BDR owners- Weak Frame or No?

LudicrousSpeed · #1 (**permalink**) 01-19-2009, 11:57 PM

Okay, no offense implied, just want to bump what I've seen & heard against the guys who know...

I've been poking through the BDR website & owner galleries and have seen picks of the bare / partially assembled frames.

Is it just me or is there not a whole lot of (cross) bracing / Beef? I've heard others speak of this as being a BDR weakness.

I plan to track the car a little & do some dragging. As these platforms employ engines with a whole lotta power & torque, this concerns me. I want a car thats going to take some abuse & still have doors that work & hatches that line up.

Your experience & brutally honest opinions are appreciated. PM if you prefer.
And hey, if I'm full of it, you can tell me that to

Thanks!
-Mark

mln385 · #2 (**permalink**) 01-20-2009, 05:32 AM

If you plan on the quarter mile I would suggest a straight axel over an IRS.
If you open track it you may want to consider their new track car.

The current street platform is a happy medium however finding the line is when you will discover it is time for a purpose built car.

Also each time they revise their platform they add certain features such as gussets to the frame. The current frame has added strength over the originals, so as you investigate be aware of the time frame of the car you are evaluating or comparing too.

Marc

Bill Bess · #3 (**permalink**) 01-20-2009, 06:12 AM

I have no clue how good the frame is on these cars, I would submit it's adequate and does a good job. If your not going to race the car competitively it's most likely just fine, it wouldn't stop me from buying a new one.

On the other hand, the reason I didn't buy that car is because the frame lacked a sub-frame ( metal on top around the engine compartment and more behind the driver. I just feel safer because my car has metal all around me and not just fiber glass.
My two cents, Bill

Rickd · #4 (**permalink**) 01-20-2009, 11:20 AM

I had read somewhere on CC in the Fall that Backdraft offered a frame reinforcement or strengthening kit for the cars. Ask Backdraft, they are quite responsive.

Dinobyte · #5 (**permalink**) 01-20-2009, 06:58 PM

Someone at Run & Gun ran one into the wall and walked away okay....he was going over a hundred MPH I think...so I guess that offers you some insight.

If you want a really safe car, buy a BMW or a Mercedes, not a Cobra.

LudicrousSpeed · #6 (**permalink**) 01-20-2009, 08:04 PM

Quote:

Originally Posted by Dinobyte

Someone at Run & Gun ran one into the wall and walked away okay....he was going over a hundred MPH I think...so I guess that offers you some insight.

If you want a really safe car, buy a BMW or a Mercedes, not a Cobra.

I'm prolly drilling down farther than I need to, but the more I learn, the more questions I have, this being just one of many to come.

As far as safety goes, I'm more concerned about the integrity of the structure and how it will hold up over time, not so much the crash-worthiness of it. Being a pilot & a former aircraft mechanic, I have a keen awareness of metal fatigue & the tradeoffs of weight vs. extra structural integrity. In comparing the BDR vs. the SPF vs. the ERA frames, it would seem that the BDR is on the lean side.

Thanks for all the good info tho, I've been learning so much these last few months, and I can tell you guys are knowledgeable & passionate about these cars.

Got the Bug · #7 (**permalink**) 01-20-2009, 08:42 PM

Quote:

Originally Posted by LudicrousSpeed

I'm prolly drilling down farther than I need to, but the more I learn, the more questions I have, this being just one of many to come.

As far as safety goes, I'm more concerned about the integrity of the structure and how it will hold up over time, not so much the crash-worthiness of it. Being a pilot & a former aircraft mechanic, I have a keen awareness of metal fatigue & the tradeoffs of weight vs. extra structural integrity. In comparing the BDR vs. the SPF vs. the ERA frames, it would seem that the BDR is on the lean side.

Thanks for all the good info tho, I've been learning so much these last few months, and I can tell you guys are knowledgeable & passionate about these cars.

The time has come LudiCrousSpeed...Pull the trigger man!

Doug I · #8 (**permalink**) 01-20-2009, 10:12 PM

"Weak Frame or No?"

No

That was the quick easy answer

The long answer involves stiffness matrices, boundary conditions, relative and global displacements and .... etc. I don't think you want the long answer though.

Just pull the trigger and make yourself one very happy camper

Dinobyte · #9 (**permalink**) 01-20-2009, 10:29 PM

Quote:

Originally Posted by LudicrousSpeed

I'm prolly drilling down farther than I need to, but the more I learn, the more questions I have, this being just one of many to come.

As far as safety goes, I'm more concerned about the integrity of the structure and how it will hold up over time, not so much the crash-worthiness of it. Being a pilot & a former aircraft mechanic, I have a keen awareness of metal fatigue & the tradeoffs of weight vs. extra structural integrity. In comparing the BDR vs. the SPF vs. the ERA frames, it would seem that the BDR is on the lean side.

Thanks for all the good info tho, I've been learning so much these last few months, and I can tell you guys are knowledgeable & passionate about these cars.

Your killin me! I'm a pilot too, but your questions....for Christs sakes! This is Not a G@D D@mn airplane that will need to fly...and it is not a race car...if you want that, buy the track car...if all you are going to do is worry about metal fatigue, maybe buying a kit car is not for you...all kits will have their issues...period. Some more than others...but by owning a kit car, especially one like a Cobra replica, with more HP to Weight than a reasonable person would need, you either have to have balls of steel, or be an alpha crazy dog to begin with...and I'm not seeing that with you...but to each his own.

Like I said earlier...check out a nice BMW M5. Plenty of power with safety built in, and you can impress your friends by how many people you can take to the local soda pop stand in luxury and safety.

LudicrousSpeed · #10 (**permalink**) 01-21-2009, 11:28 AM

Quote:

Originally Posted by Dinobyte

Your killin me! I'm a pilot too, but your questions....for Christs sakes! This is Not a G@D D@mn airplane that will need to fly...and it is not a race car...if you want that, buy the track car...if all you are going to do is worry about metal fatigue, maybe buying a kit car is not for you...all kits will have their issues...period. Some more than others...but by owning a kit car, especially one like a Cobra replica, with more HP to Weight than a reasonable person would need, you either have to have balls of steel, or be an alpha crazy dog to begin with...and I'm not seeing that with you...but to each his own.

Like I said earlier...check out a nice BMW M5. Plenty of power with safety built in, and you can impress your friends by how many people you can take to the local soda pop stand in luxury and safety.

...Hmmmm, interesting...

Dino,
You of all people should know that its the little, hidden things that can make a huge difference. I'm detail oriented & hyper finniky about the machines I operate. Part of being a safe, professional pilot is knowing your aircraft inside & out. Part of my routine when getting checked out in a new aircraft was to buy the POH, know it cover to cover, then spend a few hours in the cockpit "ground-flying" it. One of my favorite things to do as a pilot was to get checked out in, and master lotsa different aircraft.

As I will be investing a large amount of my hard earned money into this, you better believe I'm gonna read all I can, and ask every question I can think of.

If I offended you in any way, I apologize. Either which way, blow it out your ear.

-Mark

P.s. I'f i'm ever actually able to get a weekend off and show up for one of the SoCal Cobra meets, I'd love to check out your car & discuss what being a Cobra owner means with you.

Doug I · #11 (**permalink**) 01-21-2009, 11:33 AM

Lol

jhv48 · #12 (**permalink**) 01-21-2009, 12:15 PM

Quote:

Originally Posted by LudicrousSpeed

I'm prolly drilling down farther than I need to, but the more I learn, the more questions I have, this being just one of many to come.

As far as safety goes, I'm more concerned about the integrity of the structure and how it will hold up over time, not so much the crash-worthiness of it. Being a pilot & a former aircraft mechanic, I have a keen awareness of metal fatigue & the tradeoffs of weight vs. extra structural integrity. In comparing the BDR vs. the SPF vs. the ERA frames, it would seem that the BDR is on the lean side.

Thanks for all the good info tho, I've been learning so much these last few months, and I can tell you guys are knowledgeable & passionate about these cars.

Don't worry about the long term.

You'll hit a bridge long before the frame gives out!

LudicrousSpeed · #13 (**permalink**) 01-21-2009, 01:09 PM

Quote:

Originally Posted by jhv48

Don't worry about the long term.

You'll hit a bridge long before the frame gives out!

Quite possibly true

Bailey · #14 (**permalink**) 01-21-2009, 03:15 PM

To answer your original question simply, NO!.
I was the inexperienced unlucky soul that went into the wall at last year's Run and Gun. I was in the middle of fourth on the drag strip, which I guess was somewhere around 100MPH or so.
I was in the right lane, the car dived off to the left, I went across the left lane, nosed square into the wall, then bounced off.
I got out of the car and walked back to staging.
Was I sore for a while, Oh yeah, but no pemanent damage to me.
A good seat, great belts and an awesome car saved my life, I don't want to think of the alternatives.
I plan to be at it again here in a month or so, the back to St Louis in October to reclaim some trophies.
Hope this simplifies you decision. There are alwys rumours floating around about different manufacturers. I built and have owned one of the leading "component car" Cobras, and for the money, a Backdraft is hard to beat, a great rack car, and with some little mods, it'll take on anything.
Hope this all helps.
Cheers,
Richard

jp65cobra · #15 (**permalink**) 01-21-2009, 03:31 PM

No frame breaks or signs of fatigue in my BDR yet! 15900 miles and counting. #259. Mine is on the road every day I can and I have hit my fair share of bone jarring bumps in the road. I have also taken a good 60 mph run at a S10 pickup and came away alive

. The frame did not bend or break.

I have seen some posts about the very early builds way before mine that had some issues that have since been rectified.

I plan on open tracking mine soon and I personally would be more concerned with receiving a direct blow to the door of any replica cobra than I would be about frame fatigue of something as stiff as the frame in the BDR.

LudicrousSpeed · #16 (**permalink**) 01-21-2009, 06:47 PM

JP65 & Bailey,
Thanks guys, your experiences are golden.

doctodd · #17 (**permalink**) 01-24-2009, 05:07 PM

Is this straying off topic?....i understood you asking about the long term integrity of the frame, not the impact absorption, correct? If you are going to hit something, you want it to crumple and absorb as much energy as possible instead of directing that energy to the middle of the car, which is where you will be. If you want a rigid frame for other reasons, then i think it is a different topic, correct? You can buy mine if you want a relatively new one with tooooo much power.

T

Gatorac · #18 (**permalink**) 01-24-2009, 06:10 PM

I would think that the Run n Gun results from last year should tell you that these cars are not suited to the drag strip. IMHO Cobra's in general shouldn't spend any time at the strip unless they are fully prepared for it.

Baileys car that hit the wall at 100 mph was NOT the standard street BDR replica. Is was one of their new race cars that has a pretty significant roll cage that undoubtedly adds some stiffness to the chassis. Even it was obviously not designed for the strip.

The standard BDR chassis is "compliant" let's say. It makes a wonderful driving street car. It handles very well on the track. Unfortunately I have a serious track addiction. Once I got a car with a substantial roll cage around me, I never felt comfortable in the Cobra again on the track. Fiberglass is about as much protection as 2 layers of wax paper.

Looking for a car to track, drag and cruise is always going to be a compromise for at least 2 of those.

Good luck with your search.

LudicrousSpeed · #19 (**permalink**) 01-26-2009, 09:47 PM

But Doc, you just bought your car, wha happen?

I saw your pics when you first got it, Beautiful!

I have to keep reminding myself that I still need to save a few more duckets before I can get one, But your car just happens to be EXACTLY what I would want if I were ready. Hey, If you can convince my wife now is the time, you will forever be my hero.

Gimme a PM, I'd like to learn about your experiences.

bigstew · #20 (**permalink**) 02-02-2009, 09:30 AM

I have a BDR (#307) with about 4K miles on it. It have put over 400 miles on the track and it performed exceptionally well. The car has not been babied and it has performed very well with no signs of frame tweaking or doors sticking. For the money you can't go wrong with DBR.

Good Luck