TahitianGreen

Is there any performance benefit to be had by switching to an ITR-style rear LCA?

Beyond that are there any gains associated with switching to an aftermarket LCA (not KSport, Junk2, Blox, etc., I'm willing to spend to get the best)

Thanks in advance.

If this is a repost please link me to a thread that addresses the same issues.

I've searched but I wouldn't be surprised if my wording was poor.

VTECIntegra9

The only benefits I've seen with the aftermarket LCA's are ones with different bushings and of course a slight decrease you receive in un-sprung weight (only about half the LCA weight will factor in). As for ITR lca vs. the 'standard' LCA, (and this is purely my educated guess about the system) is a decrease in compliance and torsional stiffness of the part. A part with a U cross section vs a Part with a + cross section, of similar weight and bending strength will have a greater torsional stiffness (resist to twisting) because of its geometry. I am not sure how much loading is taken up by this twist - not nearly as much as the bending moment.

Also, the U shape in bending is going to have less compliance (more stiff) because the shock is mounted between the two hinged joints, all of your load is being resisted by the shock/spring at that point - so your effective spring rate at the wheel will be closer to accurate than a more flexible bar, which induces its own spring rate on the system.

Sorry for the novel - it may be complete BS if people have done any sort of studies on the two... I could actually try and squeeze in a stiffness test in at work on a machine here and compare the two when loaded at the shock mount - once I get my package of goodies.

Now put down your sword and join the winners.

P.S. Selling 2 Charlie Sheen tickets - Detroit - Mezzanine! lol

Put down the sword and join the winners.

TahitianGreen

LOL

and thanks for the explanation, it makes some sense

chrisb

Don't sweat the rear LCAs much. The design is flawed from Honda and any arm you choose is going to be problematic. The issue is the rear sway bar rotates the rear LCA and if you go with sphericals in those arms it gets much worse. If you are talking about a dedicated race car I would save any money up for engineering a solution for mounting the rear sway bar so that it won't rotate the rear LCA. For example mounting to the RTA like RealTime did.

You definitely don't want the Type R rear LCAs as no one really messes with a spherical conversion for those arms since the bearings would have to be tiny and it is difficult to press the stock bushings out without deforming the arm. I personally would never have some "forged" LCA (I would be shocked if it is actually forged) Chinese/Taiwanese slave labor made crap as a suspension component. But that is just me. I don't source my race car parts from 3rd world countries. I am a snob that way.

Edit - P.S. Missed the "not" part of your post. Good man.

Atmosfear

iTrader: (18)

The only aftermarket ITR rear LCA I would consider at this point is the Function 7 pieces which are available in a hard rubber or spherical.

I have asked Kiwi to look into what is available from Hardrace.

I wouldnt bother making the change to the ITR style but I recently came across an Ohlins suspension that requires the ITR rear lca.

kristo

The 'eye' arms (the 'Type-R' as you call them) were first used on CRX and 4gen Civic (JDM only?) top models.

Very soon these arms were dismissed in non-JDM markets since they made the cars very '***-happy', resulting in a lot of accidents. Apparently the eye-arm has a tendency to 'steer along'.

As you know they were kept on ITR models.

TahitianGreen

Thus far the general consensus seems to be stay with what's on the car + new bushings

I think I may order some brand new OEM rear LCA's from Honda...and then throw in some proper bushings.

Creator

iTrader: (1)

Sorry, not tryin to thread jack, but figured you guys would know. Does the ITR rear sway link up to the LCA differently then the the GSR sway?

TahitianGreen

^I've been wondering this too.

chrisb

My GSR race car has a Ground Control sway bar connected to Type R rear LCAs and my street car has the stock style cast arms. Both bars connect to the stock mounting location at the front side of the arm. If you are asking if the Type R LCAS will rotate as with the GSR the answer is yes. I just have stock bushings in the rear because of that.

I actually have a business designing, manufacturing and selling spherical conversions for Hondas. But for a ton of reasons I would retain the stock arms, mount the sway bar to the RTA and then and only then install the spherical parts that I make into the stock rear arms. However, I have a customer testing some turned delrin sleeves with my parts that limit how far the rear LCA can rotate. He has not tested the parts yet however.

Atmosfear

iTrader: (18)

Let me know how that works out Chris. Im looking to go all spherical, but not looking to spend the $$$ for a custom rear sway, endlinks & modified RTA.

TahitianGreen

I'm intrigued by mounting the sway bar to the RTA

chrisb

Will do Atmosfear. I think it will help. I just don't know how long the delrin will stand up to the abuse and how much better the feel will be. Obviously, I had to leave a little clearance between the delrin spacer and the LCA so the suspension can travel through its range without bind.

@TG I had a pic somewhere of the RealTime setup. It is pretty radical. The sway bar is like a huge pipe actually that passes through the spare tire well. Their particular setup would not be legal for SCCA IT racing or Honda Challenge either as far as I know. But a customer of mine is trying to have an alternate bar developed that does not require so much modification.

TahitianGreen

Well I'm not in for SCCA/Honda Challenge

It's just for track days/weekend fun

Jaker

What about mounting the lower attachment point of the sway bar link just like the shock: a fork style mount that goes to both sides of the LCA? That would easily stop the LCA rotating from the sway bar forces.

I had Function 7 put sphericals into my F7 ITR style LCAs, but I told them I wanted to retain the regular poly bushings at the outboard mounting point for this very reason. I have sphericals at the inboard end, my GC Advance Design shocks are spherical on the bottoms, but the outboard end of the LCA is still poly.

I don't currently have a rear sway bar, as the car is RWD, but I was thinking ahead should the need arise.

descartesfool

FYI, RTR's ITR rear bar pics. No chance of rotating the stock rear LCA with their rear roll bar force application point at the hub.

RR98ITR

Ugh...not to try to take anything away...but it's always RTR this and RTR that. There ARE other examples to look at. The DC cars were made by smart people who knew what they were doing, and in this case provide a more practical example of what might be done. Stand the bar mounts back off the subframe about half the width of the LCA, cut out the top of the LCA enough to get a rod end down in between the two bosses you welded in the front and back of the arm, and then box the bottom of the arm. Very Nice. And about the one big frequently expressed obvious concern: no, the subframe wont rip apart because you're going to use stiff springs cause you're not a dummy. The DC cars ran like this well into their afterlives. It works. Anything else is just making extra work for little gain.

Scott, who "Hey! What did he say?"...

Tyson

totally untrue information.

stay off the tigers blood.

slick1851

Honda never made a car *** happy, they looked to build balance and a controlled car. I have never heard of anything being that *** happy aside from a S2000.

Atmosfear

iTrader: (18)

I like your solution Scott. Seems much more practical and uses parts we already have and/or are readily available.

kristo

Some quick googling learns you have disagreed on this matter before.

As I'm of course not a CRX expert I won't argue but unless this discussion has been settled permanently somewhere I feel it has its place.

redzcstandardhatch

this is exactly what i'm halfway through doing.

kristo

Very interesting.

What in fact are the effects of such warping of the LCAs?

Any offhand solutions for the EK? The 'Type-R' style arms from F7 don't seem to accomodate such a mod.

The Destroyer

Where are you reading about warping? Can you elaborate? By warp im thinking you mean a permanent deformation.

The only thing I could pull from the thread at hand is what VTECintegra9 posted, and that isnt warping. Which I think are just internal moments and reactions in the LCA. Im not sure how much of this the driver would directly feel.

Im probably wrong like I am most times, but I enjoy the possibility of spreading misinformation and then learning from it. Im thinking the ITR got the hollow stamped units for weight reasons, and im also guessing the ITR rear strut is lighter as well. They used bigger brakes in the rear and may have been making up for it in another area.

descartesfool

Is the motion ratio the same for both types of LCA, ITR one and regular one?