I wanna buy some Lca's soon. But before I make up my mind on which ones to buy I want to ask a few questions on the different constructions and materials used on different brands so that I can understand what I am buying because I know nothing right now?

1)Whats the reasoning some companies use square lcas like edelbrock and others use round tube? One better than the other??

2)assuming both are round tube design and .120" thick steel, which is stronger one with a diameter of 1 5/8" or one with 1 6/8"?

3)Stronger between these. One with a thicker wall of .120 but smaller diameter like 1 4/8- 1 5/8 or one thinner wall like .110" and larger diameter of 1 6/8"?


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1987 Iroc 350
GTS headlight/tail light covers
Camaro SS Wheels w/Sumitomo HTR ZII 275 rear, 255's in front
K&N filters
Adjustable Borla cat back
SLP 1 3/4 headers
w/ Air born coating
3" Catco cat
Large tube runners
ported plenum
Holley afpr

FUTURE GOAL:
To go really F'in fast!!!

Some pics of it at
http://albums.photopoint.com/j/Album...949&Auth=false or (still working on) http://members.cardomain.com/john87iroc

 

First off. You get what you pay for. Saving money on cheap parts gets you cheap stuff. With that out of the way..

1) Usually copyright laws. Both are equally good. Round ones look more factory. Tubular are usually stronger because it's harder to bend a round tube than it is a square tube.

2)1 6/8", what's that supposed to be? The larger the diameter with the same wall thickness is stronger.

3) What are you trying to do, make your own?

Buy some aftermarket ones that fit your budget. If for whatever reason you somehow damage them, go back to the manufacturer for a refund.

Better yet just buy some Spohn ones and be done with it.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block

Best ET on a time slip: 11.242 altitude corrected to 10.89
Best MPH on a time slip: 121.52 altitude corrected to 125.89
Altitude corrected rear wheel HP: 497.9
Best 60 foot: 1.546

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

If your going to be asking suspention questions wouldn't these be more reasonable?
What is better solid rod ends or poly bushings? Are adjustable ones worth it? The quality of the steel is a major factor as well. Most suspention parts with rod ends are only a couple of sizes because they are tapped for the rod ends. Poly kits are bigger because the bigger tubing resists flexing and they can use a thinner wall.

 

Could you give some idea of how the car will be used? What may work OK at the dragstrip is not necessarily the hot tip for daily driving (which implies cornering and driving in bad weather) and is usually all wrong for a hard-cornering autocross or road race car.

That's really the question that needs to be answered first. And then some answers to nicmike85's questions, particularly in regard to the rod ends vs poly bushings. Go visit the autocross & road race forum at www.camaroz28.com and do a search for "lca's". The "lca's binding" thread is 4 pages and almost 100 posts long that contains a lot of info about LCA's and how they are supposed to work. Another particularly useful thread that will pop up in that search is "lca flexibility".

Making your own? If you want exotic, cut down some Coleman aluminum lca's and fit them with 3/4" QA-1 rod ends. Minimum weight, zero bind, better rod ends than Spohn uses, and about 20,000 lbs load capacity, all for about $75 per side in parts. Jon A describes his in the "lca flexibility" thread.

All of the various aftermarket lca's are strong enough for street or street/strip duty. BTW, it's not just a single measurement of strength (or stiffness) but several. Engineering formulas are available to compute these properties (that's one of the things I do for a living). My take on the cross section shape (round or square) is that it's more a marketing gimmick or fabrication choice than an engineering feature. If anything, the beefier ones add some extra sprung and unsprung weight. Structurally, I'd perhaps be more concerned about things like the dimensional accuracy and weld quality of the actual pieces that get delivered. In terms of vehicle dynamics, the low-bind solutions are much better if you take corners with any enthusiasm at all, drive in bad weather, or have a really serious strip-only warrior.

Norm



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1979 Malibu w/some cornering tweaks and a few other interesting things

 

w


[This message has been edited by john5.7 87Iroc (edited August 17, 2001).]

 

I really didnt know where to begin. I really dont know much about them and I was trying to put together some of the things I read in the archives that where still unclear to me.


Norm Peterson,


My car is and will always be daily driven and I usully drive 300 miles a week. I would like to auto cross and make it to the strip once in a while but havent done either yet. I drive my car hard on the road. I take corners as fast as possible but I am also racing from stop light to stop light in a straight line. So I want something that will be in beween street/strip/autocross but i really like cornering so I would like to put a little more emphasis on that.

I will check out those threads you mentioned.
Thanks alot

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1987 Iroc 350
GTS headlight/tail light covers
Camaro SS Wheels w/Sumitomo HTR ZII 275 rear, 255's in front
K&N filters
Adjustable Borla cat back
SLP 1 3/4 headers
w/ Air born coating
3" Catco cat
Large tube runners
ported plenum
Holley afpr

FUTURE GOAL:
To go really F'in fast!!!

Some pics of it at
http://albums.photopoint.com/j/Album...949&Auth=false or (still working on) http://members.cardomain.com/john87iroc

[This message has been edited by john5.7 87Iroc (edited August 17, 2001).]

[This message has been edited by john5.7 87Iroc (edited August 17, 2001).]

 

If you want to emphasize turning then make your next mod a bay brace. You will like the results.

 

I didn't see subframe connectors in you sig. Start with those. You can't go wrong with any of the spohn stuff.


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350 with stealth intake, holley carb, 470 lift cam. 700r4 with .5 boost valve, vette servo, tci lock-up kit, B&M megashifter. Richmond 3.73 gears, powertrax locker, timkin bearings, synthetic lube. Custom 3 inch single into 2 2.5 pipes. 1 1/2 drop springs, 1 5/16 solid front sway bar, 1 inch rear bar, custom subframe connectors, custom LCA relocation brackets. Kobel ground FX, current red metallic paint. Lots of other stuff...
82camaro