F/R bumper beams..

[Draco-REX]

I'm posting this in the Stage Rally Prep area because I'm sure you guys have the most knowledge about the Impreza's structure.

Before I get started, I will say this is for a race only vehicle that will not be driven on the street so we can dispense with any discussion about the safety concerns involved.

What I'm wondering, is if the front and rear bumper beams are load bearing components of the chassis. I want to remove them to save weight. Do I need to replace the front one with a bar of some sort to keep the ends of the frame square, or is the core support in front enough to keep the front clip from deflecting?

Thanks.

[JacksonRally]

Really the core support just hold the headlight/radiator and the hood down. Any type of front bumper beam will definetly help with structure at the front of the frame rails. Although there really isnt much need for structure in front of the front engine crossmember/strut area, this you want strong and straight.

I make these bumper beams/tow eye deals to replace the stock beam. It also doubles as the mounts for my lightbars.

As of now we are not running anything in the rear.

http://i198.photobucket.com/albums/aa15/Jackson-Rally/RLLYSTI/IMG_1192.jpg

http://i198.photobucket.com/albums/aa15/Jackson-Rally/RLLYSTI/IMG_1197.jpg

http://i198.photobucket.com/albums/aa15/Jackson-Rally/RLLYSTI/IMG_1196.jpg

With lightbar

http://i198.photobucket.com/albums/aa15/Jackson-Rally/RLLYSTI/IMG_2366.jpg

[Draco-REX]

Although there really isnt much need for structure in front of the front engine crossmember/strut area, this you want strong and straight.
So I would be ok running RallyX without a beam, and I wouldn't have to worry about tweaking the front clip? Or did I read that wrong?

How much do you sell your beams for? W/ tow loop, w/o lightbar mounts.

[JacksonRally]

So I would be ok running RallyX without a beam, and I wouldn't have to worry about tweaking the front clip? Or did I read that wrong?

How much do you sell your beams for? W/ tow loop, w/o lightbar mounts.

Yeah you are fine without.

The beam with tow loop is $225

[Draco-REX]

Yeah you are fine without.
Thanks again. :) Should help quite a bit. The bugeye beams go around the foglights so they must be a good 5lbs or so heavier than later years too. :D

The beam with tow loop is $225
Nice, I'll probably put that on my list.. Unfortunately, it looks like I might need a radiator first.. *grumble*

[Dan McGinn]

Question: would a bumper bar, similar to the nice one that Jackson Rally has, above, be legal if it bolted to the original spots, but protruded just beyond the bumper skin? Reason I ask; the other night, whilst my mother-in-law was in my house, I secluded myself to the garage and made this, not really thinking too much about the NASA rules. It bolts to the stock bumper mounts. When done, it is going to have 45 degree gussets of 1" DOM from the front of the bar on each side which bolt to the bottom of the bumper mounting area on the car. (fyi, its not done in that pic, corners will be rounded, tow hook etc.)

Thoughts on the legality?

http://lh5.ggpht.com/_96-oC7C68iU/TEhImTWjwoI/AAAAAAAAG6Q/8Nf57BxlszA/s640/0711001521.jpg

I think these are the applicable NASA rules and I don't think it runs afoul of them.

5.6 Reinforcements in front of and behind the roll cage

Longitudinally, the roll cage must be entirely contained between the
mounting points of the front and rear suspension elements carrying
the vertical loads (springs and shock absorbers). Supplementary
reinforcements exceeding these limits are authorized in front of and
behind the roll cage as follows:

5.7.1 Front core support reinforcement

Reinforcement to the front core support is allowed if:

1. For cars without McPherson strut front suspensions, a
single tube may be added on each side from the lateral or
half lateral roll bar or front roll bar to the core support that :
1. Is no larger than 1.5” diameter and .095” wall thickness,
2. has a downward bend of at least 30 degrees in the tube
to allow for bending in a frontal impact
3. has a downwardly turned portion in front of at least 8”
long

4. shall be joined to the lateral or half lateral roll bar below
the base of the windshield

2. For car with strut front suspensions, one or 2 tubes tube
may be extended forward from the front strut tower on each
side to the core support that is no larger in diameter than 1”
and .095 wall thickness. This may be bent or straight.

[geekguy]

The spirit of the cage rules are there for *cages*. This does not add significant reinforcement of the body.

But, as always, check with your scruitneer pal!

[spiwrx]

I wanted to use one of JR's bumper beam / tow hook and asked Mike Hurst for my PGT build, got a firm no for PGT.