Blackpanther99

iTrader: (8)

Hi there guys, im sure this question has been asked but where could I find a rear 4 link suspension for my 99 Trans Am project?

I also ask because some of you guys might have experience with these rear setups and could recommend me a vendor

Thanks!! Alex

Blackpanther99

iTrader: (8)

Anyone guys?

lees02WS6

iTrader: (5)

There aren't any. A parallel 4 link would interfere with the spring perch on the axle. You'd have to have the link inside of it and it's pickup point would land on the sheet metal behind the back seat which would need bracing to support the forces being put there. You'd have the same load issue with a triangulated 4 link.

There isn't a substantial advantage to either type of 4 link over the torque arm suspension to justify the extra work and expense required to put 4 link in. One person here had put a parallel 4 link in, but switched back to a torque arm suspension.

Blackpanther99

iTrader: (8)

Great info! For the same reason I was asking because I havent heard of a 4th Gen F-Body have a 4 link suspension, thanks for the picture it makes sense to me know of why they arent used on F-Bodies... Soo to what your saying I should just stick to torque arms as everyone else right?

lees02WS6

iTrader: (5)

The torque arm suspension with a watts link or panhard bar, like a three link (they are very similar), has been proven to be a capable performer in drag, road racing and autocross. It has all the adjustment of a four link while not introducing the bind that may come from a four link.

It can be argued that the 3 link/torque arm is superior to a 4 link. The one draw back for the torque arm being the increased unsprung weight. You're not being held back by your torque suspension relative to a four link at all.

Art Morrison did a straight up comparison of the two.

Blackpanther99

iTrader: (8)

Great demonstration, pretty much a torque arm suspension with a WATTS link should work similar as a 4 link correct? Ive seen that watts link on Midwest Chassis and I honestly didnt know the difference between the watts link and a 4 link. I know 4 links are capable of holding lots of drag racing on high horsepower vehicles such as trucks. My drivability shouldnt be affected by 3 link suspension for street driving would it?

lees02WS6

iTrader: (5)

A watts link, and a panhard bar are centering devices. Three links, parallel four links, and torque arm suspensions require them as there is no lateral support to keep the axle located side to side under the car. The Watts link is better at maintaining a constant roll center, and keeping side to side movement to a minimum than a Panhard bar.

On a triangulated four link no centering device is required (the triangulation keeps the axle centered). Though not all triangulated four links are equal in this regards. Ford's fox body mustangs, with their satchel link systems, were pretty bad at this.

The third link link (a torque arm or link for the three link) takes up the torque reaction, sets instant center (anti-squat), and brake reaction (anti-dive) on those styles of link suspensions.

In a four link (parallel or triangulated) those same forces are handled by the upper links. Torque arm suspensions can handle just as much power as four link. Your driveability is impacted more by springs and shocks than by the number of links in the suspension.

Blackpanther99

iTrader: (8)

Ahh everything makes more sense now, looks like ill be doing torque arm suspension soon! With watts link I got some Koni shocks and springs from BMR but havent yet installed them, I bought the LEVEL 4 Handling Performance package since my car is going to see way more street time than track time... But I believe I made the mistake of not buying double adjustable springs, could that be an issue at the track? Even if I dont plan on doing alot of track time?

lees02WS6

iTrader: (5)

Double adjustable shocks let you adjust compression, in addition to rebound which available on the single adjustables you ordered. The single adjustable is great handling shock. When you say track time do you mean the drag strip?

Blackpanther99

iTrader: (8)

Yes sir, drag time I meant

lees02WS6

iTrader: (5)

The package you bought is geared towards autocross and road racing, while maintaining daily driveability. You can use it for drag racing, but it won't allow weight transfer like drag shocks and springs will.

That said drag racing setups have a narrow useability area. They are only good at drag racing, and are poor at everything else. If 90% or greater use of this car is driving on the street, the package you have is more than fine.

Blackpanther99

iTrader: (8)

Im glad to hear that because I thought I had made the mistake for not buying a drag racing package lol I called BMR before making my purchase and they told me that the Level 4 Handling package will meet most of my goals, which are having a good street drivability suspension but that could also handle some runs at the drag strip

With that being said and what you have been telling me that as long as I dont abuse too much of my Trans Am at the drag strip with this handling suspension and I use it more as street friendly I shouldnt have too many problems right? In case I ever want to use my car more for the drag strip I should consider getting more of a drag racing suspension to meet my needs.

What do you think should be my next step? torque arm with watts link?

lees02WS6

iTrader: (5)

The watts link can be helpful if you're running wider tires, or plan to. It locates the axle better. The Panhard bar allows the axle to move from side to side slightly. The watts also lets you adjust your roll center, but that's not helpful for drag racing.

An adjustable torque arm allows you to adjust your instant center, and your pinion angle. Additionally, you can add rear lower control arm relocation brackets and you can increase the amount of antisquat the cars has.

Blackpanther99

iTrader: (8)

Looks like the watts link will be my choice as I plan on using wide wheels and tires, since it wont be much of a drag car at the moment I believe that will be my best choice right?

lees02WS6

iTrader: (5)

Which axle are you planning to run? Are you sticking the 10 bolt for a while, or upgrading to something else? If you're going to invest in a watts link you want to make sure it isn't obsolete when, and if, you move to another axle. The axle tubes and the placement of certain item on the axle (vent tube), size and shape of the differential case, can impact fitment of the watts link.

Blackpanther99

iTrader: (8)

My plans is to do a full upgrade to a MWC 9" rear end with new axles, and get rid of all my 10 bolt

lees02WS6

iTrader: (5)

Call MWC, and get the MWC made watts at the same time as the MWC Fab 9, and save yourself headaches, and the hassle of redoing the work. Other watts links won't fit that axle.

Blackpanther99

iTrader: (8)

Thanks for the advise! Im just trying to save some money at the moment for my rear end