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fence post


MaTTSuN

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Most of the stuff in front of the shock towers is there to attach cosmetics to, and not much else. Frankly, you could almost cut the front of the car off there and leave the engine hangind off the K-Member and the car wouldn't handle much differently if you have put a decent strut bar on there.

 

If the back of the car (strut towers to firewall, tower to tower, and tower to swaybar mount) is tied together well enough, that lower radiator section isn't that critical at all. Almost anything would do. I'd shy away from 'Fence Post' for the Zinc concerns mentioned above...but if the back end is tied together, then the boxing up front is not really that important.

 

Actually, if you look at some of the tube frame cars, radiator 'supports' would be an overgenerous term for what you will find...

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well im planning on doing strut bars next and running 2x2 in the subframe

im also going to put a 4 point cage in at some point this summer

this is just the first thing i wanted to do since i needed to do rad work anyways and ill be mounting my intercooler so i wanted to get everything infront of the rad nice and clean so i dont have to open it up again

thanks for all the post its really helping me with my design

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heres a little something i put together with wood to see how it looks

the red will be a plate much like the stock part looks like

not sure if im going to do it in round or square ill figure that out when i get to my buddys shop

frontmock_thumb.JPG

frontmocktop_thumb.JPG

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The galvanized coating is normally made up mostly of zinc. When heated up by welding, it not only makes the weld look like crap and prevents good penetration, but it also vaporizes and becomes airborne fumes. It has a very distinct smell when you breathe it in. In about 15 minutes to 1/2 hour you get a real bad headache. Long term health effects are probably even worse, think lung cancer, etc. Old timers will tell you to drink lots of milk before welding on galvanized, the theory being that it will coat your stomach and keep you from getting sick. Yeah...... Don't buy a word of that crap. Get a good respirator rated for toxic fumes, and remove as much of the galvanized coating as possible before welding. Even with a respirator, the fumes from zinc burning off will still get into your eyes, they'll be watery for a while afterwards too. You'll want to remove it at least an inch away from the heat affected zone. As you file or grind on the galvanized metal (Wearing the respirator if grinding of course), you'll notice a slight color change when you get through it into the steel under it. Don't just file until it's shiny, look for the change in color to make sure the coating is gone.

 

I just had to take an OSHA class at work and the instructor informed us that welding galvanized causes NO long term effects. No cancer or anything like that. Once removed from fumes within 24-48 hours you should feel fine. But in those 24-48 hours you feel like you have the worst flu you have ever caught. Now welding stainless is another story when it comes to cancer.

Again, this is according to the OSHA instructors.

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I'd wear a mask (respirator).

My understanding is during the combusion process you get cyanide gas...not sure how Zn turns to cyanide, but that was the gas I was told was produced. Anybody know for sure? TLV and Trace exposure are two different things. OSHA says you can stand next to our compressors for 8 hours a day without ear protection since they are only 85DBA...but I can tell you what OSHA allows and 'what is good for a person' aren't necessarily the same thing. Short term or long term. When in doubt, ventilate and Respirator-Up!

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Well time for my front rad support experience.

 

When doing the VG swap, we placed the driveline in and out of the car for mocking up mounts etc. It was put in and out 16 times. It was decided, to make it all easier the TOP mount was cut out.

 

With the cars weight on its wheels, the top crossmember would not fit back in. With the car on the hoist, the cross member had 1/4" + space. (more than the space created by using a sawzall blade to cut through it on each end.

 

We were quite surprised with the amount of flex in the front end. Considering there was no driveline installed, and I have a 12 point cage installed. The braces in the engine bay were obviously removed during this swap.

 

After the swap, we reinstalled the same rad support, with extra gussets, and a top and bottom horizontal bracing 1x1 which we used to mount the intercooler to. Then followed up with an X brace from the shock towers to the rad support gussets.

 

Those rad supports do have a major impact on the front end rigidity which I believe is absolutely critical if you have no other chassis bracing in the front end. Once you get into triangular braces, strut bars, then the front rad supports becomes less critical.

 

Oh btw. Consider some of the aero info we have available..maybe consider belly pan mounting, and future ducting of the front end and rad. Ya know "while your at it" hehe

 

good luck.

Scott.

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ZR8ED, Good summarization. I fully agree and have experienced the same issue. This is the primary reason why I installed the motor and transmission as a solid member of the chassis using a six point mounting, with multiple fasteners at each point. Then I triangulated the engine bay between towers and firewall (horizontally), and between towers and the engine (vertically). The cage is attached at eight points.

 

Result: The difference in chassis sag between the weight of the car on all four wheels, and when the car is fully suspended only by two points midway between the front and rear axles is about .090" (without the rear transmission crossmember mounted in place). In the end, I set the car down on its own weight before solidly tighten all the nuts on the entire drive train assembly in order to place the drivetrain in a non pre-stressed mode. It's amazing how much difference the rigid chassis makes in regards to handling, spring rates, etc.

 

MaTTSuN, This is why the all the other string comments have been made in regards to the OEM design of the core support, and you're alternative. Datsun did not have the tower bracing, and it would have been nice if they did, but they did provide a sufficient core support that did help keep front twist manageable (enough so that the radiator remained intact) even with stiffer aftermarket sway bars. You're quest to improve the core support's contribution to the front twist looks like it's headed in the right direction through continued thought and improvement.

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thanks for all the help guys

i got my square tubing today

about 14 feet of 2x2

im going to finish the lower rad support first then figure out

where i need to gusset it

after that ill mount my big azz isuzu intercooler

i wanted to make some pans for aero but that will be after a few things

 

im going to slide some 2x2 in the sub frame since half of it is rusted out anyways, then make the strut tower braces

but ill prob start a new thread for that when i get there

 

oh yeah and how do i change my fence post title?? but that hooked everyone in and helped me not use fence post haha i was half kidding but i prob would have done it and cut it out after and wasted time

thanks hybridz hehe

 

new pics to come

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ok dude's im very excited now

check this out

i still have to touch up some of the seems but it almost there

next i have to make some tabs and fit it to the chassis

then gussets and that front triangle peice and she will be ready for the rab and intercooler

2x2.0_thumb.JPG

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That looks great...

 

Make sure to tie it into the car real well. You might look into some gusset plates in the areas you are tying into. There are gussets in the front frame rails for various attachments.. try to get load transfered to those.

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thanks im very proud of this part i made

classing up my car real nice like

i started weling it to the car today but i didnt have my camera on me

there are still the tabs on the chassis where the stock part was "gussets" i guess you can say u can see them in the pic im welding to those.

 

i like the way it looks now do you think i should put trangles on the ends like the stock part looks or will this be strong enuf?

i have an idea of what i want to do

make like an I beam on the side with a hole much like how the stock part looks.

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haha thanks i like it

i got the tube for free so all in all a good upgrade

now i just need to finish it up and make it solid

it was allot funner making

putting it on the car is not as fun

ill have some new pics tonite

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ok here are some new pics from tonite

its on there pretty solid now but i need to go over it some more and make it really nice

not sure if i should make a triangle on the ends like the stock one does

i prob will just to square it off so the pan im going to make for under my airdam has more to mount on

how does it look so far?

im welding all my seams up front while i do this to give some more strength

ill be doing that over the whole car as i go from the front to back improving this classic ruster

newcam pics march 24,08 007_thumb.jpg

newcam pics march 24,08 008_thumb.jpg

newcam pics march 24,08 009_thumb.jpg

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