Need input on rear suspension

[StephenC 10]

So its getting to be the that time to upgrade the rear suspension especially with my tax refund on its way! But my question is I'm ditching the idea of an IRS and want to go with either a 3 link or a 4 link both are around the same price + or - a couple hundred but I know don't know what real difference between the two are. Visually I can tell but as far a performance and handling go which would be better? Also what are some good company's out there for them I've already looked at Heidts and TCI are there any other out there with around the same price range?

Edited February 2, 2011 by StephenC

[428scj 10]

We use TCP total control products.Its a division of Chassisworks.Its a little more money but the installs are always seamless.The G bar set up is nice with the coil overs.

[StephenC 10]

We use TCP total control products.Its a division of Chassisworks.Its a little more money but the installs are always seamless.The G bar set up is nice with the coil overs.

I looked into the TCP G Bar setup before and it looks really nice and I also like the Fab 9 rear end but it seems a little pricey its $2099 without the rear end. Heidts is offering a 4 link with 9" rear for I think $1695 right now.

[428scj 10]

Im installing a 428 into this car and gearing it low so the beefed up rear is needed.Its also getting the fab 9 housing.It is well built.Very very strong.But the price is stiff.Its all going into a 67 fastback.

[StephenC 10]

I think I'm going to go with the TCP 4 link with the FAB9. Just going to have to wait another week or two to have the extra money for it :sad:. Thanks for your input guys.

[buening 63]

Is this the one you are thinking of getting from Heidts?

 

http://www.heidts.com/boltin_rear_4_link_complete_package.html

 

 

It doesn't mention the 9" is included. If so that is a parallel 4-link, typically gear for guys at the drag strip and not exactly a corner carver. It will need a panhard rod (binding) or a Watts link (bulky and exhaust issues) for lateral axle location. A triangulated 4 link is a bit better and the triangulated upper arms provide the lateral axle location, eliminating the need for the panhard/watts. The 3-link and torque arm suspensions, in my opinion, are a better handling setup but you typically pay more for them (for this exact reason).

 

Rod & Customs sells a triangulated 4 link and is about $1700

 

http://www.rcmotorsports.net/RearCoiloverKit.html

 

TCI has a torque arm setup, and is about $1600 from Fabquest: http://www.fabquest.com/total-cost-involved/tci-independent-rear-suspension-kits/64-70-ford-mustang-or-67-68-cougar-tci-torque-arm-rear-suspension-kit.html

 

TCI has an install PDF to get an idea how easy/hard it is to install

 

http://www.totalcostinvolved.com/assets/pdf/64-70_Mustang_Torque_Arm_Rev02.pdf

 

 

 

RRS has one also but its like $3500 http://www.rrs-online.com/downloads/3-linkInstall.pdf

 

The downfall (if you'd call it that) is the torque arm suspension is more bulky than the triangulated 4 link, since it requires a watts link for lateral axle location.

 

If you want just an upgraded suspension to get rid of the leaf springs, any of them will do. Just keep in mind of the downfalls with each. Honestly, a watts link with a leaf spring setup will work wonders with handling in the twisties. Running exhaust past the axle will be a challenge with the watts link though!

[StephenC 10]

Yeah that was the one I was thinking of getting from Heidts now this is the one I'm looking at getting from TCP and I love the FAB9 rear

 

 

 

 

 

[buening 63]

You do realize the FAB9 rear is an extra $1000 on top of the $1800 suspension kit don't you? The FAB9 is nice but unless you are making stupid power, a regular 9" with the bracketry that comes with the suspension kits will do just fine.

[StephenC 10]

Yeah I know its expensive as hell! Thats why I'm looking at all my options before I drop 3K on just the rear suspension. But I'm planning on a 408 stroker and hope to get around 600 HP out of it. But I emailed Rod and Customs about there 4 link to get some more detail on it.

[stangme428 33]

YEP! I'm saving up for the TCP ...... 500hp 408clevor - i have 31 spline moser axles, daytona pinion support... so i plan on using it instead of the FAB9

 

Yeah that was the one I was thinking of getting from Heidts now this is the one I'm looking at getting from TCP and I love the FAB9 rear

 

 

 

 

 

 

[kennygunit 10]

I wanna get the TCP with FAB 9 and disk brakes.

 

Let us know how it goes once you install them. If you could do a write up for it that would be awesome! :)

[BurnRubberNotYourSoul 10]

Im bringing back an old thread but ive currently got a drag 69 but im gonna convert my 71 to the drag car and want to make my 69 into a highway runner/ twisty car. Im currently planning on putting putting a 390 in it with about 500rwhp and a 6spd manual. I was wanting to know what I should do to my rear suspension to make it handle in turns and high speed. I just know I loved the way my 05 handled with just an eibach suspension. What are my options? Am I able to take the rear suspension and axle from a newer mustang and modify it to fit my 69?

[69_Mustang 26]

Your rear axle should be plenty fine, unless it needs to be replaced. Is it a 9"?

 

You can make your own rear coilover kit or someone like Street or Track has a pretty bad ass looking system.

 

Then there's the 3 link, 4 link, panhard bar, y bar, etc, etc... To support the rear coilovers.

 

If you want to keep the stock type suspension, there are a lot of ways to upgrade that and make it handle very well, too.

[buening 63]

Ask yourself if you want exhaust dumps at the rear floorboards or if you want tailpipes going out the back, because many of the rear suspensions in the aftermarket don't allow tailpipes due to the interferences involved with a watts link (and sometimes panhard rod). I personally hate dumps, but most of these suspensions were designed for track cars where giving up the tailpipes is worth the better geometry.

[chillininnh 21]

Ask yourself if you want exhaust dumps at the rear floorboards or if you want tailpipes going out the back, because many of the rear suspensions in the aftermarket don't allow tailpipes due to the interferences involved with a watts link (and sometimes panhard rod). I personally hate dumps, but most of these suspensions were designed for track cars where giving up the tailpipes is worth the better geometry.

 

+1

Pretty much the entire reason I'm still running the leafs.

[BurnRubberNotYourSoul 10]

As far as exhaust I plan on doing dual exhaust with flowmasters coming straight back and a 45deg exiting in front of the rear tires. As far as suspension I just want something that is going to handle/grip good in the twisties but still be stable at 170+mph straight line. Will the leak springs with some coil over shocks be enough? This will be my first high speed leaf spring car so I dont know how well they do. I do want it lower than stock.

[69gmachine 15]

Some thoughts:

 

If you're goal is simply to enjoy a curvy road and not trying to compete with anyone, there are several inexpensive upgrades you can make to the leaf spring set up.

 

1) lower the CG by lowering the car. It's much better to raise the back of the spring than to raise the axle above the spring as that creates a lever arm.

2) Use composite leaf springs instead of steel so they react faster. They proabably will never be as quick as a good coil over, but noticeable improvement over steel multi leafs.

3) A panhard bar is a simple yet effective way to not only positively locate the axle laterally, but it will also lower the roll center. A properly designed panhard bar will not result in binding in the normal range of motion. The Maier bar will also clear over the axle exhaust.

4) Tires will make a huge difference, so get the biggest tire that still has room to move. Although a 315 can be made to fit, there isn't enough clearance around it for hard cornering IMO, so I would limit the size to a 295.

 

There is one other reason to ditch the leaf springs and that is ride harshness. They will beat you to death on a long trip. If you can afford to step up to a design that uses coil overs, you will have a much more enjoyable ride IMO.

[buening 63]

Agree with 69g. Get some composite leafs with the Del-Alum bushings, a panhard rod, and some quality shocks like the custom Bilsteins that Street or Track or Maier Racing sells (or Koni). There are guys running leaf setups on the track and are beating porsches and other newer suspension technology. Its all about the tuning.

 

BTW, don't mix leaf springs and coilover shocks. Thats like double-dipping ;)

[BurnRubberNotYourSoul 10]

Ok thanks guys. I dont plan on road racing or anything but I like to push as fast as I can. My 05 I could take a 25mph cloverleaf at 75 before my backend would start to get loose. I know tires are half the battle. I just dont want a soft suspension. My 05 stock when I would serpentine felt like it was fish tailing but without loosing traction and it scared the shiznit out of me. Soon the eibachs followed. I wont have that just being lower with good shocks and these composite leaf springs?

 

So right now the back is shackled up how much can these be shackled down before I lose my flexibility? Ive got the "adjustable" shackles with the mulitple holes. In theory I could just flip them over and use two holes that are closer togerther right? And how much are these composite leafs and who makes decent ones?

 

Once I get down the road I will have to put a good suspension under it. But for now I dont have 3g to spend on rear suspension.

[BurnRubberNotYourSoul 10]

And if I cant get the lower I want from just the shackles is there any acceptable amount I can block the axle(1"? 2"?) or do I pretty much want avoid that at all costs. Other than for just looks.

[buening 63]

Personally I'd use the stock hole location on the shackles. As the suspension compresses, the leaf spring elongates and the shackle swings towards the rear and upwards towards the frame rail. Determining how high you could put the leaf on the shackle would involve bottoming out the suspension and check the clearance of the stock shackle leaf spring location to the frame rail. Make a spare set of side shackle plates out of 1/4" steel and drill some holes closer together, mount, and bottom out the suspension and check clearance. Rinse, lather, repeat.

[BurnRubberNotYourSoul 10]

Ok. I was trying to find these composite springs. I found hyperco and flex-form. Flexform wanted me to order them and hyperco only mentioned chrysler and chevrolet so ill have to call one of them later. I also found from mustangs plus custom (steel) springs that I can made to order. 4, 4.5 and 5 leaf sets with std hole location, 1" and 2" drop. Can anyone help me out on whos good to talk to for the composite springs?

[buening 63]

Off the top of my head, Moneymaker Racing or Maier Racing are both good to talk to. Moneymaker has more knowledge of drag racing suspensions, whereas Maier knows a bit more about the twisties.

 

Flex-a-form are the composite ones I was thinking of. The only downfall of them is they are fiberglass monoleafs, so you have to inspect them for any damage/abrasion for obvious reasons.

[69_Mustang 26]

I don't know how handy you are, but you can always make your own to tailor your own needs. Summit sells a bunch of kits, then there's so many shocks, springs, panhard bars, y bar, etc, etc out there.

[69gmachine 15]

Ok. I was trying to find these composite springs. I found hyperco and flex-form. Flexform wanted me to order them and hyperco only mentioned chrysler and chevrolet so ill have to call one of them later. I also found from mustangs plus custom (steel) springs that I can made to order. 4, 4.5 and 5 leaf sets with std hole location, 1" and 2" drop. Can anyone help me out on whos good to talk to for the composite springs?

 

Flex a form will build a custom set to order, and I would bet that Hyperco would as well. Unless you go off-roading, you shouldn't have a problem with them. Racers using the Hyperco springs report that they last 4 to 5 times longer than steel springs.

 

In order to get the spring to move up without going back, you will need a shorter spring as Buening pointed out. I started with Mustang II springs and re-drilled the axle locating pin at the correct distance, then added a leaf to support the heavier weight of my Mach 1. That lowered the car about 1.5 inches without needing to resort to lowering blocks. For me personally I would avoid blocks at all costs.

 

I'm currently working on a truck arm suspension that will use coil over shocks. From all reports it's a much more comfortable ride, and it handles the turns just about as well as a live axle can be made to perform.