Ok I am an off road guy whos buddies convinced him to turn his 500$ RX7 into a dedicated autocross car. Its a 79 and will only be driven on the street to races close to me. Our local SCCA guys run their events with no classes and very fiew rules. I will not be building a full cage.

My question is this.

Will welding the doors closed stiffen the car or should I weld in door bars? I would like to keep this as light as possible.

I have searched for several evenings and can't seem to find anything on it.

Thanks

 

Depends on what you want to do for a class.

PaulC

 

You don't need rollover protection THAT badly just for autox. Never hurt of course.

 

just put a full cage in it

 

Do you even know what class you want to run? It makes a difference as welding the doors shut will probably put you in EMod. Get a rule book and study it before you start building your car. Better safe than sorry.

 

I think he is just talking about doing it for chassis stiffening for performance, not for safety. Also, no class rules?

If you think you'll be able to use the car enough to get the grins/dollar ratio you want out of it, why not? (unless it makes the car illegal to drive on the street)

If you think there's a chance you'll want to later step up to something like Spec RX-7, you might want to consider checking what you could do without making grief for yourself in the future...

I'm assuming you'll be refreshing bushings, shocks, etc. first, right? No need to stiffen the chassis if the suspension is sloppy..

 

seam welding will do a lot more then welding the door shut or putting in a cage and bracing (without the weight). what class?

 

"Depends on what you want to do for a class."

At the local events they don't have any "classes". They call it Solo 2. Heck they don't even hand out awards; It is a total braging rights thing. But they do hold a race almost every weekend durring the summer.

If I want to run anything like "Spec RX-7" I have to travel at least 6 hours (more if you are pulling a trailer).



"seam welding will do a lot more then welding"

I have already done alot of seam welding in areas.



"I think he is just talking about doing it for chassis stiffening for performance, not for safety. Also, no class rules?"

Yep, exactly. Only rules apply to safety. I am looking for the best weight vs chassis stiffening compramise.




"I'm assuming you'll be refreshing bushings, shocks, etc. first, right? No need to stiffen the chassis if the suspension is sloppy."

Yep, new shocks & struts, I have replaced many of the bushings with rod end, turned/cut my own bushings in other places.




Also, 1st gens are plentyfull here in Bozeman. I know of 4 parts cars right now that I could pick up if I ever needed/wanted to go back. The car is already way beyond a dayley driver.

So will welding give me the stiffness I need without a cage, or should I run a door bar?

Thanks

 

I think a door bar is more for side impact protection than stiffness.
If all you are looking for is more stiffness, then weld the doors shut.

 

I decided not to weld the doors shut. I can just get into the car but there is no way I can get out. Even if I put in a removable wheel I would have to get out thru the sunroof. I am 6'1" and about 190lbs.

That window opening is so short I just don't see how any full grown guy can do it. Not at all like the full size-american iron drag cars I am used to.

Thanks for the replies guys!

 

are you kidding me
I am 6'3" and 180 pounds and not only do I have no troubles getting into and out of my RX with the door shut, I have a CRX race car with welded doors that also must be entered in that manner.

 

What in the world is seam and spot welding??? I hear that it's a great thing but I am just ignorant.

 

There are some pictures in another thread about seam welding an FC.

 

Seam welding is applying a bead of weld to all joints (or at least important ones) in a unibody car. The factory joins parts with spot welds, which is similar to just "tacking" parts together. By adding more weld along the seams of the joint you greatly improve the resistance to bending and stretching.