I don't think the Tokicos can handle 350 pound springs. If you're running those rates, you'll need to get a better strut.

 

Pull the front struts out and check if they're blown.

 

Upgrade ROD end

decide to go with 3/4 aurora rodend

look that size n compare to my old 14mm Rod end

i am 100% sure i wont have another rodend fail this year

 

14MM ?!?? No wonder you were breaking them!

 

3/4 Rod end ready to go on the car !!

 

Well. Ready after you paint it. Unless you like rust.

 

While trying to diagnose the grinding sound from the rear of my car I followed a few threads until getting to this one. Sounds like my problem is the rear end angle since my car is slammed, so it makes a grinding sound whenever I'm on the accelerator but not when I'm coasting or slowing down.

This thread seems to have changed to mostly a discussion about rod ends and struts over the past year or two. To get back on subject:

Is there a current, consensus solution to the suspension geometry issue? Does anybody make a bolt-on solution anymore?

 

T3 actually makes all the links you need...

 

Sorry for my ignorance, but I'm trying to understand

Properly setup Techno Toys links will solve the likely problem of grinding axle components if the issue is drivetrain and suspension geometry? Is it achieved by shortening the upper links? Lengthening them? Replacing more components?

If there is a discussion available would anyone be so kind as to point me toward it? I don't want to waste anyone's time by asking them to repeat something they've said before in another thread.

 

If your car is lowered a lot your rear end has roll forward at the top because of the shorter upper links. This can jamb your driveshaft into the trans too far. That might be your problem, or it could have to do with u-joints being out of phase between the trans and rear. On throttle your problems are made worse with rear squat.

 

If you make decent power and you're slammed, the pinion flange has a habit of smashing into the chassis with stock upper and lower links.

 

I'm doing an offset 3-link plus Watt's link.
Rear Suspension & Geometry for Track Performance - Lateral-g Forums

 

Lets bump this and see if there is any more useful knowledge floating around out there. Tons of great stuff already in this thread from the past!

 

Thanks for the bump. Resubscribed, love this thread!
No rear sway-bar here, full adjustable Panhard bar conversion and stock trailing arms, poly-bushed, with one end of the uppers drilled out, ride height set so the trailing arms are horizontal, thinking of going a bit higher to re-introduce some anti-squat?
I've got no idea how roll centre is calculated for the rear end, or how it should relate to front end roll centre - if someone would shed some light on that youwould be a fuggen legend. I've got my Panhard set so its level with the bottom of the dif pumpkin.

 

The roll center of your car is where the panhard rod is located in relation to the ground. Since yours is level it is the center line of the two panhard bar mounting points.


If the bar is not level it is half the difference in height between the chassis mount and the rear end mount. IE The Chassis mount is 12 inches off the ground and the axle mount 10 inches - Roll Center = 11 inches


A panhard doesn't have to be level to work. My 2012 Mustang's panhard bar is not level and neither is the one on my friends Boss 302. Both of these cars handle very well.


On a watts link it is the location of the center pivot.


I think you will find that your front roll center is lower than your rear roll center. Google determining front roll center on a Mac Strut car to see how this is calculated.

 

Thanks MustangWarHammer. Yeah i've seen the diagrams for how to calculate McPhearson strut roll centre - mines pretty good (i think) because im running 38mm roll centre blocks and the suspension isnt overly low.
So should the front RC be lower than the rear RC?

How would having an RC higher at the front than the rear affect things and vice versa?

 

I like what I am reading here Rear Suspension & Geometry for Track Performance - Lateral-g Forums

 

Thanks for the excellent link. That pretty much answers all my questions, and is an excellent resource.

 

I am looking around for feedback on the techno Toy Tuning upper and lower arms...

My car will be getting lowered (not slammed) on coilovers and I am also looking to refresh the rear suspension. Are solid bushing (heim) TTT components the way to go or should I just stick with stock?

I will be getting the Techno Toy front end hardware.. ie control arms and tension rods. Just wondering if the rear links are also worth it!

 

What is your application?

For me, it's worthwhile to build a triangulated 4-link without any other lateral locator (watt's link or panhard bar). I'm also LIGHTLY going into the cabin and plan to maintain full interior with TONS of sound insulation throughout (grand touring build).

I'm using a very hard rubber upper link setup from Metalcloak (2" Jeep bushings) and 5/8"x 3/4"-16 Rod Ends with 5/8" to 1/2" High misalignment bushings on the lower links. This will be silent and offer very little NVH through the cabin.

As for the specifics of the T3 rear link setup, it's just a standard set of mid-grade rod ends (not top tier by any means) and aluminum, threaded links. Honestly, it's not strong enough for the application, in my opinion. You could build an identical setup to that for WAY less from Speedway Motors. I'd run steel, not 6061-T6.

Solid is fine on the street. My daily driver uses solid bushes throughout with bronze inners, so I'm sure this would be just fine. All comes down to the quality of the rod end.

***The #1 reason for doing adjustable heims on this application is to dial in thrust angle and SLIGHTLY change pinion angle.***

 

All the answers to your questions have already been posted in this thread.
Read the thread!
Heim joints in the lower links will be of benefit. Heim joints in the upper links will increase bind and make snap oversteer worse. Same should be said for polly. Never do anything with the upper links except making them more roll compliant, or throwing them away and using a 3rd link or redesigning a proper 4 link.

 

If you run solid upper and lower links you will either rip the mounts off the car or axle.. btdt. The rear suspension does not go up n down equally on both sides. Different upper and lower lengths with the upper angled in equates to bind-o-plenty when the car rolls/leans in a corner.
T3 makes some good stuff, but there upper and lower links exacerbates the bind in the rear suspension.

 

Even without solid bushings, the body mounts will fail and I have had two axle housings twist the pinion up, when under torque load and the linkage binds, it's going to preferentially twist the axle end backwards rather than forwards, which over time pushes the pinion up.

3 linking gets rid of all of that, although I get a new problem where it splits the bottom/rear of the housing open like an egg unless a brace is added. That worked until I broke the brace, then the housing split almost immediately!

I'm done with Mazda rears, the parts are far too hard to find/valuable to wreck them. 3-linking gets me so much grip that everything is failing...

 

Hopefully I won't receive too much flak for bumping this thread, though considering the valuable information contained within the thread (great read by the way, for anyone who hasn't read it in its entirety.) I don't foresee anyone having issues with it.

First issue noted. Roll center. I'll be running an FC front subframe in the front. For those who aren't aware the simplest way to achieve this is mounting the subframe directly to the frame, an inch back from the existing forward bolt hole. This method creates low front roll center. Obviously the rear needs to be matched. I've spoken with someone (whether it be the driver, builder, both, I'm unaware) regarding a certain 20B swapped time attack car, his method was to move the mounting point of the front LCAs upward and adjust the rear roll center to match as best as possible. How this relates to the rear suspension…, It seems as if the general consensus is the best bang for the buck is a three link with either a Panhard or properly designed watts. The person I spoke to regarding this time attack 7 was using a watts.

What are your thoughts on this setup? The most appealing setup to me at the moment is the three link with a Panhard, on a ford 8.8. I won't be implementing any sort of aftermarket rear suspension setup for quite a while due to budget constraints, a lack of knowledge, and lack of driver skill. Also, if you've got any recommendations for books or write ups on suspension design please do share!

So I've covered issues one and three: roll center, weak axles (the bit about me wanting to use an 8.8? I plan on running a TII)

Lastly, the stock links. Since its going to take time to have my rear suspension designed and implemented something needs to be done in the mean time. I plan on buying an energy suspension poly bushing set- drill multiple eighth inch or maybe 3/16 holes to increase compliance in the upper links. Run the lowers as is, or build my own lowers with poly bushings on the body side, Rod ends on the axle to account for pinion angle. As for the watts… I'm not sure. Does anyone have experience with the T3 Panhard bar? As for sways, spring rates, etc. I haven't gotten that far. The reason I choose to use poly bushings… It's far cheaper to use as a temporary solution than buying all new links with factory rubber bushings.

If my thoughts and plans are unclear, I'll do my best to clarify. Please do continue the conversation though!

 

Also interested to see if anyone is tracking the T3 Panhard kit. It looks good for the price but I think its a diagonal mount that goes under the diff. There's a FB thread on it but not much else out there.

https://m.facebook.com/permalink.php...18825541490643