Are the GT500 lcas a significant improvement to our cars? How do they compare to JM?

 

i've been told that the bmr or steeda'a are an upgradeabove the GT500s and probably cost less than them as well

 

How much are the GT500 LCA, BMR's is only 130.

 

i've found the GT500s for 100 bucks. JM for 115. heard great things about the JM but havent heard too much about the GT500

 

Hi dmbeard,

Is there something wrong with your stock LCA's? Is retaining a good ride and minmal NVH important to you? If you answered yes to any of the ride questions FRPPGT500 LCA's are likely the better choice for you as they are asignificant upgrade in terms of rear axle control but also retain near stock levels of NVH. Also unlike J&M (no matter what their marketing people would have your believe) or any other LCA that usespoly bushings on both endsthe FRPP GT500 bushings havea lower level of bushing binddue to the fact that theyuse a vulcanized rubber bushing design that allows more fredom of movement than the constrained poly bushings in shellsthat are the standard of the industry for some reason (I guess because they are the cheapest on the planet). But the trade off is thatthe FRPP GT500 LCA's cannot control the rear axle quite as well as a regularpoly bushing or rod end but on a normally asperated engined car this is not a problem as they were designedfor the 500bhp GT500 worked fine when used witha stiffer UCA bushing or an adjustable UCA which I can highly rcommend you install if you are lowering the car or want to run at the drag strip.

Currie (yes the rear-end &axle people)makes a superior poly bushing called the Johnnie Joint. The Johnnie Jointworks nearly the same as a rod endin terms of axle control, freedom of movement/ misalignment but is more like a standard 2-piecepoly bushing in terms ofNVH. But nobody is using themin their LCA products for the S197 chassis I supposebecause they cost too much and were NIH (not invented here). So here we are stuck trying to decide between thenoisier harsher andshort lived rod ends or the sort of quiet(except for when they squeak due to thecold orjust run dry)but firm riding (due to binding) poly bushings.Oh well...

HTH!

 

The GT500 LCA's look the exact same as ours. I'll get some pics up tonight. Dont waste your money and go buy BMR, Steeda, or CHE

 

I just installed the BMR Billet LCA's and relocation bracketsa couple of weeks ago, I have not noticed much if any ride difference or any noise difference as for performance I will know more once I get my DR's.

 

It isn't what the arms visually look like at a casual glance that matters when it comes to axle control. The important thing is bushing stiffness, and that's not something you can tell just by looking at them. The difference is that the SVT arm use bushings (FRPP catalog, PN M-5649-R, page 47) that are higher Durometer, or stiffer than the standard LCA bushings. Bushing stiffness is what locates the axle more precisely, and is what's mostly responsible for thequieting down of cases of wheel hop when you upgrade the LCAs and UCA.

Chip has provided a lot of good information in a small package. But I can add a little. One of the reasons that the FRPP bushings are slightly softer is because too stiff will start to twist the LCAs themselves, which is not the hot tip for loading a sheetmetal stamping. It's still an upgrade, however.

Conventional poly bushings work fairly well for a street/strip car that isn't cornered very hard, and that's about what those things should be limited to. In hard cornering, they work against careful suspension tuning, or at least force compromises in it. Bushing bind in roll is a topic that's been extensively discussed elsewhere, and I've done a little "one-off" tinkering of my own on this (Chip: think voided bushings). Let's just say that the effect of out-of-the-box plain poly bushings can be as great as adding a medium-sized rear sta-bar where there was no bar before - or doubling up on the one that is there.There is an associatedride quality effect that is clearly noticeable even during mild/moderate driving over certain road conditions. The S197 may be a little better off in this respect than the Fox/SN95 for which there is some actual aftermarket test data available, but the effect is still there.

What I'm getting at is that there is more to rear LCAs and their bushings than first meets the eye. Again, they're generally fine in street/strip cars that don't ever see hard cornering. But they are not "universal solutions" for all rear axle location issues, notby any stretch of the imagination.


Norm

 

I'd ask what the reasoning is for upgrading arms. I'm guessing, like most of us, you have some wheelhop. I'd not spend the money on the GT500 arms, you can get much stronger ones aftermarket for not alot more money.

There are a ton out there. Of course the Steeda's, MM's, Edelbrocks, etc, etc..... I sell a lot of them, but I always use and recommend the UMI unit's I sell. You might not know UMI but they've been around a while, and I know them from the F-body world (they are also right up the road from me).

Why do I put it on my cars when I can (depending on what class I'm running) and I why I recommend UMI products? A lot of reasons really.

The parts and materialare top-notch. Great welders, beautiful powdercoating, billet adapters when rod-ends are used and on the list goes. Value is another.Inexpensive isn'tso hot if you geta cheap product,and UMI's stuffcertainly isn't that. Expensive is fine, if the itemhas something of value forthe price. There are some very, very overpriced parts out there from "big name" suppliers.

A few folks here have bought UMI products from me, and hopefully they'll pop in with their impressions of the quality, because good word of mouth is the best proof.

All that said, whatever you decide, you would be best served by LCA's that will allow articulation. With the UMI arms, we recommend these: http://www.stranoparts.com/partdetai...&ModelID=5

I like these because they cover all bases. The are very strong. The rod-end allows the LCA to articulate and doesn't bind the axle in roll or over "one wheel" impacts. The poly bushing in front isolates noise and vibrations. And.... you can correct any axle alignment issues that you may have. And the price is right @ $179 a pair.

There are also non-adjustable arms for $114.00, http://www.stranoparts.com/partdetai...&ModelID=5and double rod-ended ones (full race) versions for $219.00 http://www.stranoparts.com/partdetai...&ModelID=5

 

Thanks for all of the info. Does anyone have any firsthand experience with the umi's? Oh, and i am not looking for any cornering help, just straight line.