That may be a silly question to some but I need to know. I ask because I am looking at getting the Roush Complete Suspension Kit along with the lower trailing arms. However, if you look at their website, there is no mention of them anywhere.

Jon

 

I don't know how critical it is on the street, but for the best possible traction at the strip, its best to get the instant center at its ideal location, espeically when the car is lowered

Just an FYI, i'm currently working on a detailed writeup about lowering your car and the negatives that may need to be corrected.

 

I'll be looking forward to that write-up. I'd like to drop mine 1 inch or so but I want to make sure I figure in all of the "corrective" parts necessary to make sure it is done right since I want this car to be safe and capable on the track and not just "look good" lowered.

 

I got BMR lowering brackets. Here is why. When you lower the car, you lessen the angle the LCA and the axel have in relationship with the car frame. All this means is you have more wheel hop. BUT since you already have wheel hop on the stock car, probably no biggie.

I put the LCA lowering brackets from BMR and I do not have any wheel hop now. No I did not weld them in, just bolted them on. They suggest welding them if you get really good 60 foot times.

For a while, BMR was the only ones who offered them, now I noticed that Steeda is also offering the welding kind. I feel that Roush will follow suit soon.

Side note, you may need to adjust your panhard bar if you start to run wider tires on the back end to avoid rub.

 

While you may not need the relocation bracket, you should also look into an adjustable upper control arm to correct pinon angle and like traffic142 said, an adjustable panhard bar to correct back wheel offset. Maybe some camber bolts to correct front end alignment. You may not need any of these things, but just an extra expense that may come up after your roush kit is installed.

 

I agree with the caster/camber bolts..... You may need them if you drop your car a good deal. Most of us have found on this forum, that if you stick with drops of less than 1" to 1.5" you will be fine (ie. steeda ultra lite springs). I have heard of extreme drops of 2" will cause you problems of alignment and later if you install headers that hang below the frame...You will drag.

 

Agreed, most experienced alignment shops can get the car back into spec without camber bolts or plates. But if Jon_Purdy is spending that much $$$ on handling mods, hey may be planning on autocrossing and may need more adjustability with the alignment.

 

A job that is worth doing is a job that is worth doing right. Its worth the effort to do the LCA pivot drop and the other mod's described above if you want your Mustang to be all that it can be. Also not mentioned is the front ball joint drop (steeda) to get the front roll center back up.

 

I came across this recently and it did a pretty good job of explaining how the LCA acts as a brace for forward forces and what happens when a lowered car changes it from being stock-level to raised up in the rear. Forces end up lifting the axle and giving you wheel hop.

http://www.cherod.com/mustang/HowTo/LCA%20_adj.htm

 

I think you win an award for oldest post resurrected.

That being said, that whole writeup on suspension has been a huge help to me over the past few years in understanding how our rear suspensions work.

That diagram simplifies matters greatly, and increased traction going straight isn't nearly the same as increased traction around corners with regards to the angle of LCAs.