ugh, not again already

[CentralWAbaja]

[dustymojave]

Now here's a good one I've never seen addressed in a forum, crumple zones. I don't want cockpit to become the easiest area to crumple. Would I be best to use 120 around cockpit area and 095 for the rest so it crumples first?

I approve of crumple zones. My Baja Bug has crumple zones designed into the front and rear bumpers. Allowing some crumple in the rear behind the B-pillar would be good, but is not so simple. Ahead of the footbox is another area with potential, but it needs to be strong enough to avoid collapse under offroad use. Then on the sides of a tube frame buggy, nerf bars can serve quite well to protect the cockpit. Not "tree" bars, as they are typically built out of the same material as the frame itself. Then what crumples 1st may not be the tree bars. My buggy has nerf bars which are removable and are made of 1" x .065 tube. 1.25 x .083 might work well too.

The Berrien style reinforcing kit would help a lot to keep the cockpit strong. But don't then add bumpers made to ram army tanks.

[Ol'fogasaurus]

I personally prefer the "long back" style of rail (vs. the short back style) similar to what you have but the style of rail where that cross bar is bolted in place, that is a major weakness of this particular version. That bar holds the long back sides in place where its job is a major part of load distribution through the rear of the rail as the down tubes from the "B" pillar do connect in that area.

Besides load distribution, the bar also holds the lower engine cage in place; the main weakness there is you have 4 bolts that hold it in place. These bolts are being loaded most of the time any action is going one whether it is a twisting load or a shear load. An impact such as bouncing the rear of the rail/skid plate off the ground or a rear impact is going to cause failure of either the bolts or can cause load distribution leading to failure via the weak join itself.

People have a tendency to either leave that bar out or bolt it in place with fully threaded bolts which should not be in shear as fully threaded bolts are (usually and I use the word usually as I am not sure if there is any that are designed to be in shear. I doubt it but just-in-case) not designed to be used that way.

I still like the esthetics of the design itself but if I had one I sure would change that rear to make it more like a horizontal hoop as fast as I could; e.g., at least weld the tube in place.

[fusername]

the man has a few good points up there^

[Ol'fogasaurus]

I am trying to figure out some things in my photo editing program and decided to try to edit your pictures. This is a clean up of the second picture you posted.



This is an enlargement of the area on the driver's side where the center tube bolts into the long back part of the frame. I thought this was a two bolt connection but it looks to be a three bolt join. This is a major weak spot I think.



This is what I wanted to look at as the first picture you posted cut this off. I thought I saw the fold of be bend but this enlargement does show it. I think this is going to be a hard thing to duplicate but it should be able to be fixed by doing the long back in a different way.

If you don't mind, I think I will try something, photo edit wise, to see if another style of long back will work (not today though).

Thanks for leaving your post in a larger format.

Lee

Your picture did not have the back in place so I couldn't play with it, so...




This seems to be fairly common style of long back rail I am seeing for sale lately. Notice that this version has the similar bolt together cross-piece as yours has.


This is a shorter backed version but notice that it is a mid-engine water pumper version.



This is a combination short back and long back version version



This version of a long back is fairly common but this one would need ti be fixed like the tubing join I already have given you.



This is probably one of the easier fixes around. I don’t think I would do the fancy narrowing down as shown but a taper down may work as you may end up wanting the extra room.

Anyway, assuming your cage area is OK these are some pix to help generate some thoughts on fixes for you.

Lee

[bajaherbie]

Hmmm, heater boxes? LOL

[Ol'fogasaurus]

It's cool and damp up here Hoib !

Actually I did a search on Craig's List to find what I posted. There were several others posted but were a step or more than these.

[cbeck]

Today was the first time I've touched it since 7/12/15. Cut out poly seats and covers and sold on cl today.
Lee, the engine cage flanges were only 2 bolt. The one on the left was about to fail and the one on the right had failed tearing @ top bolt hole and was tearing off tubing. Will be changing rear to a pick up style bed ala beelines 98" packrat. The rear will have 3 horizontal tubes. First will follow same plane as front top rail being u shaped running from new second b [c?] pillar. Second will follow the first but be maybe 2" above fan housing. Third will be a smaller 1" bar about 4" above second bar forming side of bed. Sheet al will be attached to top of second tube forming floor of bed. This will all have to be determined after exhaust and carbs are fitted because I want to create a little more room behind engine. After that is done it will be time to figure out engine cage. I know I am looking for something a little sturdier. Will probably start with something similar But will be bolting to bottom of bar 1 in rear instead of the way it was done by beeline. Then it will be time to hold up mistakes/offall and see what floats my boat with another beer drinker behind me telling me how that one is a bad idea several times until we can agree on how to beef it up a little. At least we can agree when its time to quit working and keep drinking.

[Ol'fogasaurus]

.

I like the idea of a PU box. It's been so long since I have seen one I had forgotten about the idea.

Careful with the suds when too close to doing something. Often good ideas get changed in a post job suds design review meeting .

Keep the pix and ideas comming, I for one will be following.

Lee

[cbeck]

Here is more found damage.This is the top of the roll bar over passengers head, collapsing on top and tearing on bottom. Next is my fuel tank mounts, 3/16x1" strap.Last,[first?] the failed engine cage flange. Can't stop now, sold my fuel tank and dual carbs to help fund the project. Touching this thing for the first time since July was kind of depressing, so to help myself feel better I ordered the first parts-2 corbeau baja xp suspension seats. 1st step backwards, the 4.12 rp trans is already in buggy so I need to rethink gearing to get the rpm I am looking for at cruise up by about 500 rpm. I have the 4.12 and a 3.88 type 1 but in a perfect world I would get a 002 with a 4.57 rp. Time to see builder and see how big of a dent this will put in my budget. Got a little chilly yesterday so I am finding it hard to go out to the garage. I am still trying to figure out the picture thing, but I think I am getting closer to nailing it.

[Steve Arndt]

I have the 4.12 and a 3.88 type 1 but in a perfect world I would get a 002 with a 4.57 rp. Time to see builder and see how big of a dent this will put in my budget. Got a little chilly yesterday so I am finding it hard to go out to the garage. I am still trying to figure out the picture thing, but I think I am getting closer to nailing it.

Just start with a six rib 091. The 091 has the 4.57 r/p ratio stock. 002 is shorter geared.
To change the 002 to 4.57 requires a very expensive Weddle aftermarket r/p I believe.

[GoMopar440]

.Last,[first?] the failed engine cage flange.

I'd argue that rather than failing, the frame succeeded in keeping you alive, at the cost of it's own structural integrity. Looking at it from that perspective may make it a little easier to deal with the repairs.

1st step backwards, the 4.12 rp trans is already in buggy so I need to rethink gearing to get the rpm I am looking for at cruise up by about 500 rpm. I have the 4.12 and a 3.88 type 1 but in a perfect world I would get a 002 with a 4.57 rp.

What size tires are you running with those 4.12 gears and what RPM were you getting at about 75 MPH? I think I'll be on the other side of that happy RPM zone now with 31's and a 4.86 R&P. I won't know for sure until I get it on the road to find out, but I was thinking a 4.3x or 4.5x R&P would be just the ticket with my 31's.

Steve,
Do you happen to know how much the Weddle R&P gear set goes for? Are the 4.3X R&P gear sets any cheaper or easier to find?

[Steve Arndt]

1000 bucks.
https://www.weddleindustries.com/produc ... 58/1001880

[GoMopar440]

1000 bucks.
https://www.weddleindustries.com/produc ... 58/1001880

Ouch! Yea, I can see why you recommend just buying an 091 instead. If you find one at the average price of $100 per rib ($600), you'd be $400 ahead and still have the rest of the trans for spare parts.

[jsturtlebuggy]

Weddle carries 3 different 4.57 Ring & pinion sets for and 002 trans. Two are cheaper around $400 for the set.
One made in America and the other is Chinese. For Weddle to be sell a Chinese product it must be somewhat good.
The $1,000 one is made for off road racing and is very strong. For a play car is kind of over kill.

I recommend using Weddle's gear ratio chart to find the gear combo you would like.
With a 4.86 R&P, 31in tire and a .82 4th gear at 3,000RPM it just over 70MPH. And with a .89 4th gear at 3,000RPM is just under 70MPH.