autopaul

i need some plans to make myself a panhard bar for my fb, before i put in my new gsl se rearend,

does anyone have plans or at least the measurements of the panhard and tri link bars themselves.

does anyone know if a panhard will clear with coilovers?. im making a custom coilver setup using aftermarket fc suspension,


i posted something simular in the fb section but it didnt get the attention i had hoped for, so im posting, here, hope theres no hard feelings, but its a different post all together, so i think im ok

rotarygod

iTrader: (1)

http://www.gforceengineering.net/products.htm

It is my personal opinion that this is the nicest setup for the 1st gen. I bought his setup manual. Lots of very good infor on what is wrong with the stock suspension and how to fix it.

christaylor

How do you plan to put coilovers on the rear? The only setup I've seen that could be called a "coilover" was just an adjustable perch.

The G-Force panhard doesn't interfere with the stock suspension at all - the panhard welds to the frame rails in front of the gas tank and a small piece is welded to the side of the shock bracket with a support that goes over to the axle tube. The 3-link has two tabs that are welded on top of the pumpkin, and a "widget" that bolts in above the driveshaft where 3 panels weld together. If you're looking inside the car, it bolts on either side of the interior frame cross member.

With that said, you're better off buying Jim's setup. It's engineered to work, is proven to work, and is easy to install with a little fabrication and installation knowledge. After doing several of them I can do it in a matter of hours (depending on how much stuff has to be removed from the car...). This advice is coming from somebody that actually races first gens and has seen various other "panhard" setups. You can go horribly, horribly wrong for about the same investment as the G-Force unit. Not to mention the fact that you can call or email Jim and get access to a wealth (and ever growing) of first gen suspension and setup knowledge.

NasaPro7

agreed.
Mike @ ISC is knowledgeable as well, even though the two favor a slightly different setup.
disclaimer: My car has 98% complete ISC suspension, and Susko's setup manual is in the mail to me.

Marcus

autopaul

ok how much does it cost, cause i can definately just as easily built it myself, but all i need is measurements, im a poor student at the moment, and obviousely my budget goes about as far as materials,,

i have an entire energy suspension bushing set for the rear end of the car, so i wanted to use those for the lower links, and for the 3rd link use them, and maybe just weld the 2 top pieces together, with a gusset, and then i can use all aftermarket bushings, for a somewhat more streetable ride.

for the fc suspension, i plan on using fc tokico illuminas, and i have coilover perches, that im using, the upper mount will be modified to take the extra stress, and probably have a link to my roll cage in some way,,, im not just doing this for fun, im using a fc front crosmemeber already which uses fc suspension, so that way i can order a complete set instead of pieceing things together...

my plan so far as far as not having any for the 3rd link and panhard are to put the se rearend in, (well i already have,just tonight) and bottom the diff up into the car as high as it will go, with a jack, and all links connected, and then make my 3rd link so that at the highest clearance it will clear everything... then i will make the actual link the same length from joint to joint as the lower links, (just makes sense)

the panhard will be trickyer and i will need to measure and design the link at my desired ride hight so i will get the least latteral movement,....

all this would be super easy though if someone has plans that theyve used to make thier own or just measured some they had kicking around, or at least gave me a few details, aka how many differnt adjustment holes should i make up and down on the panhard, and other such details.

welll im out for the night

thanks for the input its helpful so far... good pics on that site thanks rotarygod

Paul

RotaryAXer

iTrader: (4)

Paul,

I think you need to spend some time with a good suspension design book before you go down your intended path. There is a lot more to locating the axle than just making it fit. The 3rd link will effect a lot of things that you can't just assume will work out.

Anti-squat/dive, the pinion angle of the diff and the u-joint allignment on the drive shaft are what pop into my head. I'm sure there are others.

These things aren't worth guessing about.

What are you studying in school? If engineering you may want to think about this as a 4-bar linkage. You may even be able to use this as a project or something.

The $600 to buy the parts from G-Force Engineerng is worth it. But if you insist on making your own, please make sure you have good understanding of what it will do the driving characteristics of your car.

autopaul

i dont think it will be much different at all if i locate the mounting points the same places as popular expensive "name" brands, and make the linkage the same length as the lower 2, its not rocket science, wouldnt pretty much anything be better than the 2 puny upper links that mazda uses stock, if i think of it as a four link i still see most aftermarket four link designs being the same length links upper and lower, its not as if we have a wide range of locations to mount this thing iether, even the expensive units can only use locations that the body allows for because nobody is going to buy a unit that they have to chop a slot in the hole for to work...

correct me if im wrong, but wouldnt locating the axle in its stock location, via stiff energy suspension bushings, then maxing out the suspension travel to the top then locating the premade "equil length" 3rd link to a mounting point in the driveshaft/tranny tunnel be sufficient for a daily driver? same sort of drill for the panhard, (*the idea with the panhard 1.basically mount it however you can so it wont get in the way. 2 while making it as long as you can to reduce horizontal movement while the suspension travels up and down,

no im not taking engineering, im doing an millwright pre apprenticeshp program, yes i gues i could use it as a project still, though i would have to do most of the work myself at home anyways,,,

i know how links can effect the way a car will handle and effect the entire allignment in the rear allong with numerous other rear end motions, which is why i asked if anyone had measurements, which would make it super easy to make my own, but still use eurothane bushings instead of expensive rod ends. to make the ride not so rough,

im not going to be in any racing circuits where every little aspect of the cars suspension must be looked at together to get the best lap times or anything, i just want my car to handle to its full potential on the street, while keeping cost low, and my learning experience high.. yes i know that if it isnt all alligned and designed properly it can cause problems and perhaps even a worse handling car than before, but i want to give it my best shot, and still not have to use expensive suspension software (the reason im not currently building an independant rear suspension system for my car)
dont get me wrong i truly apreciate your input and i rethought the situation came to a simular conclusion as before i still refuse to buy the units that i can just as easily build myself the way i want them ( with energy suspension bushings,) and hopefully learn something at the same time,,

thanks for the helpful information so far guys, and thanks RotaryAxer,

autopaul

oh ya i forgot to ask, could someone please confirm that a tri link is the same length as the lower link, that would be a big help....

thanks again

Paul

RotaryAXer

iTrader: (4)

Paul

I guess that is the point I was trying to make....your assumption that they are the same length is not correct. It may just happen that they are a very similar length but it isn't because that is the way it should be or needs to be. In fact if they are the same length it is purely a coincidence and just one tiny part of the design as a whole.

Actually, I don't know if that would be the best/easiest/cheapest way to do it. Using stiff bushings in the lower links is actually still not a good idea. For the suspension to work, all of the joints need to be able to pivot as a ball joint.

If you know the reason for going to a tri-link then you know that restricting the axle movement is the exact reason the stock setup is sub-par. If you use stiff polyurethane bushings in any part of the setup you will be doing just that. A bushing, especially a stiff one, only allows motion in one axis.

When I mentioned a four bar linkage I wasn't refering to the stock setup. I was talking about a pretty typical engineering problem that you see in a lot of applications and a favorite in the academic world. A windshield wiper mechanism is a very common real world example.

In the side view the location of the suspension could be viewed as a four bar linkage. There are a lot of resources that could help you determine the ideal lengths and pivot locations to maintain proper axle allignment through the vertical travel of the axle.

On to the next part of your comment I quoted above....is there really any need to improve on the stock setup for a daily driver? If you have gotten to a point where you have run into the snap oversteer/bind associated with the 4 link/watts link factory rear end on the street then you may want to look at other easier methods to help it. The first thing I can think of is to increase the roll stiffness...higher spring rate or a stiffer anti-roll bar. Of course if you increase the roll stiffness on the rear you will need to do the same in the front.

Honestly this may be a fun, educational and very worthwhile project. I just don't know if you are approaching it the right way.

If you are just looking to duplicate someone elses hard work for no money, while making compromises in the design, then the effectiveness of the parts will be only as good as the amount of research and thoroughness you put into them.

christaylor

I didn't realize this was for a street car....

Don't waste your time. Honestly, on the street you won't be able to tell a difference. Get some new bars or put new bushings in them, read Karl's wattslink tip in the first gen section, and be done with it. Spending the money and time for something that's purely a street car is a grose waste of both. If you were going to auto-x/track day the thing I wouldn't say that, but the only place you can tell the difference is near the edge which you won't be anywhere near on the street. And if you are, hopefully you'll get arrested before you kill somebody.

DriveFast7

iTrader: (1)

Agreed.

I didn't install a panhard and trilink in my 7 until I did 2 years of track days and a rollcage.

autopaul

i forgot to mention that the car will be seeing the occasional track/drift day.sorry, i guess that wouldave been a good piece of information to have...

i already have a roll cage,, 6pt chromoly to be exact.. its going to be a very multipurpose car, for occasional drag, and autox/drift events, aswell as being a daily driver for the summer,,, ill post the specs on the car so you know where im coming from,,

-6 pt chromoly cage, proffessionally welded (track legal to 10 second 1/4 mle)
-fc gx front subframe, and brakes, (alllong with a pretty stiff fc sway bar, which should take care of how stiff i want the front)
- gutted interior, no sound deadening, partial dachboard,
- custom fi turbo 12a (being completed)
- will be installing tokico illuminas (fc) before the car sees the road again, which will have adjustable coilover perches installed,

im here seeking advise and dont want to seem like some noob whos rushing in and trying to steal measurements of someone elses hard work put into a design,,, i hardly think 1 measurement which coincidentally is the same as the mazda lower link is ripping off the design,,, i really want to figure this all out so i will be able to predict, the way the car will handle,,

i realize that yes the reason the stock system is "bad" is that in corners the bushings want to streatch,/ compress depending on corner, (especially the upper links) , and that the same thing will happen to a lesser extent if i use, stiff bushings on the lower links while using tri-link,,, i didnt think it would be severe enough to cause a problem where my suspension would be unpredictable though,,, depending on your adviese, and obviousley greater knowledge than my own of these things i may even put 1 rod end per link to give the suspension a roll "pivot" if you know what i mean, so it doesnt put stress on the links and bushings,,,, (just an idea. i really want to be able to put some sort of cushion between the body and the diff for obvious daily driving reasons,) and to cut down cost...

im already learning tons about this rearend, and i obviousely need to learn more,
what book/books do you think would be good for me to get, (from my local chapters bookstore if possible)

thanks again guys, this is really helping me,...

autopaul

thanks for that,, i really dont plan on driving like an idiot on the street.... or killing anyone by doing so.. truly unnecisary for this thread in my opinion,

thanks

Paul

RotaryAXer

iTrader: (4)

Actually, I think you have been mislead. The problem is not that the bushings are too soft...it is that the system as a whole does not let the axle articulate as much as it should. In fact the softer the bushings the better (to a point of course).

The geometry of the upper links in combination with the stock watts link causes the axle to bind in roll. Basically if you imagine standing behind the car and grabbing the axle at the center and twisting it you would only be able to twist it so far before it binds and will not twist any further. You will start to lift the outer side of the car before you articulate the axle as far as "should" be able to. If you put even stiffer bushings into the system this gets even worse due to the fact that the bushings are restricted to only allowing a pivot along a single axis.

I will assume that you have been doing a lot of searching for old posts and trying to fnd the information you are looking for. I will also assume that you just mis-interpreted some of those old posts and the description of the problem. I hope that my explanation helps you understand the actual reason a tri-link is theoretical improvement over the stock setup.

I think you probably do understand the problem, I just want to make sure before you go any further.

If you use stiff bushings anywhere in the assembly instead of ball joints you will not improve at all. In fact ideally you would have ball joints in the lowers as well. If the ruleset for the typical autocross or road racing classes allowed the lowers to be replaced with ball joints that would more than likely be "the" setup. Though old rubber bushings allow enough motion that it isn't a terrible compromise.

RotaryAXer

iTrader: (4)

Well, the most basic and straightforward book would be the G-Force Engineering setup manual.

It deals with the specific car and problem at hand.

DriveFast7

iTrader: (1)

How to Make Your Car Handle by Fred Phun. Easy to read. Theory and application. Great illustrations and pictures.

And the best tri-link goes thru the floor and mounts to a fabbed bracket tied into the factory cross memeber behind the seats. So it is straight and long as possible. The bent tri-links have snapped at the bend under hard braking. Gusseting along the bend would help.

With a heim joint at either end so you can adjust length and therefore pinion angle, and the heims allow it to rotate as much as needed. I have one on my 7 and will try to get some pics. I think I have an old measurement somewhere. The trilink is shorter than the lower links but not by much.

The Southwest Touring Cars use an even short trilink comparatively.

Set the trilink to 6 degrees downward. Setting the pinion has been a challenge of trial and error but ballpark the pinion wants to be angled upwards at same angle tranny is angled downward. (4-6*). Car shakes and shimmies when pinion angle is wrong.

Spherical bearings in the lower links instead of rubber reduced oversteer too and helped the rear articulate better. If you're going tri link, gotta go all the way to see the most benefits.

If you were to ever race it in SCCA road racing, the tri link thru the floor bumps you all the way up to GT-3. Turbo 12a makes that ITE.

autopaul

great advise thanks Drivefast7, pics and the measurement would be great if you had them handy!!

i dont know if those angles are going to work for my application,,, are you running an fc front subframe?

because im using a 12a engine on a fc subframe i have to make a custom engine mount anyways, so i thought as long as im making a custom engine mount i mayaswell have it sit lower in the bay to reduce the roll center, (made sense to me) i may also locate it furthur back when i have to make a custom driveshaft for the t2 tranny,,, just ideas for now,,,

youll be happy to hear ive been doing plenty of research and am commited to the project now i just purchased a piece of tubing to make the link, (although it will be one that bends under the car, as opposed to being a long unit with a hole cut in the floor,,,) the pipe has a greater wall thickness because it will be replacing two links, also gusseting will be used on the bend,,

i am convinced! i could not ignore RotaryAxers' explination of how the lower links compress in corners, i knew about the top ones, i just said it wrong... but i guess i neglected the bottom! i will be ordering at least enough rod ends("spherical bearings) for at least 1 per link although i was sceptical , i think one will be suitable for my application -

1 because it will have enough adjustment for my needs,
2 it will have plenty more pivot than even stock rubber bushings,
3 it will be primarally a street car so i will have some "cushioning" between me and the road, yes it is comprimising the design but it will meet and exceed my needs im sure..

as for the panhard bar, can someone explain whether i will need to use rod ends in that design or will i be ok using eurothane bushings? i dont see the unit twisting too much as long as its made properly, or would it be wise to use 1 rod end there aswell, i mightaswell seeing as i will want side to side adjustment if its not the perfect size when i make it, that way i have some leeway.

this is the site ive used as a referance of the panhard bar, 1 thing i noticed is that it pivots opposite from the gforceengineering model as far as the pictures go,, im sure this is for clearance of the stock gastank,

thanks for all the help guys im sure its gonna be an awsome project. especially now that i know im not just making junk

-Paul

jgrewe

iTrader: (1)

If Jim is still making the panhard the way we first did one with the chassis mount on the pass. side and the rear end housing mount on the drivers side it was because of some concerns with exhaust clearance(going under the rear end on a race car). Also if you have ever had one of these cars on a set of scales you know they are light in the rear/pass side. We put the mount on that side for the extra weight in that corner. Back when this setup was first being developed we couldn't do any kind of ballasting in IT cars, but you could use really heavy guage steel to make a panhard mount!

DriveFast7

iTrader: (1)

Paul, I put some pictures of my tri-link here:

http://community.webshots.com/album/523034952OAJKjP

If you click on each picture I put a short description in each caption. Another design to look at. Feel free 2 ask me questions. By all means build it as strong as possible.

The threaded link itself is 15" long. Not including heim joints. There's the length! And buy the good sturdy heims, not the low budget ones. Like $60 each. If they break then the rear will rotate up, down, however it wants too.

Heath

iTrader: (11)

So you fabbed that yourself? looks great. You should throw together a kit and sell a few to people like myself

Just weld in and roll.

autopaul

heyy thats great, how does it handle i didnt know that you were running a unit through the floor, i thought thats just what the books said would be the best haha,

that looks like and awsome setup drivefast7, i guess theres a reason nobody makes a kit like that, is cause how many people want to cut a hole in thier floor,, im reconsidering,and yes i will be getting the good quality ones, thats why im trying to use only 1 per link., im kindof on the edge about this now, how hard was it to determine the best location for it? as far as the adjustable sliders go,, whats the road noise like? ever driven it in the rain?

i may still just do the type that where it wraps under the tranny tunnel and save some hassle,

ya that makes sense about wieght distribution, jgrewe thanks... figures there was a better reason than my own..


Paul

wlfpkrcn

Do you have pics of or a link to the sub frame swap. Sounds interesting. My current project might accept a mod like this nicely.

DriveFast7

iTrader: (1)

Thanks guys.

Handels a lot better. Stiffened up the rear springs 125 to 150lbs because the tri-link reduced oversteer. Mazdatrix sold a thru the floor kit and heimed lower links but discontinued it years ago. We measured many times then cut the hole. After that it was just a matter of mounting it parallel with frame rails. Adjustable height just came naturally. We modified brackets used for stock cars, Southwest Touring type. Use slotted, not drilled for more adjustability like I did. Cost $390 parts and labor.

Road noise? YES. Not for street stuff really. Heims clackety-clack. Firm too, no compliance fore to aft but rotate left to right freely. I have driven it in the rain, no snap oversteer made it easier. GOOD SETUP.

I redid the rubber sheet over the hole. Put one sheet under and another sheet over the hole, dual layer. Banged the aluminum plate straight too. Less crud and exhaust gets in, a little less noise. You can always cover the link with a sheet aluminum box.

j9fd3s

iTrader: (3)

i was thinking you need something that looks like an ebrake boot

aussiesmg

iTrader: (1)

Just box it in after its installed with aluminum like Drivefast7 stated. Keep the moving parts outside the cabin that way.

Note: nice welds there guy. Can you show a clearer shot of the 3rd member mount, I may be using your design if you dont mind.