Been toying around with the idea of getting some subframe connectors for the RS......anyone else done this and if so, what brand did you get and how do you like them? Do they make a huge difference in improving drivablity?

I know when I installed them on my SS, they did made a difference.

Thanks for your input.

 

I installed two sets on my 'vert

Sphons on the outside, and alstons on the inside

I was told my 'vert rode like a hardtop

before that, it rode like a wet sponge being wrung out after washing the dishes..... blah

-jason

 

I have Alstons as well. Got them from top down solutions.com.
They took half the rattles away. I'm looking at getting a second set (UMI's) for when I have a real motor in the car.

 

You got a pic of that? Sounds cool.

 

Nope, no pics of the two sets installed...... was trying to get it done in a hurry

Beleive me, the spohn pieces fit a lot better than the alstons.

-jason

 

I've got the Alson Racing set on my convertible. I haven't needed a second set because it still has a stock motor in it. Probably next year when I finish my LSX swap, I'll put a second set on.

 

Thanks guys. I had not heard of the Alston's before and I think I like them better than the Spohn, since they have a bolt in option vs. welding.

 

Uhh...there's no point in putting subframe connectors on your car unless you're going to weld them in. Over time, the flexing of the chassis will only open the bolt holes and stretch them out. It won't do any good long term to bolt them in. Welding is the only way to go.

 

OK I'm confused. I thought most SFC's don't fit 'verts 'cuz of the riveted channel under the rockers. How do you get 2 sets on there?

 

I've had bolt on SFC's on my SS for years now with no issues at all. I only put like 700 miles a year on my cars, so I doubt I would have any issues with bolts stretching. Plus, I'm trying to keep the car all stock, so if I weld them in, I can't exactly take them out like I can with the bolt in ones.

 

Until my 84 was wrecked last year, I had the original type Competition SubFrame bolt in connectors. I did change the metal going from the sills to the center with flat 3/8 steel plate. I found them great and no signs of holes opening up or any other problem. To me, they were the strongest on the market. Now that I have a 91 TAm convertible, they would not work with this car. I now have Alistons and am thinking of adding the Sphons to it also. I would like to see some pics of both on a convertible. My 2cents worth.

 

A bolted connection is going to allow movement no matter what you do. Its just a question of how much. If you go ahead and weld it on after bolting it in place, that will work just fine.

 

Alston SFCs are available from Top Down Solutions. Look at the pics and you'll see how they work

http://www.top-downsolutions.com/pro...products_id=90

Spohn has a set specifically made to work with the 'vert chassis.

http://www.spohn.net/shop/1982-1992-...ible-Cars.html

Both websites have pictures of the parts installed. Take a look and you'll see how they can work together

-jason

 

No offense, but driving the car 700 per year is not going to give you a good idea of how bad the holes will stretch. Especially when I'm betting those aren't 700 hard-driven miles.

 

Exactly, which is why I see no problems with just bolt in SFC. My cars are not tracked or driven very hard.

 

Then in response to that, I would say it was pointless for you to waste the money on the subframe connectors in the first place. Again, no offense.

 

I could definitely tell a difference in the steering and drivablitiy of the SS when I installed the SFC's....if nothing else, installing them on the RS would do the same and reduce rattles and such.

 

The ones on my 84 were on there 5 years and it really handled well and they didnt come loose or wear the holes. I checked them often. If you wanted, you could tach weld them in place. I had no choice with the 91 convertible. They were only offered in the weld in type.

 

Hey Guys,
I have been reading up on the SFC's and get the impression that Alston is preferred on the verts.

My question is about any experience anyone has with the UMI ones.

The reason I ask is because the coupe guys have good things to say about them and I was looking at getting a set for my T-Top IROC....then while reading I noticed the UMI site say it now fits Verts also.

My question is whether I should get 2 sets of the UMI, one for for my T-Top and one for the 92 vert with the upcoming Group Purchase.....or is the Alston drastically better for my vert.

I have also heard about some guys putting 2 sets on the vert, but can't find any examples....if the UMI and Alston can both fit without mods, then my decision will be easier....because i can always buy the other set later on if it isn't stiff enough.

Any opinions? Experience with UMI on Verts?

 

I am planning on getting the umi ones in the GP as well. I already have the alston ones. By the way they mount you can use either or both. The Alston ones mount to the subframes and the umi ones mount to the rear lca mount and go along the rocker.
I would just get 2 in the group purchase than if you need more get the alstons later.

 

Thanks WillSpeedy!
That is exactly the feedback I was looking for. I am glad to hear that they will both fit......now I don't thave to worry about buying the "Wrong" one for my application.

You guys are awesome!

 

When they say the UMI fit along the rockers, do they mean just to the inside of the boxed in section that runs along the rocker? Mine is a 91 Trans Am Convertible and it comes with the boxed in section unlike the earlier convertible models.

 

I am not trying to hi-jack this thread but I just installed the Alston subframe connector and the TDS wonderbar. I got both parts from Lon at TDS. Great service and great parts by the way!! I could tell immediatley that the car was riding a lot better, steering was stiff and car stopped most of its creaking. My question is this... At normal speed local and highway the car ride was almost like a new car, but when I got up to 80 or better the car started shaking like crazy. It started in the rear and moved to the front of the car. I could feel it in the seat and then it slowly moved up and I could then see it and feel it in the steering wheel. I put new tires on last season and everything was balanced. Pror to the SFC and wonderbar install I never felt this vibration. Has anyone else experienced this? Thank you all for any help....

Tim

 

To do that, did you Remove your Factory Frame Reinforcement?

Any Chance you could send me pics of your setup?

Thanks,
Fred

 

I thought about removing the factory stuff but I dont think I am game to remove those large rivets not knowing what I would run into. I think the original Competion Engineering would be the best on the market but I think I will be content to add Spohn to the outside now that I have Alistons on the inside.

 

WHAT!!!!!

SFCs should be the 1st "mod" to any 3rd gen. SFCs are never a "waste of money"

 

Nope, nothing had to be moved or changed.

Really can't take pics of the SFC's. The car is already lowered, and I don't have access to a lift.

Is it really that hard to visualize???

-jason

 

ok just for the record, I personally do not like any thing they have to offer comercially, I have made a living as a sheat metal fabricator / R & D mechanic. and the things I see I am sure work well, but I think they are built a little light for my taste. I will build my own SFC's and tie them to the outer brace that the convertable's have, using what is called Bridging, Lader bars are built on this design. I am not trying to start a Sh!^ fight just my 2 pennys worth. it will be about 40# heaver but after all, I am not going to be after the land speed record. just a real nice ride. if you would like to see one of my projects look at the Willie's pick up I extended for a friend, here http://www.flickr.com/photos/tinbender59/sets/

 

So you have the Spohn up next to the Factory SFC, and the Alston ones inboard of them? I guess why it is hard to picture is that, I have not been able to find a picture of what the Alston ones look like when they are Installed.

 

Here, I found pics in the suspension forum for everyone

https://www.thirdgen.org/forums/atta...-sfcs-sfc1.jpg

https://www.thirdgen.org/forums/atta...-sfcs-sfc2.jpg

https://www.thirdgen.org/forums/atta...s-undercar.jpg

https://www.thirdgen.org/forums/atta...gep9290028.jpg

https://www.thirdgen.org/forums/atta...re-alstons.jpg


https://www.thirdgen.org/forums/atta...e-subframe.jpg

https://www.thirdgen.org/forums/atta...subframe-2.jpg


https://www.thirdgen.org/forums/susp...sub-frame.html

https://www.thirdgen.org/forums/atta...s-dcp_0020.jpg

https://www.thirdgen.org/forums/atta...riverside1.jpg

https://www.thirdgen.org/forums/atta...-passside8.jpg




-jason

 

Wow, that's some old pictures of my car.

EDIT: The 1st three pics, I just chandged his tags to IMG tags

 

Those pics from the suspension forum are pictured of a car without the side reinforcing. They wouldnt be from a 91 Trans am convertible because I have one and it has that "weak" side box made from sheet metal. I plan on Sphon or something like it in addition to the Alistons that I already have. I think the sill supports are much better.

 

I thought the point of the pics were to show the Alston SFCs installed in general, not a 91 Trans Am vert.

It doesn't really matter what 3rd gen f body they are in, they install the same on all of em.

I'll tell you what though, the car turned into a totally different car after the install. I know from 1st hand experience that they work.

 

will the alstons or any SFC fit with 3in exhaust piping?

 

Like I said earlier, the 84 Z28 I had before was a ttop car. The competition engineering after I made a slight change was really great. I change the metal piece that runs from the sills to the center member to a flat piece of steel to eliminate ground clearance problems. Mine changed from a two inch piece of metal to a 3/8 piece of metal from the sills to the center member. I had no ground clearance problem at all. I now with a 91 Trans Am Convertible with Aliston connectors plan to add a Spohn connector or something that I make up to add to it. I know what I want and I will get to that point. To me, Camaro or Firebird should not have put that box on the sills but should have put something much more structural instead. Fight with me if you will, but this really is a convertible forum and should be aimed at convertibles and not the "Run of the mills" GM product. Any opinions?

 

Ok, since I took the time to *search* for the pictures, I'll tackle your statement

Most people posting didn't know where the alstons mounted to the car. The alstons mount the same way, no matter if its a coupe or 'vert.

The spohns mount similarily, sans welding them to the pinch weld. There are people who couldn't visualize that.

With the perimeter style SFC's, the only style I'm aware of that will clear the factory boxes are Spohns. Of course, I haven't been researching if anyone is offering 'vert specific SFC's either.

So while those pics are not of 'verts, they are still relavent as they give a visual to how the Alstons mount/install. I will try to get my 'vert up on a set of ramps, rearend on jackstands and take a picture or two of both sets installed to make this 'vert specific' if that is what is required

-jason

 

There is not much different under the car from a convertible to a hardtop/t-top, making a big deal about the factory SFC's not being in pictures (that you would likely not see or wouldnt matter) is silly if you ask me. In fact of all the pictures and recommendations for SFC's posted above, only one of them (dont know what those are, Jegs? They look similar to the discontinued SSM's) shows SFC's that would not fit a convertible.

This picture (which is a nice shot of the entire "frame" anyway)
https://www.thirdgen.org/forums/atta...gep9290028.jpg

 

Whelp, here are the pics I snapped of mine today to appease the 'vert specific questions

http://s292.photobucket.com/albums/m...z28/Vert/SFCs/

FWIW, thats a 3" exhaust, no cat obviously....

-jason

 

Aftering looking at the install pictures of the three different SFC's (UMI, Spohn & Alstons). It looks like only the Spohns and Alstons will be able to used together just because of how the Alstons and UMI both weld to the subframe. Structurally the UMI's look stronger then the Spohns but I like how the Spohns are welded along the rails. Would the rivets still have to be shaved off for either set?

Jay

 

Thanks for the Pics that helps a ton.

 

Please disregard my last post... After looking at the pics again I can see that you will be able to use the alstons with both the umi's and spohns.

Jay

 

I have a 91 Z28 vert and was going to have a shop install the Spohn SFCs. They told me the job with all the spot welds required pulling up all the interior seats and carpet (to prevent fire) and removing a fair amount of the undercoating. With the factory boxed in rocker supports he didn't see that much benefit for the cost of the work it would take to install these. He quoted me around $1000 in labor. Ouch!


I had SFCs install on my '92 Z28 ttop by another shop for less than $400.


Is the vert install really that bad and costly?

 

No, he just didn't want to do the work.