Modular Mustang Cobra for autocross/weekend driving

I had a 96 Cobra for 3.5 years. It was extensively modifed (QA1 tubular front LCA's, Eibach Pro-Street coilovers, QA1 tubular rear UCA and LCA's, Eiback F&R swaybars, Steeda bumpsteer kit and offset rack, GRIPP C/C plates, Mach 1 SRA, StopTech Track pads/rotors, BBK LT's, BBK catless X-Pipe, Flowmaster 40's with dumps, Canton overflow tank, MSD coils/wires, BBK TB, BBK CAI, Hypertech tuner, wideband, Walbro fuel system, 17x9/10.5 FR500's with 245/275 Falken Azenis RT615K+'s, MGW shifter, Luk clutch, etc, etc). I ran it in my local SCCA region in CAM-C versus previous national CAM Challenge winner Dennis Healy's S550 and won the season (simply because he broke more than I did). I also raced at an SCCA National ProSolo in Packwood, where I placed 9th of 11 in CAM-C. 

The Cobra is better suited to CAM-T, simply put I would have won or trophied every single event I entered in CAM-T. It also dynoed at 310 rwhp at only 6600 RPM (redline 7800 but wheelspeed was too high for the dyno). It was also a *terrible* street car. The interior is quite literally crap. All the plastic is cheap and rattles and breaks. The A/C sucks. The seats are stupid uncomfortable. There is no room for anything beyond a highback booster in the back seat. It autocrosses like crap (compared to how it track days, which is phenomenal, and drag races, which was pretty good). I loved the drivetrain and hated everything it was bolted to. The chassis/interior are sorely lacking, being neither particularly good looking (and I personally like SN95's) or quality.

The 99/01 cars have the IRS, but it is a seriously compromised design, and it costs 3-4x what the SRA suspension does . The S197's have a vastly better interior, but it is also pretty terrible. If you want to run a CAM-T car, I would suggest finding a classic you actually like. If you want to be as modern as you can, I would build a fox Thunderbird, especially an 87-88 Turbo Coupe, or an SVO Mustang to start with. The TC is a *much* better street car and actually take a car seat in the back. The SVO is a true fox platform and actually benefits a lot from being light and easier to upgrade than an SN95.

I'd have a really, really hard time buying any older mustang instead of an E46 M3.  The M3 is just a much better car at everything comparatively...

docwyte said:

I'd have a really, really hard time buying any older mustang instead of an E46 M3.  The M3 is just a much better car at everything comparatively...

It is, but there's a price tag for that, both to buy the car, and to maintain and modify it. And the BMW is certainly going to need more maintenance. I don't remember any generation of Mustang that had a self-destructing cooling system.

Tom_Spangler (Forum Supporter) said:

docwyte said:

I'd have a really, really hard time buying any older mustang instead of an E46 M3.  The M3 is just a much better car at everything comparatively...

It is, but there's a price tag for that, both to buy the car, and to maintain and modify it. And the BMW is certainly going to need more maintenance. I don't remember any generation of Mustang that had a self-destructing cooling system.

Doesn't the S54 have $2k VANOS rebuilds and rod bearing failures more often than they should?

When people say the mustang independent rear suspension is compromised, what does that mean for the driving experience?  I get that there are a bunch of problems with stock bushings but I also see a $500 kit to replace them.  How does it do on bumps while street driving or putting down power around a corner compared to a similarly prepped live axle?

I am going to disagree with Jav on one point, the AC in my mustang is the best I have ever had. It will freeze me out and blows very cold.  A great bonus for hot autocross days is the leftmost vent is ideally positioned to blow directly up inside the pantleg of a  pair of shorts.  

docwyte said:

I'd have a really, really hard time buying any older mustang instead of an E46 M3.  The M3 is just a much better car at everything comparatively...

That depends entirely on how one defines the words "older", "better", and "everything".

STM317 said:

Tom_Spangler (Forum Supporter) said:

I don't remember any generation of Mustang that had a self-destructing cooling system.

Doesn't the S54 have $2k VANOS rebuilds and rod bearing failures more often than they should?

Yes...And don't forget the sardine-can engineered chassis.

ojannen said:

When people say the mustang independent rear suspension is compromised, what does that mean for the driving experience?  I get that there are a bunch of problems with stock bushings but I also see a $500 kit to replace them.  How does it do on bumps while street driving or putting down power around a corner compared to a similarly prepped live axle?

I haven't read it all, but this looks to cover most of it: http://fulltiltboogieracing.com/mystery_of_irs.htm

I know it's not the triangulated 4-link in the Fox/SN95/NE, of which I still have a secret desire to run one fully (8) spherical jointed, but I found myself impressed at just how not-bothered I was by the 3-link live axle in my S197. The lack of lateral support from the seats however...

In reply to Driven5 :

I am used to BMW semi-trailing arms with variable toe on compression.  When the car is fully leaned over, the wheels are toed into the corner.  Then, when one wheel hits a bump or in the transition to the next corner, they fight against each other and snap in the other direction.  When my car had worn out shocks and bushings, I spun it on a dry public road while going the speed limit.  The road had an S-curve and the car kept rotating after the left-right transmission.

Somehow, I was expecting something worse from the Mustang after all the "compromised" comments I read.  It looks like you replace all the bushings, add a bumpsteer adjuster for your ride height, and you are good to go.  It isn't cheap but it doesn't feel like a compromise once you fix the compliance issues.

In reply to ojannen :

I think some of the "compromise" label comes from the fact that the chassis was never designed with an IRS in mind. So in order to get the IRS into the car some compromises were made, like a heavy cradle to mate the IRS with the chassis.

Cooling system is easy and cheap to replace.  Vanos kit is available for cheap and is easy to replace.  Yes, rod bearings, yes rear subframe mounting points.  Having to not totally re-engineer the suspension so the car will turn?  Priceless. 

Driven5 said:

I know it's not the triangulated 4-link in the Fox/SN95/NE, of which I still have a secret desire to run one fully (8) spherical jointed

Those big squishy bushings are the only reason the rear suspension in those cars works at all. The control arms have different arcs, so if you put spherical joints in there, it essentially won't move.

In reply to Tom_Spangler (Forum Supporter) :

Maybe that’s a good thing? 

Isn't there some adage about not letting a bad suspension move?

In seriousness, I really got tired of BMWs during my decade love affair, and would love if a Mustang could be a good option rather than an E36/46, but the quality of the car and the archaic suspension might be tough to get over. I think I’d have to drive one again, as it’s been so long.

In my mind, the SN95 is less problematic because not BMW, but my mind isn’t factoring in the Mustang-ness at all because I haven’t owned one.

In reply to Tom_Spangler (Forum Supporter) :

As far as I have found: None of those claiming it will bind have tried it themselves, and none of those who have tried it themselves claim it will bind. 

Even though there is FAR more of the former, the free articulation observed by the latter few is also supported by fundamental kinematic design principles...It's just not at all intuitive.

Driven5 said:

In reply to Tom_Spangler (Forum Supporter) :

As far as I have found: None of those claiming it will bind have tried it themselves, and none of those who have tried it themselves claim it will bind. 

You've never read anything from Maximum Motorsports obviously, THE biggest suspension company for these cars.  This is the main reason for the snap oversteer in these cars.  It's good for drag racing though.

Patientzero said:

Driven5 said:

In reply to Tom_Spangler (Forum Supporter) :

As far as I have found: None of those claiming it will bind have tried it themselves, and none of those who have tried it themselves claim it will bind. 

You've never read anything from Maximum Motorsports obviously, THE biggest suspension company for these cars.  This is the main reason for the snap oversteer in these cars.  It's good for drag racing though.

I'm plenty familiar with their marketing materials, that are all be very carefully crafted to only address bushings in the uppers. Funny you should mention MM though. A design engineer of theirs was one of the few that claimed to have tested it, and confirmed there to be no binding.

In reply to Driven5 :

That's honestly interesting.  I wonder why Cortex, MM, Steeda, and Ford all developed alternatives along with the "poor man's 3-link"

Patientzero said:

In reply to Driven5 :

I wonder why Cortex, MM, Steeda, and Ford all developed alternatives along with the "poor man's 3-link"

Because no one wants to run 8 sphericals on a street car, and the chassis side would take a beating. By the time you put that much effort into a Fox 4link, most everyone has a better plan. Offroad guys run full spherical triangulated 4links quite often, because they don't bind, but that doesn't make it right for every application.

I hate the factory 4link, personally. Handling is trash, and the ride is terrible. I IRS swapped my previous Tbird and the current one is getting a torque arm. I got smoking deals on both suspension setups at the times, so I can't really say which is cheaper to build up(IRS vs SRA), but I wouldn't waste any money trying to improve the stock 4link.

First mod when upgrading the Fox/sn95 chassis should always be subframe connectors.

In regards to the solid rear.

Having seen torn floors from binding, and having driven someone elses car with spherical uppers; I'm not buying the "mm is full of it" conspiracy theory you are pushing. 

There's a reason everyone who races in a turn at all seriously goes to the steeda 5-link or a torque arm (Maximum Motorsports, or Griggs). Don't just take my word for it. Go to a NASA American iron grid and ask, or an SCCA A-sedan grid.

A big warning, there are plenty of parts on the market that will fail if you autocross or track day the car, make sure you talk to people actually racing the parts before buying. Some of the failures could kill someone. 

-an engineer who has owned one of these cars for 18 years and raced it for 16.

I drove a 2001 Mustang Cobra today.  Overall, I liked the car.  The interior was not as bad as I thought it would be.  Interior room had a little less than our old Mini but I think it is workable.  I need to test fit our child seat to make sure it fits comfortably.  I wouldn't want it as a daily car with the kid in the back but I think it could work as a weekend car.  Unfortunately, the car was on all season tires so I can't say much about handling other than the tires are terrible.

The big problem was headroom.  My head was pressed hard into the ceiling with the seat in a reasonable driving position.  I need another two inches of headroom to fit with a helmet and really need another 3-4 inches to be comfortable.  I am not sure if that is doable with bottom mount, padded seats that allow access to the back.

In reply to ojannen :

How tall are you?

In reply to Patientzero :

I am 6'5" with a tall torso.  Fitting in cars is an adventure.

6' 5"?

Maybe you missed this article from my favorite sports car magazine.

In reply to Patientzero :

Probably because the basic Mustang geometry is still pretty crappy compared to what you can get from re-engineering the geometry entirely. My only desire to do it is simply because so many people unjustifiably assume that it will bind, and/or cause binding related issues, not because there aren't better alternatives available.

.

In reply to Apexcarver :

That's good, because I never tried to sell any of the words being put into my mouth. MM is not to blame for the general enthusiasts and racers lack of understanding, nor is it their responsibility to (re)educate them on unsupported solutions either. Racing development of the 5-link and torque arm was really a no-brainer though, as they were still going to inherently be the the better performance options.