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Did you ever put spherical bushings in all of your rear end bushings on the stock 4 link?
No, that wouldn't stop the rear from moving around at all. Panhard bar would, and then you remove one UCA, that's called the "poor man's 3 link" and is actually not terrible.

Interesting, Car and Driver got these results:

99 SVT Cobra made a .88 g

95 Cobra R made a .96 g

The stock Koni Yellow shocks and stock Eibach springs on the 95 Cobra R made a HUGE difference.
No crap a SRA with top end shocks and good springs could beat a stock IRS with what amounts to white box springs and shocks on a prepped track with a professional driver... Take both cars and prep both the SRA and the IRS and THEN do the test.
 

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No, that wouldn't stop the rear from moving around at all. Panhard bar would, and then you remove one UCA, that's called the "poor man's 3 link" and is actually not terrible.
Funny you say that, I've been running spherical uppers for several years now. The rear end feels more planted than it did with the factory rubber bushings, and seems to drive better. The rear end does not wobble in the corners. I know of a another guy with an SN95 running coil overs, and all spherical bushings in all corners of the rear axle, who actually runs better times than guys with panhard bars, and torque arms ( who are also running coil overs).

I do know that on uneven surfaces where roads randomly dip is dangerous for any solid axle set up. The solid axle simply cannot transition smoothly over these dips. This is why the IRS is superior, and much safer under rough road conditions.


No crap a SRA with top end shocks and good springs could beat a stock IRS with what amounts to white box springs and shocks on a prepped track with a professional driver... Take both cars and prep both the SRA and the IRS and THEN do the test.
My point is that with an 94-04 solid axle Mustang you can have a car that pulls .96 g with relative little cost. You can get the same Koni shocks, and Eibach springs for less the $1k. This should be the very first modification to any SN95. The stock 4x4 springs/shocks are hiding what should be an otherwise great handling stock car.

Now lets see,

1995 Cobra R pulls .96g stock (example of Koni shocks + Eibach springs factory stock)

2000 Cobra R pulls 1.02g stock (example of Bilstein shocks + Eibach springs factory stock)

The 00R is almost on par with the stock 2017 GT350 which pulls a 1.03g.

This proves that the IRS is superior, but it also proves that solid axle can be a good platform for a guy on a budget who doesn't have the money for a proper IRS or Solid axle set up.
 

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Because my car is a street car first and foremost where the stick axle cannot compete with an IRS. Again, that's a lot of words for you've never driven a well setup 3 link or IRS. Or any car at a road course for that matter... Post all the articles from magazines you want, doesn't sub for actual IRL experience. You can have a car with a LOT less power run way faster times. Go drive a prepped Miata, you'll never have as much fun with 160hp as you will in one of those.

I've driven both, the IRS is better FOR THE STREET if you care about handling and its not close. If you are track prep only then the GR40 Griggs Cobra and some of the S197 stuff with the stick axle can be world class but even then its a toss up. For drag no idea why Ford went with the IRS for the Terminator, they shouldn't have but probably because they had it in all the New Edge Cobras prior. It does ok at the drag strip with the full tilt treatment and proper drag springs and shocks and drag setup up front but most ppl serious about drag do the SRA swap.

And at this point where the youngest New Edges are 16+ years old it doesn't matter what you had, the stock suspension needs replaced regardless.
I’m fairly certain the IRS was an attempt at better handling and comfort instead of straight line performance. Otherwise corner carvers wouldn’t be swapping their live axles for irs and hardcore ‘03 cobra drag racers wouldn’t be swapping the irs out a solid axle setup. You don’t agree??
Yes, 20 year old cars have old worn out suspension. The cars I linked in the articles were new when tested though and there was not a night and day difference between their handling test. Can we agree on that? The one article even said something to the affect that Ford said the reason the Mach was a little slower in the slalom than the Cobra was due to the Mach’s solid axle vs the Cobra’s IRS. Cobra IRS for drag racing- certainly not. Slightly better handling (stock for stock) and less bumpy yes.
I’m not knocking an IRS swap, but it’s not the end all be all, and frankly the majority probably don’t even need it. There is more than one way to skin a cat, pour money into a stock rear end, or rip out the control arms and go independent. For the masses though, the standard upgraded rear control arm, shocks/struts, and springs will suffice. I’m more into a jack of all trades, master at none kind of thing. A street car that can handle as well as a street car needs to handle as well as not wheel hop it’s azz off if I was to take it to a drag strip.
Like you said though old cars need suspension work, and once again cash is king. Whoever has more money into their suspension is probably going to have the quicker car. Unless it’s a stock for stock application, like the Camaro vs the ‘03 Cobra. Two different cars, both with a compromised suspension that is geared more towards street use. One of them was built more towards drag racing, the other for corner carving, and in this case the street suspension solid axle can hang with the street suspension IRS. The Mach and the Cobra was even more of an apples to apples. Both suspensions were built to be a compromise for comfort and performance and neither car was light years ahead of the other with its handling prowess.
You’ve driven both and that’s wonderful, and if I read it correctly you said the irs is more comfortable. I’m sure that’s probably so. Can a solid axle out handle an IRS? Yes, depending on which car and what suspension parts.
For the masses- IRS swap, overrated.
 

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I’m fairly certain the IRS was an attempt at better handling and comfort instead of straight line performance. Otherwise corner carvers wouldn’t be swapping their live axles for irs and hardcore ‘03 cobra drag racers wouldn’t be swapping the irs out a solid axle setup. You don’t agree??
Yes, 20 year old cars have old worn out suspension. The cars I linked in the articles were new when tested though and there was not a night and day difference between their handling test. Can we agree on that? The one article even said something to the affect that Ford said the reason the Mach was a little slower in the slalom than the Cobra was due to the Mach’s solid axle vs the Cobra’s IRS. Cobra IRS for drag racing- certainly not. Slightly better handling (stock for stock) and less bumpy yes.
I’m not knocking an IRS swap, but it’s not the end all be all, and frankly the majority probably don’t even need it. There is more than one way to skin a cat, pour money into a stock rear end, or rip out the control arms and go independent. For the masses though, the standard upgraded rear control arm, shocks/struts, and springs will suffice. I’m more into a jack of all trades, master at none kind of thing. A street car that can handle as well as a street car needs to handle as well as not wheel hop it’s azz off if I was to take it to a drag strip.
Like you said though old cars need suspension work, and once again cash is king. Whoever has more money into their suspension is probably going to have the quicker car. Unless it’s a stock for stock application, like the Camaro vs the ‘03 Cobra. Two different cars, both with a compromised suspension that is geared more towards street use. One of them was built more towards drag racing, the other for corner carving, and in this case the street suspension solid axle can hang with the street suspension IRS. The Mach and the Cobra was even more of an apples to apples. Both suspensions were built to be a compromise for comfort and performance and neither car was light years ahead of the other with its handling prowess.
You’ve driven both and that’s wonderful, and if I read it correctly you said the irs is more comfortable. I’m sure that’s probably so. Can a solid axle out handle an IRS? Yes, depending on which car and what suspension parts.
For the masses- IRS swap, overrated.
It is the OE bushings in the cars that make the comps you posted useless. Not sure why you keep beating this horse

And not many folks are swapping the IRS these days, 5-10 years ago yes.
 

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It is the OE bushings in the cars that make the comps you posted useless. Not sure why you keep beating this horse

And not many folks are swapping the IRS these days, 5-10 years ago yes.
I’m not sure why I’m beating this dead horse either. Yes it’s the OE bushings, but it doesn’t make the comparisons useless. The Mach vs the Cobra was a pretty valid comparison and the Cobra didn’t blow it away did it? Valid because it’s the same darn chassis. Swap out the OE bushings in the Mach and it’ll probably be right on par and or beat the Cobra with a stock IRS.
I bet not many people are swapping out irs in their Cobra’s these days because there just aren’t that many SN95/ “new edge” IRS Cobra’s out there anymore to swap them into. I still see a crap load of old GT’s and V6’s though and since there’s a crap load of them you’ll see more people swapping parts. Here’s some more googling for you. A couple of these guys said they can’t tell much of a difference in handling after getting rid of the independent rear. One guy broke his irs.. So how about solid axle setup with aftermarket good bushings? That could equate to a car that handles well and also launch from a dead stop.
You’re right though it is soft rubber bushings in both setups that are holding them back. But still the fact remains that the Cobra with its rear suspension that’s “superior” for handling wasn’t all that superior to a “crappy” old school solid axle that had rubber control arm bushings.
 

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Yes because they are both crap in stock form. That's like 2 ppl racing on crutches.

And again, magazines are not really the most reliable... next up you'll post a MM/FF on how a BBK cold air kit adds 15hp... and those do exist.
 

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If you really need verification of the max capabilities of fully modified live axle versus a fully modified IRS, you need look no further than Maximums' Fox body American Iron car. If I remember correctly they gained something like three seconds a lap at their home track with the IRS. That's no small thing I can assure you!

Jay
 

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Yes because they are both crap in stock form. That's like 2 ppl racing on crutches.

And again, magazines are not really the most reliable... next up you'll post a MM/FF on how a BBK cold air kit adds 15hp... and those do exist.
Yes it's not good to completely adhere to magazines as bearers of absolute truth. I remember Magazines the world over were telling me that the Acura NSX and Porsche 911 turbo were the ultimate driving machine, and that the Mustang was basically a pile of poo poo compared to them. Even though I remember it was a solid axle Saleen Mustang that beat the NSX and Porsche 911 across the finish line in the mid 1990's. It was also displayed on live television.

I mean it's also shocking watching videos of those old races seeing a stock suspension solid axle 1995 Cobra R beat Porsche 911's, Ferrari 348's, and the best handling car in the world... the Miata. I know it's shocking, it's not supposed to happen, but it did more than once. It's surprising that Magazine companies and the corner carvers forums haven't found all the 1990's race footage and burned it all like the Spanish Inquisition.



If you really need verification of the max capabilities of fully modified live axle versus a fully modified IRS, you need look no further than Maximums' Fox body American Iron car. If I remember correctly they gained something like three seconds a lap at their home track with the IRS. That's no small thing I can assure you!

Jay
This is true. The IRS is superior, and exactly why the Saleen RRR Le Mans Mustang used an IRS. Personally I think an IRS is safer for the street, because it can keep the car under control better under rough conditions. It's also better on the track when modified.

My only complaint about the IRS is the stock bushings which are easily fixed. Of course that's like complaining about the stock bushings in the stock 4 link solid axle. In the end it all comes down to budget, and if my car ever becomes a max effort track build, I'm switching to an IRS, period.
 

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I switched to IRS because it wasn't a max effort track build but a street car to handle. I swapped straight up with a guy who had a 99 IRS with some 03 goodies on it. Still has the 99 diff and axles and I will upgrade those when I go to a blower but for a sub 400hp car... 99 axles and diff are fine. It had the Eibach swaybar, Prothane Subframe bushings and heim joint endlinks already done and also had an 03/04 front brace. We swapped exhausts too. I spent probably $1k on the Delrin UCA/LCA bushings, cross axis links, tie rods and diff mount/front bushings. There really isn't anything else I can do to it except go coilovers which I'm not sure I'll ever do. Has D Spec shocks and Steeda springs on it now. You will NEVER sort a solid axle properly for $1k. Not in a million years. If I upgrade it to 03 axles figure another $400. Still half the price of a 3 link and a built SRA.

And yes agreed the MM AI car is an IRS with their stuff and the Full Tilt stuff is better IMO. I have absolutely 0 MM stuff in the IRS but the whole MM shebang going in up front. Car should outhandle pretty much anything on the road and I live in Europe where there are a LOT of handling cars. 20 minutes from Jerez, Spain which has one of the better road courses on the continent.

That said, the Griggs GR40 car is a stick axle but that with EVERYTHING done to it plus a full SLA setup up front.

edit: I should say the car itself should be capable of outhandling most everything. My ass driving it=no lol.
 

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I switched to IRS because it wasn't a max effort track build but a street car to handle. I swapped straight up with a guy who had a 99 IRS with some 03 goodies on it. Still has the 99 diff and axles and I will upgrade those when I go to a blower but for a sub 400hp car... 99 axles and diff are fine. It had the Eibach swaybar, Prothane Subframe bushings and heim joint endlinks already done and also had an 03/04 front brace. We swapped exhausts too. I spent probably $1k on the Delrin UCA/LCA bushings, cross axis links, tie rods and diff mount/front bushings. There really isn't anything else I can do to it except go coilovers which I'm not sure I'll ever do. Has D Spec shocks and Steeda springs on it now. You will NEVER sort a solid axle properly for $1k. Not in a million years. If I upgrade it to 03 axles figure another $400. Still half the price of a 3 link and a built SRA.

And yes agreed the MM AI car is an IRS with their stuff and the Full Tilt stuff is better IMO. I have absolutely 0 MM stuff in the IRS but the whole MM shebang going in up front. Car should outhandle pretty much anything on the road and I live in Europe where there are a LOT of handling cars. 20 minutes from Jerez, Spain which has one of the better road courses on the continent.

That said, the Griggs GR40 car is a stick axle but that with EVERYTHING done to it plus a full SLA setup up front.

edit: I should say the car itself should be capable of outhandling most everything. My ass driving it=no lol.

I've been contemplating going IRS, with a Maximum Motorsports full front coil over conversion. My biggest problem is having the time to do the swap, or finding a shop that can do the work without messing up my car. I'm pretty sure your car will haul ass through the corners, and most cars will have problems catching up.

I'm focused on going faster for now, but as much as I love driving my car the IRS seems very tempting to do.
 

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Well to go faster you're going to have to sort whatever rear you decide to go with before you can REALLY go faster. Gotta be able to put the power to the ground. IRS assemblies are still pretty common on SVTP and the facebook sale groups, you just have to find one within a reasonable driving distance. For mine we both drove 2.5 hours and met in a gas station half way.

If you're on a budget and can't do the full MM front treatment then good budget is to go with the Global West Del a Lum bushing set and X2 balljoints in the stock A arms. MM aluminum rack bushings, good swaybar/endlink setup and just a good set of coil springs like HR Race with MM CC plates. You don't HAVE to do coilovers unless you are doing the K member.
 

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IRS assemblies are still pretty common on SVTP and the facebook sale groups, you just have to find one within a reasonable driving distance. For mine we both drove 2.5 hours and met in a gas station half way.
Next time you see one pop up, 99-04 doesn't matter, please let me know. No facebook here
 
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