Dave M

The next mod I want to do to my car is the rear suspension. I've been looking at UMI LCAs and PHR and was wondering if the adjustable versions are worth twice the price. When do I need to spring for the adjustables? Only if the car is lowered? Are there other times it's better to have the adjustable version?

For reference here are the two versions I'm looking at:
Non-adjustable: http://www.summitracing.com/parts/up...20-b/overview/
Adjustable: http://www.summitracing.com/parts/up...29-b/overview/

NewOrleansLT1

Stock height and stock tire size? If so then non adj is fine if your on a budget..

Badazz 97 TA

iTrader: (18)

its really nice being able to adjust it yourself if needed. It all depends on what you plan on doing with the car. Its more expensive to buy things twice then to just save a little more and go with something that will work no matter what you plan to do later down the road. Ex: keep stock, lowered, other suspension pieces, etc...

Dave M

Stock height but not stock tire size. And I do want to consider that I may make changes down the road, so I guess it'd be best to spend a little more now than a lot later. What is the difference between these two sets?

http://www.summitracing.com/parts/up...21-r/overview/
http://www.summitracing.com/parts/upi-201829-b

Is it simply that one is on-car adjustable? Are there other differences? What does the rod end get me over the more traditional design?

pillarpod

your first link, the rod ends can be rebuilt. Don't know how crazy your build will be, but single are fine.

Paul Bell

iTrader: (9)

Stay away from rod ends on the street. They will eventually make noise.

guppymech

iTrader: (7)

All the searches I turned up say that Poly is good for the drags but binds up the rear for everything else, no side to side compliance. Don't know if there is a happy medium, maybe UMI's roto joint. Moog makes a solid rubber bushing for the stock lcas, kind of a 1LE equivalent.

sweetbmxrider

iTrader: (13)

Probably the dumbest thing you could do is buy non adjustable suspension. Leave it stock or get adjustable ****.

Paul Bell

iTrader: (9)

BMR has a rear lower control arm with hard rubber bushings-way better than the flimsy stock arms with Moog harder bushings.

I also stay away from Poly when I can.

smitty2919

Def an adjustable PHB. I'm unsure if you REALLY need adjustable LCA's.

And even with the possibility of added noise, I would still go with him joints over anything poly.

What are you using the car for?

Dave M

I'll be using the car mostly for weekend cruising but there will be the occasional strip day and I'm hoping to do a little SCCA racing, but I'm not looking for a race-only car. What's so bad about poly? When I was in this hobby 10 years ago everything was poly poly poly.

02ls1gun

Have you called any suppliers to get thier take? Im in the same boat. Im about to be ordering the rest of my suspension and were wondering the same thing

guppymech

iTrader: (7)

The following is from Global West's web site but a search of the suspension topic forum will turn up many similar resposes.

"Polyurethane bushings used on both ends of the control arm. This type of a control arm is best used for drag racing. The bushings however, limit the rear end from articulating. Many drag cars can get away with this because of the way the car is set up. If this type of arm is used on the street or road race applications the rear suspension will be placed in bind when the car goes over bumps and around corners. This is because the control arm bushings will not allow the rear end to have proper movement.

Consequences: High speed oversteer, possible over stressing the suspension mount, reduces tire loading during cornering and ride change."

Dave M

Every aftermarket suspension piece I've seen has poly bushings, at least that I've noticed, other than those rod ends. What's a good aftermarket setup that is best for my application (mostly street, a little strip and road racing?) would the rod ends be best or am I looking for rubber bushings?

Paul Bell

iTrader: (9)

I'm a big fan of Delrin. For the front lower control arms, the closest you'll get to it is the UMI Delrin/Rotojoint arms.

I HATE the front lower arm bushing design. I wish it'd be two straight bushings in-line like the upper arms. And why hasn't the aftermarket (UMI & BMR) made a K-frame and lower control arms with in-line bushings?

Shownomercy

iTrader: (1)

Yup, I have all non adjustable stuff expect my torque arm and its prob all gonna get replaced before next fall.

Dave M

Ok, so I've decided on adjustable, now I just need to decide on a bushing.

bufmatmuslepants

iTrader: (3)

I had DA poly ended LCAs, double rod ended LCAs, and non adjustable poly ended LCAs. The double adjustable poly ended ones would actually bind and twist and pop at the center under a hard turn, like it would force itself unlocked, that got annoying. The double rod ended stuff articulated great but transferred all vibrations to the car and I got tired of it. Now I'm on the non adjustable polys now and they do not MOVE. I got them for free and will be stepping up to poly 1 end rod on the other end soon to get articulation and noise isolation.

Dave M

So you would recommend something like these?

http://www.summitracing.com/parts/upi-2016-b
http://www.summitracing.com/parts/upi-5022-b/overview/

bufmatmuslepants

iTrader: (3)

That's exactly it. There are other brands, vendors and prices though if you shop around.