TCCoA Forums banner

1 - 20 of 22 Posts

·
Registered
Joined
·
2,655 Posts
Discussion Starter #1
I'm curious to know something about this. On an RWD car with a staggered set of wheels, say 225 tires up front and 275 tires in the rear, the car will oversteer. We also know that having mismatched sway bar sizes will cause either oversteer or understeer depending on which side is the larger bar. This is where my question comes into play.

Would it be possible to compensate for the oversteer in such a staggered setup in my example above by getting a 1-1/4" front sway bar and a 1-1/8" rear sway bar? I know the "go-to" answer is to get an equal sized set of bars front and back.
 

·
Super Moderator
1994 Cougar XR7 DOHC/5-Speed
Joined
·
17,476 Posts
Actually it's the opposite, narrower front tires and fatter rears induce UNDERsteer. Think about it, you'd have more grip on the drive wheels than the steered wheels. That's a very odd tire staggering, seldom used for handling unless it's an old school Porsche 911 Turbo (a naturally tailhappy design)

Having said that I disagree with the go to answer regardless because sway bars are not the proper answer for heavy handed handling changes because they A. make the suspensions behave more like solid axles the fatter they get and B. equal doesn't equal equal. Everyone simply ASSumes because these cars are biased for understeer stock it must be the sway bars fault.... not really taking into account the 58/42 weight bias, springs and shocks or soft durometer bushings, or the toe compensators - literally there in the words of an MN12 project engineer - to induce understeer!!!
 

·
Registered
Joined
·
1,916 Posts
As said above, the wider the tire, the more traction you get.

Sway bars are, in my opinion, the last thing to "upgrade". Start with something known to be good, such as good rear end bushings, good front end bushings, wider than stock tires, etc to get more traction. Replace all the 20 year old, worn out stuff so that you're starting with everything fresh, then see what needs tweaked.

The 225 series tires will give you better MPG, but be a limiting factor when cornering due to small contact patch. My question is, assuming you have 225 front, 275 rear, is that for better straight line acceleration, or for appearance?

I like having same size all around when possible, since tires aren't cheap, I like to rotate them (front to back for me as mine are directional) to get more life out of them, and you can't do that staggered. I run 255's all around, and with good suspension, she corners very well.

So, long story short, what are your goals?
 

·
Super Moderator
Joined
·
11,007 Posts
... or the toe compensators - literally there in the words of an MN12 project engineer - to induce understeer!!!
The Ford road cars found out in the 60's that track times go down if you add understeer under acceleration.

I saw a show on Velocity channel about modding an old GT40 with a factory IRS setup they found, and they were terribly disappointed at finding this out.

But the track data they took opposed their opinion; I don't think it changed their opinion tho. :)

I Like the rear wheels not toeing out under drive power, but maybe that's just me. :zdunno:

Bad bushings would wobble like crazy with no compensators; even blown, they only have ~1/8" play.


Who was it here that left them out of their mark arm swap?

I'd wonder how it drives?

It should have way more oversteer under throttle. :)
 

·
Super Moderator
1994 Cougar XR7 DOHC/5-Speed
Joined
·
17,476 Posts
The compensators were a substitute for stiffer bushings. I would never recommend ditching the compensators if you're running the stock bushings, but if you use polys you can leave them out, and Jay's Delrins have filler material in place of the compensators so you couldn't use them even if you wanted to.

Joe Cesarz, Ford's specialty-car suspension guru for midsize cars, detailed the philosophy behind the car's neutral handling. "When I tune a car's suspension, I don't want any funnies," he explained with a smile. "Sure we could have tuned a bit more oversteer character into the car's handling, and I could take about two seconds off my times on the handling course. But that'd be the type of suspension that would get most drivers in trouble. Instead, we installed our special toe link."

This extra bit of hardware between the lower H-arm and the subframe and a soft bushing in the H-arm's front pivot point help steer the rear wheels in the same direction as the front wheels during braking or acceleration. This helps eliminate the rear suspension's natural propensity to toe out-which would cause the back of the car to swing out.

"Actually, you'll find that type of oversteer behavior that enthusiast drivers like in early IRS vehicles," said Cesarz. "But, really, that kind of handling was essentially a flaw in older IRS-equipped sedans. And I think if you have a chance to drive the latest BMWs, you'll find that they're much more neutral in their handling behavior."

But what if a Thunderbird customer wanted a s a more of that oversteer handling "flaw"?

"Well, right now we've got a slight bit of initial toe-in at the rear to control that, " explained Cesarz. "But the owner could always try changing the curb toe settings to either 0 degrees or even toe-out. That's if he wanted the car to oversteer-and was willing to accept more tire wear."

GT40 was a mid-engined car so it was prone to oversteer naturally, weight biases are literally double edged swords in car dynamics, so taming excess oversteer on that to make it competitive is to another team taming excess understeer on a front engine car to make theirs competitive.
 

·
Registered
Joined
·
2,655 Posts
Discussion Starter #6
Actually it's the opposite, narrower front tires and fatter rears induce UNDERsteer. Think about it, you'd have more grip on the drive wheels than the steered wheels. That's a very odd tire staggering, seldom used for handling unless it's an old school Porsche 911 Turbo (a naturally tailhappy design)

Having said that I disagree with the go to answer regardless because sway bars are not the proper answer for heavy handed handling changes because they A. make the suspensions behave more like solid axles the fatter they get and B. equal doesn't equal equal. Everyone simply ASSumes because these cars are biased for understeer stock it must be the sway bars fault.... not really taking into account the 58/42 weight bias, springs and shocks or soft durometer bushings, or the toe compensators - literally there in the words of an MN12 project engineer - to induce understeer!!!
Apologies for my misunderstanding on oversteer / understeer and the narrow-wider tire combo! My curiousity stemmed when I read a post (I forget if it was here on TCCoA or on the TCCoA FB page) about ADDCO having production issues becuase of having moved and only able to supply 1-3/8" FSB at the moment. My thinking was to go with such a setup if at the time that I would have been ready to get the wheel and F/R sway bars they would still have production issues.

I have been planning on F/R 1-1/4" combo for the ADDCO bars.

As said above, the wider the tire, the more traction you get.

Sway bars are, in my opinion, the last thing to "upgrade". Start with something known to be good, such as good rear end bushings, good front end bushings, wider than stock tires, etc to get more traction. Replace all the 20 year old, worn out stuff so that you're starting with everything fresh, then see what needs tweaked.

The 225 series tires will give you better MPG, but be a limiting factor when cornering due to small contact patch. My question is, assuming you have 225 front, 275 rear, is that for better straight line acceleration, or for appearance?

I like having same size all around when possible, since tires aren't cheap, I like to rotate them (front to back for me as mine are directional) to get more life out of them, and you can't do that staggered. I run 255's all around, and with good suspension, she corners very well.

So, long story short, what are your goals?
I very much agree with replacing all the old worn stuff first, but as you know my bird is down and out for two reasons, one of them being all the suspension. I am in the process of buying everything (hopefully that will speed up quickly here in the next month or two), and I mean EVERYTHING, and then moving to do an MT swap immediately after as her failed transmission is the other reason why she's down.

I frankly won't care much about her MPGs as she won't be my DD, that's what my Honda with 302k miles is for. Frankly, the 225 / 275 combo is more for appearance than anything, but on track days, I'm hoping to stuff the biggest wheel and tire combo possible on all four corners without having to roll any fenders.

Long story short, I want my bird to be both a showroom car and be awesome in the canyons, mountains, and Auto-X track. :D

Who was it here that left them out of their mark arm swap?

I'd wonder how it drives?

It should have way more oversteer under throttle. :)
I think you're thinking of @jco1385. I'm following his lead in his suspension thread and getting Poly everything where possible.
 

·
Super Moderator
Joined
·
11,007 Posts
...

I think you're thinking of @jco1385. I'm following his lead in his suspension thread and getting Poly everything where possible.
The handling is certainly different with the all poly setup. :)

I changed from a setup with konis and front sport springs only, to konis, poly rear everything, DLF's irs bushings, and sport springs all around.

:facepalm:

The sport springs are too stiff (and tall) for the rear; with all the poly, it's almost solid, lol.

It handles very well, but does not feel like it has the finesse in handling that it had.

I'm actually building another set of arms with stock bushings to try, and see if I like it better.
 

·
Super Moderator
1994 Cougar XR7 DOHC/5-Speed
Joined
·
17,476 Posts
Why are you constraining yourself to a 225" front tire? 245 or 255 will fit without any issues whatsoever, most of us with aftermarket wheels are running that size, you won't have handling issues and it will look better.

IMO stock front/bigger rear(89 SC or ADDCO 1.125" or 1.25") > ADDCO 1-3/8". I'm not harping on the replace the old worn out stuff (duh), but the sway bars are not the components that are going to make the difference between grandma's church cruiser and canyon carver.
 

·
Super Moderator
Joined
·
12,532 Posts
I run a 1-1/4" ADDCO bar in the back with a stock front bar and a 285 Rear / 245 Front stagger. This set up works great. The 1-3/8 ADDCO Bar is overkill.

A 275 Rear / 245 Front stagger would also work well. You could also run a 255 all around set up like Woodman. Personally, I wouldn't put 225's in front.

Like Matt said, the sway bars are not the components that are going to make the difference between grandma's church cruiser and canyon carver. You'll get better canyon carving performance out of upgrading the bushings, springs, shocks and tires over upgrading the anti-sway bars.
 

·
Registered
Joined
·
2,655 Posts
Discussion Starter #10
Thanks for the input guys! I was planning on having a 255 setup on all 4 corners, but I've landed a part time gig that has potential to make funding Project Pearl move along much more quickly, and also potentially allow for two sets of wheels; weekend cruise and track / canyon. Thus my asking of various configurations that would work. I have always been planning on going with the 1-1/4" ADDCO bars, but like I said before, with limited availability I was considering different options depending on tire size setup.

I may end up ordering the ADDCO bars and if they're not immediately available when I do buy them, I may also just buy a set of poly sway bar bushings to replace the worn OEM stuff as a temporary place holder until the ADDCO bars come in. Adding to that, if one side of the sway bars come in first before the other, I won't install it without the other. I'll install both sides at the same time.
 

·
Registered
Joined
·
1,916 Posts
I agree with the above... Ditch the 225's.

My setup is as follows, most work done by Traveler before he sold me the car.

Mark VIII rear lower control arms, Mark VIII pumpkin with 3.73TL, 93 Mark VIII driveshaft. Eibach springs, 1.5" drop. Poly IRS bushings, I installed Energy Suspension knuckle bushings as mine were worn out.
I have 89 SC front and rear sway bars. Shock connectors front and rear, and I added 18x9 35mm offset wheels with 255/40/18 tires. The 255 is a great width, no rubbing issues (as long as you don't route your oil filter lines too close to the tire, DOH!) and again, I like them balanced all around as I don't need to tune out any additional understeer with more sway. You don't "need" as much sway in the rear as you do the front due to the weight balance, so a lesser diameter bar in the rear is fine. I LOVE going around corners, and this car corners better than my previous 97 (which was all stock), my 99 Mustang GT (which was VERY twitchy). I'm stable, comfortable, not too much stiffness, just right. I can feel the road under my butt, and I corner flat unless I'm pushing VERY hard. I haven't gotten it to wag it's tail unless it's wet or I'm too gas happy when turning while going from 1st to 2nd, and that was on the bald tires I got it with. On my new tires, she sticks and holds the road like glue. Very stable, very confident.

As much as I appreciate the exhibition of control when drifting, it doesn't interest me. I prefer to just go around the corners very quickly, with minimal fuss. I will admit, it's fun passing Mustangs and Corvettes on the inside at 20 or so above the posted limit in a corner like you're not trying. :) Precision is my goal, and my car is VERY precise (from my limited point of view).
 
  • Like
Reactions: CDsDontBurn

·
Registered
Joined
·
2,655 Posts
Discussion Starter #12
Woodman, your setup is more or less what I'm going for. For detailed info on what I'm going for, check out my more recent posts in my suspension build (link in sig).

When I had my RX-8, it got me into driving the corners because, the RX-8 by nature is not a fast car. It's a nimble car. I pursued that a little bit in my Accord when I first got it, but it being FWD is not the same. I know my Bird will probably not be as nimble as my RX-8 was, but I'm hoping to get the same amount of thrill out of my Bird as I did in my RX-8. I do know though, that with the right setup, that thrill I had in my RX-8 will come back.

As for taking corners and such, for a point of reference, "There is this one turn in Mexico" I that had the posted speed limit at 55. My RX-8 was able to handle it at 110 without even flinching. I'm curious to know my bird will be able to do the same...or close to it, at least.
 

·
Super Moderator
1994 Cougar XR7 DOHC/5-Speed
Joined
·
17,476 Posts
Thanks for the input guys! I was planning on having a 255 setup on all 4 corners, but I've landed a part time gig that has potential to make funding Project Pearl move along much more quickly, and also potentially allow for two sets of wheels; weekend cruise and track / canyon. Thus my asking of various configurations that would work. I have always been planning on going with the 1-1/4" ADDCO bars, but like I said before, with limited availability I was considering different options depending on tire size setup.

I may end up ordering the ADDCO bars and if they're not immediately available when I do buy them, I may also just buy a set of poly sway bar bushings to replace the worn OEM stuff as a temporary place holder until the ADDCO bars come in. Adding to that, if one side of the sway bars come in first before the other, I won't install it without the other. I'll install both sides at the same time.
I guess I don't understand the point of multiple wheel configurations unless one set will be shod R compound tires, which really aren't meant for streets, including canyons. You can run a square or squarish setup either way so I don't know if your intentions are to save or splurge by using 225s?

To your second point, why? You can install the rear bar in about 10 minutes and you don't need an alignment. The front is a pain so it doesn't hurt to get the easy end out of the way, and you'll probably like the result in the interim.
 

·
Registered
Joined
·
2,655 Posts
Discussion Starter #14
I guess I don't understand the point of multiple wheel configurations unless one set will be shod R compound tires, which really aren't meant for streets, including canyons. You can run a square or squarish setup either way so I don't know if your intentions are to save or splurge by using 225s?

To your second point, why? You can install the rear bar in about 10 minutes and you don't need an alignment. The front is a pain so it doesn't hurt to get the easy end out of the way, and you'll probably like the result in the interim.
One set will be sticky summer tires, 300 treadwear rating or less. The track tires will be slicks, lol.

As to why install at the same time, I'm basically following the recommendation I've read over and over again here on TCCoA and install the sway bars at the same time.
 

·
Super Moderator
1994 Cougar XR7 DOHC/5-Speed
Joined
·
17,476 Posts
TCCoA or TCCoA Facebook? Because one is filled with morons :D


Seriously, I have never once heard that suggested. You do endlinks in pairs, you do ball joints in pairs, you do tires in pairs, you do bulbs in pairs, etc, because those are all wear items, and when one wears out on one side the other isn't going to be far behind. That's not the case with stabilizer bars, do whichever is most convenient, you won't be staggering their lifecycle.
 

·
Registered
Joined
·
2,655 Posts
Discussion Starter #16
I've read it on both, actually. Fairly recently at that. So does that mean both are filled with morons? :confused: :confused:

:D

And the reason for installing at the same time has always been consistent, and it's not due to it (the stabilizer bar) being a wear item, but rather because of the significant oversteer / understeer that would come from installing only one bar at a time.....which is why I began my OP. :)
 

·
Super Moderator
Joined
·
12,532 Posts
IMHO The stock front bar is good enough. I honestly am happy with it in the front and a 1-1/4" ADDCO bar in the back on my own car. I highly doubt you'll notice that much difference between stock and a bigger bar in the front. Save your money. Again, like Matt said, "The front is a pain so it doesn't hurt to get the easy end out of the way, and you'll probably like the result in the interim."

Just try it for a while and then decide if you want to replace the front one as well.
 
  • Like
Reactions: CDsDontBurn

·
Super Moderator
Joined
·
11,007 Posts
TCCoA or TCCoA Facebook? Because one is filled with morons :D


Seriously, I have never once heard that suggested. You do endlinks in pairs, you do ball joints in pairs, you do tires in pairs, you do bulbs in pairs, etc, because those are all wear items, and when one wears out on one side the other isn't going to be far behind. That's not the case with stabilizer bars, do whichever is most convenient, you won't be staggering their lifecycle.
The rear swaybar doesn't Look that hard to swap; the front one is not easy to remove, from what I've read here.

Here's the article:

ADDCO MN12 front anti sway bar install procedure

Only one? :)

I know I saw a pic here somewhere of someone who cut the end of the front bar off to get it out; IDK how that helped the reinstall, but wtf, right?

I was thinking it was Shadowdragon that posted it, but I can't find the post. I'm probably just hallucinating from the flu. :)
 
  • Like
Reactions: CDsDontBurn

·
Super Moderator
1994 Cougar XR7 DOHC/5-Speed
Joined
·
17,476 Posts
I've read it on both, actually. Fairly recently at that. So does that mean both are filled with morons? :confused: :confused:

:D

And the reason for installing at the same time has always been consistent, and it's not due to it (the stabilizer bar) being a wear item, but rather because of the significant oversteer / understeer that would come from installing only one bar at a time.....which is why I began my OP. :)
One's only about half full :D

It's not significant, like I've been saying the sway bars aren't the components that will have a meaningful effect on the car's oversteer or understeer characteristics in a night and day sort of way, they are fine tuning components. Even if you put the huge 1-3/8" bar on the back only it wouldn't make your car behave like a Porsche 911, it would pretty much corner the same as is with an extra hint of dartiness, but mostly you'd just notice the ride is harsher over bumps(like a solid axle).
 

·
Registered
Joined
·
3,779 Posts
I think you're thinking of @jco1385. I'm following his lead in his suspension thread and getting Poly everything where possible.
Without going back thru this thread..... I'll respond to the post I was tagged in...

I left the toe comps out of my Bird when I went poly on my steel arms. I then swapped that setup over to my Cougar and have not had any issues as far as I know, and nothing was bent/smooshed/broken when removed. My Bird now has Lincoln arms with poly and I kept the toe comps only because I had a like-new pair on hand to install.
 
  • Like
Reactions: CDsDontBurn
1 - 20 of 22 Posts
Top