How much for the TRi-LInk?
 

Kentetsu,

How much are you asking for the tri-link/panhard setup?

Brendin

How much are you asking for the tri0link/panhard setup?

If I were to sell it, it would have to go locally. The mounts are already set up on my spare 3rd member, which would have to go with the trilink. Just not willing to try to ship something of that size/weight.

But really, I have not decided that I will sell it. I still might install it simply out of curiosity, or if I reach the point that I need to shave off one more tenth of a second and just can't get it any other way. lol.

Sorry if what I said gave the wrong impression. I wasn't actually being all that serious.

Agreed. And I can get on the gas earlier exiting a corner with a panhard in lieu of stocker Watts. Some people love the stock Watts, and change their driving style to work around it's flaws. Even in E Prod. But we still can't deny MAZDA missed the boat with it's design.

And, I have a 3rd link that goes thru the floor (straight link) and it really made the car more predictable. And higher cornering speeds.

http://inlinethumb02.webshots.com/14...600x600Q85.jpg

http://inlinethumb09.webshots.com/16...600x600Q85.jpg

http://inlinethumb45.webshots.com/12...600x600Q85.jpg

http://inlinethumb24.webshots.com/45...600x600Q85.jpg

So how adverse are these effects on cars that aren't lowered? How much more balanced and less prone to snap-oversteer is a car at stock height with stock springs? I suppose there's less preload and axle twist, but at the same time there's more body roll.

With the R-comps, you can push the car harder and it ends up leaning further. That little extra movement might be just enough to hit a binding point.

I run lighter springs and heavier swaybars. Gives a better ride on the streets, higher overall traction (too high a spring rate = skipping across pond effect), swaybars and ride height cancel out body roll. Seems pretty stable set up that way. No surprises, unless you work really hard to create them.

(sorry, I was answering an older post apparently. weird.)

DriveFast7 - like the 3 link setup. That is what I had in my C Prepared Mustang and it worked really well. It is also what I will be putting in my RX7 as a part of the STU build

What class do you run in? Do you have a cover to goes over the link.....as I recall in Solo I was required to cover all suspension that entered the interior with a metal cover/bulk head

I pulled the fuel cell out of my car to work on the rear suspension. Here are some pictures of the current panhard bar I have in my car. You can see the Tri Link mount in some of the shots.

I did the fab work on the rear axle housing and made the rod. The rod ends are 3 piece 1/2" stainless. The mount on the chassis has been there for around 10-12 yrs. It looks like crap but has never cracked or failed.

I'll be replacing the chassis mount along with the rear axle housing as a part of my STU build up. The new setup will use a big bearing axle, longer panhard bar, relocated lower control arms and a third link that goes into the car.

http://inlinethumb47.webshots.com/31...500x500Q85.jpg

http://inlinethumb02.webshots.com/32...500x500Q85.jpg

http://inlinethumb54.webshots.com/13...500x500Q85.jpg

Here are some shots of the 4 Traction Bar setup on my friends E Production car. This setup has proven superior to the G-Force Tri-Link system as it allows the driver to apply power earlier in corner exit. The car also has a panhard bar that is extremely long. This car was built by KC Raceware......the KC Raceware rear aluminum hat/rotor setup can be seen.

This is the view from the left rear wheel well.

http://inlinethumb48.webshots.com/43...600x600Q85.jpg

The upper traction bar attaches to the stock upper control arm mount on the axle housing. The other end of the upper traction bar attaches to a mount that is mostly contained in the car.

The lower traction bar uses the OE mount on the chassis and mounts to the rear axle a couple of inches lower than the stock lower control arm. Moving the lower traction bar mounting point on axle corrects suspension geometry issues caused by lowering the car

This is upper traction bar mount in the car

http://inlinethumb30.webshots.com/75...600x600Q85.jpg

The mount is welded to the floor just in front of the wheel well. It allows for three mounting positions and is braced to the cage.

Here are a few more shots of parts on the E Production car. The transmission is a Jerico Y2K 4sp transmission. It came from a Nextel Cup team and was originally used for road race qualifying. It has gun drilled shafts and narrowed/lightened gears. It has proven to be bullet proof behind a rotary. Ratios are extremely tight.....1.81:1, 1.50:1. 1.25:1, 1:1. The Clutch is a 5.5" 2 disk Tiltion on a Mazdaspeed aluminum flywheel. The engine is a 85 13B street port built by Roger Mandeville

http://inlinethumb12.webshots.com/43...600x600Q85.jpg

http://inlinethumb33.webshots.com/33...600x600Q85.jpg

thank you so much for those 4 link picutres (heads to garage...)

I was just doing NASA HPDE's, never made the leap to racing. Was planning to race with a local club in SoCal that is now barely surviving and my not make it. Was considering Performance Touring years ago and the points put me in PTA but they want bridge and peripheral ports to run a ST class now.

I don't have a cover but really should make one out of 1/8" aluminum.

Nice work on the EP car.

I've always wondered how a fully built FB making real power would do in one of those time attack events. You should enter yours.

So is it not possible to just make adjustible upper links, that can be easily shortened or lengthened based on ride height, the way tie-rods are? Sure they'll still have different rotation radius to lower links, but at least they would allow you to untwist the axle a bit, making the suspension behave as it would at stock ride height.

This would solve pinion angle issues only. It doesn't address bind or geometry issues with the lower control arms.

A Tri link does allow you to make pinion adjustments as well as helping with bind because the upper arms are no longer used. But it isn't a complete solution on a lowered car because the lower control arms will be still be out of geometry.

I raced my RX7 with the rear suspension setup like this for years and with 100-135HP it was not an issue. However if you add power - like what you have with a good race engine - this will become an problem. Basically it will cost you time on corner exit.

Yeah, the upper links are too short. Threaded rod ends wouldn't fix that. The golden rule is to make the upper and lower links the same length, and the lower links should be parallel to the ground. Uppers angled down a very small amount.

Can't the bind simply be addressed with softer bushings? It's obviously not an optimal solution for hard racing, but for lowered daily drivers and occasional track cars it might be enough.

Even with tri-link and panhard, you still have lower links, right? And they still need to twist.

Yes, softer bushings are better because they allow compliance without adding an artifical spring rate. There is an excellent write up on this on the mazdatrix web site in the racing section. The owner of Mazdatrix very successfully campaigned an FB in PRO7 using new control arms with factory bushings.

The suspensions that I have pictured in this thread- my panhard bar and the 4 link setup - have spherical bearings at each location. If you remove the springs from either car you can manipulate the rear axle through an incredible range of motion with no friction and no binding. Roll rate is controlled by the springs only in both of these suspensions.

I already added a link in this thread on how to modify your bushings to give more roll compliance.
PB&J racing mod.
http://www.pbandjracing.com/rear_suspension.html

Yeah, spherical bearings work too, but they're probably a lot noisier than bushings, which may or may not matter. I was also thinking that instead of adjustable upper link, there could be a link with a vertically offset pivot and, it could possibly have a bend in it too, so that as it travels up and down, it's not a constant radius in relation to the lower link. That could possibly do away with adjustment. In fact I can think of a few ways to make a plug-and-play self-adjusting upper link, that would likely be guided by the lower, or vice-versa, but it would probably be kind of expensive.

Yeah, I've seen it, I was mainly talking about that as an addition to adjustable link(s), as a way to do a simple setup that doesn't require welding or cutting anything.

Unless you change the pivot points you are accomplishing nothing. The shape of the control arm is not relative. Some how you would have to have a variable pivot point that corrects for geometry issues. I have seen stuff like this on circle track cars...but they only turn one way and can be setup for a specific track.

Using the G Force Tri-Link as an example, the Tri Link arm is "J" shaped to clear the floor. However the axis that the link operates on is a straight line that intersects the axis of the mount on the rear axle and the mount on the body. If the rules allowed....the Tri Link would be a straight control arm that passes through the floor of the car.....like what you see on DriveFast7's car.

I would not recomend spherical bearings for a street car - at least not with out having at least one end of the suspension element fitted with a poly or rubber bushing. They are not only noisy but they also rattle themselves loose constantly. Also they have no protection against moisture and dirt and would be short lived. I use the racing suspensions I am familar with as examples of what you "can" do if you have a racecar.

I think there are examples of the successful use of the stock suspension on this thread. So it can be done. These are compromise solutions but so is driving a lowered car on the street. I think that if you follow the advice of those that are doing what you are trying to do, as well as adopting their driving style, you will be successful.

My opinions with respect to suspension run more towards the complete optimization for full on competition. The starter of this post is working with a car in a class that has few restrictions. In that situation it makes sense to take full advantage of you can do with a car.

My lower links have spherical bearings, and they rattle to hell. Just by themselves they did reduce oversteer a very small bit. But I wouldn't use them on the street - rattle rattle, bang, and firm ride. POLY would be a much better choice.

i'm using rod ends on my front end and getting ready to do the rear.

and i daily drive it lol doesn't bother me though. its a bumpy ass loud car already

I had heim jointed lower links on my Turbo FB, they were noisey as hell, but I found the perfect fix for it. I turned the radio up! LOL!

interesting idea, BMW and mazda have done this on the steering for years.

the mazda 6 uses 2 upper control arms, and 2 ball joints, so when you turn the steering wheel, the upper axis of the kingpin changes, so it changes scrub dynamically

i dunno if there is SPACE or its legal to do something like that, but i guess it would be possible to make some sort of dual/virtual pivot thing...

t

Scott, does your exhaust run over or under the axle in this set-up. Would you still go with longer rod if you were staying in IT?

So, after all this, what is the general consensus for a lowered street car? Tri-link? But for a serious racecar (rules permitting) a redesigned 4-link, or a 3 link going through the floor?

Sorry I missed your question. The exhaust is routed over the axle. Yes a longer Panhard rod would be better and I plan on putting one the car as a part of the STU build

Thats my take!

Exhaust routing

http://inlinethumb15.webshots.com/43...600x600Q85.jpg

This is a 2.5" ID pipe.

This is my all time 2nd favorite thread!

Lets see if we can make this your FAVORITE thread!

These are some shots of the panhard bar on my friends E Production car. The panhard bar is REALLY long and the car has a 3" stainless exhaust that routes over the axle. This is the car that has the 4 link

http://inlinethumb37.webshots.com/44...600x600Q85.jpg

http://inlinethumb14.webshots.com/17...600x600Q85.jpg

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great pic's. Thanks

How many people out there are running a lowered car on an otherwise completely stock suspension setup? How low can you go before you start to hit any pinion problems realistically?

If by "otherwise stock suspension" you mean no Trilink/panhard, etc. Then mine is probably one of the lowest around. Using coilovers and the stock Watts. No weird noises from the rear end, or anything else that would imply stress in that area.

Also, damn near no body roll, no snap oversteer, just a very happy car. :)





.

My ITA/PTE (ex PRO7) still sports stock watts, links, bushings, etc. and has ground control Eibach springs with cut dead coils and Koni shocks. Lowered to close to the 5" min per IT rules. Been racing it this way for about seven years. Won a NASA PTE race at Infineon a few weeks ago against a bunch of miatas. So you can race it that way. However, there is room for improvement and Scott has been providing outstanding info/pic's in the areas I am looking to change. I am relatively new here but this IS my favorite thread.

PS, I purchased Scott's Panasports thru this forum and he has been one of the best individuals I have ever dealt with. The packaging was incredible all by itself. Thanks Scott.

Thanks Kurt! You are a pleasure to work with as well.

I have been making some progress on my STU build and will post up some shots of my new real axle housing. It uses coil-over springs in place of the stock 5" springs. It also has radically revised lower control arm geometry with adjustment options that are 1.5, 3 and 4.5" lower than stock. Pictures tomorrow....

Waiting for photos of her rear end :)
This is one of my favorites too. What is it about rear suspension geometry that gets us all interested?

because its one of the worst things about our cars

some really good info here

Because it's critical in a RWD vehicle. Good geometry that also lets the suspension move means you don't need to make the whole suspension incredibly stiff to take out the bad habits. Soft suspension = grip.

I just finished up my 3 link/Panhard arrangement, just need to make the cover and then pull the bits off and paint them. It's all very 5 minutes and 5 dollars kind of work, not picture-worthy at all, but it's a far sight better than the stock 4 link/Watts.

With the 4 link and Watts arrangement, the first thing to hit the floor is either the Watts arm or the driveshaft, depending on how twisted your diff housing is.

Agreed, there are so many that do not understand that. They end up running super heavy springs rates with inadequate shocks to control them.

Also, consider this, the only way to accurately tune the suspension is to have known variables. Binding becomes part of the spring rate resulting in an unknown variable.

-billy

Well, the stock setup binds until the constant forcing against the upper links causes the mounting points to break off of the body. Then it works very freely :)

I had a weird one. I took my old 3-linked rear and cut the top arm off to fit in a stock shell, after I split that car's rearend down the middle. The 3-linked car did not use the upper links for quite some time. After a few months in the strong shelled car, the right upper link bracket broke off of the rearend. It was rusty, but in the original car, the shell was the weak link...

BTW - I did the 3 link for corner exit power-putdownability. I ditched the Watts for a Panhard because, on grippy tires, in a tight corner, my car would make like a VW and lift the inside rear tire off of the ground. Not from body roll, the back end would rise slightly because the axle was rotating under the car. Down, rollcenter, down!!!

I don't totally agree with the assertion that soft = grip. Grip is generated as a result of the correct suspension geometry and weight transfer. On a drag car the suspension needs to be soft so that you get allot weight transfer to deal with the shock of a hard launch. But in addition to having a compliant suspension a drag car also has to have a rear suspension that has the correct geometery.

On a solo or club racing car you cannot have a super soft rear suspension and expect the car to be balanced. Basically your car won't turn in properly if the car is too soft in the rear. The STU car I am building will most likely have anywhere from 250-300lb rear springs. This will be a variable depending on the track I am at and the size of the rear sway bar I am using or not using.

My CP Mustang - pictured earlier in this thread - had a 3 link rear suspension that was very effective. The interesting thing was that rear spring rates had very little to do with how well it hooked up off of a corner. The final spring rate package on that car was 1650lb front springs and 780lb rear springs. The car hooked up so good that it would lift the inside front tire on corner exit anywhere from 2-6 inches with these springs installed. At one event it was so bad I had trouble seeing the next cone/manuver until the front end came back down. I later corrected this by installing a rear swaybar. This really helped with the front end lift issue. This also had no effect on traction.

Okay here are some photos of my progress:

http://inlinethumb53.webshots.com/44...600x600Q85.jpg

This is the right side lower control arm mount and spring mount. The top hole on the lower control arm mount (the hole closest to the axle tube) is the stock location. The holes below are in 1.5" increments. I anticipate using the mounting hole that is 3" below the stock hole.

The spring perch combines the adjuster with the seat. It is not welded directly to the axle tube. Instead it is located by plates that are welded to it that also welded to the lower control arm mount. This way the axle tube should not be warped.

http://inlinethumb25.webshots.com/26...600x600Q85.jpg

This is the 3rd link mount. It is off set to the left to by about 2-3 inches. This was done to make the chassis mount more serviceable as the drive shaft in these cars is offset to the right. Since access to the chassis mount will be from under the car I didn't want fight the drive shaft when making adjustments.

Grip is generated by tread compound and keeping the tires in contact with the ground. Everything else is handling.

The point is that you do not need to make the FRONT suspension super-stiff to counteract the fact that the rear suspension sucks.

Look at off-the-shelf performance suspension setups for a prime example. Front spring rates are in the range of double OEM, rear springs are the same or softer, and the sway bar is removed from the rear and/or increased in size for the front.

The front suspension is being stiffened to counteract the rear suspension's not wanting to work. Make the rear work, and you don't need to go overkill on the front end like that.

I noted something similar in my RX-7. It handled really well at 200lb front and rear, with the 3 link and Watts. With the stock arrangement, 200lb wasn't stiff enough in the front and 100lb was too stiff for the rear...

My first cut this year is 250lb front and 175lb rear, no sways. The suspension already doesn't really move...

Some would argue that you'd be better off keeping all four tires on the ground.

Personally, having been in a VW environment, compromises always have to be made. In the case of my VW, stiffening the front to keep the rear tires both on the ground hurt turn-in too much. Lowering the rear excessively helped keep both tires (close to) the ground, and actually helped corner exit power.

two of the guys on our team (25 hour race = 25+ people) were comparing setups between a CSP FB and CSP Fox Body, and the were basically running the same springs and alignment, kinda funny

i think with FWD getting the rear tire off the ground might be ok, ours just cause understeer... case in point, at this 25, when the rear tire fell off (pics are in the link in my sig) mario was happier with the balance, and it was only 3 seconds a lap slower, which is about what it ran with Ra1's

It is really hard to respond to the points that you have made here. To a certain extent I am not sure you understand what I am saying or I am not being clear. Suffice to say I do not agree with many of your opinions but there are allot of ways to skin a cat.

Basically I think you are discounting the effect that a racing tire has on a car's suspension. If we raced on 185/60x13 all season tires then we wouldn't have to work this hard. The reality is that while racing tires provide grip they also introduce loading and forces into the suspension that have to be controlled. The heavy spring rates I listed for my Mustang were not on the car to fix a handling issue that the car had. They were there to fix handling issues the car had BECAUSE of the racing tires.

The spring rates on my Mustang were pretty extreme but then again so were the tires I was trying to control. They were Hoosier 25x12x16 GT1/Trans-Am road racing tires mounted on 16x12 wheels - front and rear. The heavy spring rates were necessary to keep the tires on the ground. The point I was trying to make is that despite the stiff springs the car still hooked up. Soft doesn't = grip.

I Solo'd that car for 15 years and I did use softer springs as well as a more stock suspension early on with the same size tires. It was slow, in part because soft doesn't equal grip. The move to the three link rear suspension, 2.5" drop front spindles, 26 point roll cage, racing shocks/struts, a 400HP engine and heavy springs was necessary to get the most out of the tires. Of note is the fact that the three link was on the car for a long time. But the car wasn't fast until I addressed the whole package.

My RX7 was used for club racing in Improved Touring. The suspension has all spherical bushings - there is no bind. The final spring rates were as follows:

400 Front - racing beat sway bar
250 Rear - no sway bar

The tires were Kumho 215/50x13 ECSTA V710's

I have raced against cars that have softer suspension settings. They were not faster that I was.

It would be incorrect to assume that only the rear suspension on our Rx7's needs attention. It is the most glaring problem because getting a high HP RX7 to hook up is really hard with the stock suspension or with a suspension that is out of geometry. I am fixing that with a 3 link because the rule set I am working with allows it. The front suspension will also be optimized.....more on that when I get to the front end of the car.

Finally got another front sway bar. Now I'm running RB front sway bar, stock rear, 300/200. RE-speed coils. Car drives amazing. Next step I'm going to do the PB&J racing mod to the upper links then fix the lower control arms mounting on the axle to get them parallel. Then maybe a panhard and 4 link.

I thought I put my setup in here, but I just looked through and I guess I didn't. Here's what a proper watts link looks like in a fb. It's not finished yet, the bars are a bit too long in this picture, but at least they're equal length and centered on the rear end :) The reason I didn't go with a panhard bar is because they like to pick up one tire when turning. If the bar is connected to the rear end on the left side, when you turn right it loads the left rear wheel, but when you turn left the bar will unload the left rear and possibly pick it up in the air.


http://memimage.cardomain.com/member...21_42_full.jpg
Yes, I'm using 2 forklifts as a lift....:)
http://memimage.cardomain.com/ride_i...0049_large.jpg

Fawking beautiful!! Alright I'm back on the Watts wagon.