The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by ChefMike, Feb 2, 2012.
each vette hub has 2 supporting arms, the jag has 1
Most people I see with independent rears on trucks did it so that they could bag the truck and drop it in the weeds. If you are going to put ifs and bags all the way around the irs makes sense. It will drive nice and smooth plus disks brakes are built in
the original HMMWV ( HUMMER) had four wheel independent suspension and was made to be able to handle a trailer but is a bunch beefier than the ifs you will be putting under your truck. most people will not see your suspension or will have any idea whats going on til they climb under it and look.
Looking at pics of both I really don't see anything that looks to give the corvette and advantage. The jag looks to have a beefier bottom arm and 4 coil overs, wouldn't by your reasoning make the Jag a better choice, it has 4 shocks and springs?
I am planning on using the Jag IRS for 4-wheel disk brakes, chevy bolt pattern, chevy bearings, nice handling, lighter sprung weight, posi rear (for dealing with the snow), and it will be coming with the IFS donor vehicle anyways, seemed like a no-brainer to use it!
you have to look at it from the hub, its absorbing/trasmitting all the torque & the vettes arms inline with that torque.
Anyone have any facts related to towing with IRS? Is this just a matter of opinion due to the relative strength, or is there some issue related to the actual suspension geometry? My owners manual says towing is not recommended with my off topic c5 zo6, but doesn't say why. Like most hot rodders I'm planing to put on a hitch anyway, although I will only be towing a kayak trailer. I'm also planning on using C5 suspension in the future on a car that might haul a little more.
With a unibody frame/body construction from 84 up, made of fiberglass & metal, aside from the kayak (that did make me LOL) heavy towing might fracture/crack the unibody.
There's nothing wrong with IRS in a truck. You can get better handling with the lower unsprung weight, But you don't have to compromise towing capacity, either. You just have to engineer it to do what you want.
I put an 8.8" irs in my A because I got it Cheap and thought I could just put the suspension in as a unit. It took a lot of work to graft in. In the end, it's heavy and takes up a lot of space in the car. It does not look good from behind.
Pro: nice ride and good brakes
Con: ugly, so keep it covered
I respectfully disagree. I think my Vette rear looks tits under the Burb, but this being the HAMB I don't post pics up of it, nor discuss it much.
I don't think my rear end looks bad at all....
Its not a unibody . Its a hydroformed steel frame. actually its not even fiberglass. Its sheet molded compound. The hitch wouldn't attach to the body anyway. Sounds like the can't tow with its statements are guesses.
I think pick-ups lack the necessary weight in the rear to take advantage of the IRS designs.
If you are going by just the weight, the IRS would be the one to choose.
Because if the rear end is light, the weight of a rear axle ( unsprung ) will be high in comparison to it.
Personally, I like Non IRS axles.
And not just for aesthetics...
Then I am wrong. Thanks!
Not really. Actually, just the opposite if the rear end and related components are chosen wisely. Hers why: One of the major factors in achieving a good ride and absorbtion of bumps by the suspension, as opposed to transferring it to the body/chassis and occupants, is the ratio of sprung to unsprung weight.
Sprung weight being what the name suggests...any components whose weight is borne by the springs.....Unsprung, just the opposite. Unsprung is wheels, tires, brake assemblies (if not mounted inboard) axle housings (for live axles), portions of control arms, etc.
So, with that in mind, the lighter the weight of the vehicle, the greater potential for it to benefit from an independent suspension that minimizes unsprung weight. This of course assumes the springs, shocks etc. are also selected appropriately for the loads involved.
All this is at least part of the reason everybody always used to say light cars ride rough, you gotta have a heavy car to get a good ride. It really had less to do with the weight of the light car, but light cars were typically cheap cars, and they didn't (couldn't) spend any money for a more sophisticated suspension to get a good ride. As a consequence, the ratio of sprung to unsprung weight was unfavorable and a poorer ride was the result.
The heavy car, by contrast, had a much more favorable ratio of sprung to unsprung weight and generally a much better ride as a result. The weight of rear axle assembly in Falcon or Chevy II is only marginally lighter than that in a Galaxie or Impala. But the weight of the larger vehicle is substantially greater, so better ratio of sprung to unsprung occurs as a 'natural' consequence and without a significant increase in cost.
slight detour, but great signature
You say Guess, I say Hypothisis. Either way, dont tow with a vette. Well, unless its a kayak.
Just because people do it does not mean that it should be done.
To use an IRS effectively, you should have a stiff frame. With a solid rear axle, you can use a more flexible frame such as '30s era vehicles. Manufacturers were well aware of frame flex and used a lot of rivets instead of long continous welds. The longer a coil spring, the better the ride with a heavy vehicle think '50s Cad, Olds, Imperial, and so on. Lighter cars that have IRS and IFS, need a stiff frame so the "Independent" components can work as designed. A flexible frame with independent suspension is a lot to try to control effectively on the typical street or road.
Why not just put a power stering box and pump on the suspension you have? Seems like it would be a lot cheaper and just as effective for easing the effort it takes to turn the stering wheel.
You must have some other reasons you didn't mention for swapping out your entire front suspension. I'm sure you've thought it through a lot longer than the time it took me to type this.
Care to tell the reason(s) to those of us willing to hear?
IMHO, it's a truck. With almost no exceptions, it should have a leaf sprung solid axle. Handling and steering has almost nothing to do with the rear axle.
I see all those semi-trucks on the road with solid axles. Modern trucks are still using solid axle rears with good results. If it ain't broke, don't fix it. If you want better gears or brakes, get a newer truck axle and swap it out.
It's a truck.
I say do it. But I'm also biased as I'm finishing up putting 95 Vette suspension at both ends of my 55 Caddy and am going to use 04 GTO rear under my 48 International KB1 with probably S 10 front clip. But hey, its YOUR deal so you will have to live with whatever choices you make
My old o/t C4 was a no tow, and this is why:
If the irs is installed in a full framed vehicle correctly, then I don't see how it would be an issue. I still wouldn't do it ( why try to wear out the rear end? ) but it should work.
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