I am finally able to afford a Cobra Replica - Please help me decide on one

[patrickt]

Originally Posted by Scrivy

Can someone list the pros and cons of IRS vs solid axle.

Unless you're building a pure dragster only, there are no advantages to a solid. Ride, comfort, performance, and control hands-down favor the independent rear. It's not even close; you'll want a limited slip of course as well. There's also a safety issue -- these cars, on occasion will come out from under you on hard acceleration. Some call it "snap-oversteer" and it can be quite dangerous. A quality rear that is properly set-up will help reduce this rather nasty characteristic.

[Scrivy]

Originally Posted by patrickt

Unless you're building a pure dragster only, there are no advantages to a solid. Ride, comfort, performance, and control hands-down favor the independent rear. It's not even close; you'll want a limited slip of course as well. There's also a safety issue -- these cars, on occasion will come out from under you on hard acceleration. Some call it "snap-oversteer" and it can be quite dangerous. A quality rear that is properly set-up will help reduce this rather nasty characteristic.

Patrick,

Does "snap-oversteer" only occur on a solid rear?

Scrivy

[patrickt]

Originally Posted by Scrivy

Patrick,

Does "snap-oversteer" only occur on a solid rear?

Scrivy

No. But solid rears tend to suffer from "torque steer" which can contribute to an unsafe condition under hard acceleration (meaning the rear becomes loose and the car can get out of control). Other than price, I can't think of a single reason why you would want a solid rear.

[mrmustang]

Originally Posted by Scrivy

Can someone list the pros and cons of IRS vs solid axle. I will do some more research but would like have some opinions also. Maybe someone that has built and used both systems.

Scrivy

Having done both systems and variations of both systems I first need to know what your ultimate end use is going to be? Street cruiser, weekend warrior, drag car, road racer, or ????? Only then can anyone really attempt to respond to your last question.......


Bill S.

[patrickt]

Remember that the drive shaft in our Cobras is pretty darn short. With a solid rear, the wheel travel becomes a real issue -- you're going to bottom out your shocks with softer springs and you're going to have an uncomfortable ride with springs that are stiff enough to do the job. While it's debatable, this just might be the most sophisticated rear in any of the Cobra cars (it also gives you the beauty of outboard brakes): http://www.erareplicas.com/427/frsusp.htm

[Scrivy]

Originally Posted by mrmustang

Having done both systems and variations of both systems I first need to know what your ultimate end use is going to be? Street cruiser, weekend warrior, drag car, road racer, or ????? Only then can anyone really attempt to respond to your last question.......


Bill S.

Bill,
I am looking for (as far as suspension/powertrain/engine):

(in this order)

1st - good handling, back roads
2nd - nice highway cruising
3rd - speed / acceleration

Scrivy

[mrmustang]

Originally Posted by Scrivy

Bill,
I am looking for (as far as suspension/powertrain/engine):

(in this order)

1st - good handling, back roads
2nd - nice highway cruising
3rd - speed / acceleration

Scrivy

1: Could go 3 link or IRS in that case, 3 link is less expensive and easier to set up for neutral handling.
2: Standard coil overs front and rear should keep things smooth for the highway and twisties.
3: How much speed and acceleration is something you have to ask yourself, but as little as 200hp in a 1,900lb short wheelbase car is enough to have sub 5 second 0-60 times and 14-15 second quarter mile times or less. It could also get you or someone you love and care about killed. Not trying to say it will happen, but we've seen what can happen with those who think "I know what I'm doing and I can handle it". Some are still with us, some are not. Bottom line (as I get on my soap box), don't let yourself get cocky about it, treat it with respect or it can kill you.

As for kits, I've owned big block ERA, FFR(sb supercharged, BB, naturally aspirated, and fuel injected, 4 link, IRS, and 3 link suspensions), SB SPF, and BB Contemporary, while I keep gravitating back to FFR's, I would not hesitate to own any of the ones I've owned in the past as they all have their pluses and minuses to them...It all falls back to what you plan to do with them...Road racing I stick with a SB, sheer looks, a BB, best and closest to original, Contemporary hands down, followed by ERA, SPF, then FFR. Bang for your buck and the chance to change things (upgrade, downgrade, etc) whenever I want, FFR. Again this is just my personal choices.....It's your money you are asking people to spend, eventually you'll need to make a decision based on your own wants and needs.

Again hope you find this helpful.


Bill S.

[RMHINC]

Make/Model: Backdraft Roadster from Vintage Motorsports
Manufacturers Web Site: http://www.vintagemotorsports.com
Year/Miles: 2008/400
Built by/Time to build: Factory
Engine: Roush 402SR with Twist Wedge Cam / 489HP
Pros: everything & I like it !
Cons: Picking the color from so many choices. Putting up with purists and their version of a replica. Cold winters and rainy days.
Comments: This is my 2nd BDR Cobra (sold my 1st one) The guys @ Vintage are great from the purchase through the install. They are always fair & honest which are rare qualities to find in the car business !

BDR GT 40 Roush 342 SR
BDR Cobra Roush 402 SR
65 Vette Coupe 327/350
05 SL 55 AMG
67 GT 500 R Roush 427

[lovehamr]

Scrivy;
PM sent. Besides the fit, the BDRs longer WB and IRS will help your #1 and #2 as well.

Steve

[TButtrick]

Scrivy,

Do you want to build the car from a kit or buy a roller? That might narrow your choices down a bit.

Race cars don't use those dangerous solid axles... do they?

[madmaxx]

The good thing about RSIMOES was he had the money to burn. But when you read the post not that even the $118K Kirkham had a long punch list of items needing repaired after he took delivery. The bottom line there is not a new cobra delivered by anyone that will not have some teething problems. In other words you must be somewhat mechanically inclined to fully enjoy these beast, or buy one I have gone through. LOL!!

[ZOERA-SC7XX]

Some things to consider: Cars like Kirkham, ERA, Contemporary (no longer produced), Unique and Shelby are much like the original car, which is a beast. The newer cars, like SPF, Backdraft, FFR, and some others tend to be more modern and refined, and may look like a Cobra on steroids. They are very fast, and many have Roush small blocks or the like. There are also some Cobras that are somewhere in between. If you want a car that is close to original in looks and performance, you gotta pick one of the top five. They look original. If you can live with less than that, one of the others may be your ideal Cobra (and for less money). It's all about what YOU want.
Either way, you should visit a few manufacturers, as many as possible. It will pay off in the long run. What you don't want is to buy or build a car that you wish you didn't. Spend the most that you can afford and don't settle for less than what you really want. Good luck.

[CNGreen]

Wow, I hadn't considered that my FFR doesn't even make the top five...

Sheesh.

[ZOERA-SC7XX]

Originally Posted by CNGreen

Wow, I hadn't considered that my FFR doesn't even make the top five...

Sheesh.

Every parent loves their own child best!

[patrickt]

Originally Posted by ZOERA-SC7XX

Every parent loves their own child best!

Yes, and posts seem to get just a bit more acerbic shortly after the cocktail hour.

[madmaxx]

If you just called me acerbic, i will take it as a compliment since I do not know what it means, LOL!!

[patrickt]

Originally Posted by madmaxx

If you just called me acerbic...

Not at all!

Originally Posted by TButtrick

OK then.. I guess we have the Kool-Aid thing under control.

No Kool-Aid drinking about it, torque steer and live axles are a well known, and well discussed, malady. Here, this was the simplest torque-steer/live axle/FFR thread I could find for you. Torque PULL hard to the right

If you want though, you can just skip down to the last post by Mr. Smith:

Originally Posted by B. SMITH

KSTADT,

IF YOU HAVE A LIVE AXLE, THE PROBLEM COULD BE THE FOLLOWING;

LOOKING FROM THE REAR, UNDER ACCELERATION, THE REAR AXLE ASSEMBLY WANTS TO ROTATE COUNTER-CLOCKWISE. THIS EFFECT PRESSES THE LEFT REAR WHEEL HARDER TO THE PAVEMENT THAN THE RIGHT, ACTUALLY LIFTING THE RIGHT WHEEL, LIKE OLD MUSCLE CARS.

THE END RESULT IS A LEFT SIDE LIFT AND A RIGHT REAR DROP AS THE CAR TRIES TO COMPENSATE. EVEN WITH A TIGHT DIFFERENTIAL YOU PULL TO THE RIGHT BECAUSE THE LEFT REAR IS DOING MOST OF THE FORWARD PUSH DUE TO THE ADDITIONAL TRACTION ON THE LEFT SIDE.

THIS EFFECT IS DRAMATICALLY REDUCED IN I.R.S. VEHICLES.

B. SMITH

[TButtrick]

Those posts threads don't even remotely conclude that this is a properly working live axle anomaly. There can be numerous causes for that type of car behavior. Tires, frame torque, suspension, misaligned driveline, bla, bla, bla. NONE are subject to a live axle and suspension that is set up correctly and the diff working properly. That's what limited slip reduces. Your IRS has the same limited slip. Suspension is what makes an IRS work better but like anything, there is a cost in complexity. And BTW... who the heck is B. Smith anyway and why is his word they say-all on the subject? I don't get your pointless.

[patrickt]

Originally Posted by TButtrick

I don't get your pointless.

OK, I give up.

[Sharroll Celby]

Meanwhile, to get back on-thread the original poster should sit in as many Cobras as he can, to get a feel for the cars' fit for him. And when he finds one he DOES fit in, I would hope he would get a chance to drive one, escorted by the owner, on a deserted street somewhere.