Did GM ever produce or have RPO code for factory sub frame connectors? I know the IROC-Z28 have the wonder bar in the front. Reason being a friend of mine insists that his IROC came with factory sub frame connectors. I could and or understand that maybe a dealership would install aftermarket on a t-top car with a 5-speed. But don't see a RPO code for factory sub frame connectors.

No. Probably the closest thing to a subframe connector would be the reinforcements added to the convertibles.

Does anyone have pics they can post showing the convertible reinforcements?

my uncle owns a 89 GTA convertible, I'll ask to see if he has any pics of the undercarrage.

I've seen the undercarrage of it and i have to say it's much more beefy then a typical 3rdgen chassis.

Cool. Never seen the underside of a factory braced convertible. Don't the t-top cars have the same type of bracing?

No the T-top cars may have had a more substantial floor, but beyond that there was nothing significant about the structure. The biggest difference is T-top cars had the door jamb wedges that would stiffen the car, it transferred the load to the door jamb itself rather than the Chassis.

You can see the "factory" SFC's on my car here...

wow, didn't know this topic was off for awhile, time flys after the holidays are over!
well i was searching and searching for a pic of the undercarrage of convertible 3rd gen and finally found a good one, off a ebay pic....so i thought i post it here to show what it looks like for the undercarrage support of a 3rdgen convertible. Also Ofkoz, i haven't ignore you about the information for my uncle's gta convertible. He just hasn't had any time for the past few weeks for me to go down and see it....but i'll keep you inform as soon as i can...

No problem

Looks fairly beefy. But I wonder if it is solid or a U shaped hollow piece of metal.

It's thin sheet metal and it's pop rivited on. Frt quarters are cut to make room.

They are as Twin_Turbo said, they are a hallow. They are a little more hefty than simply sheet metal when we think about sheet metal. They are a little more substantial than run of the mill fender sheet metal, I would think around .080" - 100" thick, I have not measured one however. But they are a bent, or stamped piece for sure. I guess They could be extruded.

I know the sunbird and cavalier used similar subframe connectors, not sure how different they are. I know our cars are shorter for sure because you can take the trim piece from a Cavalier convertible from the same era, cut it to fit my Formula.

John

Here's a good shot of the passenger side:



You can see it's a u-shape, but is formed to follow the floor pan curves. It pretty much covers just the pinch weld and does not tie the sub-frames together.

The UMI pieces make great additions and improvement:




Kevin D.

Yea, the aftermarket subframe connectors look to be far more superior. I hate it when manufacturers want to go the cost cutting, last minute route.

I am not positive, but it would not surprise me if they used basically the same SFCs for most of the cars they converted, from the Rivieras to the F-body, they would trim and modify them to fit.

John

If ASC did the conversions, i'm sure they may have.

Those look nice. It almost makes a framed car out of a thirdgen. How effective are they?