solid rear axle or IRS and why

[56_3100]

If you had the choice would you go with solid axle or C4 independent rear suspension? pro and cons to both, but want to hear your opinions.

Thanks

[Dan in Pasadena]

I am constantly trying to decide between IFS/IRS and stock suspension with a dropped axle. IF I go with independent suspension (and I likely will) it'll likely be C4.

With C4 IRS it is somewhat less strong for all out, uber high horse power drag racing type use. Do you plan to do that? But remember, it came out of a Corvette which IS made for performance use. So I'd not worry too much about that.

It also can't tow significant weight - a consideration for me because I have a boat and two Jet skis. I THINK it would be capable of towing the skis but definitely not the boat.

[47 Fasttoys]

For the of the rear in a truck, solid every time. IRS is great for a sports car. It can even work well in a 4WD. In a truck you may be hauling a load which is heavy on one side, on an IRS this will effect ride more then it would on a solid axle. Also, a solid axle can be set up to handle quite well with proper suspension tuning. I just don't see the benifits of IRS on a truck. It's a truck, it is not going to handle or ride like a Corvette. The Corvette is a complete package which involves much more the just suspension parts. I've seen trucks that have had IRS installed only to find it would corner worse do to the high center of mass and a lot of body roll. If you add a large enough sway bar (anti-roll bar) and shocks to overcome the body roll soon you find it rides just like your solid axle. Now, for the wow factor, yeah, go for it. You can tell all your buddies you've got a Corvette under the body, just make sure one of them isn't driving a Vette that day.
Rant over, have a nice day,
Rob

[Speedbumpauto]

IMO, biggest reason for installing a /vette IRS in a truck, other than the great brakes is.......because you can......and there's nothing wrong with that.

[mr48chev]

A couple of good points there. For the handling and ride and just because you can.

I had serious plans to go C-4 front and rear a few years ago then decided that it wasn't in my budget to do so. I even had a deal made for the Corvette suspension already out of the car sitting on a pallet but couldn't come up with the 700 asking price at the time. I was also going to put a 396 and matching turbo 400 in it at the time and still have both stashed away.

Current plans are Jag XJ front suspension and a Firebird posi rear axle with Dodge Caravan rear springs and hangers. Not exotic and it may not give the absolute best ride or handling but the XJ steering matches the wheelbase better than the MII kit I have in the shed and the leaf spring rear setup is simple and easy to setup and will give
problems later.

The main thing is that we build trucks with safe and well thought out suspensions and good brakes be they drum/drum, disk/drum or Disk/disk setups.

I'd still like to have the ride and handling of a properly set up independent rear suspension though. The truck will never haul a load beyond duffel bags, lawn chairs and cooler and will see a lot of serious long distance road trips of several thousand miles each.

[NEWFISHER]

Originally Posted by 56_3100

If you had the choice would you go with solid axle or C4 independent rear suspension? pro and cons to both, but want to hear your opinions.

Thanks

Will you be using it as a truck or using it as a car?

You can then decide which way to go based on the way YOU will want it to drive, handle, haul , brake, look etc.

[whitedog76]

Parallel leaf spring suspension is about as reliable and trouble free as it gets. They've been used on cars, well since covered wagons to be precise. There's a reason that we're still using them, because they work.

There's literally thousands of types, lengths, etc... of leaf springs. You just have to pick what's right for you.

On the other hand, IRS- like they said, depends on what you want out of the truck. If you want a great handling truck, go for it. It's a little pricey, so break out some Benjamins.

A good compromise is rear 4 link. You can get the adjustability, ride, and handling of the IRS and the ease of installation of the parallel leaf.

[56_3100]

Good opinions from all you!

Yes it's a truck, but like mr48chev it wont be hauling much weight (cooler full of beer at most). This will be a wknd driver, no drag racing. I'm hoping the C4 Dana44 can handle a little abuse ~350 hp

47fasttoys gets me thinking of the potential body roll with the higher center of mass on these trucks in comparison to a vette.

Another question is the face to face on a C4 setup? anyone have experience with this on a 55 chevy truck. Solid axle can be cut to size C4 on years 84-87 is a set size.

[49bowtie]

My two cents worth, I drove my 49 around for years with a Camaro clip up front and a straight axle from the same donor car. My 350/350 was nothing special, but could lay rubber when needed. I came across a C4 IRS for dirt cheap and grafted it in. The biggest difference I notice whenever I drive it, is it doesn't break the tires loose nearly as easily. It seems to get much better traction and just goes. I feel much less body roll when cornering. I'm not racing mind you, but even on exit ramps, it feels more confident. I wouldn't switch back to straight axle. Much nicer ride. It was easy to do also. I purchased $80 in steel and experimented with cardboard until things fit, then copied the patterns to steel and started welding.

[nacho55]

Originally Posted by 49bowtie

My two cents worth, I drove my 49 around for years with a Camaro clip up front and a straight axle from the same donor car. My 350/350 was nothing special, but could lay rubber when needed. I came across a C4 IRS for dirt cheap and grafted it in. The biggest difference I notice whenever I drive it, is it doesn't break the tires loose nearly as easily. It seems to get much better traction and just goes. I feel much less body roll when cornering. I'm not racing mind you, but even on exit ramps, it feels more confident. I wouldn't switch back to straight axle. Much nicer ride. It was easy to do also. I purchased $80 in steel and experimented with cardboard until things fit, then copied the patterns to steel and started welding.

Not to hijack but do you have any pictures of your install? I too am wanting to install a corvette rear in my next project, not looking to road race or anything but because I think it would be something different...

[whitedog76]

Just a thought here. I was driving yesterday and it dawned on me when a Ford Explorer turned in front of me. The 02 and newer Explorers had rear IRS, with a modified 8.8 center section.

Might be an easier swap than the Corvette or Mustang setups.

Here's a blue oval truck with a T-bird IRS.

O.k. I'll admit, it's cool

http://team321.com/truckirs/TEAM321TruckIRSInstall.html

[jetnow1]

When Carroll Shelby did the Mustang based Shelby's he had the option of converting them
to IRS. He said the solid axle was simpler, dependable and on most tracks would work at
least as well. Seems to me that logic still works.