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Posted by: Lawrence Oct 13 2003, 02:23 PM

Brad,

Once upon a time, we talked about a method to increase torsional rigidity by reinforcing the lower inner firewall and insides of the longitudinal.

Can you post some pictures to show this method? I've looked around, and can't seem to find any.

-Rusty

Posted by: Jeroen Oct 13 2003, 02:30 PM

I could be wrong, but I think what was reinforced was the area where the heaterducts come out of the long, not the front firewall.
But like I said, I could be wrong... wouldn't be the first time

cheers,

Jeroen

Posted by: SirAndy Oct 13 2003, 02:38 PM

and not the last time

he (brad) was talking about the rear firewall.
U-Shaped brace (well, sort of) from long to firewall to center tunnel.

Andy

Posted by: Lawrence Oct 13 2003, 02:39 PM

That might have been another reinforcement.

The idea, IIRC, was to take a continuous piece of sheet metal, and wrap the inside of the passenger compartment. The metal covered one long to the other, going along the lower edge of the firewall (back of the seats), in a gigantic U shape.

-Rusty

Posted by: Mueller Oct 13 2003, 02:46 PM

Hey Rusty......


I too am interested in this, as much as I'd like a http://www.tcdesignfab.comcage, I don't think I need to go that route (cost, and turning the 914 into a daily driver, I need and want to be able to easily get in and out of the car....)

Hopefully Tony C can chime in on this to see what his professional recommendations are to stiffen the car up without going all out with a cage.

I've heard of some people welding tubes(round and square) along with sheets/plates of steel to the inner tunnel and the outer longs to help stiffen it up.

It would seem that almost any additional reinforcment would help, but the key is to optimize the designe and placement.

I thought Brad said the cars flex the most right at the floor area below the mirror on the window.


HTH

Mike

Posted by: Jeroen Oct 13 2003, 02:50 PM

Ok, I have a hard time visualizing this...
BRAAAAAD... PICTURES PLEAAAAZZZZE ! ! !


cheers,

Jeroen

Posted by: Lawrence Oct 13 2003, 02:53 PM

I agree that *almost* any stiffening is good.

But Brad Mayeur warned me years ago about making some areas too stiff. Using metal that's too too thick in an area that traditionally flexes can causes rips/breakage in an adjacent area.

I look at it like the (alleged) dangers of boxing the trailing arms... The stress has to go somewhere, right? Better the trailing arm than the suspension console.

Just my opinion,
Rusty

Posted by: Jeroen Oct 13 2003, 02:53 PM

See... I'm not the only idiot on this BBS tonight

cheers,

Jeroen

Posted by: SirAndy Oct 13 2003, 02:57 PM

actually, the top bar comes in very handy for getting in and out of the car.
as long as your arms are strong enough to lift your belly

Andy

Posted by: SirAndy Oct 13 2003, 02:58 PM

we need a "idiot" smiley

Posted by: Jeroen Oct 13 2003, 03:31 PM

Yeah, so I can make that my avatar

cheers,

Jeroen

Posted by: Brett W Oct 13 2003, 03:37 PM

According to Richie Ginther and Lcokheed Martin the 914 flexes the most in the middle of the door openings. thus the style cage that they used in the early BP cars. They did not use the NASCAR door bars , those cages were very simple affairs. This is one of the reasons, I haven't put an Autopower cage in the car. they are not as effective as they could be.

From looking at my crash damage I get a better idea of what happens to the 914 chassis when it is loaded. Obviously this is an extreme way to find out but.... The big thing to me is the way the chassis tries to twist when loaded through the rear suspension mounts. The thought that the trailing arms are flexing in is false. The trailing arms do not push inward under cornering, they twist up and down.

Posted by: Mueller Oct 13 2003, 03:46 PM

Brett, what did happen with your crash...street, track, driveway?????

I don't remember reading about it.........

Posted by: brant Oct 13 2003, 04:17 PM

I remember the comment about the firewall point being weak too...

I'm just positive about it (one anyways) being a weak point.... I even incorporated additional bracing in this area to my roll bar pads.. (my new and improved cage)

my back roll bar pad wraps over the side- runs forward on one side, and to the rear it makes the corner and runs towards the center of the car..

brant

Posted by: Brett W Oct 13 2003, 04:59 PM

Mike,
I slid over a curb sideways and kinda backwards at around 70mph.

Posted by: Jeroen Oct 13 2003, 06:57 PM

cheers,

Jeroen

Posted by: Aaron Cox Oct 13 2003, 07:18 PM

OUCH
how did you manage that? spin?
- we need a towtruck/ambulance smiley!

Posted by: Brett W Oct 13 2003, 09:04 PM

F$%@# Dunlop Sp8000 tires on cold pavement and driving to hard for the conditions at hand. The tires were shot at 10k and I was still running them at 12k they were hard as hell and I knew better, but this guy was pushin' hard and I couldn't have that. Damn learned the hard way.

Posted by: Bleyseng Oct 13 2003, 10:32 PM

Hmmm, I have those too and they have about 12K on them. Yep, they are slippery on cold mornings or wet roads.
But no worse than the Kuhmos Victoracers....
Geoff

Posted by: maf914 Oct 14 2003, 01:40 PM

Here is the thread that Brad described the stiffening mods that he recommended. Check the third page, about halfway down.

http://www.914world.com/bbs2/index.php?act=ST&f=2&t=4544&hl=stiff&st=40

"Your can strengthen your frame rails by adding one or two of the following:

1. outside clam shell behind rocker from Restoration design
2. Brad Mayeur clam shells (more for rust repair)..but you get the same effect..they are crude however compared to the form fitting of no. 1. on the list.
3. weld flat steel in a U shape from one side to the other on the INSIDE of the tub. It all gets hidden with carpet when you use 16 gauge. The U shape starts at the bottom of the fenderwell and wraps all the way around to the other fenderwell. You can weld it on every few inches. It takes some work to get around the E-brake setup.. and to get over the center tunnel on the firewall... but it works MUCH better than No. 1. and No.2 because you have now tied both sides of the car together with a very strong piece (lower firewall)."

Mike

Posted by: Brad Roberts Oct 15 2003, 12:51 AM

Thanks Mike.

I have been busier than a one legged guy in a ass kicking contest.


B