Best subframe connectors?
04-27-2010, 08:19 PM
#21
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Yes.
I had 2-point weld-ins on a previous F-body, I didn't notice much improvement at all after installing them. But the 3-point bolt-ons on this car made a noticeable improvement in stiffness though.
With the better bolt-on designs (like SLP and UMI) there is really no need to weld. Some people complain about the bolts coming loose, but the only reason for that is if you don't get them tight enough in the first place. I used a pyramid of washers on each bolt so they wouldn't cave in, then took a 4ft. breaker bar to torque these things down so tight that they are truly formed to the frame. That was 5 years ago, they've never once come loose.
I had 2-point weld-ins on a previous F-body, I didn't notice much improvement at all after installing them. But the 3-point bolt-ons on this car made a noticeable improvement in stiffness though.
With the better bolt-on designs (like SLP and UMI) there is really no need to weld. Some people complain about the bolts coming loose, but the only reason for that is if you don't get them tight enough in the first place. I used a pyramid of washers on each bolt so they wouldn't cave in, then took a 4ft. breaker bar to torque these things down so tight that they are truly formed to the frame. That was 5 years ago, they've never once come loose.
04-27-2010, 08:56 PM
#22
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I have a nearly BONE STOCK car (check sig below) It's 99.99% of useage is on the street. Do I hammer it every now and then on the street, yes. I took the car to the track ONCE. Never did a crazy launch or anything of that nature...a few weeks later after a few more cruises and the occasional "spirited drive" that I wouldn't even remotely consider beating on the car, I notice I had torque dimples developing on my quarter panel.
I know that this wasn't done by anyone or anything else for that matter because I detail the car on a daily basis and it never gets left alone in a parking lot and things like that. So would SFC's have helped me in this instance? I'd definately say yes. Especially as the mileage increases and things start to get looser and looser.
I know that this wasn't done by anyone or anything else for that matter because I detail the car on a daily basis and it never gets left alone in a parking lot and things like that. So would SFC's have helped me in this instance? I'd definately say yes. Especially as the mileage increases and things start to get looser and looser.
04-27-2010, 10:35 PM
#25
I looked at a few when I first started modding my car and was never really inrerested in bolt on ones. I looked at UMI and BMR and wasn't that thrilled with them either. I saw a few cars around here with J&M 3 point diamond subframe connectors and liked their design a lot better. They really hug the floor pan. Clear everything on my car (read someone on tech not being able to get their tranny out since they welded their connectors in) You cannot see them if you lay on the ground. They don't even go as low as the pinch welds on the car. Unfortunately I have no pics of them on my car. Just pieces of them in the pics since I was focusing on the bigger items 
http://www.hotpart.com/shop/index.ph...ct_detail&p=56
http://www.hotpart.com/shop/index.ph...ct_detail&p=56
04-28-2010, 10:02 AM
#26
Yes.
I had 2-point weld-ins on a previous F-body, I didn't notice much improvement at all after installing them. But the 3-point bolt-ons on this car made a noticeable improvement in stiffness though.
With the better bolt-on designs (like SLP and UMI) there is really no need to weld. Some people complain about the bolts coming loose, but the only reason for that is if you don't get them tight enough in the first place. I used a pyramid of washers on each bolt so they wouldn't cave in, then took a 4ft. breaker bar to torque these things down so tight that they are truly formed to the frame. That was 5 years ago, they've never once come loose.
I had 2-point weld-ins on a previous F-body, I didn't notice much improvement at all after installing them. But the 3-point bolt-ons on this car made a noticeable improvement in stiffness though.
With the better bolt-on designs (like SLP and UMI) there is really no need to weld. Some people complain about the bolts coming loose, but the only reason for that is if you don't get them tight enough in the first place. I used a pyramid of washers on each bolt so they wouldn't cave in, then took a 4ft. breaker bar to torque these things down so tight that they are truly formed to the frame. That was 5 years ago, they've never once come loose.
04-28-2010, 10:03 AM
#27
Yeah man, the earlier you do it, the better it is for the car down the road in my honest opinion. It can't hurt anything at all having the 3 pointers bolted in.
04-28-2010, 10:45 AM
#28
We have probably run more boxed BMR subframes than any of them. However, we have installed everyone's and as long as you go with a good brand name you can't go wrong. SFC's are a good way to prevent annoying squeaks and rattles as well as prevent a lot of body flex. We definitely recommend them as one of your first mods to these cars!
Jon
Jon
04-28-2010, 10:46 AM
#29
i like them welded on personally. i have bmr's convertible subframe connectors which are welded along 3 spots on each side of the car, but do not connect to each other like the 3 point ones do. if i didn't have a convertible, for a less invasive approach which should be fine for street use, i'd probably go with a bolt-in 3 point.
04-28-2010, 11:33 AM
#30
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This is what I'm gonna go with even tho the car is a street car. UMI 3 point bolt in. It can't hurt. Did you ever go underneath the car after you installed the bolt ins to see how everything fit? It always concerned me as to weather or not the areas of the SFC's that meet the under carriage of the car (where you would bolt them in) will cause scratching+corrosion over time due to the metal vs. metal friction going on there.....
As tight as these things are, I'm sure there is no movement.
04-28-2010, 11:40 AM
#31
Good to know, thank you. My car doesn't see any foul weather either so I'm guessing its gonna be OK.
04-30-2010, 07:36 PM
#33
I have SLP Bolt-On's on my Firebird.
I'm completely satisfied with them, but if I were to do it over again, I'd go with the UMI 3 Point Bolt-On. They're priced less than SLP's and tuck up under the car a little tighter. Looks like they'd be nearly unnoticeable.
I'm completely satisfied with them, but if I were to do it over again, I'd go with the UMI 3 Point Bolt-On. They're priced less than SLP's and tuck up under the car a little tighter. Looks like they'd be nearly unnoticeable.
01-08-2013, 06:48 AM
#36
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I know im digging up a old thread but no need to start a new one, im thinking about the umi 3pt bolt in. Question is what are the differences between the bolt in weld in? Im thinking about buying the bolt in and running a few small welds on the connectors for added security. Anybody see anything wrong with doing that?
01-08-2013, 08:45 AM
#37
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01-17-2013, 02:53 PM
#40
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the best kind are the ones you have ON YOUR CAR...
Had a perfect dash before the big motor, didn't have any SFC and ouch... busted dash. Not even looking for torque dimples...
