Tub type body.. why not?

[Raceral]

Just thinking out loud. In the next F5R design.. why not a tub interior. Still use the Aluminum in the trunk. The F panels, and maybe even cover the underhood foot box with aluminum if you like.. The reason I say this is.. just to plug up those stinking air leaks that folks with tops have always been flustered with.
I love the alunimun look during the build, but you cover all that pretty stuff up with carpet.
It would save a lot of useless work, maybe even make a more stronger body. Slightly heavier , I know.
Not to mention the water leaks.
Fire away

[LuckyWinner]

I dont like that idea at all. The aluminum panels in the interior is what makes it different than the rest of the kits. It gives it better balance ratio, and the its lighter. Also there is the chance of cracks with fiberglass. Dont like that idea at all, but to each there own.

[riptide motorsport]

sounds fine to me.

[3kcarbon]

Since I'm knee deep in body fit up I'm thinking all kinds of things they should do... A sectioned body with fiberglass foot boxes like the Chicken Rancher edition would be nice.

[David Hodgkins]

Sacrilege!!!

[mrmustang]

I dont like that idea at all. The aluminum panels in the interior is what makes it different than the rest of the kits. It gives it better balance ratio, and the its lighter. Also there is the chance of cracks with fiberglass. Dont like that idea at all, but to each there own.


Do you honestly believe what you just wrote/posted?



Bill S.

[Raceral]

Having built one and having one on the road for almost 10 years.. I can see many reasons for the tub.
Having built one and having one on the road for almost 10 years... I can see the reasons why some would not like it.
Sitting in the garage without the body on.. seeing all that aluminum just gave me the shivvers. Loved the look... BUT, after the body goes on.. and the carpets in.. all that goes away.
Nothing about the frame would have to be changed. I just like the idea of a totally closed unit.
You always read about folks with tops trying to stop up the air leaks.. I was one of them.
If you have ever drove one of these thing in down pours... you would like the tub.
You could save HOURS on the build also..
It doesn't make me mad if you disagree.. I totally understand that end of it.
If the frame isn't changed at all, I don't think you would loose that much strenght.
Like I said.. just thinking out loud.

[Olli]

I think that you make some very sound points Al. I would have no problem with a tub body.

Olli

[AJ Roadster NJ]

Only if the tub is designed to drop into a space frame, as opposed to sitting on top of a ladder frame. Those old replicas with 700 pound body tubs over ladder frames just looked like instant death to me in an accident. There is no one safe place to bolt down the seat belts, you're just plain screwed. Plus you pay a huge weight penalty. I just don't see the point.

[riptide motorsport]

My hunter has a tub, very strong. the tub has no floor, the floor is all steel in the Hunter C0bra. Its as strong as any FFR or stronger and the seats arent going anywhere!

[AC Bill]

I wonder if you could stamp a tub from aluminum? The foot box tops would be separate of course, and actually these could be made of fiberglass, just like the originals.
You could just set the entire aluminum tub onto the frame, and rivet it on. As Al suggests, nothing about the frame would need to be changed. Sure save a lot of hours on a build.

The air/water leak issue's with our current cars set up, has never really been really seriously addressed, perhaps as much as it should be. I gather that most just accept this as another quirk.

There are all kinds of makeshift ways of trying to prevent them, but I have never seen a solid study done by a builder (or FFR) of how to effectively prevent them altogether. The supplied expanding foam is limited in effectiveness, as are pool noodles, water pipe insulation, garbage bags filled with expanding foam, etc., ideas I have read about. Considering the time and effort that is spent on some areas of the build to improve it, this seems like one aspect, that has slipped through the cracks.

[Raceral]

Seat belt bolt in locations would not change.. Nothing should change.. you just have a fiberglass interior instead of aluminum, except there are no gaps up under the dash, footbox's . Seats would bolt in exactly the same. Just a seamless unit..

[3kcarbon]

I know where there is a really sweet golf cart built that way...

[AJ Roadster NJ]

And everything will stay good, right up until the moment of the side impact, which is when all the fiberglass shatters, and the occupants are protected only by...WAIT, the occupants aren't protected by anything at all (zero, zip, nada) in a collision. Their last thought will be, "Geez, all those shards of fiberglass hurt like heck and I wonder..." [the end]

For me, the FFR spaceframe and the aluminum panels were THE selling point for me to buy the car.

Question: How many racecars from back in the day (pre-carbon fiber, let's say through the sixties and into the early seventies) had fiberglass tubs on ladder frames? I can't think of any. Almost everything was made the way our cars are made, and for good reasons. To get anywhere the stiffness you need from the body in a tub-over-ladder configuration, the weight penalty becomes enormous.

[riptide motorsport]

Ahh............. now lets debate round verses square!

[Raceral]

Side impact.. unless you built a different car the I did there is no side impact protection that I saw in my car.
The Frame would not change so why would a fiberglass interior make it less safe.. I'm not getting something.
The Aluminum is in the floor, trans tunnel and behind the seats, and the foot boxes.
Frame would stay the same..

[Raceral]

Come on Brother Dave.. jump on in here!!! I know you are reading this :)

[riptide motorsport]

Not if he's smart!

[CRZN 427]

My first build was an LAExotics (now B & B) with a fiberglass tub cockpit.

There are still issues in sealing aroung the tub to the chasiss and body in several locations to keep the weather out.

I prefere the FFR approach with the aluminum panels to be able to do the changes I have done, and a couple more I'm considering.

Regards, Rick.

[Chepsk8]

You all have missed the single greatest part about the complete chassis and the aluminum, the best part of building our cars.....

The First Go Kart Ride!

Good Lord, give that up? NEVER!!!!!!! :cool:

[3kcarbon]

While there are many areas the Mk 4 could be improved even after all these years I doubt we will see a major retooling anytime soon. The FFR R&D money is going into the Ricer Roadster. The Hot Rod may see a revision next since the GTM and Coupe got it this year.

[LuckyWinner]

Do you honestly believe what you just wrote/posted?



Bill S.

Oh course I believe what I said, or I wouldnt have wrote it. Like anther guy posted, how many race cars had a fiberglass tub? Like I said to each there own Bill.

[mrmustang]

Oh course I believe what I said, or I wouldnt have wrote it. Like anther guy posted, how many race cars had a fiberglass tub? Like I said to each there own Bill.

The misconception is that all fiberglass tubs are the same, in your post you stated that cracks can occur, in response I should have shown you teardown pictures of 20+ year old ERA and Contemporary Cobra tubs that have no cracks in them at all. The other misconception on your part would be that because of a fiberglass tub being used, that structural steel and aluminum panels would not be (which both ERA and Contemporary use, and yes, they are structural in nature far more than the pop riveted panels used on the FFR). Again, I can show you both ERA and Contemporary chassis with both designed into them. The final two misconceptions you did not bring up would be the round tube vs square tube, and the 1X1 steel tube birdcage. The round vs square has been beaten to death (if properly engineered they both work the way they are designed), while the 1X1 steel birdcage has been shown to be non structural (in regards to minor or major accidents). Now, for the record, I am not anti FFR (anyone here will tell you that), having built/rebuilt/personally owned 17+ of them.

So, again, after reading my post, are you certain that what you stated in your original post is sopmething you want to continue to believe in? If so, I'll be more than happy to arrange with a local ERA or Contemporary owner to show you why your misconceptions are just that.


Here is wishing you well.

Sincerely,

Bill S.

[David Hodgkins]

There is absolutely NOTHING you can say that will convince me that a fiberglass tub is superior to aluminum panel construction.

[3kcarbon]

There is absolutely NOTHING you can say that will convince me that a fiberglass tub is superior to aluminum panel construction.

I don't think anyone thinks it superior. It may be easier or quicker for some builders. I don't see a price advantage for FFR since they would have to R&D the tooling over CNC cut panels. The R&D cost to get a good fitting tub even if was seperate from the body shell would be a consideration. If its not a good business decision I bet Dave's not in for it even if it could be a option.

[David Hodgkins]

My opinion is that it would be more costly to produce and would result in an inferior product. Rather than simply having a machine laser-cut the panels and then bending there would be plugs, manual layup of the glass, a redesign of the substucture, a substantial weight penalty (not an option for the 818, for example) and then there is the kit-car perception of a fiberglass tub vs a race-car inspired aluminum sub panel structure, etc.

As far as easier construction is concerned, the cockpit of the roadster was redesigned for the MKIV and reduced the number of panels and their complexity. I never considered aluminum panels to be a hard part of the build, and I was a newbie going into it...

Sorry for sounding harsh in my previous post. It's just such a foreign concept IMO. Square frames and tubs may work for other makes, but the race-bred aluminum subframe and round tube construction is a major advantage for FFR, again IMO. I don't see any instance where they would go away from that model.

:)

[Hankl]

To go back to Al's initial post, I feel that you would have the same problems sealing a "Tub" vs a "Structure". It's all about the attention to detail, if you look closely at Russ Thompson's Coupe, you'll see great attention to detail. I would venture to guess that his Coupe has 10% of the air and water leaks of most other builds. I was at Laguna Seca two weeks ago watching the Spec Racers and Karen and Her Coupe. She had a slight oil leak at the dip stick, and the drivers floor was coated with oil. A small opening allowed a very low viscosity fluid to enter the cockpit and make a mess. It looked like the foot box was well sealed, but there was a small entrance some where for the oil to enter. Any other time, and that small opening would not be a factor, but that day it was. Same with driving on a rainy day, one spot missed, and your getting wet, attention to detail!!!!

Hank

[cwrandolph]

Tub = YUCK!! Maybe they could make it fit over a Volkswagon chassis too.

[LuckyWinner]

Tub = YUCK!! Maybe they could make it fit over a Volkswagon chassis too.

Amen Brother, if someone wants a tub and a square frame there are places that that they can buy that. Big Dave dont change a thing!!!!

[RMB]

Top...now that's funny! If I wanted a top, I would have built a coupe.

Rob

[mrmustang]

There is absolutely NOTHING you can say that will convince me that a fiberglass tub is superior to aluminum panel construction.

David,

A little harsh,but perhaps you need to open your eyes and look closely at some other quality cobra kits. Find a Contemporary(most now 20+ years old), or better yet,find an ERA under construction (they sell more as kits than they do as rollers/turn key) and take a close look at their "tub", you'll find a mix of fiberglass, aluminum and steel bonded within their passenger compartments. Weight wise, believe it or not, a finished car vs finished car, the weight differences were less than 184lbs (small block vs small block)...That was the big eye opener at Englishtown (Raceway Park scales) 6 years ago while I was having a grudge match with my FFR (against an ERA FIA). Most of the weight could be explained away (lightweight wheels vs knock off Trigo/Halibrand, aluminum heads vs steel, etc), I'll bet less than 4-5% difference when all was said and done. Again, yes, there are kits out there with "cheap,ill fitting, and poorly designed body tubs, but you can't condemn all of the kits based on those cheapy ones. To do so brings us down to the level of the "why would you want an FFR,it's just a rebodied mustang" (remember those who thought that way,I do, as I spent countless hours, days,months convincing them otherwise, as have you and plenty of others) uneducated enthusiasts. Dave Smith will tell you, I am a fierce supporter of FFR, but I also do not allow this to cloud my judgment on all other cars and their manufacturing techniques.

Have a great day.


Bill S.

[mrmustang]

Just thinking out loud. In the next F5R design.. why not a tub interior. Still use the Aluminum in the trunk. The F panels, and maybe even cover the underhood foot box with aluminum if you like.. The reason I say this is.. just to plug up those stinking air leaks that folks with tops have always been flustered with.
I love the alunimun look during the build, but you cover all that pretty stuff up with carpet.
It would save a lot of useless work, maybe even make a more stronger body. Slightly heavier , I know.
Not to mention the water leaks.
Fire away

Al,

I meant to ask, what do you have up your sleeve (or have in mind)? I ask because you rarely ask a question without first thinking of the answer.


Bill S.

[Raceral]

Funny...

1. Just trying to bring some intrest to this forum.
2. Trying to get my post count up without having a car these days.
3.

[Raceral]

Really... I do to much thinking..
But, I was just thinking back about all the time I spent drilling, getting the rivits just right and spaced out... How pretty and cool it looked... then having to cover it all up with carpet.. Then from that.. I just got to wondering why driving in a down pour, water came up from God only knows where and fills the floors up....
Crap I said to self... a tub would fix all that..KEEP in mind in my first post, I said keep the frame just like it is.....Hell, I hated when it came time to put my body on... looking at that bad boy without out the body on gave me goose bumps.. Then with the body on.. all that pretty work was covered up.....
Thats what got me just thinking out loud about the tub deal. I know it will not be done.. just jaw bone ing here!!!! We're having fun tho!

[MPTech]

I'm in the panel stage (fitting and drilling) and not liking it much. But when it's complete, I DO like it better than the tubs, in the go-kart stage and in the completed stage from the engine-bay view.

btw, what do the tub-kits do for the trunk area? If it weren't for the noise and sliding / scratching, I'd leave the trunk raw aluminum. I think it looks more race-tech, than the carpet.