Indepedent Rear Suspension (IRS) in a 4th Gen
05-03-2012, 08:14 AM
#41
Of course you can buy the Watts link for $650, bolt it on in an afternoon, and it won't throw you in to some custom class. The IRS on the other hand, well, see page 1.
Last edited by lees02WS6; 05-03-2012 at 08:33 AM.
06-13-2012, 05:41 AM
#43
I'm in the middle of doing this swap right now. My swap is a bit more invasive since though. Iv'e already cut out the wheel-wells and have removed about 50lbs of metal since I started.
I'm going to build a square tube cradle to connect the IRS mounts to the roll cage. Im also going to install a fuel cell since the space for the stock tank is being used for the cradle.
It should be fun.
I'm going to build a square tube cradle to connect the IRS mounts to the roll cage. Im also going to install a fuel cell since the space for the stock tank is being used for the cradle.
It should be fun.
06-26-2012, 09:28 PM
#45
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This thread has me with stars in my eyes. The only red flag is the classification change. I autocross my car, and I wouldn't want to shoot my foot over this kind of swap...
06-27-2012, 09:25 AM
#46
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I've added this to the Suspension & Brake Tech FAQ:
https://ls1tech.com/forums/suspensio...-tech-faq.html
https://ls1tech.com/forums/suspensio...-tech-faq.html
06-30-2012, 01:11 AM
#52
07-02-2012, 05:41 PM
#54
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If I can get my hands on a camera I'll do it soon for you 
Where you are going to weld all depends on how you want to install the differential/batwing/spindles. To be very basic though you will be welding to the primary frame rails. The factory cross supports over the stock axle are cut out and you weld in your new brackets there. There are many options to how you mount the spindle/front differential mount though.
Where you are going to weld all depends on how you want to install the differential/batwing/spindles. To be very basic though you will be welding to the primary frame rails. The factory cross supports over the stock axle are cut out and you weld in your new brackets there. There are many options to how you mount the spindle/front differential mount though.
07-02-2012, 09:11 PM
#55
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This is one of the best threads I have seen on this site. So many questions answered. Now how about other IRS types? What about 5th gen/G8 type IRS? Has anyone looked at that as an option?
07-03-2012, 06:26 PM
#56
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. I know Lee is currently working on one for the C4 and he will keep everyone posted on that.
07-03-2012, 07:21 PM
#57
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To be honest the reason no other rear assemblies have been considered is because of weight and design of the systems. Both setups you mentioned above are bulkier, heavier, and will not provide a large improvement over a C4 properly setup to accustom someone's goals. The only next step for improvement will be C5/C6, which I will be working on within the next year to replace my C4 setup. Once the new setup is in I will make a kit for the C5/C6 rear setup, that'll be a year or so down the road; keep your eyes peeled for updates. I know Lee is currently working on one for the C4 and he will keep everyone posted on that.
. I know Lee is currently working on one for the C4 and he will keep everyone posted on that.
07-05-2012, 01:36 AM
#58
I've been looking around for an easier option and came across this and its meant for a C4 and has all the mounting points already set up. As a bonus i think it might be possible to extend the frame to connect the rear with the front K member for more chassis stiffness and less body flex.
Will be a reasonable option? The kit is only $250 which i think isnt bad.
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Will be a reasonable option? The kit is only $250 which i think isnt bad.
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07-05-2012, 06:30 AM
#59
I was looking at the cradle as an option myself... After looking at it long enough, I came to the assumption that it wasnt worth the trouble to entirely "back-half" the car to fit this cradle into it. Unless you've got some decent metal fab equipment to make another bulkhead, I wouldn't try it.
Also not too happy about the fact that the trailing arm mounting points arent adjustable.
Now maybe if you bought one and used it as a "jig" to build one more suited to the underside of the F-body, or just chopped and modified this one to fit, then maybe buying one is a better idea.
Also not too happy about the fact that the trailing arm mounting points arent adjustable.
Now maybe if you bought one and used it as a "jig" to build one more suited to the underside of the F-body, or just chopped and modified this one to fit, then maybe buying one is a better idea.
07-05-2012, 11:37 AM
#60
I've been looking around for an easier option and came across this and its meant for a C4 and has all the mounting points already set up. As a bonus i think it might be possible to extend the frame to connect the rear with the front K member for more chassis stiffness and less body flex.
Will be a reasonable option? The kit is only $250 which i think isnt bad.
Will be a reasonable option? The kit is only $250 which i think isnt bad.
There are advantages, ease of install just doesn't seem to be one of them.
To me, a jig that squares the rear end up, a datum on the car that's square to the frame, and a four post lift would be the easiest method to do the install.
Last edited by lees02WS6; 09-04-2023 at 03:58 PM.