Chassis Stiffening.., How far to go? Options

[OllieG]

Hi,

I'm at the stage in a very slooow build where I need to think about chassis stiffening.. I'll do the regular GT kit but I don't know whether to do either or both the Inner Long Kit and Roll Cage.

The long term plan is to fit a Suby 3.0 N/A and use it for mainly street but also hill-climbs/sprints/autoX here in the UK...

Any thoughts or advice?

Thanks, Ollie.

[914forme]

There are several ways to stiffen a 914 chassis how radical do you want to go?

My current chassis has a Brad Mayer 914 Limited outer log kit, runs all the way back from the front of the log to the rear outer suspension console. Has an Egmann inner kit, and full seam welding. I built the inner suspension console stiffening bars much like Tangerine racing sells, Chris was not making them at that time. Don't forget the suspension console while your there. I also have an outer one that ties the rear outer suspension arm to the logs. It is adjustable and makes setting the suspension toe much easier. If it stiffens I am not sure. Since it is auto-x mainly I have a Roll bar, added a lower bar that ties the lower points together. It pickups the lower Seatbelt points also and is mounted to 1/4" plate that wraps down the logs to the floors, ties in at 4 planes super strong mount for a bolt in roll bar. And a Petty bar down to the passenger footwell, which was re-enforced and ties into the logs. Not bolted to the floor like most I have seen, The petty bar is removable, at the track a passenger can ride with it in, though I normally remove it. For the road, I will remove it all the time.

Oh it has a GT kit, but that was done before I got a brain. In reality it was done after it became legal in PCA racing, thank you Jon Lowe, it was not hte best thing, but with no other choices legal choices it helped.

I had a bolt down top which I laced with a set of metal gussets it added about 10 pounds up top. It has since been removed as the Windshield pillars proved to be to flexible for its installation. I cracked two windshields with it in place. This was before I stiffened everything else up, so I might add it back in. Considering I never take the top off, I have also thought about bonding a carbon fiber skin up there over a metal frame. Or doing a metal skin like the 916.

For a street driven subby I would just add the 914Ltd outer logs and be done.

And the Engmann Kit was good, it would be even better if it extended through the firewall section and went up the inner logs to the inner suspension console.

Then that will lead you to rear suspension arms stiffening, don't wrap more metal around the box, make the box into smaller boxes. And the front is pretty stiff from the factory, a long as you don't cut out the trunk wall or floor. If you do you will need to add metal back in to stiffen it back up.

You can also add lower door bars and tie them through the logs with DOM and build a dash bar that runs up under the dash. put it as high as you can get it. You can add a Box section to the inner tunnel to make a raised console, don correctly it would stiffen the car the key is getting the loads moved to the outside of the chassis.

I have also seen two different home grown systems. One 914 I parted was supper solid even though the logs where rusted apart. At some time someone welded 3/16" plate steel to the bottom of the bottom of the car. That would stop small caliber rounds. And my favorite part out ever agin semi rusted logs, door gap true as ever, some one took the time to get pressure treated 4x4 pounded into the log section. Still to this day figure it took a lot of (IMG:style_emoticons/default/smash.gif) by one (IMG:style_emoticons/default/screwy.gif) group of guys to solve that issue in the most original way I ever found. Or maybe it was a group of Morgan enthusiasts.