What do you have for chassis stiffening? Options

[Justinp71]

I put some more horsepower in my car, so far I have just autocrossed it on street tires. I have the bolt in roll bar that has the mid bar going to the floor.

Besides that my chassis is stock and I am wondering what I should do for more re-enforcement... so I can comfortably run on slicks.

Below is a photo of the roll bar. I don't consider the roll bar to give to much chassis stiffening, but it just might help with cracking the longs.

Edit: I mainly just use the car for street and the occasional Autocross or DE

[J P Stein]

It doesn't take an engineering degree to see where the points of load are on a 914......hint....there are 4 and round black things right near em'.
Once that tough bit is over, then you gotta figure out where you can attach structure & how to bridge between them.

As Brit wrote, a butt dyno reveals a huge difference. The chassis moves more like a single unit and the suspension does it's work in a more controlled manner.
This causes the car do the same thing every time when loaded....or close enuff. (IMG:style_emoticons/default/biggrin.gif)

BTW, there is closer to 60 lbs than 20 lbs extra. Bridges aren't light.

[Randal]

It doesn't take an engineering degree to see where the points of load are on a 914......hint....there are 4 and round black things right near em'.
Once that tough bit is over, then you gotta figure out where you can attach structure & how to bridge between them.

As Brit wrote, a butt dyno reveals a huge difference. The chassis moves more like a single unit and the suspension does it's work in a more controlled manner.
This causes the car do the same thing every time when loaded....or close enuff. (IMG:style_emoticons/default/biggrin.gif)

BTW, there is closer to 60 lbs than 20 lbs extra. Bridges aren't light.

I've taken JP's approach on adding front and rear bars tied in front to the shock towers, then to the front torsion bar mounting. In the back we have run the bars as close to the towers as possible, although not as nice as JP did it.

Can't wait to see the performance difference. Who knows, with a clear head, the car might be competitive.

[Randal]

It doesn't take an engineering degree to see where the points of load are on a 914......hint....there are 4 and round black things right near em'.
Once that tough bit is over, then you gotta figure out where you can attach structure & how to bridge between them.

As Brit wrote, a butt dyno reveals a huge difference. The chassis moves more like a single unit and the suspension does it's work in a more controlled manner.
This causes the car do the same thing every time when loaded....or close enuff. (IMG:style_emoticons/default/biggrin.gif)

BTW, there is closer to 60 lbs than 20 lbs extra. Bridges aren't light.

I've took JP's approach on adding front and rear bars tied in front to the shock towers, then to the front torsion bar mounting. In the back we have run the bars as close to the towers as possible, although not as nice as JP did it.

Can't wait to see the performance difference. Who knows, with a clear head, the car might be competitive.

Update:

Having gone pretty much all out I believe using (essentially) a cage from the front torsion bars to the front shock towers, then back from there to the cockpit cage and back from there to the rear shock towers plus bars in the cockpit to the engine hump, all make a huge difference. In addition reinforced ears with alumimum standoffs to the firewall and Foley reinforced trailing arms, with needle bearings really work.

Reinforcing the ears is simply a requirement if your going to run big slicks, as the sheet metal won't hold up otherwise. In fact I broke mine my first time to the track.

Anyway the car not only does what you want it to do it has lost any tendency to snap spin under extreme situations. But some of that has to be credited to the tires and tire setup, which is another subject.

And you can buy this chassis if you'd like. (IMG:style_emoticons/default/idea.gif)