4x4 IFS Front suspension idea

[CanyonMan]

OK, I've got a crazy idea here for 4x4 IFS Chevy's and GMC's. Has anyone ever thought of making a Corvette IRS suspension work in one? I know you can buy killer steel half shafts for them. Get someone form High Angle driveline to make halfshafts for it, modify your hubs etc. I stayed awake all night last night thinking of suspension ideas for my 4x4 IFS. I think IFS can work for the common man, it just needs a bigger following (other than the "disco" crowd).

Lyrch

[tkr]

It sure doesn't seem like it would be all that difficutl...for someone who knows what they're doing...t to use 930or934 cv's with longer axles and make up some longer a-arms, shock hoops, etc. If I had the knowledge and skills I would've done it 5 years ago when I bought my truck. I'm sure someone must have tried it by now!
Anyone?????

Matt Nelson
Team Kwik Racing

[JrSyko]

Talk to the guys At Full Tilt, they are claiming 12" out of the GM IFS on the new H2's.

See ya in the dirt!

[elcaprerunner]

How about this idea for 4X4 IFS S-10.........Make extended arms and all of that shiz......steering, brake lines, etc....... Make the arms wide enough to where you can use 4WD axles from a fullsize 4X4 Chevy. Would this work? This is the same idea as the TC "Caddy Kit" but for an S-10. The only thing I can think of is that the CV's might not be conmpatable with eachother (fullsize to S-10 i mean) Will this work? I can't be the first one who has thought of this.

DIRT'S FOR RACING, PRERUNNERS ARE FOR GETTING THERE!

H.O.R.E.
Hemet Off-Road Enthusiests

[rdc]

What about the torsion bars? You now have the front halfshafts all custom fabbed up and the arms extended but what about the tbars? Do you think you could get those to function well? You could mount an offset coilover but thats alot of money. Also 2wd chevys are hard allready to make a custom long travel kit for so with the 4wd you just have more problems. I think ibeam swap would be the best idea for lots of usable travel and would be cheaper than mounting coilovers, extending arms, steering and fabbing up some halfshafts.

[BlaZair]

Ive been thinking about this for a long time, and plan on doing something about it one of these days. Im thinking 930s w/ micro stubs, longer arms (3-5 inches) and custom axles. I am not sure about parts compatibility and such, but I have the running gear from ZR2 in the garage (bigger FWD wheel bearings and a 8.5" 10 bolt, 4 inches wider) and will be experimenting. I ve been e-mailing some one on this board who claims to cycle 14" on his S-10 4x with custom arms and extended stock axles. I am still waiting for the pictures.

Anyone know how much front travel the ex-MacPherson (Hardin) S-10 has, or how the front end is set up?

Thought about, but dont know squat about the Corvette or full-size swap.

[tkr]

Now why would you want to go backward and take a perfectly good set of a-arms off and replace them with I-beams? If you're going to spend the money on 930 cv's, custom lenght axles, custom a-arms and probably custom uprights and spindles, why not go with coilovers?? If you're going to custom make an upper arm, how much more difficult would it be to design a j-arm instead?



Matt Nelson
Team Kwik Racing

[tkr]

I think Lil Mac had either 8 or 10 inches of front travel. Amazingly little considering how well in handled.

Matt Nelson
Team Kwik Racing

[AaronDixon]

We are currently finishing up a 4wd long-travel suspension for the IFS F-150s. The kit cycles 14" of travel with a 2.5" coilover and a 2.5" bypass. Truck will be 8" wider using stock CV joints with new axles. The Upper A-arm features a vertical uni-ball and the A-arms bolt up to the stock pivots.

[KitRacer]

i dont know how much travel you consider good, but i have thought of the same idea too. before you get to serious, cycle a 930 cv as i did, it may get 27 degrees before bind, but that is with the wheel straight, dont forget you have to be able to steer as sharp at full droop as you do at normal ride height. when you get all done, you are left with hardly any cv angle. i scratched the ides when i saw how little angle was available when steering became an issue. another issue is ground clearance, instead of the spindle hub being towards the bottom of the spindle, it now has to be in the middle to allow for the micro stub to go through it. now the whole arm is a lot lower. these are the reasons i ditched the idea.
on another note, how much travel did the front of that gray prerunner suberban cycle?

[tkr]

The 4x4 IFS Ford isn't much different than the Chevy is it? Aaron do you have any pictures?

Matt Nelson
Team Kwik Racing

[AaronDixon]

No pictures yet, but I should have everything done in a few weeks.

[JrSyko]

Check out H&M website as they are currently building a F1 4x4 IFS long travel suspension that uses a bypass and a coilover. It is in the pictures section under "Vossey's prerunner."

See ya in the dirt!

[FABRICATOR]

Nearly every front wheel drive and all-wheel-drive-capable vehicles in the world use Rezeppa joints (real CV joints). The Lobro style (930's, etc) will not provide enough angle for steering. The Rezeppa joint can go up to about 45 degrees with no problems. Like any joint, torque limits decrease when drive angle increases. The full size GM trucks have strong, high-angle Rezeppa joints.

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>

[tkr]

Wow, good to know. Thanks Fabricator. Is there some reason why we don't use the Rezeppa type joints in off-road. For example on the rear of an IRS buggy?

Matt Nelson
Team Kwik Racing

[partybarge_pilot]

"The Lobro style (930's, etc) will not provide enough angle for steering."

They won't? I don't seem to have a problem getting enough angle out of them for steering. They have alot more travel than a stock one like a toyota.

[rdc]

If the gm joints are so great then you can just get them machined so the joints clears at steeper angles. Where can you get that done?

[FABRICATOR]

BTW, most of the world spells it Rezeppa however, it is also spelled Rzeppa...

RE: "Is there some reason why we don't use the Rezeppa type joints in off-road. For example on the rear of an IRS buggy?"

Yes, sheer laziness. Actually they do. People do not like to use these joints off-road because they do not conveniently provide any axle plunge (in and out axle movement). In all other ways they are superior. For a given diameter or angle, they are much stronger and cooler running. The OEM's do not use them for more than the outer axle joint because they are more expensive.


Re: "I don't seem to have a problem getting enough angle out of them for steering. They have alot more travel than a stock one like a toyota."

27* x 2 equals 54*... Most steering systems go around 70* to 80* some nearly 90*.


Re: "If the gm joints are so great then you can just get them machined so the joints clears at steeper angles. Where can you get that done?"

I'm not sure what you mean. Most Rezeppa joints do not need any clearance to run these angles. The angle limit is usually from the axle coming close to the outer shell. You can cut the axle down in that spot and this has been done. But this is usually for exceeding 45*.




<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>

[rdc]

"I'm not sure what you mean. Most Rezeppa joints do not need any clearance to run these angles. The angle limit is usually from the axle coming close to the outer shell. You can cut the axle down in that spot and this has been done. But this is usually for exceeding 45*. "

I heard from Greg (Sparky) at autostylz in Lake Forest that they could be machined some way to give you a few more degrees before they bind. Who would do this? Does it make it weaker?

What do you think of autostylz service, fabrication etc PM me.

[ntsqd]

Try this link for some background on CV's: <A target="_blank" HREF=http://www.rpsthompson.com/hisory_cvj.html>http://www.rpsthompson.com/hisory_cvj.html</A>
A google search on "Rzeppa Joint" turned up all kinds of info. Read the one from vernco.com, it has a couple amusing things in it. One site was a Citroen DS page.

I had always thot the Rzeppa joints, like Birfields, consisted of an inner radially grooved race, an outer radially grooved race and some balls; with the difference btwn them being that the Birfield's grooves were exactly radial while the Rzeppa's grooves were crossed. That is not the case.


TS

I used swerve around my halucinations, now I drive right thru them.

[FABRICATOR]

Even though Rzeppa joints are of the same design, they are not identical. Most (not all) will go very close to 45*. The most common limiting factor is the axle hitting the inner edge of the outer shell. This inner edge is also the end of the ball races. Some joints can have their angle limit increased by grinding away that edge, others will loose angle capability if that edge is modified. This is because the balls are that much closer to coming out of the race. Even two joints the same size from the same manufacturer can have different angle limits depending on what axle size they are broached for. A small axle will never touch, but a big one can. The late Mickey Thompson spent considerable effort exploring this. He used to run axles that had a smaller diameter in just that area along with special heat treating. It worked well enough.

Of course this brings up the question of vehicle design. If you need to run more angle than a Rzeppa joint can provide, there is probably something else wrong. Control arms, corresponding joints, and steering, all loose effectiveness and/or strength past these angles.

The grooves in a Rzeppa joint are all the same, going the same direction. Under power, all the balls are working the same and all are rolling. Other than swiveling in place, the inner race is stationary. The Lobro style has 3 grooves facing one way and 3 another. Under power the torque is not divided up to all 6 balls at the same time. There is a combination of rolling and sliding. There is also more force acting on the ball cage. The grooves are placed this way so the inner race and the cage can slide in and out in relation to the outer race. (axle plunge)



<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>

[FABRICATOR]

Thom,
That site is more than just opinionated. It belongs to the inventors of the Thompson CV joint. The language used to "knock" other joints is obviously borrowed from their patent application. They also obviously put all the ball type joints together under the name of Rzeppa. It is interesting but IMHO not accurate. There are European trucks that use the Rzeppa joint in their drivelines The large front drive axles from Rockwell, and many military axles and drivelines use Rzeppa joints.

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>

[JrSyko]

Sorry to interrupt, but a quick question, but what is IMHO? Please carry on now......

See ya in the dirt!

[partybarge_pilot]

930 CV with good cages 32 deg. X 2 = 64 deg.

The truck We are setting up only has 55 deg of wheel movment on steering. With this it will turn a very tight radius. The wheel base is about 122'. I fail to see the need for more movment unless your running a longer wheelbase.

[BlaZair]

Does anyone know what type of CVs a Hummer (H1, not goofy H2) uses?

[CanyonMan]

IMHO = In my humble opinion.

Lyrch

[AZmiik]

they use Lobro type CVs that really didn't seenm that big. They run pretty messed up to. I remember seeing a set our mechanics had apart. They were worn pitted and galled but back together and on teh truck they went.

MIke

[partybarge_pilot]

the reason the Cv's on hummers aren't that big is that they have gear reduction hub's. With something like a 2 to 1 reduction it cuts down on the driveline sizes. But there is an increase in driveline speed. The H1's were designed to go about 65 max, when you drive them around on the freeway at 70 your cv's burn up a lot faster....

[ntsqd]

There are also two generations of CV's on HMMV's, early (=small) & late (=bigger).

Ya Fabricator, after I posted that link I had a chance to really read & study what they were saying. I think their design is too complicated with too many small, exposed to the elements, parts to ever be a workable design. Google did turn up a lot of links on the topic and I only investigated a couple.

TS

I used swerve around my halucinations, now I drive right thru them.

[Bob_Sheaves]

Hi all!

As an aside to the discussion, everyone is missing one thing that will cut down on joint angularity at the limits of travel...that is to say-a floating axle. Imagine a carrier housing attached to the left lower control arm with a "barrel style" engine mount, attached to the right lower control arm with a 4 inch long (center to center) shackle, and a Camaro or Corvette style torque arm running from the pinion end of the housing parallel to the front propshaft and attached to the vehicle frame using another "barrel style" engine mount (Barrel mounts are another name for voided engine mounts and are barrel shaped on their bolt axis).

Just food for thought (BTW- it's been done before-check out the US patent office web site and look through the Chrysler Corp suspension patents)....

Additionally, double Rzeppas can be utilized (at axle flange and at knuckle flange), but a conventional slip shaft assembly must be installed to allow for shaft plunge. Careful assembly and alignment of the joints is also critical, lest you chatter the joints to dust due to unsyncronised vibration.

Best as always....

Bob Sheaves

<P ID="edit"><FONT SIZE=-1>Edited by Bob_Sheaves on 12/19/02 06:39 AM (server time).</FONT></P>

[tkr]

Good to see you back Bob. I always like your input, but man....you make my brain hurt!!


Matt Nelson
Team Kwik Racing

[CanyonMan]

Does anybody have any experience with the Doetsch-Tech 4" lift kit for 4x4 Chevys? Are their shocks any good?

Lyrch

[FABRICATOR]

Yes, Welcome back Bob.
BTW, there are alternatives to slip joints on the shafts...

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>

[tkr]

Re: "BTW, there are alternatives to slip joints on the shafts..."

Such as??? I have been thinking about this pretty much non stop for a couple days now and I can't come up with a thing.

Matt Nelson
Team Kwik Racing

[Ryno]

Great to see you back Bob!! Always good to see your posts. I just need to read it about 4 times to get all the info. =) Good stuff nonetheless.

Matt-Me too...I drove my friends 01 Silverado with 40" swampers....BADASS!! He used a custom/ whiplash kit, and custom made alot of stuff on the truck. I'm thinking the Ibeam idea....but I know someone will do a 88-98 long travel kit sometime. Too many working class guys without funds for a new truck, and like the old body style anyways. Just my .02

Ryno

Build it like a Rhino, and Leave it be.

[Bob_Sheaves]

Thanks guys...I'm back in the US for Christmas holidays.....

I made a mistake before and should have stated that the double fixed Rzeppa and slip shaft was my personal preference. There ARE several ways to fix the plunge issue:

1. Use a Rzeppa at the wheel end and a "tripod" plunging joint at the axle (see this under most front wheel drive cars)

2. remove the retaining clips from either side of the inboard (axle end) Rzeppa and machine a longer plunging shaft, fitted with high load retaining springs (like 320lb. valve springs) on either side of the spider, concentric to the axle shaft centerline to allow for plunge motion

This is not intended as all inclusive, but rather to get some other thoughts started.

Best as always,

Bob Sheaves

[FABRICATOR]

Re: "I have been thinking about this pretty much non stop for a couple days now "

MATT, A lot of things take weeks to figure out and months to iron out. (plus the $,$$$)

I can't get into it too much, but think of a slip joint with rows of ball bearings instead of splines. Now think: where can such a device go??? You end up with something that has very close to zero friction and wear. The low friction means no effect on the suspension and much less plunge pressure applied to the CV joints. This is especially important when dealing with high torque figures. And it does not have to weigh much either.

BTW, the Tripot or Tripod joint can be very strong, allow ample plunge, durable, and is nearly frictionless, but none of them go more than about 18 degrees. Very popular in many forms of road racing, up to and including F1.

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>