I mentioned this in my LS3 swap post but I thought I should write a review here as well.

I decided to install subframe connectors in my 92 RS to stiffen the body up to handle the power of the new LS3 motor. I decided to go with the DSE subframe connectors being that DSE has an excellent reputation for quality.

The install was pretty intensive and it did require a lot of cutting into the floor pans. I mean a lot. I also had to relocate the wiring harness that goes to the fuel pump, headlights, and trunk from the sides and have it run down the console. The subframe connectors will not give you enough room to safely run wires down the side like the factory did.

The frame is much much stiffer now. I mean it practically feels like a battle tank its so solid. The squeaking that seems to be chronic with third gens has completely gone away. The connectors also make an excellent jacking spot. Its a million times easier then trying to jack it up from the k member or A-arms. They also make a really good spot to rest the car on jack stands. They also replace the factory seatbelt bracket and give you a bracket to easily install a racing harness.

The only thing I didn't like about the connectors was price. I'm not going to beat around the bush, they are much more expensive then the Spohn ones. The install is also very intrusive. I am not very good at fabricating or body work so I had to have a body shop install them. Not exactly the cheapest project. But still very much worth it.

I also had a roll bar installed. Just a simple 4 point one from Jegs. I didn't want anything tubes that went toward the front like most roll cages because I didn't want to loose the leg room.

 

Thanks for posting this tomtom89. I don't venture into the LS conversion area.

And thanks for the honest review. The Mopar guys have been reinforcing their unibody cars with connectors like this for many years, and they ARE intrusive to install. But they are also believed to be the strongest.

Looks like a nice clean installation. I'm glad you are happy with the results.

 

I bought a set for the DSE sub frame connectors as well. They look like what GM would have installed had they put SFC's on third gens. Anyway, I was concerned about whether or not the carpet will still fit after install. I think the carpet will be too short to cover that little bit of extra height. What do you think? (I called DSE and they were not sure)

 

I still haven't put the carpet back in yet. I'm still working on my LS swap so it might be a while before I get around to putting the carpet in. It does look like it will fit though. I ordered new carpet because the old one was really nasty and fades. The new carpet looks like its bigger than the factory stuff so I think the chances are good that it will fit. If not, I guess I'm going to have to rig up something.

 

tomtom,

Any update on the carpet situation? I'm thinking about buying a set of these as well and am concerned about the carpets.

 

I've got these and I will be installing a full interior back in, so I will try to remember to note about the carpet once I finish. I am working on some rust repair right now, so it will be a few weeks

 

good stuff. Looking at DSE's website, these don't connect to the front frame rails? Would it be worth running bars horizontally from the DSE rails to the front frame rails near the transmission tunnel?

 

Running horizontal bars isn't necessary. The connectors themselves and doubler plates add to the rigidity of the car greatly. The front doubler plates also serve a a torque box to even the load. the crossbars would be overkill and unnecessary weight.

 

I am planning on using these in an 89 convertible. How many hours of welding/install at the shop would you say it took? (ie not counting the carpet removal, etc).

 

Not sure about the hours, but I just had someone install the DSE SFCs, fix/reinforce my panhard bar, and straighten some under body work for $725. This was in a guy's shop at his house and he's a machinist.

 

I finished installing and put the carpet back in. Except for a trim around the seat belt retractor bracket, you wouldn't really even know they are there. I had to get rid of the wire channel on the LH side of the vehicle, but the wires all basically stay where you want them

 

Which cage did you go with? Do you have a part number by chance?

 

Any images of the install from under the car?

I was considering these but am worried about all the plates and boxes with regards to rust. Did you coat everything inside and out? What about between the plates and the body under the car?

My biggest fear is the install looking great and then 5 years down the road, seeing rust creeping out from seams.

 

I haven't coated anything yet, but I did put in some silicone in some places. I'm going to take of possible rust issues after I get it back from the motor and tranny getting installed.




Pax side front. Not the best pic, but I the guy that installed them took more pics of the lanyard bar he repaired for me.

 

Do you have pictures of the routing/fix you had for the wires on the LH side?

 

There's literally no SFC in that picture, lol, it's just a picture of the floor

 

You don't have to do anything but remove the plastic gutter and lay the wire on the floor, once I put the carpet back, you really can't even tell there was anything done since the sill plate somewhat covers that area. The only other thing you need to do is trim the carpet around the seat belt retractor anchor that you have to weld in, and only because the carpet can't stretch. I just had to make one or two slits in it and the carpet laid back down and looks fine

 

Here is a couple of pictures of my install (passenger side). They are a great product albeit they require a lot of cutting. The only area you really need to worry about rust is at the ends. I don't have any rust but my issue was a badly bent pinch weld. It is imperative that you do all you can to straighten the pinch weld.

 

Actually, with these you have to worry about the SFC under the cat hump on the floor, between that and the pinch rail since you really cant weld in that area, stuff will go behind the SFC from underneath. When I was painting stuff I went crazy with the epoxy in that area to try and make sure all that had something on the bare metal.

 

Realized that after I posted it....

 

nice to see more and more aftermarket parts still... I did my car when it was brand new..
back in 92 with a SSM set up.and a 6 point bar...to this day..the doors close with a finger tip. and the car is rock solid...
with todays aftermarket things are getting better and better.

back 25 years ago after payn $750 for the install of the SSM set up (a lot of welding)...use POR15 and its good forever!

 

Is there a reason to go with the DSE pieces, given that every other SFC out there also performs well, and doesn't require all this custom work?

 

No, provided they are stitch welded. Many do not do this. I had my GW SFC's stitch welded, then even filled-in in between with seam sealer. I think this is critical to effectiveness.
The DSE's force you to do that and the cache' value of the name.

 

its like any part ya can buy..some are better then others...some take a bit more to install. but do a better job...and in the long run..ya get what ya pay for..

 

I think the answer to that will always be open to debate. These could be considered better than the competitors if they are thicker or the same thickness but longer in an X/Y direction. The UMI subframe connectors I have are 3/16" thick.

Much of the DSE connector strength is going to come from them being fully welded along the sides to the floorpan/substructure. If you fully weld the UMIs and boxed in the front better I don't think there would be enough to warrant the cost discrepancy. I think these connectors are going to be more for the guy who has a 500+ hp street car that doesn't want a 6 point or cage but they still want to make it as stiff as possible with parts like this. The LS swaps using the Holley transmission Crossmember are becoming popular and that crossmember makes it more difficult to use off the shelf inner SFC so using these may be an answer for that but then again if you can install these connectors yourself or pay someone else then making a set of inner SFC work with the Holley mount work shouldn't be an issue. It's all subjective.

 

those answers make sense. My UMI's have served me well for many years, and the stiffness is night and day. Install was easy. I just wondered if there was an advantage here. Certainly not something I'm gonna do.

 

My car had rust along part of the area the DSE SFCs went into, so it was a no brainer for me to completely eliminate some of the cancer out of the floor. I do like them over all the other designs though, you cannot see them from the side of the car any they tank very little room, there is little chance of them interfering with the exhaust on the RH side

 

For one, I think the DS SFC are great. Looking at the engineering behind it, I like them a lot. My car also had a lot of rust in that general area anyways so putting them in would be no big deal for me.

Issue is I didn't know about these when I bought my BMR outter box SFC that I still have new in my garage.

I think I will simply use them and weld tabs to the pinch rail every few inches or so. Then maybe add some cross bars to the inner sub frames further back.

That all being said, I am selling most just about all the parts I have on my car that DS makes so I can swap in the DS components. Their stuff looks very well thought out.

 

Glad this was brought up, wasn't aware of these as an option. I had been looking close at the UMI's myself. My goal is to remain as stock as possible, so subframe connectors scare the hell out of me, but would love to have them on. It looks to me the advantage of these are you can hide them away better than the UMI's, at the expense of tearing into (my case) a rust free car. Thats a pretty big trade-off, not sure if I could bring my self to do all this cutting on the car. My driveway is pretty steep at the end, so its hard for me to get the car out, these would help, as it would seem they have more clearance. Or I could just fix the driveway!

Here is their install manual in case your interested:

http://www.detroitspeed.com/images/i...connectors.pdf

 

Has anyone used the DSE SFCs with the stock style dual cats? Seems they might interfere.

 

I went for the DSE connectors because to the untrained eye, you cannot see them. Having a rust free car only helps with the install. My car too was rust free but these seem almost factory once installed. The only give away is the welds that will be hidden under the carpet. The benefits outweigh the negatives with these IMHO.

 

Thank you for your input! Our goal at Detroit Speed, Inc. is to make modifications with our products appear factory.

 

And so do they work with the stock style dual cats?

 

We have not fitted a car with stock dual cats with our subframe connectors, but we did measure how far in board they are located. The SFC sits flush with the bottom of the pinch flange and will protrude in 1.5".

 

The DSE Installation PDF gives you all of the pictures you should need.

http://www.detroitspeed.com/images/i...connectors.pdf

I would be interested in the dual cat question too as I plan on adding the dual cats setup to my car. Thanks!

 

Just from looking at photos, I'd put the clearance between the rocker flange and the stock dual cat pipes around an inch, maybe 2" maximum. I'm thinking it's probably a no-go.

 

I can't give a definitive answer on the N10 exhaust, but I used a Magnaflow Y pipe on my LSx conversion and I put the DSE SFCs in the car. Since it isn't exact with the LS in the car instead of a SBC, I can only say I think it would be very close to the SFC. I should have put the SFCs in first, then did the fab on the Y pipe as mine kind of rattles on the SFC. I need to pull it out and give it a little clearance with a BFH right where it bends to go to the cat. I tried massaging with a big bar, but it didn't give me enough clearance.

 

So since you've owned some parimeter style (the spohn's, I'm assuming that they were welded to the pinch seams?) and these, how does the body stiffness compare?

These seem like they could be a trick deal for someone putting a cage or a 6pt in since it looks like it would be fairly easy to tie that into these connectors making for one big rigid 3d structure.

You're in MD somewhere? I'm in Laurel.

 

I've just started my subframe connector and ran into quite a learning curve. I have always Tig welded so naturally I thought I would tig weld these in. What I didn't know is that theirs gens (at least my 88 gta) is made of electro galvanized steel. Now what happens when you tig weld this it melts the zinc in the plating and it explodes! Leaving little holes everywhere. After fighting holes for a day and discovered you can't really tig weld electro galvanized steel. You see in there video that they mig weld and use a stitch weld to keep the heat down. I thought originally that this was to keep the metal from warping but I think it keeps the heat affected area down so the zinc doesn't pop on them. So I bought a mig welder and a different weld gas bottle and I'll start back on it this weekend unless work decide I have to change an engine on a 737.

I ground down my welds because they looked aweful you can see the holes caused by the zinc also note they are away from my weld joint.

 

Some days it just doesnt pay to try to be fancy.

The zinc treatment goes a ways up from the bottom. GM was thinking ahead, which is part of why if you see a thirdgen with rust, it's usually really bad just under the surface.

 

Ah c'mon, CFM's practically bolt themselves on

 

I had ground down into the metal a bit trying to get rid of the zinc but at this pinch weld you can't remove the zinc from the inside layers.

 

Whats next POR15..? that's what I did mine in..

 

Next is the quadralink rear suspension then a 10 point rollcagethen por15 on the bottom topcoated with por15 bed liner then I'm going to repaint the engine bay. Oh and I'll be putting in racing seats as soon as I can pick one out.

 

This is true. And even easier on a A320.

 

Yuck a SCAREBUS!!! LOL

 

LOL, Yeah I refer to them as 'Airbusted', but I actually have grown quite found of them.

 

I’m surprised you guys are havin that good of luck with por15 on clean material. I had descent luck on stuff that was rough, or had mild scale surface rust. But on clean metal it seemed to not stick very well and kind of just flake off after a while. On clean stuff I had much better luck with a good bare metal primer and some chassis black. The poor worked pretty good on suspension stuff that had maybe some surface rust, or floors pans that were crusty, but not rotted through.just my

 

I used Chassis Saver paint on a mower deck I was rebuilding. It's just a less expensive version of POR-15. I had sandblasted the deck itself and pretty much had bare metal. I used a metal conditioner (for painting purposes) to make sure the surface was clean, and used a foam brush to apply a couple coats. Six years later, that stuff is still on there, and simply will NOT come off with anything short of a grinder. I tried sandblasting some that was in the wrong spot, and it didn't even touch it. Keep in mind, I used this stuff on the underside of the deck, where it gets a serious amount of abuse...... Used it in the belt well also, just to keep it from rusting.

 

POR15 needs to go over a rough texture for mechanical tooth. It won't stick to clean shiny steel. That's why they sell a 'metal prep' etching solution, and suggest painting right over the rust. The rust provides the tooth. Sandblasting again gives it mechanical tooth. If you want something you can spray on clean steel that will stick look at epoxy.

Learned the above the hard way. Cleaned up rust as much as possible, applied POR15 to shiny metal with the occasional pit, the stuff peeled off everywhere that wasn't pitted. I ended up sanding most of it off, or spraying it off with the garden hose and a nozzle. It worked great on my pitted to oblivion battery tray. Expect it'd work great on a crusty 10-bolt housing, or an old rusty frame, suspension members that are heavily rusted, floor pans that should be cut out and thrown away, you know, stuff that looks like the pictures on the can, not new or shiny steel.