Super Strong IRS

[KWladyka]

I like the IRS for daily driving and would prefer to keep an IRS for drag and road racing. Anyone considered doing something like this? Is it feasible on our cars?

http://www.geocities.com/~concourswest/page3.html

 

[03Sssnake]

Given enough determination, time and money..Especially money, anything is possible.

 

[Shadowgray03]

With the estimated street price of the new 06 cobras at 50k and the fact they will likely have more power(I would guess due to a better blower) I would also assume they will have a stronger IRS. Hopefully we will be able to utilise it in place of ours.

 

[JKD COBRA]

any info on what type of car that will be? From the looks of it, it would cost way too much to be worth it unless your only using the car as a race car. What you have to remember is that unlike the corvette's IRS which is actually built into the car our IRS is a bolt on IRS. It can be swapped around. Thats why we get so much wheel hop and break halfshafts. I don't know what it would take to put an IRS in the pic in our cars, but I doubt it would be worth it.

 

[ShelbyGuy]

its a vintage mustang. it suffers from the same problems ours does, which is due to the compromise of having to be a bolt-in system, and a lack of development.

this setup was starting to be developed by shelby-american on the fuel injected green '68 test mule. the gentleman who designed the 427 cobra suspension did this setup, too; using ford off-the-shelf parts mostly [galaxie control arm bushings, etc] to keep costs down.

http://www.geocities.com/ctmengineering/mustanghome.htm

 

[PhillyCobra]

Problem with our IRS is not it's "strength." Rather, I agree it's a lack of optimum tuning of bushings, springs, shocks and tire flex superimposed on an obscene amount of torque. Except for wheel hop, the system is plenty strong. I think the halfshafts and universals could be stronger, and you can get replacements, but I bet the stock pieces would hold up to near 600 lb ft torque if desructive wheel hop were avoided.

 

[JKD COBRA]

you are correct. As long as we don't launch the car hard with DR or slicks and we keep the wheel hop to a minimum than our IRS should be ok. But what I mean was that we have the wheel hop because of it being a bolt on IRS.

 

[03DOHC]

That looks like a cool setup. Half-shafts look like driveshafts. Look at the size of that rim, damn.

 

[CobraBob]

Originally posted by Shadowgray03
[color=orange}With the estimated street price of the new 06 cobras at 50k and the fact they will likely have more power [/color](I would guess due to a better blower) I would also assume they will have a stronger IRS. Hopefully we will be able to utilise it in place of ours.

Where did you hear the street price is going to be around $50,000? It has to be a rumor because there is no way they're going to sell the new Cobra for that much. That a 40% jump. I don't see it even being a remote possibility.

And where did you hear/read that the engine output will likely be more than 390/390?

 

[08snake]

Originally posted by CobraBob
Where did you hear the street price is going to be around $50,000? It has to be a rumor because there is no way they're going to sell the new Cobra for that much. That a 40% jump. I don't see it even being a remote possibility.

And where did you hear/read that the engine output will likely be more than 390/390?

Was wondering the same thing......

 

[03Sssnake]

Originally posted by CobraBob
Where did you hear the street price is going to be around $50,000? It has to be a rumor because there is no way they're going to sell the new Cobra for that much. That a 40% jump. I don't see it even being a remote possibility.

And where did you hear/read that the engine output will likely be more than 390/390?

LOL... I am sure his car salesman/dealership have some inside info on what the 06 cobra pricing will be....that and it specs..I mean if anyone should know it your car salesman!!!! -/sarcasm off

 

[Joe Lynch]

You have wheel hop because of low unsprung weight and lack of traction. You will break the stock pieces when you put on big enough tires to keep from spinning. No spin, no wheel hop.

You won't have any wheel hop on a completely stock IRS Mustang if you put a set of ET Streets on it. You can fool with all the other stuff you want, it comes down to this. If you don't spin, you don't hop. With tires sticky enough to avoid spin, you break stuff.

Joe Lynch

 

[Antex]

With wheel hop you break halfshafts -

What do you break with the sticky E/T street tires?

 

[Rwick7]

I still don't see what is so great about the IRS, Ford should have made it an option...they didn't, so I did

People spend alot of time and money with stiffer shocks, springs..etc to try to get the IRS to act like a solid axle...do you think it's still gonna ride nice? Just ditch that anchor

 

[JKD COBRA]

stlblack03 - I also think Ford should have made it an option. But even more so, I wish ford would have made our IRS like the corvette/viper. If they would have taken some extra time/money to make our IRS a true part of the car instead of a bolt on piece than I think we would have barely any complaints about drag racing with the IRS.

The corvette/viper can do some awsome launches and handle just as good because their IRS is built into the car.

 

[PhillyCobra]

I agree live axle is best at the strip, but I wouldn't have bought a Cobra unless it had IRS. Having suffered through lousy handling, particularly on crappy roads around Philly, with my previous Mustangs, there's no way I would go back to live axle for a street car. Can't even begin to say how much better IRS is for handling and ride.

I still think problem with our IRS at the strip isn't it's basic design (or lack of design!), rather a poor choice of springs, shocks, bushings and tires, allowing a resonant frequency we have all felt with the gut wrenching hop occuring as tires slip and grip on launch. Changing to stickier tires cures it (especially if you heat them up), and apparently stiffening the bushings or going to drag shcoks cures it.

Increasing unsprung weight might help at the strip, but it's bad in every other situation.

 

[Shadowgray03]

Originally posted by CobraBob
Where did you hear the street price is going to be around $50,000? It has to be a rumor because there is no way they're going to sell the new Cobra for that much. That a 40% jump. I don't see it even being a remote possibility.

And where did you hear/read that the engine output will likely be more than 390/390?

http://www.auto123.com/en/info/news/news,view.spy?artid=14309

 

[Joe Lynch]

All you do with springs, shocks, bushings is change the combination of surface and tire spin at which the wheel hop will occur. It is not possible to eliminate hop with street tires under all conditions, some but not all. Every time I changed something on my car to cure the hop, it just changed but was never eliminated with street tires. If it spins, it will hop under some combinations, no matter what you do.

Halfshafts break whether there is wheel hop or not. Impact stresses due to the initial launch or due to spikes when it hops will break them.

Joe

 

[94SVT Coupe]

Originally posted by KevinJKD
stlblack03 - I also think Ford should have made it an option. But even more so, I wish ford would have made our IRS like the corvette/viper. If they would have taken some extra time/money to make our IRS a true part of the car instead of a bolt on piece than I think we would have barely any complaints about drag racing with the IRS.

The corvette/viper can do some awsome launches and handle just as good because their IRS is built into the car.

How could they? They had a 99 Mustang body, and the task to put a IRS under it. They did the best they could. They couldn't get new floor pan stampings created or the subframe modified or anything.

The reason the IRS is there because back in 95, 96, 97, 98 owners bitched about the crappy handling the solid axle offered and how they thought the Cobra should get a IRS.