i have a 91 firebird 305 i want to make a set of subframe connectors does anyone have any plans for some? my car has the single cat but wider pipes all the way down.

 

you don't have to work for NASA to make SFCs. get under your car and take a look.

 

I'd be intrested in hearing stories about anyone making their homemade SFC's.

 

i made mine, not much to tell

 

Does anyone have pictures of their home made SFC's? I'm thinking about making a pair for my camaro and a friends FB.

 

Like Ede said it really isn't that hard. I finished mine about a week ago. They tightened up the car alot . they are almost invisible from the side of the car and they don't rub on anything. They cost me about 50 dollars to build. ( I have a welder,torch, and a chop saw)
Hope this inspires you to lay under your car with a tape measure. they really are eaisy to make.
Kory

 

I'm making mine next week on my days off.
Just go under your car and take a few measurements.
I'm going to weld in two lengths of square tubing connecting each end to the subframes, front and back.

nothin fancy..

 

i am also set to go with welder, chop saw,and needed tools ...i have looked for some good pic's and only found maybe two that were hard to make out ....to just take a look under your car and guess at it is not very helpful info!i've seen on on a vett that it used an X type SFC is that whats needed on these for "twist effect"???or is it just front to back and find the best/ strongest place to weld plates and square tubing?

 

Every car is different, If you don't know what to look for when your under your car, maybe you should get someone to watch over your shoulder when your welding

Go under your car, find your subframes on the front and on the back. measure how far apart they are, measure how much clearance you need to clear your exhaust or any thing else that might get in the way. Cut/bend/weld accordingly.

The typical SFC is just a straight length of square tubing that runs parallel with the car body connecting to each subframe (hence "subframe connector")
you do NOT want to weld to your floorboards. just weld to your subframes.

You can try doing an X design, but that's more material which=more weight. if youstill want that or something fancy like that. you best design them so that everything is still removable, like your trans, driveshaft, exhaust, diff.

here's a design a member of this board drew out awhile ago.

 

Why do you say not to weld them to your floor boards? Everyone I have heard talk about it including Steve Spohn says that you should for extra strength. If your reasoning is that the floorboards arent that strong to hold them anyway, that in my opinion is a reason why you should. It will help hold your floorboards straight since it is a unibody car and the roof and floorboards act as the frame/support between the subframes.

Ben

 

Here is a pic of what the southside machine subframe connectors look like on a 89 RS.

Ben

 

forgot the pic

 

If and when you decide to weld them to the floor board, don't be lazy like me, take the carpet and deadening material out, I had the ole smoke just a rollin!! It'll be gutted this winter anyway as mines more a strip than street, but if you have somethin nice, get everything outta harms way.

 

thanks for the info thats what i need to know for the most part,momar thanks for the pic ,but thats what i'm talking about you can see the trans great!! but the sub frame NO! .....you just can't see it in the picture it is to dark on the sides even with my screen turned up on full bright.

 

To those of you who have welded your SFC's to your floorboards.
take another look under your car now.
You will no doubt start seeing your floorboards cracking.
Your floorboards are nothing more than sheet metal. welding your SFC's to them even if by some rare chance they don't crack, welding to them will do nothing to strengthen or tighten your chassis.

Floorboards like to flex regardless, if you weld them to something solid like your SFC's they will crack around your welds.
I have experianced this all too often in my work field.

simply welding your SFC's solid to your subframes will be no less stiff/strong if you left your floorboards alone.