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Adam Hartzell
11-15-2011, 06:02 AM
I know that the RSX LCAs move the knuckle 5mm forward on an EP3, but are they wider than the stock EP3 LCAs? Or is the extra width in the RSX chassis in the chassis and subframe?

27rocks
11-15-2011, 07:57 AM
You must be thinking about the ITR ones... and its just the LCA's. All the base RSX and RSX-S from 02-04 have the exact same LCA as our EPs. The 05-06 RSXs have a larger ball joint hole but he geometry is the same. The only one that is different in the way you are thinking is the ITR.

Adam Hartzell
11-15-2011, 08:18 AM
Yea, I was thinking of the ITR ones. Mugen lists the same part number for EP3 and DC5 chassis on the Alu. LCAs, but I can't find anywhere that says if they push the track width out. I do remember reading awhile back, that they do push the knuckle 5mm forward which will help with he amount of caster I want to run.

Hasbro
11-15-2011, 11:34 AM
I believe they are 10 mm wider each. They do widen the track.

Adam Hartzell
11-15-2011, 11:58 AM
Thanks. I'll just stick with the OEM arms and put sphercial bushings in.

Hasbro
11-15-2011, 08:17 PM
They are also 6 lbs. lighter and can be found used for around $250. .8" more track and keep in mind it will change the spring weight a little (I think). Not sure how much but I figured about 5-10%. Anyone know?

Adam Hartzell
11-16-2011, 05:15 AM
The more angle you put on the shock, the more leverage you give the arm, so it would result in a softer feeling rate. The spring rate itself doesn't change, but the amount of force needed to compress it is lower.

Also the more you angle the shock the faster the car can roll. Not really something I'm looking for as I'm building this car as a dedicated time attack machine. Loosing an extra 6lbs would be nice, but I'm already removing anything that isn't 100% necessary.

Zzyzx
11-16-2011, 03:10 PM
your focusing on the relatively minor problems associated with these LCAs and glossing over the benefits. Benefits like less overall weight transfer on the nose thanks to the wider track (nothing but good) and the Increase in static positive caster (Yippee free dynamic negative camber gain!). And you haven't even looked in to what it does to the cars suspension geometry (instant center).

the first two in my opinion far out weighs the minor increase on leverage the suspension has to use against the springs... Which is easily mitigated by a minor increase in roll resistance. And the alteration of the cars front end geometry begs further investigation.

the only other thing to look it is the restrictions on anti-roll bar choice. as they would limit you to only ITR bars. Which really isn't a problem given that you are planing on building a track car. In which you probably should be planning on not running a front anti-roll bar at all and tuning the rest of the suspension around that.

27rocks
11-16-2011, 06:28 PM
your focusing on the relatively minor problems associated with these LCAs and glossing over the benefits. Benefits like less overall weight transfer on the nose thanks to the wider track (nothing but good) and the Increase in static positive caster (Yippee free dynamic negative camber gain!). And you haven't even looked in to what it does to the cars suspension geometry (instant center).

the first two in my opinion far out weighs the minor increase on leverage the suspension has to use against the springs... Which is easily mitigated by a minor increase in roll resistance. And the alteration of the cars front end geometry begs further investigation.

the only other thing to look it is the restrictions on anti-roll bar choice. as they would limit you to only ITR bars. Which really isn't a problem given that you are planing on building a track car. In which you probably should be planning on not running a front anti-roll bar at all and tuning the rest of the suspension around that.I highly disagree with this!!

Hasbro
11-16-2011, 10:31 PM
I highly disagree with this!!

Why? It's been proven many times. Steve Hoeschler, a major advocate of heavy springs and no bars has 7 National Championships. So far.

27rocks
11-17-2011, 06:02 PM
Why? It's been proven many times. Steve Hoeschler, a major advocate of heavy springs and no bars has 7 National Championships. So far.Is he a cone dodger?

Zzyzx
11-17-2011, 10:39 PM
Is he a cone dodger?

Irrelevant, the laws of physics do not change simply because you've changed venues. The end tuning may differ, but the theory remains constant. It is in your best interest with a FWD car to run the softest front anti-roll bar you can get away with. If you are able, for a track car, running no front bar and tuning the rest of the suspension around that would be optimum in my opinion. You maximize front end grip by minimizing lateral load transfer; and given that the front end on a FWD car will always be the weakest link handling wise any thing you do to improve grip there can only be a good thing.

Can you make a fun and well handling car with a stiff front anti-roll bar? Sure, but you are sacrificing front end grip to do it (and thus would be slower on track because of it).

Remember, Grip & handling balance are two very different aspects of a cars handling package. And improving/altering one does not necessarily improve/alter the other.