What do you think are the most functional bolt in (with minimal welding) sub frame connectors? I know the ones you burn into the floor are best however the underside of my car is already painted and fully assembled. Cuda with 528" Hemi, Tremic TKO 600, AlterK, XV cowl and rad support, modern 17" & 18" rubber.
Thanks!

With that much torque potential I would get 2 X 3 connectors welded in and touch up the paint underneath. Do it right and enjoy the power worry free. Just my

Yep 74, I know but I hate to tear into it and most likely won't be on the track a lot. I would certainly go that route had the bottom not already been so nice

Initially, I bought the MOPAR Performance Bolt-In subframe connectors. Seems to me I still needed to modify (cut and re weld) them to get them to fit, and I welded them in place. They were sort of flimsy in my opinion, so when I welded in the Roll Bars, I removed the MP connectors and welded in 2x3 straight rectangular tubing, notched the floor pan and fully welded connectors to floor pan. Repainted everything when completed. A whole lot stiffer, removed the body flex.

You think I am expecting too much for a simple weld and bolt in system like Hotchkis?

Yup...........

Welding and paint touch up is a small price to pay. Especially with 18 inch sticky rubber that can be mounted on those rims if you so chose. I'm making my own frame connectors that I am welding to the floor, and from my own research there is no better option if you want the best result.

Best of luck to whatever you choose to do.

Mark

I have a set of theUS Cartools that are to be welded to the floor already sitting in a box but was rethinking the labor and repaint costs vs performance gain. I know it is a better way to go but was hoping you guys with experience would say the bolt ins were pretty ok

Fit the connectors to the floor with no gaps then weld plates(maybe four) at the top of the U with a nut welded in. Then bolt to floor with plates like the seat reinforcements, these will tie the floor to the connectors since the floor is a structural member of the car. Won't be as good as welding but...
Then you only have eight 3/8" holes in the floor.

I have the bolt in connectors from Magnum Force Racing out of San Jose Ca. They are a tubular design and have worked well on my gtx with 700 hp hemi and 4spd setup. Prior to the install the top of my quarter panels, both sides above the door jams were cracking due to body flex. I had it repaired and installed the connectors and have put over 15,000 miles on them with no issues, they work! I did weld mine in but my buddy bolted his set on his 500 Hp challenger with the same results. Do a web search and you will find the website and bet they would cover your needs. if my regular home pc was not on the fritz i would post a couple of pictures.

Not a bad idea Cudaman?!

Regardless a major design limitation is this frame connector has portions where the vertical Height (ie stiffness) is very short. Little can overcome that shortcoming. Adding tabs as suggested is an interesting solution, but IMo if that effort is made, I don't see why the entire U shape connector is not just boxed in, and use as many thru bolts as desired, IMO a lot of 1/4" grade 8's would be a better solution then say 3 3/8" when connecting to the floor sheet metal.

Gotta say I'm cringing at the thought of rows of bolts across the floor. I'd weld it in an instant over the floor-bolting approach.

If a row of bolts must be used I would have a strip ox 1/8" X 3/4" strap drilled and weld studs in so when carpet is installed it wouldn't leave a row of bumps and would give better support to the floor overall. The best way to do that would be to drill each end to hold the strip and then drill from the bottom all the other holes to make sure everything lined up.

That's My