Adjustable Rear Spring Perches

[captainron]

I want my car's stance to be lowered and aggressive. I've come to realize that installing rear lowering springs is a crapshoot, and while coilovers could be the answer, they are expensive. These adjustable rear spring perches from TRZ Motorsports look like a good alternative and the exact rear ride height could be acheived by dialing in the spring perch height. Anybody have experience with these? Feedback is appreciated!

 

[dsapper]

All they can do is raise the height if its to low, not lower it further from a stock spring. Your still adding material between the spring and the perches. Its not really a crap shoot, there are only a couple of companies offering springs for the GN and plenty of pictures and threads of the end result.

 

[novaderrik]

All they can do is raise the height if its to low, not lower it further from a stock spring. Your still adding material between the spring and the perches. Its not really a crap shoot, there are only a couple of companies offering springs for the GN and plenty of pictures and threads of the end result.

if you use a spring that's shorter than a stock GN spring, you could use those in conjunction with some adjustable spacers to get a ride height that is lower than you could with regular drop springs.. of course then you have to deal with the funked up geometry of the arms and how that compromises the handling of the car..

 

[captainron]

Stock springs would not be used. These things are designed to use a 2.5" I.D. spring which can be found in many different heights. So the idea would be to use a shorter than stock spring, say 110 lb. then couple that with a dual adjustable shock. Then you could screw these things up or down to the desired height. How would using these change the geometry of the arms any differently than using lowering springs?

 

[novaderrik]

Stock springs would not be used. These things are designed to use a 2.5" I.D. spring which can be found in many different heights. So the idea would be to use a shorter than stock spring, say 110 lb. then couple that with a dual adjustable shock. Then you could screw these things up or down to the desired height. How would using these change the geometry of the arms any differently than using lowering springs?

if you get lower than you could with a stock spring you'd be in different territory.. it might make it better, might make it worse, it might not matter all that much.. but it could screw things up..

 

[Mike E]

I built some for my 9". The other advantage to them is you can adjust weight side to side. As for adjusting suspension geometry. Most g-bodies have better geometry when lowered a little. But there is a limit brfore you need to look at adjusting mounting points.

I run a 10" long 110 lb. spring.

 

[charlief1]

You can use weight jacks and racing springs like afco or one of the other makers or you can get buckets that go on the top of the spring. Fairly cheap and they hold up fine but may be noisy on the street. The buckets adjust for height and have different legnths so you can get it how you want. They're mostly used in circle track but I've seen them used on street cars as well so it's not that unusual.

 

[captainron]

I think I may try these. It sounds like the diameter of the spring doesn't really matter as long as the correct spring rating is acheived. I have heard of issues with spring alignment however. I just like the idea of being able to fine tune the height +/- 2" without having to guess with a standard spring and shock lowering combo.

 

[murphster]

You can try the ones from Wolfe also:
http://www.wolferacecraft.com/detail.aspx?ID=849

My want to try something like a 12" 130lb spring. Seems like a 10" 110lb would be very low on a stock setup and would need to dial the perches in a lot. A friend is using a similar spring to the 12"/130lb and had to dial up the perch to get back to stockish height. I'm running Belltech 2" lowering springs out back but will be switching to this setup and will start with that spring to see if I can get a similar ride height with the perches all the way at the bottom. With fiberglass out back you may need less spring though.

 

[charlief1]

Stock springs are 122 lbs/in Murph and they need some help. A 130 lb/in with a lighter rear shouldn't hurt a thing.

 

[liquidh8]

You can use weight jacks and racing springs like afco or one of the other makers or you can get buckets that go on the top of the spring. Fairly cheap and they hold up fine but may be noisy on the street. The buckets adjust for height and have different legnths so you can get it how you want. They're mostly used in circle track but I've seen them used on street cars as well so it's not that unusual.

I have used the afco springs and coils, short than stock to adjust the ride height. Daily 100 mile a day driver, no problems.