subframe connectors - when?

-

Abodysrule

FABO Gold Member
FABO Gold Member
Joined
Jan 30, 2018
Messages
416
Reaction score
141
Location
California
I'm planning a swap of my slant 6 to a 360 magnum. They weigh about the same, 440 pounds give or take, but what about the weight distribution? Should I install my frame connectors before or after the engine swap, or does it make no difference?
 
Won't make a difference as far as adding subframe connectors.

Depending on the weight gain/loss it may move your CG a little bit, but unless it's a lot of weight you're not likely to notice the difference. The suspension set up might change if you're doing any kind of AutoX/Road racing, but again how big a difference that makes would be up to how big the weight change is.
 
If the engines weigh about the same, it shouldn't change the weight distribution much, if any, either. But the overall weight and distribution will start changing if you start upgrading the rest of the car to be more compatible with the V-8 - brakes, 904-727, bigger radiator, etc. Check the rest of the front & rear suspension parts for wear while you're at it

"When" you install the frame connectors shouldn't matter much, but "after" would be better. It's most important to keep the chassis and suspension level and properly "loaded" during installation. Welding them to or through the floor wherever possible will increase their effectiveness. If adding a roll bar too, it should be tied into the frame connectors, usually around the main hoop.

Welding along body panel seams is also helpful in stiffening the overall structure instead of relying on factory spot welds.
 
If the engines weigh about the same, it shouldn't change the weight distribution much, if any, either. But the overall weight and distribution will start changing if you start upgrading the rest of the car to be more compatible with the V-8 - brakes, 904-727, bigger radiator, etc. Check the rest of the front & rear suspension parts for wear while you're at it

"When" you install the frame connectors shouldn't matter much, but "after" would be better. It's most important to keep the chassis and suspension level and properly "loaded" during installation. Welding them to or through the floor wherever possible will increase their effectiveness. If adding a roll bar too, it should be tied into the frame connectors, usually around the main hoop.

Welding along body panel seams is also helpful in stiffening the overall structure instead of relying on factory spot welds.
Thank you, great feedback. Yes, I'm familiar with the proper technique for installing the frame connectors. Also, I built the suspension for a V8 from the start, i.e., heavier torsion bars, 8 3/4 rearend, heavier leafs, front and rear swaybars, gusseted K frame, 15" rims, front power disk brakes, larger rear drums.

I was more thinking about the lateral weight distribution of the two engines, the slant vs a v8, is the slant due to its slant weighted more heavily on the passenger side? I may have to adjust the T-bars after the swap, for sure, but I was wondering if the slant's lateral weight distribution would throw off my suspension vs what appears to be a more laterally balanced weight distribution of a V8. Given I don't know, I agree with you, probably best to install the v8, get the suspension where I want it, then install the frame connectors - better safe than sorry.
 
I think guys get a little too worked up about the frame connector install thing. It's not like they make the chassis a rigid unit. They're a single part of a complex system. Yes, they do add some torsional rigidity, but there's still flex there.

I honestly think you'd have to TRY to put a twist in the chassis with the frame connectors in order to actually do it. Like you'd have to put one wheel in the air with all the others on the ground and then weld in the connectors. I've seen the US Cartool subframes installed while the bare chassis was on a rotisserie on multiple builds, with the chassis upside down or even sideways. Cars always went back together and I've never seen a thread about someone that couldn't get their car aligned right after a subframe connector install.

I'm not saying it can't happen, but I don't think it's as big of an issue as it's made out to be. Best practice is to level the car and make sure everything opens and closes before your start, that's how I did mine. But yeah, I think the margin for error is bigger than most make it out to be.
 
Last edited:
Go for them, if nothing else it will improve the handling
I posted a thread asking at what hp frame connectors were advised
The general consensus was 400 plus hp
 
-
Back
Top