C4 IRS help

[Bad94]

I know a guy who has a C4 IRS that want to sell cheap.

I got thinking and wondering how much wouk it would be to put under my S-10, im building.

I was going to do a 9" with some type of 4 link. But a IRS would be cool to have.

[HectorM52]

Subscribed. I'm curious to see what you guys have to say too.

[multiplex]

check out this guy, perhaps he can help... how different can the frames be right?

also which c4 rear are you referring to. dana 44 or dana 36?

http://cgi.ebay.com/ebaymotors/55-56-57-58-59-Chevy-Truck-Rear-Kit-C4-Vette_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3 a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q 2ec0Q2em14QQhashZitem140276731840QQitemZ1402767318 40

[Bad94]

check out this guy, perhaps he can help... how different can the frames be right?

also which c4 rear are you referring to. dana 44 or dana 36?

http://cgi.ebay.com/ebaymotors/55-56-57-58-59-Chevy-Truck-Rear-Kit-C4-Vette_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3 a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q 2ec0Q2em14QQhashZitem140276731840QQitemZ1402767318 40


is that ur BMW in ur sig?

I have looked over that rear swap about 10 times now.

Im kinda worried about cutting it down 4" each side. I will need it about 56" MS to MS. Not sure if its a 36 or 44.

[multiplex]

yeah that is my car. have you seen my build threads on other sites?

let me know if you have any questions. I'm in the final stages of tweaking everything, and am pretty happy with the results. definitely ran into a few stumbling points after all of the major construction was done - but those are behind me now.

so far the shorter axles haven't been a problem. I wouldn't go much shorter than 4" though. Only problem i see with shorter axles is it requires your overall geometry / layout to be that much better since it exaggerates all of the movements more

car handles great, and has pretty damn good traction on the street with my 315 drag radials

[Twentyover]

Multi- can you post links to build threads? Sure the mods won't take offense..

[greencactus3]

i think it would be awesome, but not worth the effort/cost to get it to work well.
it will most likely end up being easier to fabricate an irs setup from scratch, not limiting yourself to using c4 components and modifying them.
and then again, it will be even cheaper/easier to work with the solid axle.

just slapping a modified c4 irs will be cool, but it will not necessarily help with handling. it may actually hinder performance if the geometry is so far from what it 'should' be

[multiplex]

once you start to get into it, you will find that the C4 components dictate the placement with only a few areas open for error.

i think its definitely better to start with some known working components (C4, etc) and go from there.

one of the biggest things is you want your axles almost parallel to the ground at ride height. and you what the toe adjustment bars parallel to the ground (otherwise it will effect toe in / out as the suspension moves).

axles are kicked forward a little bit from the centerline location of the diff. like a degree or two, which i think allows the bearings in the universal joints to cycle.

here is a link i found that lays out the geometery points very well, and talks about the changes over the years

http://forums.corvetteforum.com/showthread.php?t=1224152

when i fabricated my brackets, i left in a few extra holes to allow re-positioning of the trialing arms and differential height. I'm glad i did because i did need to move things around to get them to work

another important lesson i learned was do not install polyurethane bushings in the trailing arms. These arms not only move up and down with the suspension travel, they also move left to right because the axles create an arc. And due to camber change, these links are also required to twist.

with the urethane bushings, my car was actually getting stuck at the wrong ride height.. either too low, or too high.

the fix was to switch to heim joints on all ends. The rear suspension now has 20 heim joints (camber, toe, trailing), which you would think would make for a horrible ride - but its actually very smooth and not noisy

here is a link to a pretty condensed post about my build

http://r3vlimited.com/board/showthread.php?t=119358

let me know if you guys have any questions

[TheDoug]

Wow man Kudos to you. Thats a lot of work.

[multiplex]

thanks!

i busted my ass from april until august getting everything done, hoping i could still make my way to the track before the end of the season. of course there are always little things to finish up after you really think the project is done, but i did get one run in. :nopity:

next year - no projects during the summer :)

[multiplex]

heres a little video i made today of the suspension in action.. i've been dying to see how it operates

http://www.youtube.com/watch?v=XvxLdSQxwP0

click on 'watch in high quality', its much better.

first part is in slow mo.

second part, keep an eye out for some rubber being laid in 2nd gear :)

[HectorM52]

Schweet!!