Are sub frame connecters enough?

[carnutt71 10]

How much added stiffness does a fastback need for about 600 rwhp?

[latoracing 256]

"What are you going to do with it" is the most common responce you will get. If you are going to run the 1320, then it might be enough, depending on the rear suspension and the ET you are wanting to run. There are some people who run just sub frame connectors with leaf springs, and not much more. Then the subject of what type of connectors are you wanting to put on the car...kind of an open ended question. If you are wanting to go around some corners, then NO, they might help a little for twisting of the body, but it won't be much. What trans, and just some general info on your needs and wants will be helpful.

[carnutt71 10]

I'm wanting a driver, but i want to be able to get on it with out tearing up the car. Not looking for a g machine (yet) or 10 sec quarters. It has a turbo charged 347 with a TKO 500. For starts it will just have the stock leaf springs.

[sportsroof69 13]

I ran just subframe connectors on mine for a few years. Now it has a little extra chassis support.

[carnutt71 10]

I'm worried about the shock towers, but I dont think I will be doing wheelies with mine. lol

[sportsroof69 13]

I still have the stock strut tower brace and nothing else in the front of mine.

[69gmachine 15]

If you're planning to drag race I would at least add a main hoop with attach points to the upper seat belt anchors and a couple of braces to the rear. With that much power to the wheels you could tweak the sheet metal at the sail panels, and if you run too fast at the track you risk being kicked out. Of course if you end up crashing it would be much worse than that.

[RPM 1,190]

How much added stiffness does a fastback need for about 600 rwhp?

 

That is a whole lot more power than stock. I like these 2 stiffening items:

 

Shock tower reinforcement kit

http://www.opentrackerracingproducts.com/towerkit/

 

Convertible inner rockers

http://www.streetortrack.com/Installing-convertible-rockers-into-a-65-68-p-14.html

 

This article has some very good info on chassis stiffness.

http://sn65.com/Fire%20&%20Ice%20unibody%20reinforcement.htm

 

A simple stiffening trick is to add a solid plate in the vertical opening behind the rear seat. It adds a ton of torsional strength to the body.

 

Bob

Edited April 8, 2013 by RPM

[mach1jim 10]

wow that is a lot of information some support is better than none I realy like the shock tower supports and crossover

[69_Mustang 26]

U need to do some of that for my chassis! Thanks for the info RPM.

[carnutt71 10]

WOW thats alot more than I had planned, and I just fixed my floors and installed new carpet.:mad: I was planning on sub frame connectors and the cross bars for sale on ebay, dont seem to be enough. I still plan on pulling the motor and fixn engine compartment so the cowl reinforcing is now in plans.

[RPM 1,190]

By no means do I plan on doing all those mods, but thought it was good to know info and a good read. I don't think you can do too much to stiffen these creakey old cars, but it really all depends on your intended use.

 

Bob

[sportsroof69 13]

WOW thats alot more than I had planned, and I just fixed my floors and installed new carpet.:mad: I was planning on sub frame connectors and the cross bars for sale on ebay, dont seem to be enough. I still plan on pulling the motor and fixn engine compartment so the cowl reinforcing is now in plans.

 

Just do the SFCs...especially if it won't be on slicks. Horsepower won't hurt anything without traction.

[cphsonic 11]

Simple subframe connectors can go a long way, especially if you weld them thru floor like this: