3 link vs 4 link poll

[tailpilot]

Hello, New to the thread and planning my build. I picked up a block the other day and sending it off to the machine shop. So far I am doing a 408 Stroker, TK500 and Basic MK4 kit. Trying to decide if its worth the extra up front cost to go with the 3 link? My car will be used on the Street of TEXAS for some fun sunny day cruising.

[CraigS]

Yes. The problem w/ the 4 link is that it binds when the car rolls. Ford handled that by using relatively soft rubber bushings. The problem w/ them is that you get wheel hop if you try to spin up the tires. There are aftermarket control arms which help the wheel hop but then you are back to the binding in turns. The 3 link is a well designed modern solid axle suspension. The 5 link is also a modern solid axle suspension but it adds weight to an already heavy axle assembly.

[scottiec]

My car isn’t on the road yet, but very close. When I was in your shoes and doing all the research, you really can’t go wrong with the 3 link.

[Mike N]

I drove my Mk1 for many years with the 4 link with stock arms then FFR arms with spherical joints at the diff ears and it was fine for a cruiser. As soon as you push the car or get on a rough or washboard surface you will notice that the rear of the car moves around and doesn't feel settled with the 4 link. I went from the 4 link to a 5 link and there is a very big difference. You won't notice it cruising around but on rough surfaces the rear doesn't skip around and it feels much more planted when you push the car. If your budget doesn't allow for a 5 link now I didn't find it that tough to do as a winter project later.

[feadam]

Is there a difference in the four link if it has coil overs compared to springs and shocks?

[tailpilot]

I wondering if its worth it to go to the IRS.....hate to spend the money but Im not sure its all that much more in the end

[NAZ]

"My car will be used on the Street of TEXAS for some fun sunny day cruising."

Craig does a good job above detailing concisely the issues with the four-link and informs us that the three-link is an improvement. I agree that the three-link is a significant improvement over the triangulated four link and may be a good choice for those that want more performance. But it still has lots of room for improvement for a track car. IMO, for an all around good performance suspension it's hard to beat the IRS. But remember, the best suspension system is only as good as how it's set-up. The more complex a design is and the more adjustability the harder it is for a novice to get it dialed in correctly.

Based on your intended use the four-link should work just fine. It's the least expensive and simplest design. But whatever you go with consider it permanent unless you have the fabrication skills or a fat checkbook to make the serious mods necessary to change from one design to another.

[GoDadGo]

I like Gordon Levy's 5 link; however, my car won't be on the race track for any serious action so I opted for the 3 link.
While the IRS offers superior ride and handling, the 3 ink saved me money and is keeping things as simple as possible.
My pal Donny (Hottrodder427) has the IRS set up and it does ride a lot better than mine, but it is more complcated.
My only recommendation is to avoid the 4 link since it is the lowest performing of all of the set ups.

1. Current IRS
2. Gordon Levy 5 Link
3. Factory Five 3 Link
4. Ford Style 4 Link

[FFinisher]

"My car will be used on the Street of TEXAS for some fun sunny day cruising."

Craig does a good job above detailing concisely the issues with the four-link and informs us that the three-link is an improvement. I agree that the three-link is a significant improvement over the triangulated four link and may be a good choice for those that want more performance. But it still has lots of room for improvement for a track car. IMO, for an all around good performance suspension it's hard to beat the IRS. But remember, the best suspension system is only as good as how it's set-up. The more complex a design is and the more adjustability the harder it is for a novice to get it dialed in correctly.

Based on your intended use the four-link should work just fine. It's the least expensive and simplest design. But whatever you go with consider it permanent unless you have the fabrication skills or a fat checkbook to make the serious mods necessary to change from one design to another.


I agree with this statement, Except that the 3 link is an easy upgrade later on the MKIV as the mounts are there on all cars, You would need to purchase some parts to upgrade to the three link but its do-able later.


For sunny day cruising I would bet you $1000 you could not tell the difference from a 4 link to a three link.

I am sure there are over a million mustangs with 4 links on the road and would hate to guess how many cars and trucks in total with all brands included there are on the road.

Pretty sure they were designed with cost and performance in mind. Lowest cost, best overall performance in the expected use. Note In the expected use

As with all decisions its easy to overthink and overspend.

[Avalanche325]

Well, reality dictates that "Sunny day cruising" will at some point involve stepping on the loud pedal a little harder than if you were driving Miss Daisy. That is when the 4 link can hop. Suspension bind is never a good thing even if just cruising.

"Over a million Mustangs have it" is hardly a shining endorsement. You can watch hours and hours of Youtube footage of Mustangs loosing the rear end and launching themselves off the road.

I don't agree that it is over-thinking. FFR found the 4-link to be problematic and designed something better.

[Scotty's65]

F5's 3link is so good that Ford copied it for the 05 to 14 Mustangs!!
Seriously though, I used it on my MKII and there was no wheel hop and even when spinning the rears at speed it was solid and predictable - if you're not going irs then the 3 link is a no brainer

Scott

[CraigS]

Coil overs are a definite improvement over the stock mustang springs and shocks. Mainly in ease of height adjustment and ease of trying different rate springs. However the same coil overs can be used on either a 3 link or 4 link so the ride would be the same w/ either suspension as long as you are talking just driving normally in a straight line. Where the type suspension comes into play is when driving over a rough surfaces in a turn. Another time when the suspension matters is when going into a turn, and it is tighter than you thought, so you need to lift out of the throttle. In that situation the 3 link is the better choice.

[edwardb]

When talking about 4-links, I think it's important to say there are differences. Very often a "4-link build" is a straight up donor build with Mustang donor control arms, donor quad shocks, etc. This was (and still is) the most basic and cheapest build, and also deservedly has the worst reputation. Worst ride, worst handling, bad manners, etc. A very common upgrade was to replace the quad shocks with coilovers. This made them a bit better. At the other end of the spectrum is a 4-link build with aftermarket control arms, bushings, coilovers, etc. When pushed to the limit, these also would exhibit some of the 4-link bad habits. But I would agree with previous posters that for street cruising, works quite well. My first build, Mk4 #5125, has this setup. I didn't know any different at the time and drove it thousands of miles for a couple seasons with no issues. It didn't have any problems with wheel hop. It's still going strong today with its new owner. Given the choice, I'd probably agree with the comments to go with another option. But just wanted to say, in regards to the poll question, not all 4-links are created equal.

Regarding the high cost of IRS, I get asked this question a lot. My answer always is "it depends." It's possible to get a donor or salvage 8.8 solid axle for a very reasonable amount. Many do. Often they do require some work though, and usually it's not of the DIY variety. At least for many. It's also possible to buy a ready to use 8.8 solid axle (Moser, Forte, etc.) but now you're talking about much more serious money. You can buy the 2015+ Mustang IRS center section for around $800 NIB for the non-Torsen version, which is the same as most 8.8 solid axle diffs. The knuckles are $300+ brand new as well. The parts are also now pretty widely available in salvage for considerably less. It's a very different picture compared to what it was like over the last few years finding and rehabbing the older style IRS components. Yes, the IRS option adds to the kit price. But depending on the direction you go, it may not be as much of a cost adder as expected. As far as complexity, I didn't find the job of installing the various IRS parts any more difficult than installing a solid axle. Having owned and extensively driven the 4-link (mentioned earlier), a 5-link, and now the new IRS, I highly recommend the IRS. The ride is very noticeably better. I don't push my cars that hard, but I've found the handling to be outstanding with nothing negative to report. No one ever wants to talk about resale value ("I'll keep this thing forever...") but there's no question an IRS build has more interest and value than a solid axle. I'd give IRS a hard look for any build.

[FFinisher]

When talking about 4-links, I think it's important to say there are differences. Very often a "4-link build" is a straight up donor build with Mustang donor control arms, donor quad shocks, etc. This was (and still is) the most basic and cheapest build, and also deservedly has the worst reputation. Worst ride, worst handling, bad manners, etc. A very common upgrade was to replace the quad shocks with coilovers. This made them a bit better. At the other end of the spectrum is a 4-link build with aftermarket control arms, bushings, coilovers, etc. When pushed to the limit, these also would exhibit some of the 4-link bad habits. But I would agree with previous posters that for street cruising, works quite well. My first build, Mk4 #5125, has this setup. I didn't know any different at the time and drove it thousands of miles for a couple seasons with no issues. It didn't have any problems with wheel hop. It's still going strong today with its new owner. Given the choice, I'd probably agree with the comments to go with another option. But just wanted to say, in regards to the poll question, not all 4-links are created equal.

Regarding the high cost of IRS, I get asked this question a lot. My answer always is "it depends." It's possible to get a donor or salvage 8.8 solid axle for a very reasonable amount. Many do. Often they do require some work though, and usually it's not of the DIY variety. At least for many. It's also possible to buy a ready to use 8.8 solid axle (Moser, Forte, etc.) but now you're talking about much more serious money. You can buy the 2015+ Mustang IRS center section for around $800 NIB for the non-Torsen version, which is the same as most 8.8 solid axle diffs. The knuckles are $300+ brand new as well. The parts are also now pretty widely available in salvage for considerably less. It's a very different picture compared to what it was like over the last few years finding and rehabbing the older style IRS components. Yes, the IRS option adds to the kit price. But depending on the direction you go, it may not be as much of a cost adder as expected. As far as complexity, I didn't find the job of installing the various IRS parts any more difficult than installing a solid axle. Having owned and extensively driven the 4-link (mentioned earlier), a 5-link, and now the new IRS, I highly recommend the IRS. The ride is very noticeably better. I don't push my cars that hard, but I've found the handling to be outstanding with nothing negative to report. No one every wants to talk about resale value ("I'll keep this thing forever...") but there's no question an IRS build has more interest and value than a solid axle. I'd give IRS a hard look for any build.


As usual Paul is Spot on.


that's what I meant. :-)

[TexasAviator]

3 link for aforementioned reasons

[GoDadGo]

If money is not an issue, then go with the I.R.S.

If you want to keep things simple, get the 3-Link, especially if you plan to play the stop light to stop light game with people expecting you to play. Also, every two-three years I have to replace the U-Joints in the half shafts of my Beater Mobile / 1995 Corvette and it's a pain in the neck. I've done it a 10-12 times over the past 23 years so avoiding extra driveline components in my FFR MK-4 will allow me to avoid extra maintenance down the road, I hope.

[Richard Oben]

EdwardB is correct. In my opinion (FFR owner since 1998) FFR should not offer the 4 link any more. Buy the 3 link IF going live axle.

My opinion IRS is the best way to go. So lets compare, 3 link plus discs, plus gears, plus coil overs is in end a lot of money. Sure searching craigslist can save some money but in the end it is about 2 Gs

IRS comes with disc, comes with coil overs, the new IRS comes with 3.55 gears. In the old days it was about 3K to get the IRS in the car. On a project of this scope the 1,000 extra was well worth it.

Again this is only my opinion. Richard

[clancypm]

I bought a 1996 salvage mustang cobra for my donor. It had been rolled, and that was all it took for me to decide that I was going to upgrade to the 3link. I really don't want to worry about rolling my mark4 when I take it for a drive.

[Avalanche325]

Since it hasn't really been mentioned, but it is in the poll. I would only consider the 5 link on a serious track car. The advantage to it is that the rear stays "perfectly" centered as it travels up and down. With a panhard bar (3 link), it shifts a little bit left and right as it travels up and down. Very much a will not notice item on the street.

If I were building today......I would likely go with the new IRS. (With some additional research of course) I autocross, so was looking for max performance. That is why I went 3-link over the old IRS.

[Joee]

I have 3 link with Gordon's upgraded control arms. Love it from 1/4 mi to AutoX to track days, I can also run very smooth on all twisty hiways.