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Discussion Starter #1
I've been drudging through the long tedious process of deciding which 427 replica will suit my needs as well as my wallet. The only thing I'm not sure I can get over is the "perky butt" of the FFR. Don't get my wrong, I love the looks for the most part but really like the longer rear end that matches closer to original.

1st)Anyone know if & when FF will release the contemporary molded body I've been hearing about?

2nd)In regards to the frame strength, how does the FF compare to some of the other square tubing replicas, is there a lot more flex?. I'm not really convinced that the pitch about the tubular chassis being 37% stronger than square is accurate. I'm not so interested in numbers; I just want to know what you, the owners, think and what your comparing it to.

All comments and opinions are welcome, please!
 

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Hey 4Gotten, Before you judge the perky but of the FFR you should see one of the cars beside the like's of a Contemporary, if you haven't already. I thought the Contemporary's and the like with the wider rears were better looking too ,mostly for originality reasons untill I'd seen them side by side. I'm very happy with the looks of the FFR and I think that most people that see you driving around in one of these cars wouldn't even know the differance anyways. So if Prestiege is what you want you'll still get it with the FFR Roadster! Just my opinion of the FFR though. As for the frame,I can't answer that mine isn't on the road yet. Bottem line is do what what makes you happy,you only live once,I say .
:D Happy Motoring
 

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Discussion Starter #4
WOW! Nobody on the FFR forum want to pop in with comments on the frame feel of their snake?? Hmmmm. Come on guys/gals, I need some opions from owners.

Thanks again!
 

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Almost all of the modern replica frames are better than the originals. And almost none of the modern replicas are anywhere near as good as the JBL frame.

I don't think you should pick a car bacause of the frame, unless it's the JBL. Look for the level of build vs. completed assembly and the amount of dollar$ you want to invest.
 

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Discussion Starter #6
Robert, don't take this the wrong way but not looking at the frame on a Replica is like not considering the condition of an engine in the first plane you fly, Hmmmmm.

Have you ever been driving down the road, you come up on an obvious replica (of any car) due to the body shake and frame twisting. I know this would be an extreme example but I was hoping to hear the way owners felt when compared to other replicas. Is there squeaks etc.., can you feel the body flexing at any time?

Thanks again all.
 

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I think you’re thinking of fiberglass panels on a VW. I don’t think any Cobra replica mfg are doing anything like that anymore. They are all welded tubular frames that are all fairly strong. It’s going to be hard to compare any two with doing it side by side with the same engine and suspension setup.
 

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4Gotten - The body on an FFR is not a stressed member - it's not likely that you'll see it twist, even if the frame does (which is highly unlikely - try jacking one up on a corner and watch for deflection).

This is one of those 'religion' topics - you will never get anyone to agree, everybody has a favorite (and/or a bone to pick with the different manufacturers). Do a search here (and on Cobraforum and ClubCobra) using the term "comparison" and you'll see what I mean.
 

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The term unstressed is a misnomer. The FFR body has solid mounting points to the chassis and the chassis flexes too. So the body has to flex also.
 

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Note that two tubes, one round and the other square, that are the same WEIGHT, the round tube will be about 30% stronger resisting compression, torsion and deflection.

Therefore, for the same STRENGTH as a square tube, the round tube is lighter.
 

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Ok, get a length of square tube of 4” size and the same length of round tube of 4” size
Start to hang weight in the middle of one of the tubes to a measured deflection distance. When you get to that point record the weight. Do the same for the other tube. The tube that had more weight will be the stronger tube.
 

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Not sure if this is the kind of answer your fishing for. As for my driving habits, FFR2302 has 9000 miles over two summers in the Northeast. I don't slow down too much on bumpy roads, I don't worry about chipping the paint on gravel roads and I drive it hard at times. I am amazed that the car does not rattle or squeak AT ALL. Not ever.

As far as "flex" this would be the world of mechanical/automotive engineers and race car drivers. Not me.

I just drive the car. I have never felt any "flex" nor have I seen any "flex" while following, passing or racing any other FFR's or other Cobra replicas. Not sure if I would know it was "flex" if I did feel or see it. I can't compare my car (FFR) to any others as I have not driven any others. Why the hell did I respond to this post? :confused:

Oh yeah, sqeaks and rattles. None.
 

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To be the devil's advocate, how does a wheelstand show a cars strength, or for that matter jacking up one corner of the car.
I assume cornering is a much better test of torsional rigidity.
Hell my honda CR-V lifts both right side wheels if I jack up the front wheel. That thing has to flex like crazy when being driven. Same deal with my buddies F150 and you can actually see the frame flexing when he went out driving without a bed on it.
I have done wheelstands in lawn tractors (dont ask:)) and they are far from as ridgid or strong as the FFR frame.

They best test of the ridgidity would be a true chassis test. I bet the FFR is inline with the others, not the best, not the worst. I would also bet that FFR has done some sort of test with ft-lbs and has some results. Maybe someone should try to pry the info from them?

All I can say in conclusion is that I really dont care because I promise you I will never ever be able to tell if the frame is ridgid or strong or whatnot.
 

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My lovely wife summed it up when she took her one ride to date(she has no interest in my addiction). She said the car is too loud, too fast, but was very surprised that it rode like a "real car". No squeaks, rattles, or flex to be seen or felt.
RR
 

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the beautiful FFR frame was a significant reason i bought an FFR. light, strong and uses round tubes like the original. the JBL is a different animal with a VERY non original frame. this is an important part of the character of a car.

there was an everett morrison with about 550 HP at the AMCC last weekend. i think my car was about 4 seconds faster than it (same type of tires). ive never seen any replica but an FFR go fast in autocross, and the frame has a lot to do with that.

it certainly flexes far less than any of my street cars. its not quite as stiff as my ITS road race car with its full 6 point cage. all in all, the FFR has exceeded my expectations as a serious platform for a performance car.

-james
 

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No creeks,groans,or rattles in mine.I hate to qoute specs of the top of my head but I believe the original frames were round and made of 4040 DOM steel.The FFR round tube frames are 4041 DOM.If the original was good enough with 4040 then,all things being equal,a close copy of it made from better steel,IMHO,has to be a better chassis.
 

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Aaron, I'm no frame expert either. What I meant to post with the wheelstands was there is no side to side flex showing. Seen a lot of cars leave the line with the front left side higher than the right. Not sure if from the motor torque or tire traction differences.
 

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Rob, how does squeeks have anything to do with the chassis being stiff? You did a good job building the car I bet, and IMO that has ALOT more to do with it.

I am not arguing with you guys that the FFR frame is ridgid or great, I would just like better proof than it can wheelie, hang a wheel when you jack it up, or does not squeek.
 

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As far as torsional rigidity, the new FFR MrkII is about twice as stiff as the old version. I know what the numbers are, and they are respectable.

I have installed the backbone in my old chassis, and added a few other braces.

While supporting the rear of my car on the frame on a 4 post lift, I used a lazer sighting diagonally across to the front suspension pickup point.

When jacking up the car on the very front of the suspension, an pulling both front wheels off the ground, I get barely .0625" of deflection.

Thats pretty decent in my book, since Im still missing two very important braces in my backbone.

I dont have data, but based on the books I have read and my understanding of ladder frames(what 90% of other manufactures use) The FFR MrkII frame is going to be stiffer in torsion due to the properly designed and tested backbone and round tube chassis.

JBL was designed from the ground up for torsional stiffness, and therefore looks nothing like the original design. JBL is more like a racecar chassis adapted to a cobra body than visa versa.

SPF, ERA, Midstates and Unique are very solid cars, getting some of thier torisonal rigidity from the fiberglass body. I have never heard of anyone complaining about issues with these cars either. The cars end up being heavier though. I cant speak to other brands.

Do a search on this forum and others, you will find FEW if any people complaining about chassis flex, shake, vibrations...etc when it comes to the FFR cars if built well. This is especially true for the MrkII.

Our car FFR 1046 is one of the first FFR's. Its been driven 37,000 miles, and driven brutally hard, and its still tight as a drum.

BTW, autocross is one the biggest tell tales to chassis handling and balance in determining how well a car handles and how fun it is to drive.

Most guys who autocross Cobra replicas end up coming out once or twice and throwing in the towl. If a car is not designed or setup well, it will be misserable to autocross. Unpredictable, SLOW, and no fun.

I agree with James... I have yet to see another brand replica lay down the times of a FFR in our area in autocross competition...

Just ask James how quick our old FFR 1046 is when it comes to that game


David
 
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