Indepedent Rear Suspension (IRS) in a 4th Gen
07-13-2013, 07:18 PM
#121
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I thought the point of the kit idea was that you were making up the brackets and other things for your own project so why not recoup some of that cost by selling sets to other guys who similarly wanted to DIY this swap but didn't want to start at ground zero? Is your project complete already I'm not sure i understand from this thread?
10-29-2013, 01:30 PM
#124
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It will be nothing like Lee's or my build. I'm sure there is a way but I would still prefer the C4 IRS and if I wanted better just jump straight to the C5/6 setup. Do some searching for multiple posts in this and other threads we've made on why we wouldn't use the 5th gen IRS.
11-10-2013, 02:59 AM
#125
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I just found this on a Mustang site and was wondering if it could be made to fit or if there was enough demand maybe they would make a bolt-in setup for the f-body.
http://www.mustangirs.com/
http://www.mustangirs.com/
11-10-2013, 01:25 PM
#126
I just found this on a Mustang site and was wondering if it could be made to fit or if there was enough demand maybe they would make a bolt-in setup for the f-body.
http://www.mustangirs.com/
http://www.mustangirs.com/
Perhaps we can reach out to him and see how many commitments he needs to make a kit for the 93-02 cars?
11-12-2013, 08:40 AM
#127
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I just found this on a Mustang site and was wondering if it could be made to fit or if there was enough demand maybe they would make a bolt-in setup for the f-body.
http://www.mustangirs.com/
http://www.mustangirs.com/
I know everyone is looking for a "simple" and "bolt-on" application, but the reality is that will never be the case. The reason is the car is completely being modified from its original design and intentions. Sure you can keep looking for an easier and "cheaper way", but the truth is they will all run around the same cost and require the same amount of time/labor. The reason there will never be a simple bolt on is because at the age of every single F-body in existence there is variance in their frames, mounts, and several other factors due to the differing environment and stresses each has uniquely faced in its life span.
Each is welcome to their own unique approach and way they desire going about this. A great example of this is Lee and my approach to the install vs Driver_10's (see his thread if your curious). No matter what you choose if you are wanting an IRS in an F-body, the facts as listed above will not change.
11-12-2013, 10:18 AM
#128
Yes its very possible, but then again its no less possible than a C5/C6 or the C4 assembly. Each design, though different, will require roughly the same amount of work and fabrication.
I know everyone is looking for a "simple" and "bolt-on" application, but the reality is that will never be the case. The reason is the car is completely being modified from its original design and intentions. Sure you can keep looking for an easier and "cheaper way", but the truth is they will all run around the same cost and require the same amount of time/labor. The reason there will never be a simple bolt on is because at the age of every single F-body in existence there is variance in their frames, mounts, and several other factors due to the differing environment and stresses each has uniquely faced in its life span.
Each is welcome to their own unique approach and way they desire going about this. A great example of this is Lee and my approach to the install vs Driver_10's (see his thread if your curious). No matter what you choose if you are wanting an IRS in an F-body, the facts as listed above will not change.
I know everyone is looking for a "simple" and "bolt-on" application, but the reality is that will never be the case. The reason is the car is completely being modified from its original design and intentions. Sure you can keep looking for an easier and "cheaper way", but the truth is they will all run around the same cost and require the same amount of time/labor. The reason there will never be a simple bolt on is because at the age of every single F-body in existence there is variance in their frames, mounts, and several other factors due to the differing environment and stresses each has uniquely faced in its life span.
Each is welcome to their own unique approach and way they desire going about this. A great example of this is Lee and my approach to the install vs Driver_10's (see his thread if your curious). No matter what you choose if you are wanting an IRS in an F-body, the facts as listed above will not change.
11-13-2013, 12:52 PM
#129
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The problem with that is it leaves those of us without the fabricating skills no option to go IRS. I would be willing to spend some coin to have a C4 setup fabricated on my car, if I had some assurance it would be done right with attention brought to the details of the suspension geometry and shock availability. I don't think any shop in the Northeast would be willing to do that, unless I show up to Lee's home in PA with my car and a suitcase of cash...
Even if Lee, Driver and myself were to put together a kit for everyone, there would be custom measuring, welding, and varied changes for every individual no matter how perfect our kit was. This alone requires a base level of knowledge that most still do not have and skills that are not developed. That is the main reason I myself haven't continued with creating a kit design.
11-13-2013, 09:42 PM
#130
I completely understand that, and that is what is unfortunate about the decision. If I wasn't in medical school I would be offering and have accepted several offers to do it for members already. There are very few shops that would want to do this because of the lack of experience and knowledge in the area; and the ones that do require large sums of cash money.
Even if Lee, Driver and myself were to put together a kit for everyone, there would be custom measuring, welding, and varied changes for every individual no matter how perfect our kit was. This alone requires a base level of knowledge that most still do not have and skills that are not developed. That is the main reason I myself haven't continued with creating a kit design.
Even if Lee, Driver and myself were to put together a kit for everyone, there would be custom measuring, welding, and varied changes for every individual no matter how perfect our kit was. This alone requires a base level of knowledge that most still do not have and skills that are not developed. That is the main reason I myself haven't continued with creating a kit design.
11-13-2013, 10:51 PM
#131
They do make a kit for irs for 4th Fbody owners. It's called the corvette, and it's a turn key setup that is "no assembly required" and doesn't require any fabrication skills or tools for that matter. At the price of a used c5z these days, save the ~$3000 and countless hours of labor of putting IRS in your Fbody, sell it, and go buy a c5. In all reality, this makes way more sense. Not that I don't love my Fbody, but if you're trying to make an Fbody into a corvette, just got buy the better car.
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edster75 (11-07-2023)
11-14-2013, 02:05 AM
#132
The issue with building a "bolt-in" IRS kit, is the car itself.
The dimensions of the C4 IRS (and C5 IRS) require more clearance than what is offered underneath the butt of an F-body, (assuming you want ANY type of correct geometry) without some serious cutting. Even the "Zeus performance" firebird (the most minimally intrusive swap Ive seen so far) needed quite a bit of cutting to accommodate the suspension.
Also, cutting away portions of the body causes an loss of rigidity. There simply isnt enough structural bracing for a "cut-n-bolt" set-up. It's the reason that I opted to back-half my build and fabricate a supporting roll-cage to accommodate the install.
Some real fabrication work will be necessary to do this swap. No way around it,
I will be returning to Texas from Alaska in 2 days. I will complete my suspension swap by the end of November. For any of the LS1-TECH'ers living in the Houston area who want to duplicate my rear-cradle assembly, your welcome to make the pilgrimage to my house in Katy and take some measurements.
Im more than happy to share my work with the LS1TECH community.
The dimensions of the C4 IRS (and C5 IRS) require more clearance than what is offered underneath the butt of an F-body, (assuming you want ANY type of correct geometry) without some serious cutting. Even the "Zeus performance" firebird (the most minimally intrusive swap Ive seen so far) needed quite a bit of cutting to accommodate the suspension.
Also, cutting away portions of the body causes an loss of rigidity. There simply isnt enough structural bracing for a "cut-n-bolt" set-up. It's the reason that I opted to back-half my build and fabricate a supporting roll-cage to accommodate the install.
Some real fabrication work will be necessary to do this swap. No way around it,
I will be returning to Texas from Alaska in 2 days. I will complete my suspension swap by the end of November. For any of the LS1-TECH'ers living in the Houston area who want to duplicate my rear-cradle assembly, your welcome to make the pilgrimage to my house in Katy and take some measurements.
Im more than happy to share my work with the LS1TECH community.
11-14-2013, 02:28 AM
#133
They do make a kit for irs for 4th Fbody owners. It's called the corvette, and it's a turn key setup that is "no assembly required" and doesn't require any fabrication skills or tools for that matter. At the price of a used c5z these days, save the ~$3000 and countless hours of labor of putting IRS in your Fbody, sell it, and go buy a c5. In all reality, this makes way more sense. Not that I don't love my Fbody, but if you're trying to make an Fbody into a corvette, just got buy the better car.
For those who want a corvette, go buy a corvette... and just like anyone else who's ever owned a corvette, you'll own a corvette.
For those who want a F-body with a custom IRS swap, go through the fire to become one of the few, the proud, and the broke
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edster75 (11-07-2023)
11-14-2013, 02:41 AM
#134
BTW: Here is my build thread. (Still under construction)
https://ls1tech.com/forums/suspensio...-irs-swap.html
https://ls1tech.com/forums/suspensio...-irs-swap.html
11-14-2013, 03:55 AM
#135
Another option for comfort and handling which a lot of people overlook is a Watt's link setup. It's not an independent rear suspension, but the improvement in handling and increase in comfort level is significantly better than the panhard setup and in my opinion brings it close to a vette in terms of handling. I've driven a c5 z06 for comparison's sake.
11-14-2013, 08:48 PM
#136
Another option for comfort and handling which a lot of people overlook is a Watt's link setup. It's not an independent rear suspension, but the improvement in handling and increase in comfort level is significantly better than the panhard setup and in my opinion brings it close to a vette in terms of handling. I've driven a c5 z06 for comparison's sake.
11-16-2013, 04:12 AM
#137
)The only real advantage of having IRS is lower unsprung weight without "axle walking".
A live axle will never match an IRS's unsprung weight or stability on transitioning surfaces (bumps and dips), but "axle walking" (lateral movement while cornering) can be handled easily by removing that panhard bar and installing a watts link.
11-16-2013, 10:19 AM
#138
I've driven a z06, and had both an aftermarket adjustable panhard with poly/poly on the lca, poly/roto, and finally watt's with poly/roto for comparison.
First and foremost, tires are a big deal. Can't emphasize this enough.
My cousin's z06 handles nice, but because of the tires, tends to break loose under similar turns and rough roads my car hugs with ease. If grip is ideal, they are near similar with me having to say the irs feeling slightly more planted than my car.
The panhard done right is very effective as well, but articulation is key. I fell into the poly trap early on in modding suspension and suffered with a rear that was rougher on roads and hopped a good amount off bumps in the road.
Once you have a fully articulating panhard setup, it rides nicer, the "hopping" situation is greatly reduced (still there, but less steering correction).
The improvement of the the watt's link to a fully articulating rear setup is two fold. a) It is always centered within. I run 315's on back and still had rubbing with a proper panhard under tight cornering or simple long sweeping highway speed turns. b) It articulates the rear much better in handling road imperfections and bumps
First and foremost, tires are a big deal. Can't emphasize this enough.
My cousin's z06 handles nice, but because of the tires, tends to break loose under similar turns and rough roads my car hugs with ease. If grip is ideal, they are near similar with me having to say the irs feeling slightly more planted than my car.
The panhard done right is very effective as well, but articulation is key. I fell into the poly trap early on in modding suspension and suffered with a rear that was rougher on roads and hopped a good amount off bumps in the road.
Once you have a fully articulating panhard setup, it rides nicer, the "hopping" situation is greatly reduced (still there, but less steering correction).
The improvement of the the watt's link to a fully articulating rear setup is two fold. a) It is always centered within. I run 315's on back and still had rubbing with a proper panhard under tight cornering or simple long sweeping highway speed turns. b) It articulates the rear much better in handling road imperfections and bumps
11-17-2013, 12:34 AM
#139
I've driven a z06, and had both an aftermarket adjustable panhard with poly/poly on the lca, poly/roto, and finally watt's with poly/roto for comparison.
First and foremost, tires are a big deal. Can't emphasize this enough.
My cousin's z06 handles nice, but because of the tires, tends to break loose under similar turns and rough roads my car hugs with ease. If grip is ideal, they are near similar with me having to say the irs feeling slightly more planted than my car.
The panhard done right is very effective as well, but articulation is key. I fell into the poly trap early on in modding suspension and suffered with a rear that was rougher on roads and hopped a good amount off bumps in the road.
Once you have a fully articulating panhard setup, it rides nicer, the "hopping" situation is greatly reduced (still there, but less steering correction).
The improvement of the the watt's link to a fully articulating rear setup is two fold. a) It is always centered within. I run 315's on back and still had rubbing with a proper panhard under tight cornering or simple long sweeping highway speed turns. b) It articulates the rear much better in handling road imperfections and bumps
First and foremost, tires are a big deal. Can't emphasize this enough.
My cousin's z06 handles nice, but because of the tires, tends to break loose under similar turns and rough roads my car hugs with ease. If grip is ideal, they are near similar with me having to say the irs feeling slightly more planted than my car.
The panhard done right is very effective as well, but articulation is key. I fell into the poly trap early on in modding suspension and suffered with a rear that was rougher on roads and hopped a good amount off bumps in the road.
Once you have a fully articulating panhard setup, it rides nicer, the "hopping" situation is greatly reduced (still there, but less steering correction).
The improvement of the the watt's link to a fully articulating rear setup is two fold. a) It is always centered within. I run 315's on back and still had rubbing with a proper panhard under tight cornering or simple long sweeping highway speed turns. b) It articulates the rear much better in handling road imperfections and bumps
It will be at least three more months before I have my car inspection/ road ready, but if your'e in the Houston Katy area, feel free to drop buy for a bit of comparison driving then.
11-17-2013, 07:38 AM
#140
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I did not read all the posts in this thread, but why not just put a Jag IRS under your car? Easy to mount, Dana 44 set-up with easy to find LSD, wide variety of gears, and with a few bucks extra, you can put a Watts linkage.
There are numerous Cobras running around with 600-700 hp engines using Jag IRS set-ups. You can get inboard or outboard brakes depending on which year IRS set-up you buy as the donor and they are really plentiful.
There are numerous Cobras running around with 600-700 hp engines using Jag IRS set-ups. You can get inboard or outboard brakes depending on which year IRS set-up you buy as the donor and they are really plentiful.