SVT Cobra, how good does it really handle?

[5.0GT]

Hello,

I'll start this here, I'm sure there are people that tried multiple vehicles that happen to drive the IRS Cobra. I saw one on craiglist and the price is very tempting for a project. 10k 400whp and it's very clean. How good is it really? Is it better than a boss around corners for example? I always sense bad feelings when people talk about the that car's IRS, did it suck in drag racing or something or is it just not a very good handling car?

 

[darreng505]

It's not better than the Boss around corners. Not even close. Dampers. Balance. Body stiffness. And lack of 3rd link rear suspension just a few reasons.

 

[Greensix]

It's not better than the Boss around corners. Not even close. Dampers. Balance. Body stiffness. And lack of 3rd link rear suspension just a few reasons.

Why would an IRS car need a 3 link rear suspension? The solid axle is not ideal for road racing or auto-x in any way. Ford has just done a REALLY good job at getting the absolute most out of a stick axle but it is far from ideal. That is why the new generation Mustang is going with an IRS and not a stick axle.

"Handling" is subjective to a point. I use to track a 2002 Mustang with a stick axle, then swapped to an IRS, then sold everything and now race in Spec Miata. The IRS was just as fast around the track as the stick axle with the MM 3 link but felt a lot more stable over bumps. It was easier for me to go faster in it and didn't feel as much of a white knuckle drive.

I have driven several 05-10 Mustangs on track (including an FR500S) with upgraded 3 links and watts links. Darreng is correct about the chassis being much much stiffer and well designed. Ford has done the homework for you and matched proper spring rates with dampening rates. It is just so much easier to set up a S197 chassis than it is a SN95 chassis.

Is there a reason you are wanting to compare it to a Boss? If you want a pre-2005 to handle really well, get ready to spend some serious cash on either the IRS (coilovers, bushings, braces) or the live axle (3 link, coilovers, control arms, etc.)

 

[darreng505]

Why would an IRS car need a 3 link rear suspension? The solid axle is not ideal for road racing or auto-x in any way. Ford has just done a REALLY good job at getting the absolute most out of a stick axle but it is far from ideal. That is why the new generation Mustang is going with an IRS and not a stick axle.

Oh yeah. That's right (about the IRS). Your point is valid but the Boss is still better handling than an old cobra with IRS. So that much is fact. A boss with IRS would handle even better! Lol. So yeah. IRS better. Buy not on an older car with other drawbacks in my opinion. Stock for stock.

 

[apex32]

The s197 chassis is much better to begin with. Throw some suspension on a newer GT/Boss and you have a very capable road course car.

 

[99COBRA2881]

Get ready to spend money front to back on the older car to make it perform. Or add bushings and higher spring rates onto the newer chassis and have a better platform than the old car with the entire mm catalog thrown at it.

This fact is why I haven't started rebuilding my AI race car. I could rebuild the old chassis or start with a new 05+ chassis that's already better than what I have and build it into my next AI race car.

 

[gcassidy]

Hello,

I'll start this here, I'm sure there are people that tried multiple vehicles that happen to drive the IRS Cobra. I saw one on craiglist and the price is very tempting for a project. 10k 400whp and it's very clean. How good is it really? Is it better than a boss around corners for example? I always sense bad feelings when people talk about the that car's IRS, did it suck in drag racing or something or is it just not a very good handling car?

All that is said above notwithstanding (cause it's so true), you say it's for a project. Do you want to just have cheaper car to track? The Cobra IRS would be good. And for 10K you have about lots left over for entry fees as opposed to even a used Boss.
Is the one you're looking at a Termi or earlier? And are you just looking to have cheap thrills with it?

 

[5.0GT]

Thanks a lot for sharing your knowledge guys. I don't think I'll pursue that.

I have a 2011 GT, I think it handles as good as a boss at least since I don't really have any stock suspension left, but a turbo is going in soon and I won't be able to drive it nearly as hard as I used to. I never drove an SN-95 mustang ever and I certainly don't want to go down in performance. I felt like it's a very good price. I might just go with shifter karts, those were a blast!

It's listed in Phoenix, AZ if anyone is interested in that car.

 

[Charlington]

The Cobra IRS got a bad reputation from abuse. The engineers were tasked with fitting the SN95 with an IRS and had they come from the factory with Coilovers they may not have gotten such a bad rap. If you look at every car that was designed to have an IRS you'll see the rear springs are Behind the axle. The Cobra's IRS was designed to fit a car already in production and the rear springs were located in front of the axle to fit the chassis. Having the springs in front of the axle contributes to wheel hop making the problem worse. All cars wheel hop to one degree or another. It's not a problem specific to the Cobra. I broke the pinion shaft on my Camaro 4 times (about a million years ago) until I fitted it with Lift Bars and street slicks, then no more wheel hop or broken parts.

 

[99COBRA2881]

The Cobra IRS got a bad reputation from abuse. The engineers were tasked with fitting the SN95 with an IRS and had they come from the factory with Coilovers they may not have gotten such a bad rap. If you look at every car that was designed to have an IRS you'll see the rear springs are Behind the axle. The Cobra's IRS was designed to fit a car already in production and the rear springs were located in front of the axle to fit the chassis. Having the springs in front of the axle contributes to wheel hop making the problem worse. All cars wheel hop to one degree or another. It's not a problem specific to the Cobra. I broke the pinion shaft on my Camaro 4 times (about a million years ago) until I fitted it with Lift Bars and street slicks, then no more wheel hop or broken parts.

The IRS is the one thing the car has going for it. Bushings and coilovers and most of the IRS problems are solved. It got a bad rap cause most mustang guys only turn left after the lights at the end of a 1/4 mile. For road racing it makes the car forgiving and well planted. Wont even mention that its a large amount of weight that's on the right end of the car and its slung very low. 50/50 on these cars is easy with the irs out back.

 

[Charlington]

Truth!
Bought a V6 for DD and swapped in the IRS. Looking forward to track days. Pieced together a 2nd IRS for a spare. Wished I had bought one years ago but been stuck in the truck world.

 

[wheelhopper]

I track a '90 GT with an IRS and the car is outfitted with a fair amount of aftermarket parts. I also have a full cage, frame connectors, and jacking rails, so the car is pretty stiff. I have buddies that track the older Mustangs with straight axles and have some aftermarket parts as well. I can say I don't think an IRS equipped fox chassis is any better than a straight axle car. They may have some different handling characteristics but IMO the end result is similar. If you had the older car already I would say fix it up and go for it. If I mashed my IRS equipped fox up and had to replace it with another car it would not be a '79-'04 Mustang with an IRS or straight axle. I would look for an '05 and up Mustang and possibly a 3 series BMW or C6 Corvette.

 

[Force4.6]

I'm similar to wheelhooper (although he is about a 1 second faster on the track), I run a 02 GT and it does just fine with few suspension parts and brakes. If the track isn't bumpy or has a lot of camber changes the differences between solid and IRS are negligible. But the more changes in track surface the better the IRS is.

I would not say that 01 or 03/04 Cobra is a bad handling car at all when compared to it's peers from the same time period. Having driven the cars comparing the Cobras to the newer cars isn't a very fair comparison. The newer mustangs are just more stable platforms for the road course. 10 years of improved technology goes a long way. However eventually the stick axle needs to go which has been addressed on the next generation car.

If you like the Cobra better, it's in your price range, and you would like to fix it up to handle go for it. If you want to get something newer that is better out of the box get the 05 and up Mustang.

But if you want to scare passengers it's hard to beat a Cobra, drifting through every corner has it's fun too.

 

[gcassidy]

But if you want to scare passengers and please tire resellers it's hard to beat a Cobra, drifting through every corner has it's fun too.

Fixed for you, Rick.

 

[Charlington]

On a track it may be harder to tell the difference between IRS and SRA (IDK) but I bought a New Edge Coupe because every Mustang owner I talked to said you can't see out of the newer Fastbacks (blind spots). 2004 was the last Coupe model. Only choice since then is Convertible or Fastback. But if you are passing everyone there is no need to see who is behind you, right? O yeah, red and blue lights, back to reality.
The IRS is expensive once major repairs are needed. Knuckles and hubs can get damaged from just being forgetful. Have to torque the axle nuts every pre-race inspection and every 2-3 months on the street. I'm not used to owning a 20 ton hydraulic press just to change wheel bearings but Harbor Freight has one right now for $155usd!

 

[R.D.P.]

I think you would be terribly disappointed going to an IRS Cobra after owning a newer GT.

 

[tomsgarage]

Love mine, even after 12 years of on track events. Is she the fastest car out there like the 1st couple of years, no. Time marches on and cars do get better especially with all of the technology available now. But she is still a blast to drive, in fact we will knock one off the bucket list next month as I am prepping her to run the Rolex Course at Daytona!!!

 

[Charlington]

^^^ Time Marches On. Funny seeing a picture of a Ford Focus riding the bumper of an old 60's 289 AC Cobra on the track
Ditto, Bucket list. HPDE, then track time. Again, I went with the coupe/irs because it's a DD. It is much easier to install an irs than to install torque arm, watts link/panhard bar, contol arms etc. Sure you can buy either car right off the lot but what's the fun in that? The 2015 mustang is where the fun is now but I could have 4 Cobras for 1 of those.