I found a Cobra IRS on craigslist supposedly with 19k mi. Its the first to be on in awhile so I'm halfway considering it for my car. My car is going to be pretty much just a Auto-X car from here on out. My plans were to throw a panhard bar and LCAs on the rear, coilovers all around, and some subframes and bushing and odds and ends like that. But I found this IRS setup for about the same price as the Panhard bar and LCAs new from Maximum Motorsports. So what do you guy think I should do? I'm leaning towards the IRS simply because it's only $500 but that means I'm dropping from 4.10s to 3.55s and thats about all I have going on performance wise ahah. So what do you guys think?
Panhard bar and LCAs or Cobra IRS?
- Thread starter duh09
- Start date
JonBeast said:
I'm already running dumps so that won't be any issue. Might need a slight adjustment, but nothing major in that department.
ReplicaR said:
My car is already in and becoming more and more of a C-Prepped car so I'm pretty open on nearly any sort of mods to my knowledge. I'm pretty sure both are allowed, but I should check. I'm not really worried about being too competitive at this point although it'd be super great to rise from the bottom of the list for once.
My main concern with it is I'm not very familiar with IRS. Would it, coupled with coilovers, be as fun and handle as good as a solid-axle equipped with a panhard-bar, good LCAs, and coilovers? I'm not really wanting to sink TONS of money into it, so the IRS would probably be going into the car stock and eventually upgraded to coilovers. The rear cobra brakes would be a plus as well, I suppose.
MadStang
Well-Known Member
IRS has several advantages. the suspension will adjust better for non-level racing surfaces, ride quality will be leaps and bounds better, the added weight in the rear wheel make the car more planted on acceleration and if you couple all of that with an upgraded bushing kit, coilovers, and stronger halfshafts, you will be dominant on a road course or auto-x.
Disadvantages are the stock bushings suck, if you're pushing power down the stock half shafts will blow themselves to smithereens, and lastly you need a custom exhaust for the IRS or side exit. I don't recommend dumps ever, last thing you need is exhaust heating up the rear axle. But I'm picky about that anyway.
Disadvantages are the stock bushings suck, if you're pushing power down the stock half shafts will blow themselves to smithereens, and lastly you need a custom exhaust for the IRS or side exit. I don't recommend dumps ever, last thing you need is exhaust heating up the rear axle. But I'm picky about that anyway.
MadStang
Well-Known Member
oh and keep in mind you're increasing your track width by 3/4" each side since it's a new edge axle.
I don't think IRS is any quicker than a properly setup 3 link solid axle on the road course. What's more is IRS is a lot harder to setup then 3 link for racing. You have to deal with toe, bumpsteer, camber, wheel hop. 3 link does not have any of that to worry about, just set the pinion angle, center it, and it's ready to go.
MadStang said:
The added track width would be a plus right?
From what I'm reading, the 03 IRS (which is what this is) is a little stronger than the earlier ones. Would I really NEED to upgrade half-shafts and bushings? I'm still trying to get the most bang for my buck, and if I have to throw in a full set of bushings and half-shafts before I put it under my car, I'm more than likely going to pass. My motor is still stock, and is probably going to remain fairly stock for awhile so I can't imagine the halfshafts being completely destroyed by my 5.0L when it could handle the power of the Termis.
MadStang
Well-Known Member
ReplicaR said:
true, but, for someone more experienced the IRS would be more rewarding IMO.
If it weren't for my roush specific bilsteins, I would've dumped the SRA already and be rolling on an IRS. The feel of IRS is a lot more smooth and forgiving to me.. but it just depends on the driver when it comes down to it. I just don't like the way SRA feels on a road course, hence why I won't be doing too many track days with the roush. My next racecar will be IRS.
MadStang
Well-Known Member
duh09 said:
the added track width is a plus, just watch for tire clearances if you have wide tires.
you don't necessarily have to do do bushings. but it's a good idea since it's much easier when the IRS is out of the car. As far as halfshafts go, no you don't need them, but it's a good idea eventually.
Bushings I would not go without. the difference just from that is night and day.
I'm sure that there are quite a few racers who will disagree with you on that one. There are tons of cars out there, which are fast as hell, have tons of rear traction, and are running a 3 link. When the tracks are smooth enough, which most of them are, solid axle hooks up really well. There are some things that I'm not big on, after the torque arm install, but most of those come from daily driver perspective.
There are some really good advantages to having IRS, such as fixed differential location. This means that pinion angle will stay the same no matter what, unlike torque arm for example, and no matter how much you lower it, you will never rub drive shaft on the e-brake bracket.
My thought is that converting car from one setup to another is kinda pointless, because they work about the same on the road course. If your car came with IRS, then you can keep it and make it work. But if you have solid axle, it will be cheaper for you to make that work, especially seeing how well a good 3 link setup will work on the track. To swap IRS into Mustang, then get all the mods on there to make it run right, will cost probably twice as much as a good 3 link setup with centering device.
There are some really good advantages to having IRS, such as fixed differential location. This means that pinion angle will stay the same no matter what, unlike torque arm for example, and no matter how much you lower it, you will never rub drive shaft on the e-brake bracket.
My thought is that converting car from one setup to another is kinda pointless, because they work about the same on the road course. If your car came with IRS, then you can keep it and make it work. But if you have solid axle, it will be cheaper for you to make that work, especially seeing how well a good 3 link setup will work on the track. To swap IRS into Mustang, then get all the mods on there to make it run right, will cost probably twice as much as a good 3 link setup with centering device.
MadStang
Well-Known Member
Like I said, it's all a matter of opinion. I've always had great success with an IRS based car. I dislike the feel of SRA compared to IRS on the street as well as the track. I put up up with it on the Roush, but, my fox is going to have an IRS...
I agree with Madstang (who needs to check the Calendar contest thread)
The 3 link will perform better for traction, but it will also ride harsher.
IRS rides nice, and you'll be wanting a bushing kit if you're going to race it, bushing swap is an involved job.
(I've done both) 3 link with panhard on my 96 and IRS with MM bushing kit on my 67.
I also agree with Replica, good advice.
The 3 link will perform better for traction, but it will also ride harsher.
IRS rides nice, and you'll be wanting a bushing kit if you're going to race it, bushing swap is an involved job.
(I've done both) 3 link with panhard on my 96 and IRS with MM bushing kit on my 67.
I also agree with Replica, good advice.
After reading all this and doing just a hair bit more research, I've decided to just keep trucking along.
In the end, the IRS might be better all-around but thats a lot more money than I'm willing to spend right now.
In the end, the IRS might be better all-around but thats a lot more money than I'm willing to spend right now.
Win
Legend
duh09 said:
I was also going to say you would also need to look into cooling that IRS they can heat up very Quick.
