretty heavy duty, not sure how much it twists around.
I dont notice any extra noise or vibrations etc. so as far as downsides...
jprine01
Established Member
 
Posts: 1218
Joined: Wed Dec 22, 2004 9:02 pm
Location: Chicago

Postby b00staholic » Tue Oct 04, 2005 2:42 pm

Looking at that thread makes me question how adding rear spacers on our car can actually improve handling (decrease understeer), as some people on this board seem to say. To me it makes logical sense that inreasing the rear track gives the rear more grip and thus increases understeer and decreases oversteer, which is the opposite of what we want.

I have spacers too, but I'm now considering taking them off when I autocross to see if that helps, although I'm a beginner and not sure if my driving is consistent enough to do an accurate with/without spacer comparison :P

Or how about even putting those spacers on the front wheels? It seems like the Japanese folks have had success w/ wider tires in the front vs. the rear, aka more grip in the front.
Vincent
'90 ST185
b00staholic
Club Member
 
Posts: 933
Joined: Mon Aug 09, 2004 1:34 pm
Location: nor*cal

Postby CMS-GT4 » Tue Oct 04, 2005 2:54 pm

I would run an autocross and try both. You may talk to the instructors and ask if there will be a free run after the event. Sometimes it is something like $1 a run.
I would run the entire autox in one way. Perhaps w/o spacers. Then I would run the same amount of free runs with the spacers and compare times and how the car felt. I liked how the car felt with the spacers. I did them the same time as the rear diff mount. It seems to increase the grip of the rear. Which is what seems to work for me. My theory is that the center lsd is sensing more grip on the rear, thus reducing the power to the front and moving more power to the rear. I really notice this on turn exit.

It is still a tricky theory which is hard to figure with awd. There are so many varibles. Once my car is running again, I will be spending a bit of time testing and tuning.
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
User avatar
CMS-GT4
GTSilver Member
 
Posts: 10342
Images: 7
Joined: Mon Aug 09, 2004 9:12 pm
Location: St Louis Area (IL)

1992 Toyota Celica

Postby furpo » Tue Oct 04, 2005 8:39 pm

i have noticed the less mid corner understear with a wider rear track which to me does not make sence either. i have a bit of a theory that because our cars are so nose heavy increasing the rear track has a similar effect to using a stiffer rear sway bar.

we are noticing a similar thing with our speedway cars. the saloons are quite nose heavy as well and increasing rear track helps but on the midget and the sprint car it does not help at all.

roger
don't mind me, i always need help
furpo
Club Member
 
Posts: 897
Joined: Mon Sep 13, 2004 12:45 am
Location: new zealand

Postby CMS-GT4 » Tue Oct 11, 2005 2:33 pm

A link that has a good explination of unsprung wieght and how various suspension works.

http://www.chris-longhurst.com/carbible ... bible.html

A good link about everything for suspesnion tuning. Explains what all the bits do even tires.

http://www.turnfast.com/tech_handling/handling.shtml
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
User avatar
CMS-GT4
GTSilver Member
 
Posts: 10342
Images: 7
Joined: Mon Aug 09, 2004 9:12 pm
Location: St Louis Area (IL)

1992 Toyota Celica

Postby furpo » Sat Oct 22, 2005 3:26 am

i was scutineering today for our local car club and one very cool evo 9 turned up. anyway they have go for a wider rear track than for the front so it seems the mitsi guys are noticing the same as what we are in terms of rear track

roger
don't mind me, i always need help
furpo
Club Member
 
Posts: 897
Joined: Mon Sep 13, 2004 12:45 am
Location: new zealand

Postby b00staholic » Sat Oct 22, 2005 11:25 am

Hmm, are you sure it wasn't just for aesthetics?

I've yet to come across any info here in the US of Subaru/Mitsu guys widening their rear track, but this is just from some quick searching on their forums.
Vincent
'90 ST185
b00staholic
Club Member
 
Posts: 933
Joined: Mon Aug 09, 2004 1:34 pm
Location: nor*cal

Postby CMS-GT4 » Sat Oct 22, 2005 2:14 pm

Its not an issue on other cars due to the manufactures already making the tracks close to equal. The DSM and the Sti, evo etc... all have close to equal track width, front and rear. Other than rwd cars, the alltrac has the most narrow rear track vs the front track I have seen. I really think toyota's primary objective was for the consumer to purchase aftermarket wheels and to have used dished wheels on there rear.
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
User avatar
CMS-GT4
GTSilver Member
 
Posts: 10342
Images: 7
Joined: Mon Aug 09, 2004 9:12 pm
Location: St Louis Area (IL)

1992 Toyota Celica

Next

Return to Handling and Braking

Who is online

Users browsing this forum: No registered users and 1 guest

cron