So I got to talking with my friend about finishing my car, and the only thing left is the rearend and the potential for a 4-point rollbar. My friend is an avid career drag-racer and he said that he has often seen the bodies flex on these cars and tear the corners where the window meets the top (this is a hardtop car). I've heard of this, but this is generally in cars making big power with no structural support. I'm realistically probably around 475HP at the flywheel, so not a whole lot in retrospect.

My question is this: will a rollbar help the car be more rigid realistically? The guy that's doing the work is willing to give me a great deal, and I've seen his work.. and he does a fantastic job. He quoted me for $2,000 for a bolt-in brakes and all Ford 9" installed, my BMR subframe connectors welded in, and a 4 point rollbar installed. Unfortunately, that's a lot of money for the meager hours I work with school and all so it might take a minute to save up. Ballpark quote for just the rear was $1,200.

Is it worth the extra expense for the 4-point when I already have SFC's going in and a Strut tower brace? This is one of those "since it's already over there" installs I guess you could say, but I still have plenty of other bills like everyone else.. and if this isn't necessary to buy, then I'll save the money for other stuff.

 

I would say no. 4 point isn't going to be certified to do anything besides just be there for support and maybe a mounting point for a harness, which aren't even DOT Approved.

If you don't have a wonderbar on the car I would recommend that has that is only $70 or so and bolts on and prevents stress cracks for the front sub frame.

 

Got that part taken care of I have Lon's TDS wonderbar, actually.

That's the other thing, though. Like you said - the 4-point isn't going to be certified. That's what makes me a little hesitant I guess considering the price gap we're talking. Really, the NEED here is the rearend.. but I'm willing to throw the extra down if it's worth the structural support difference.

 

Only 4 points won't do anything for stiffness either.

 

Subframe connectors are a must with any of these cars and should be done 1st.
A 4point will help a lil and be a good 2nd step. If you like it, you can add more bars.

 

I installed a 4 point in my 91 firebird and it stopped most of the noise from flexing when I go over speed bumps but I made mine for under $100 bucks if can find a pipe bender

 

Install SFC first.

A roll bar is mainly to protect the driver. A 4 point roll bar is a street bar. To run quicker than 11.50, you'll need a 6 point bar. You can easily make swing out door bars for easy access in a street car.

The more tubes you add, the stiffer the car will become. The first year I raced my t-top car, I installed SFC before I went to the track. The second year, I needed a roll bar. Never cracked any body panels. I Now have a full cage in the car.

 

a 4-point is almost worthless and definitely wouldn't do much in reducing chassis flex. a 6 point roll bar on the other hand will stiffen thing up a bit, as long as they aren't swing out door bars.

 

The OP never specified if this is for drag racing or road racing. A 4pt may not get you anywhere for drag racing but will let you tech for a lot of non-wheel to wheel racing.

 

you can add side bars to any 4 point. swing out are fine also.
added with SFC, not bolt in ones..there are a few who make the ones you weld in, stich weld, the full length of the car. with your 6 point on top. makes it way better then stock. the feel of even how the doors close with just a fingrt tip. push and ride feel, is a 100% better then stock...

so stiff, my car was on 4 jackstands..( i thougt)..kick one out when i was on a kreeper under the car..car did not move!
and the doors still closed with just a finger tip push! when still on just 3 stands!