Factory Five Racing Forum banner
1 - 15 of 15 Posts

·
Premium Member
Joined
·
4,703 Posts
Discussion Starter · #1 ·
IRS in a completed car sounds near impossible.
Please tell us how difficult it was to install.
On a scale of 1 to 10.(10 being the hardest).
Please also tell us if you were coming from 4-link or 3-link? Was it worth it?
 

·
Premium Member
Joined
·
7,237 Posts
Dave Borden and James Creasy have done it (among others). I think both have pictures detailing the conversion. I don't remember either commenting on it being difficult. I doubt it would be much more work than the 3-link.
 

·
Vendor
Joined
·
8,399 Posts
I've done it twice coming from a 4 link and it was a huge improvement. I got James his parts for the IRS in fact. Do you weld? If so I rate it as 5. Not real hard to do and it is actually easier to put the pumpkin in than when the car is all together from the factory. Paint the cage except for the welding areas, bolt the pumpkin to the cage and then stick the whole assembly in. Put in the upper arm mount first, then the cage, then arms/spindles, put a T in the brake line, connect the brake lines, bleed lines, align and drive. Call me if you have any questions and budget a day to install. 760-403-6266
 

·
Daily Driver since 2/03
Joined
·
995 Posts
If you don't weld, is it easy to describe to a weld shop what to do? Do you weld on small attachment items or something bigger? I was wondering if you could drive to the weld shop with a 4 link in place, have the welding done, drive home, then put in the IRS.
 

·
FFCobra Master Craftsman
Joined
·
1,291 Posts
dwheeler, I do not think you would fit the cage in there with the 4 link in place.

Nathan
 

·
Registered
Joined
·
3,154 Posts
I retrofit the IRS right behind Dave, Wayne and James. I learned to hate the 4 link. When given an IRS FFR with bars to do a couple laps at Willow Springs I couldn't even sleep until I ordered the upgrade on Monday. The ride alone makes the upgrade worth the trouble.

I powdercoated the cage and used a 99 Cobra center section and chose pin drive width.

The tank, battery and complete rear disassembly took a couple hours. This was my opportunity to repaint the complete rear frame with gloss black rustoleum.

I bolted the cage into place, did some metal prep to weld along the old quad shock brackets and also where the cage bolts to the end of the frame tubes. About 4 hours and the cage was in. Some touch up black paint and rest is history.

If you don't weld have someone come over with a 110 MIG for and hour or so.

Like Wayne, I would give the work a 5 with the results being a 10+.

Roger
 

·
Premium Member
Joined
·
4,703 Posts
Discussion Starter · #7 ·
Welding is no problem for anyone. There are a lot of welders that will come to house. Some don't like the liabilty of welding the IRS brackets to the gas tank, but you can always find someone to do it.
 

·
Registered
Joined
·
628 Posts
I went from a 4 link to IRS after the first year I had the car. I did it with the body off - body was out being painted. However, the aluminum was still in place. Welder came to my shop and did the deed. The fuel cell was out so tank was not a problem.

I feel the main considerations would be how much time do you have to do the job, (meaning a weekend, or over the winter), and do you have a lift at your disposal.

Don't see how anyone could use the 4 link unmodified to begin with after going to the IRS. Well worth the effort, time, and money. BTW, I installed the pumpkin alone with the frame work already welded in the car on my back. Wasn't easy, but it can be done.

Score it a 5-7 depending on the two above items of time and lift.

Hank
FFR 1776-II
 

·
Registered
Joined
·
3,154 Posts
There is NO welding of IRS brackets to the gas tank! Like Russ said, the spring perches are cut off with a sawzall in about 5 minutes and the brake line has enough length to install a T-fitting in place of that Mustang bracket with the rubber hose.

Disk Brakes R Us has ideal length flex lines to accommadate the travel of the brake calipers.
Roger
 

·
Senior Member
Joined
·
5,559 Posts
I'll let you know this winter! :D

I'm going from a 4 link that is very well sorted (tubular lowers, Autoweld adjustable uppers and coilovers) - meaning that I don't "need" to upgrade. I just hate leaving things alone, and with all of the glowing reviews, I figured that it would make a cool project with great benefits in ride and handling. I'm also machining the setup for spherical bearings while I'm at it. ;)

Brian
 

·
Vendor
Joined
·
8,399 Posts
Uh Brian, I would hold off on the spherical bearings, those uprights are a die cast piece. The rubbuer bushings are relatively hard (durometer of 95) but provide great shock protection to the upright. You won't see hardly any benefit going with the spherical or Delrin and will have to inspect the uprights more often for cracks.
 

·
Premium Member
Joined
·
4,703 Posts
Discussion Starter · #14 ·
I can't just leave well enough alone either, but once I fiqure shortening rear axle, coil overs, 3-link, etc....I'm getting close.
Just kidding about welding to gas tank...I'll attach to gas tank with self tapping screws and silcone. ;)
 

·
Senior Member
Joined
·
5,559 Posts
Wayne,

That is the first I've heard of that - but it makes sense. I was planning to convert them for these reasons.

1. the obvious advantage of self-aligning to prevent any binding through the entire range of motion.

2. the stock bushings were shot anyway.

3. I have a full machine shop at my home, so added cost isn't an issue.

4. if I ever decide to track the car it will already have a great setup ;)

Brian
 
1 - 15 of 15 Posts
Top