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Suspension Upgrade Review

8K views 22 replies 8 participants last post by  Rorin67 
#1 · (Edited)
I spent the weekend rebuilding the suspension on my 1965 Mustang Fastback. Below is a list of add-ons/modifications:

Front:
Grab-A-Trak 620 Coil Springs
Street or Track Billstein Street Valved Shocks
Opentracker Roller Spring Perches
Street or Track Adjustable Strut Rods
Shelby Drop (used Street or Track template)
Opentracker roller idler arm (steering upgrade)
(I already have a 1" Front sway bar)

Rear:
Street or Track Billstein Street Valved shocks
Street or Track 4.5 Mid Eye leaf Springs
(I already have traction master bars)

I aligned the car to +5 degrees caster (4.5 on driver side) 1/2 degree of negative camber, and 1/16" toe in.

First impressions:
In limited street driving, the car handles great. Compared to before, it handles like it's on rails. I don't have a lot of body roll and my car tracks significantly better. Mission accomplished. However, these upgrades came at some expense. I can hear everything on the road. From lines in the road, to cracks and bumps. It's noticeable, which I figured it would be despite some peoples insistence that it wouldn't increase road noise. Trust me, it does. However, this isn't my wife's soccer-mobile. It's a performance machine and it's about time it started acting like one. These modifications truly do transform the handling characteristics of the car.

I want to give a shout out to Shaun at Street or Track. He's a good guy who helped me decide on the direction I wanted to go. Also to John at Opentracker. He answered all of the questions I had and was willing to help anywhere he could. I highly recommend the services of these two companies. They're top notch.

I've also got a couple of videos that shows the stock spring perch vs. the roller spring perch. I may post them up to YouTube if anyone is interested. Let me know.
 
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#3 · (Edited)
No. I'll take some pictures and post them up soon, but I don't think it needs to be any lower. It's got a nice, ever-so-slight rake.

EDIT: If I had my rear fenders rolled, I think a 4.5 reverse eye would level the car and give it the perfect stance.
 
#5 · (Edited)
Was there any bushing left in your stock perches? To be honest, it's not even close. I noticed it backing down my driveway for the first test drive. That's not to say I'm not pleased, but it's definitely louder.

Can you replace the bushing without replacing the LCA? I don't see that SoT offers just the bearing.
 
#10 ·
some people are more sensitive to NVH than others. one question i do have, did you opt for poly bushings? if so then that is likely where your noise is coming from.
Nope. Stock rubbers.

The only thing I didn't do is repair/replace the control arm bushings. Maybe my stock perches were absorbing some of that impact that is now being put on my control arm bushings? Not sure, but I'll do some more investigating.

I don't want this thread to turn into a bash-fest for the parts I installed. I am VERY happy with the upgrades. No regrets with the parts or the companies involved.
 
#11 ·
Nope. Stock rubbers.

The only thing I didn't do is repair/replace the control arm bushings. Maybe my stock perches were absorbing some of that impact that is now being put on my control arm bushings? Not sure, but I'll do some more investigating.

I don't want this thread to turn into a bash-fest for the parts I installed. I am VERY happy with the upgrades. No regrets with the parts or the companies involved.
no bashing intended. as long as you are happy with your build, then the parts you selected are just fine. another question, did you lube the metal part of the bushings before you installed them? also did you want until the car was on the ground and the weight on the suspension before torquing the lower control arm bolts? sometimes little things like these make a difference as well.

in the end it might just be that mustangs plus used a harder rubber bushing than what came from the factory, and that can cause NVH issues as well.

all i want to do is help you troubleshoot the increase in NVH and perhaps figure a way to solve it.
 
#6 ·
Nice job, that took me about a year to rebuild all my suspension and brakes. I pretty much used the same parts except I bought Eibach Progressive Rate Coil Springs and a roller lower arm. I don't have traction bars in the rear. My car rides great, no complaints here. It is much smoother and responsive then the stock suspension because I drove that for a while before I rebuilt.

david
 
#12 ·
I wasn't referring to your post as bashing. I just didn't want anyone to think I was complaining about the parts installed as being of bad quality. Sorry for the confusion.

As for the LCA torqueing, I never removed it. I didn't do LCA bushings. Just the Shelby drop with the UCA.
 
#19 ·
I'm gonna go another route and say that your increased noise is due to those Grab-a-Track 620 coil springs. I had those exact ones as well originally, with almost the same suspension parts as you, and road noise was evident, and the ride was pretty harsh (especially on L.A.'s terrible streets). I swapped those out for 550 springs (or 520, I don't recall) and the ride got smoother and road noise went away a lot. All is better in the world now.
 
#20 ·
oh wow... never thought the spring might cause it. makes sense though - i had full grab-a-trak suspension and it was complete ****. i swapped out everything BUT the spring because I just figured a spring was a spring.



I agree the 620 can be harsh for any sort of bump - do the 550 springs have a lower ride height from being softer?

also what brand spring would you recommend?
 
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