Giving the alltrac better road feel

CMS-GT4 · Sep 13, 2006

So, the gtfour was called souless. I could never quite put my finger on why till recently. I think it earned that title due to Toyota making the road car more luxurious than a track machine. It was more refined compared to its raw econo based counter parts.

Due to its luxury status, it was numbed a bit. It is a bit heafty than it should be due to sound proffing and all the fancy extras. These we can remove.

I would like to dedicate this thread to determining what things Toyota did to soften up this car, so that we might come up with solutions for either fabricating or upgrading bit to give it more feed back, more control and better handling.

Things we know that soften the alltrac:

* The struts and springs.
The spring rates are too low and the struts do decent but are not quite up to part for circuit.

* Strut tops. Rubber tops are better replaced with adjustable pillow mounts.

* The rear diff cushion. Gives too mcuh slack in the rear end. Either a soild bushing or poly helps in this respect.

* Suspension bushings. Mostly due to being worn out in our cars. Superpro replacements help things out quite a bit.

These are the only things I can say for definate for now. I have replaced all of these with great results.

If you list an item, please explain why it is a problem. This should help lead to the solution.

Here are a few other items I suspect might be good for study.
The tie rod ends, steering rack, chasis mounting point and bushings.

Discuss.... :?

RIalltrac · Sep 13, 2006

only because of the age of the car do I even mention this, but the front & rear motor mounts. Throttle response sucks in my car at this moment and time, now they arent completely shot, but after 16-17 years of abuse they are anything but perfect. I can just feel the engine lurching around in the engine bay. Its almost scary sometimes. Poly is obviously the only real option for street driven cars. And to all those people buying window weld or even the people like myself who have taken a serious attempt at the diy route, dont even bother, get the speed source mounts and call it a day. Thats all I really have in comparison to what you mentioned above. I've done the superpro's, koni struts, whiteline springs, poly'd rear diff mount (but to be honest with you I'd prefer to upgrade to mario's solid mount instead), rear sway, rear strut tower brace. I'd like to get a front brace and pillow mounts to sort of even everything out, that and obviously the poly mount inserts. Then theres things like end links and tie rod ends that get you thinking, but if you have new stock tie rod ends you should be fine IMO. I would like to upgrade the rear end links, but I cant seem to get a solid confident answer from anyone as to what is the "best" route.

I didnt really think of it, but a shorter steering rack is definately something to think about, its like 15 turns of the wheel from lock to lock (ok obviously i'm exaggerating a bit) my arms get tired just thinking about u-turns.

CMS-GT4 · Sep 13, 2006

I have had no luck locating the company that used to make short racks for st185s. One idea I had was to see if the gears from the st205 steering might convert over to the st185. Only other option is get a company to make a custom steering box.

Some talk has been about removing power steering, that it seems to improve feed back and control.

I beleive fensport offers a larger pulley for power steering, which might aide in this and still offer some power steering.

RIalltrac · Sep 13, 2006

you think that pulley would actually help with the steering response? To me it just seems like one of those things that would help when your at full lock and the pump is demanding more power than you care to give it. Interesting note on the 205 gears, but until someone gets brave enough (and rich enough to be wasting cash on a potentially hopeless project) I doubt we'll find out on that one. I would consider removing the power steering, but I remember my high school days doing deliveries in my boss' ford ranger with no power steering and that was anything but fun. My car is a DD, so a little luxury isnt neccessarily a bad thing.

CMS-GT4 · Sep 13, 2006

I thought the larger pulley on the PS would act like a dampner. The way I see it, the steering would be less assisted giving a more accurate control because you have more feel for the resistance against the conditions. I may be wrong, but that is how I was seeing it.

furpo · Sep 14, 2006

the spring rates being to soft coment completly depends on what type of driving you are doing. over here our roads are goat tracks and most of our motorsport events are conducted on them. i find the standard spring rates just fine.

roger

CMS-GT4 · Sep 14, 2006

Another issue, most have dealt with, is the stock tall sidewalls. By going with a larger wheel and shorter stiffer sidewall, you are helping with control and ability to feel the road.

db · Sep 14, 2006

^^ 215/40/17s without power steering. Trust me, I feel every variation in the road.

Anything over 20 miles per hour and I don't even notice the lack of power steering (after a few months of getting used to it). However, sharp turns at slower speeds requires two hands minimum. One handed turns at slow speeds tends to strain my wrists.

I think no power steering is great if we can maybe "lighten" the feel of it for slower speeds (when needed in autocross for example).

CMS-GT4 · Sep 15, 2006

furpo":yju815s4 said:
i would start by comparing the scrub raduis of each car.

i have never had anythng to do with the rx8, however i guess it has got some sort of veriable power steering set up where the st185 does not. our steering rack is quite powerful and the factory scrub raduis is quite small meaning the steering mechanism has a large mechanical advantage over the wheel. put a larger offset wheel on and you will notice a difference.

i am also geussing the rx8 has a double wishbone set up much like the latest lexus. these have a very long knigpin assembly which allows the arms to be a long way appart which is great for things like camber gain, and the amount of caster you can have. unfortunatly it took a long time for toyota to click onto what the poms where doing with their cars in the early 60's so our cars where outdated before they where even designed.

roger

Our cars have a fairly high pressure power steering. This is what couses the vauge feel. Without power steering the car does have a very nice feel when you are moving, but like others have said it sucks to park. It would be nice if someone could make a bypass that would lower the amount of pressure once the car gets moving. Alot of Hondas do this (the NSX actually shuts off about 40 mph or something like that) and I think it would be the best of both worlds. Or if someone could have a larger pully made that would also lower the amount of pressure being made which should increase steering feel.

Fensport makes such a pulley.

Alloy Power Steering Pulley, CNC machined, Light weight and oversized to reduce power loss.

I will be using a st205 PS pump. I know its different, but I am not sure if it reduces the problem. I will report back once the car is running.

I am curious if we could do something to help this with the shut off method. I would think the pulley is the simplest method.

Gary ST165 · Sep 15, 2006

* Suspension bushings. Mostly due to being worn out in our cars. Superpro replacements help things out quite a bit."

I was not happy with the feel of my car after replacing the rear no.1 & no.2 control arms bushes with an aftermarket poly equivalent . The poly replacements allow far too much (slop) movement and do not mimic the function of the original part. I would recommend replacing the if worn items with 4 x genuine toyota spherical bearings from a Supra MA70, part # 42210-14010.

ruffneck · Sep 16, 2006

I was not happy with the feel of my car after replacing the rear no.1 & no.2 control arms bushes with an aftermarket poly equivalent . The poly replacements allow far too much (slop) movement and do not mimic the function of the original part. I would recommend replacing the if worn items with 4 x genuine toyota spherical bearings from a Supra MA70, part # 42210-14010.

AWWWW DAMMIT!!! I had literally JUST ordered all the control arm bushes for the rear yesterday when I read this. A question though, why not just replace with the original bearings for the Celica, why do you need to use Supra ones?

furpo · Sep 18, 2006

CMS-GT4":1433gnyb said:
Fensport makes such a pulley.

Alloy Power Steering Pulley, CNC machined, Light weight and oversized to reduce power loss.

Click to expand...

I will be using a st205 PS pump. I know its different, but I am not sure if it reduces the problem. I will report back once the car is running.

I am curious if we could do something to help this with the shut off method. I would think the pulley is the simplest method.

i doubt it will, i am guessing the pressure is controlled by a pressure releif inside the pump. it is no like our the steering changes with rpm.

roger

Gary ST165 · Sep 19, 2006

ruffneck":16uz1vxu said:
AWWWW DAMMIT!!! I had literally JUST ordered all the control arm bushes for the rear yesterday when I read this. A question though, why not just replace with the original bearings for the Celica, why do you need to use Supra ones?

because Toyota do not list the bushes separately, as replacement parts for the Celica GT-Four.

Toyota would have us believe that you need to buy the entire hub + control arm set up!

ruffneck · Sep 19, 2006

TOYOTA!!! curse those bastards....well the spare parts division anyway :wink: yeah I read about this after I posted...could have even been on your UK site??? very informative it was too. It's ok, I didn't get those bushes now, just got the other control arm bushes instead. So basically, unless the spherical bearings have side-to-side movement then don't bother, save your money??

Denver_whiteST185 · Sep 19, 2006

Gary ST165":1c602blw said:
I was not happy with the feel of my car after replacing the rear no.1 & no.2 control arms bushes with an aftermarket poly equivalent . The poly replacements allow far too much (slop) movement and do not mimic the function of the original part. I would recommend replacing the if worn items with 4 x genuine toyota spherical bearings from a Supra MA70, part # 42210-14010.

Thats a cool find, im going to have to order my self a set.

Im not sure of how big of a differance they'll be, but i have a set of Mario koing's rear crossmember poly bushings on order, which should firm up the rear and let the frame flex less. i have a set of his rear diff mounts too and they should firm up the back.

Also, looking around on the cusco website, i noticed that they have both front and rear pillowball mounts, but 935 only offers the rear ones. i shot an email to one of the usa distributors listed on the site with a part number, so maybe we could get a set of those, which are ajustable too.

SBCelicaGT · Sep 19, 2006

Gary ST165":hkbrhian said:
* Suspension bushings. Mostly due to being worn out in our cars. Superpro replacements help things out quite a bit."

Click to expand...

I was not happy with the feel of my car after replacing the rear no.1 & no.2 control arms bushes with an aftermarket poly equivalent . The poly replacements allow far too much (slop) movement and do not mimic the function of the original part. I would recommend replacing the if worn items with 4 x genuine toyota spherical bearings from a Supra MA70, part # 42210-14010.

Good call, Gary. The polyurethane bushings in that location will cause the suspension to bind anyway. Does some company market those polyurethane bushings or did you find something that happened to fit?

CMS-GT4 · Sep 19, 2006

I believe that st185performance sells the oem bushing for that and recomends not to use the poly version.

He was also supposed to be making a caster bushing for us, I might need to send him an email to remind him.

TheAutoholic · Sep 19, 2006

. It would be nice if someone could make a bypass that would lower the amount of pressure once the car gets moving. Alot of Hondas do this (the NSX actually shuts off about 40 mph or something like that) and I think it would be the best of both worlds. Or if someone could have a larger pully made that would also lower the amount of pressure being made which should increase steering feel.

My RX7 does that,its pretty nice, but I am taking the PS all the way off since it its kinda dying.

FCs, FDs, 3rd and 4th gen Supras all have power steering that shuts off at certian speeds. It allows you to park easily, maneuver at low speeds easily, and have the benefit of manual steering at higher speeds.

CMS-GT4 · Sep 19, 2006

Anyone want to look into the controls of the the FD/FC or supra PS pump? Maybe we can retro fit it onto the factory alltrac pump. I would assume they are all made from the same company? At least teh supra/alltrac version.

Denver_whiteST185 · Sep 23, 2006

Gary ST165":35p8i5li said:
* Suspension bushings. Mostly due to being worn out in our cars. Superpro replacements help things out quite a bit."

Click to expand...

I was not happy with the feel of my car after replacing the rear no.1 & no.2 control arms bushes with an aftermarket poly equivalent . The poly replacements allow far too much (slop) movement and do not mimic the function of the original part. I would recommend replacing the if worn items with 4 x genuine toyota spherical bearings from a Supra MA70, part # 42210-14010.

which bushings do these replace?

Also, what kind of bushings are those red ones in the second pic?

Giving the alltrac better road feel

Active member

Active member

Active member

Active member

Active member

New member

Active member

Active member

Active member

New member

New member

New member

New member

New member

New member

New member

Active member

New member

Active member

New member