Kev, I used 1.5 x .065 on my front bumper as well. The only thing I did differently is that I used HREW instead. It's a tube that should crush/deform/etc, so who cares if it's the strongest it can be?

It's also cheaper when it's not DOM. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)

Wicks aircraft supply had the 1.5x.065 DOM for $1.53 a foot and I paid about $23 to ship 30 feet of that and some tungsten for my tig (yea, I needed more tungsten, I may have to start the "tungsten exchange" for people who had to buy 10 of something just to try one). They didn't list HREW or I'd have used it. It seemed cheap enough and all my local metal places are open the hours I'm at work, so mail order was the easy way without taking time off. I'm going to borrow Jon A's idea and build a similar structure to support a splitter (that I'm yet to design), brake ducts and my oil cooler. I'm pulling the oil cooler out of the radiator due to cooling issues and adding an external cooler and fan in the bumper assembly. Or that's the plan.

So, how strong is this stuff? I'm trying to build something that will give if I hit it hard enough and not deform the frame horns. Any do's or don'ts?

That's a good price for DOM. I think I paid at least that for my seamed, but that was 2-3 years ago. Mine is just a piece bent to fit the contour of the nose and one kicker per horn and no cross bracing.

1.5 x .065 is strong enough that it will still tweak the frame horn, but it collapses fairly well. I tried it out last May. It's a lot better then the 1.625 x .188 seamed I used last time (1 1/4" IMC conduit). That bent the frame horn and the bumper hardly bent.

I got a look at a NASCAR COT last year at the local liquor store when the Cup race was in town. Their front bumpers are probably 1" or 1.25" x .083 and they used more bracing around it that was smaller tubing yet.

This post has been edited by nape: Feb 16 2010, 02:04 AM

In that case, I might frame the bumper out of this and make the supports that tie to the frame horns out of something smaller so it will bend in a hard shunt. Maybe 1" with a moderately thin wall. Something that still rigid when loaded vertically, but will potentially kink before going through the nose. I have some ideas that shouldn't be too heavy or expensive.

maybe try EMT tubing? its thin, light and bends pretty easily when you want it to, its pretty rigid. and cheap

This post has been edited by Phil: Feb 16 2010, 03:00 AM

I don't know if I'd go as small as 1". You've got to think about harder hits too. Fixing a frame horn is better then fixing a radiator, steering box, or the front of the motor.

I hit a guard rail offset to the LF at 20-30MPH and it did this:

Picture linked for size

My tubes are not straight going to the bumper bar, they angle upward from the center of the frame rail. This allows them to bend on impact since the tubing would be strongest in compression. This also puts a decent lever arm to bend the front of the frame rail, but like I said, I'd rather bang the end of the frame rail back into shape instead of putting it on a frame rack because it pushed the whole rail backwards.

Here's a pic later in the year after the damage was fixed. Same fender, nose, and bumper bar with some hammer and dolly work and some aluminum backing plates and rivets on the split nose. Oh, and touch up out of a rattle can. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)

(IMG:http://www.ploader.net/files/33bb757c7509697777da1836f3468fb9.jpg)

This post has been edited by nape: Feb 16 2010, 03:33 AM

I have a thought of running some of the 1.5" across the plates bolted to the frame rails and then supporting the bumper with an "X" so it can bend and not spread the horns. Or something along that line.

My PHB relocation kit came from Unbalanced Engineering today. We'll add that to the list of things to weld while we're at it. Looks like a great kit, I'm anxious to see how it all fits.

Thanks for the great service Jason!

I'm starting to find myself in a familiar position. The NFME is 2.5 months away and I still have a list of parts to buy and work to do, which includes installing lots of parts that I've already collected for this project.

Last night the driver's side impact bar (finally) came out as well as more inner drivers door structure that is just ballast. That rest of the list:

Install:

Distributor (and time the engine)
MSD 6AL
MSD coil
Plug wires
Plugs
Starter
Exhaust (bolt it back in place, or mod the Y pipe for pan clearance, depending on time and if I change to a Canton pan)
Battery (Odyssey PC680 and relocate and rewire it)
Switch panel, EFI harness and ECM (and wire entire car/brake lights)
All gauges (build dash first)
PHB relocation bracket
Steering column and wheel (Have to order from Alan)
Kirkey full containment seat (still have to order that from Alan) and fab mount
Window net mounts and net

Fabricate/finish:

Cage
Dash (even something basic)
Front bumper (install external oil cooler and add fan)
Paint interior (when cage is done, before wiring)
Paint exterior (before windshield is installed)
Front and rear bumpers (front bumper for brake ducts, oil cooler and tow hooks, rear for tow hook)
Build a mount for the accusump and shorten the lines

Fix cooling issues (ducting?)

Of that, if I hit crunch time, the essential items are:

Distributor (and time the engine)
MSD 6AL
MSD coil
Plug wires
Starter
Exhaust (bolt it back in place)
Battery (Odyssey PC680 and relocate and rewire it)
Switch panel, EFI harness and ECM (and wire entire car/brake lights)
All gauges (build dash first)


Fabricate/finish:

Cage
Dash (even something basic)
Paint interior (when cage is done, before wiring)

Fix cooling issues (ducting?)

In this case, it's still got a stock seat in it and a stock steering column (until I get back from the event and finish it) and it's still teal with a white hood. I suspect we'll wind up somewhere in between the two lists.

I'd really like to debut the car "finished" (and painted). We have paint, just need to get it sprayed, assuming we have time after completeing the rest of this list.


Guess I need to get busy (again). At least I have longer than 2 weeks this time. I just have to quit going "I have plenty of time, no problem". That's a much bigger list than I was thinking it was.

Yep, I'm running up on that before the start of the season too. If you knock out some of it every night you'll put a good dent in the list.

Don't worry about paint and don't worry about it being "finished". They're never finished and taking it on track with soft paint will only let it chip easier anyway. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)

It wasn't a super productive weekend. We did get one rear bar for the inverted V (those are tough to fit) and the middle door bar fitted today. My friend Chris (aircraft fabricator) came down for the weekend and while he was here, he tigged the oil cap to the valve covers for me.

Other updates:

The lexan windshield is on order (3/16 Margard coated stock replacement "drop in" lexan from Harwood), most of the electrical bits (breakers, fuse holders and other power distribution stuff) has arrived and the rest is coming. I gathered up an Impact racing helmet and found that their extra large helmet will NOT fit me so I'm going to have to order another Bell. I can't wear Simpson helmets either, so I guess I should have known. My tubing notcher has been shipped and I hope to be breaking it in this coming week.

I spent most of the evening in the garage and got some things accomplished. The upper door bar for the passengers side is fitted, but it hits the door. I have some stuff to trim out of the way, but if that doesn't do it, I'm going to have to straighten the bar slightly and notch another 1/8" off of the end. No big deal, but I won't know the answer until tomorrow. I fitted the main hoop diagonal so that I could fit the harness bar and I tacked all of them in place.

(Yes, I know I have to clean the paint off before final welding. I'm just tacking and fitting tubes to make sure there are no issues, then we'll clean and weld).

Yes, I'm going to recut the front upper bar...

You converting this to RH drive? (IMG:http://www.frrax.com/rrforum/style_emoticons/default/nutkick.gif)

Looks good TB. Top bar is in line with haness bar and dash bar. I can tell that you've been studying Alan Blaine photos.

Double nascar bars are the new rule since I didn't get a log book in time to grandfather in an X bar. Alan has taught me very well. I was on the phone with him at 2 am last night for one of our updates/chats. I'm doing the passengers side first for practice. I figure I'd rather goof on the side that I don't sit on. The car should be pretty strong when it's all together (or just heavy).

Didn't know that. Bummer. I guess that only applies if the doors are gutted?

I may be wrong. That might have been due to my original intent to run AV8SS. The CCR says:

But, for NASA, the AI rules supercede the CCR:
AI/AIX 2010
5.13 Door Safety Bars
All vehicles must meet the door safety bar requirements found in the NASA CCR at Section 15.6.12 but
gutting of the door beyond what is solely necessary to fit cage bars is allowed.

So Stan, when you're ready to ditch the windows for AI you can gut the doors. Altho not required, at that time I would consider adding an outer crash structure to your driver side to put a little more room between you and an offending bumper.

CMC, however, is MORE restrictive than the CCR, requiring DRV side impact beam to remain unless door bars curve out to the skin:

CMC 2010
4.12 Door Safety Bars
In addition to meeting all of the CCR specifications the roll cage in a CMC car must meet the following
additional specifications. At a minimum at least two door safety bars must be used on the drivers side, and
one door safety bar on the passenger side. Gutting of the door beyond what is solely necessary to fit cage
bars is allowed. However, removal of the OEM door impact beams is only allowed if door bars extend out
towards the door skin on the driver's side, and on the passenger side if a minimum of two door bars are
used.

I thought that was the case Alan. I skimmed over the 2010 rules so I wasn't sure if missed that or not. I thought I read somewhere that NASCAR style door bars were required on the drivers side if the doors were gutted but I don't see that in the 2010 Nasa CCR. I found something like that in the SCCA GCR:



Maybe I just implied or read on a (this) forum that Nascar bars are required on the drivers side with gutted doors.

I'm sure instructors will appreciate the gesture of the additional door bars. And it isn't too much more weight than a X, each bar in 1.75x0.095 is ~8 lbs and 10 for 0.120".

I was reading the rules to have NASCAR type bars on the drivers side if the door is gutted, and if the passenger side door is gutted then "X" bars are required if no passenger seat, if you have a passenger seat then NASCAR type bars will be used.

Now the NASCAR type bars must go out to the inner panel of the door to put as much safety distance between you and the bars ( I like to call this entry area and with closed doors I need all the room I can muster to get in through the window!) Is there a requirement like NHRA where you are required to exit the car in 15 seconds in full gear? I did not see any requirements in the CCR's....