shelbystang
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Over a Independent Rear Suspension?
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What are the advantages of solid live axle suspension
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Vickstang
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Lighter, stronger (can handle more torque and impact), better for straight line dragging, to name a few....
shelbystang
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Is the live rear end axle cheaper to maintain and more durable than IRS?
Yes to both.
Cheaper to fix because it's a simpler design, which also means it should have less problems on the whole. Also much more durable than IRS. It can take a beating.
As for the lighter part, live axle can actually be 85-150 pounds lighter than IRS.
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MustangDizzle
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A dedicated drag car needs a SRA.
A high performance street car is better off with an IRS.
A high performance track car is better off with an IRS.
A high performance street car is better off with an IRS.
A high performance track car is better off with an IRS.
Thed
Future Pre-Runner
More durable? Absolutely.
Cheaper to maintain? Well, maintain may not be the right word for it. You still have to change the diff oil in both, which is probably the only maintenance you have to do. And most shops charge the same for a two or four-wheel alignment, so that is also negligible.
Cheaper to repair if you break something? Yeah the LRA is a lot cheaper.
shelbystang
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I guess the only 2 main things I dislike is the rear end jumping up on large bumps and the bumpy ride. Cost to maintain and durability are the positive notes maybe LRA isn't that bad as they keep saying.
shelbystang
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:ford:
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Whiskey11
Kill ALL the Cones!
Wheel hop is curable, I'm not sure what you mean by powering the wrong wheel in a corner though... Power application is a function of the rear differential. Each type powers wheels differently. A Torsen will supply power to the outside wheel while cornering up until the inside wheel gets light enough to spin, a clutch based one will try and lock the wheels and tires together forcing the power to go to the outside, an open differential will power both wheels equally up until one gets light enough then it will light the inside wheel up like crazy.
If you are getting a proper limited slip to "power the wrong wheel in the corner" then you may wish to re-examine your rear diff and if it is fine then I suggest fixing the setup issues your car has. Reducing the swaybar size and increasing spring rate will help keep the axle on the ground. When set up properly you'll have a hard time lighting up one wheel without lighting up the other.
Anyway, IRS and Live Axle have unique advantages and disadvantages. IRS tend to be a lot more flexible in how to set up a car, a live axle tends to be easier to set up. Generally speaking IRS is preferable for handling environments due to the quicker suspension response times. Folks will say they tend to handle mid corner bumps better. That works up until you start throwing real springs at an IRS, then they are basically the same crappy response to mid corner bumps as a track prepared live axle car.
One thing is certain, you HAVE TO drive a live axle car correctly in order to be fast. IRS cars can be a touch more forgiving and are a little easier to setup to drive fast while cornering.
Grimace427
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Correct me if I'm wrong Whiskey, the LRA requires a stiffer spring/shock assembly to control the unsprung weight whereas the IRS can run softer springs/shocks to still maintain the same body control and at the same time improve ride quality and stability over rough roads.
Whiskey11
Kill ALL the Cones!
Yes, no, and maybe.
IRS cars have a much easier to tune roll center height which can create more geometric anti-roll (for lack of a better phrase) whereas it is a little more difficult to tune that with a live axle. On the S197 the PHB's center point defined the majority of the rear roll center and it was reasonably high from the factory but it didn't leave much in the way of adjustment or tweaking. A factory IRS wont have much adjustment for roll center height either but the methods of changing it are much less complex and generally cheaper. The price of ball joints or offset bushings as compared to a watts link or custom PHB mounting configuration drives that point home quite well.
Live axles generally have much, much, much lower spring rates than IRS cars and this has to do with the additive nature of the spring rates in 2 wheel bump. It doesn't take much spring rate on a live axle car to drastically change how the car behaves and that goes back to the additive nature in 2 wheel bump and how that impacts body roll during cornering. Since an IRS is independent (mostly anyway) they will run more spring rate to compensate for the loss of roll resistance, or higher rear roll center or any combo of those. For instance, the Boss 302R or 302S race cars shipped out with 600lbs/in front spring rates and 300 lbs/in rear spring rates on coilovers front and rear. In contrast, my buddy's Evo IX SE's Ohlin Coilovers came with 500/400 spring rates. He runs 700/600 now so way more rear spring rate than any live axle car should have. Part of that is the motion ratio difference but his wheel rates were higher in the rear than the Boss 302R and 302S Race Cars in a factory street car.
The ride thing with an IRS comes from unsprung weight and it's effect on the chassis. In a live axle, all 250-300lbs moves upwards which requires a really well valved damper to reduce the upward jolts in the chassis. You'll notice in the 2013 GT500 reviews the reviewers complained about the vertical chassis movement over bumps... it's hard to defeat physics and momentum and the effects can only be mitigated, not removed. By contrast, the unsprung weight of an IRS unit is something like 10x less and thus there is less momentum carried through the springs to the chassis. That results in better ride quality. Damping wise, a live axle car tends to have more rear compression damping which is necessary to control the 250-300lbs of rear axle where an IRS will have far far less and need far far less.
shelbystang
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:shocked::eyebulge::doh::headbonk::shrug:
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