well i finally got around to taking some really good pictures of both sets on..... the difference is unreal.... drives like a different car... no squeaks or rattles at all....i only suffered a tiny bit of ground clearance with the alstons but none at all with the bmr connectors... if you have the money i would suggest the same setup... these cars flex like crazy... i virtually have none... it honestly feel as smooth as my dads friend 2008 cadillac cts....

So do you notice the difference between just BMR vs BMR+Alston SFC's?

theese cars due need as much bracing as possible, originally when i installed my UMI SFCs i just did the basic weld points and left off the optional passenger side brace.

i didn't feel that the main driverside brace really connected a whole lot to the front sub frame. so i added a little piece of scrap steel between the veryfront of the SFC and the pinch weld area, where you would jack the front of the car using the factory mini jack for changing the spare tire. and the difference was very noticible, i ended up having to modify the passenger side brace to clear the exhaust but after that was done, it felt even better


i plan on adding the alston's in the next few months as well,


thanks for getting up thoose pics, it's about time

yes i noticed a huge difference when i first installed the bmr frame connectors... much stiffer although i also have a wonderbar and a strut tower brace... drove around with one set for about a month... the alstons made even a bigger difference... made it alot stiffer...it killed all the squeaks and rattles and "looseness" that the bmr frames didnt.. no more rocking back and fourth movement when going over speed bumps..... cornering feels MUCH better espically at high speeds when your changing lanes...acceleration seems to be alot better because its not twisiting and flexing the body with all the torque i have when i take off.... when i have the windows up i do not hear rattles or squeaks at all just my exhuast.... i have never been able to listen to just the exhuast without having the annoying rattle sounds...... it was stunning how much it done to the car..... i will have my bmr torque arm reloaction bracket, bmr torque arm, bmr panhard rod and bmr lca's late this month... then i will be taking it to rockingham dragway which is about 90 miles from me.. i want to get quarter mile times with my new chassis/suspension mods along with my stout 355 tpi build...... i cant wait.. i will have pictures of all that stuff soon also...

Pictures are big and great. They tuck very closely to the pans. I really can't wait to get my Alston's.

I wish that we would develop connectors like the alston's. When combined with our connectors they tie the entire subframe together.

yes your connectors do look beefier than the alstons... no doubt about that.... but when you add them together they are amazing...

Yeah, the BMR's are quite big compared to the Alston's. Also I am unsure why BMR/UMI/SPOHN haven't made a full undercarriage bracing kit? Since more and more people are doing the Alston with BMR/UMI/SPOHN, I'd see one of these companies finally doing a full undercarriage bracing kit soon. Just wait for it. God those pictures look good. 1 more winter guys...I'll be out.

Maybe it is just my screen, but those pics aren't that big. They are only like 3.5"x4" on my screen...

Anyway, do you have g-force numbers or anything to validate the extra bracing instead of just "it felt better." Sorry if I sound like **** for asking for proof, but someone probably would have brought it up so I figured I might as well do it. Have you ever considered welding in other braces that connect the Alstons and BMR connectors to see if that makes a difference?

I know what you mean about flexing. I can't wait to get my Spohn subframe connectors back on my car!

the pics are huge on my screen... but no i dont have any g-force numbers... i dont race at all... i added them because i got tired of the squeaks and rattles and i wanted the car to feel much more rigid which i achieved that.... but there is a noticeable difference in stiffness when two is added as compared to only having one.. yeah i actually thougth about adding bars to connect the two subframes together but i dont think its really help...

i ordered my alstons on thursday, can't wait to get them on, they're only 20 pounds, i think my UMI SFCs are closer to 60, time to pull the AC out to justify adding more weight....

Guys, I know everyone is saying that you should only weld these on with the cars suspension loaded, but I have mine tore all the way down to the shell and plan on putting it on a rotisserie. It would be so nice and easy to weld these on while on the rotisserie. Just wondering if anyone has actually had problems after doing this.

Care to treat your car as a test subject? It would be interesting to see how it would affect the car. I would think you would be putting A LOT of preload into the chassis which may screw with the handling. However, if you don't mind having to possibly cut them off in the future, you would greatly be helping the TGO community.

Mike

got my MAC SFC's on last night in addition to the UMI SFC's.


wow what a difference, i noticed it before i even drove the car, i had the car lifted in the air and i was dropping it corner by corner, i was lifting/jacking the front passenger side when i realizedd the car was kind of slidding..... the chasis is so stiff that when i was jacking the front right tire, the front left and rear right tires came off the ground just one tire touching, and no sag what so ever. handling is much tighter/responsive, and the ride is incredible, it's so smooth and quiet it didn't even feel like iwas driving the same car

That's really interesting that you both got great results, I always wondered how it would turn out if someone did this.

looks like a sale is over on summit? Which pair should I get, mac's or alstons, and umi is heavy? where did you order from?

i'm really not sure if tyhere is a difference between the mac/ alston, i read som where a few years back that they were the same, you can buy the MAC SFC's n ebay for $144 shipped, the UMI SFC's are very heavy, if i would have known i was going to use dual SFcs i would have probably bought spohns, to save some weight, byunspeed.com is the cheapest for the UMI SFCs and most parts for our cars

thanks, looks good. I was going to ask where to get spohn's, found it a few inches down from here.
The welds on them in the video are beautiful. I've tried welding a few times. Mine looks like old gum scraped off the street and stuck on some metal. I like their bare tube option. going to order those and a wonderbar and mac's or alstons within a few weeks. My t-top car just twists way too much over things and rattles alot. i wouldn't have thought to do two sfc's until the success in this thread.

Anyone tried alstons first alone, then added the BMR's? I wonder if the change would be as drastic.

I'm hearing conflicting opinions, though. From what I've heard, the suspension should be unloaded, as in jack stands on the LCA brackets of the subframe, and under the K-member, but you guys are saying to weld them on with the suspension loaded? I would think the connectors would fair better if the car were unloaded, to elimiate the couple of millimeters of sag that the center of a T-top car might have encountered over the years.

well i dont have a t-top car but the bmr sfcs instruction says to weld them on loaded meaning with all four tires on a lift... they actually say on a lift with all four tires being the best option... they know thier stuff... so i went with what they said....... i really dont think welding them on unloaded is a good idea because once on the ground then suspension will never rest because its being forced to stay that way by the sfcs causing issues....

Well my car is going on a rotisserie and the SFC's are going to be welded on while its on the rotisserie. The doors and fenders will be on the car and gaps aligned. I am probably going to even temporally tack weld the doors shut. As far as the suspension settling, I don't see how the SFC's would have anything to do with the suspension. My car will have to be completely realigned anyway if thats what you mean.

I think the car will ride just as a chair would sit with one leg higher/shorter than the others, giving the chair that rocking back and forth feel from the higher feet to the lower feet.

Adding the SFC's before settling the suspension means it is possible that the front or rear subframe may want to sag a bit more than the other once everything is on, but since they will be connected you will get the chair example I said above, where the front will want to sit one way and the rear another.

Test it out, let us know how it goes. But it does seem it will be a good long time before you get this car on the road so...it will be some time before we can know for sure.

Glad to see that I wasn't the only one that had a few gaps between my alstons and subframe. Now granted my car had been wrecked before and may have slightly tweeked the body but I remember I had trouble getting the "cups" of the connectors to fit snug all on all sides. They still work great though.

i need to find a lift where it stays on the tires also. putting 'em on lifts, you ever notice how always the lift is tweaked, so that one part of the lift hits the liftpoint or frame a few inches before the others make contact?
thats not so bad for just a lift to change oil, but i dont want to weld in frame reinforcments to keep that tweak in my frame. at least if its 'loaded' on the tires, the springs will take some or most of that few inches out of the tweak.
probably on a perfectly level racecar shop floor and jacks it would be less important the loading. though i could imagine gaps would change a little and e.g. the doors may not shut quite the same etc.
going to look more at the bmr, sphon's and hawks since they are sponsors when i purchase. was thinking umi''s first but will try to support sponsors if i can.

Best analogy with the chair example. That's exactly correct.

But after reading all these post- nobody truly gets the problems and how to get a good solution.

1)It does NOT matter if the suspension is loaded or not
2)Watch out what the "so called experts" that manufacturer and sell products tell you- they more often then not have no clue and just reiterate what they too have read.
3) Even a car on a lift is not perfect- Tell me how a lift is going to fix a car already tweaked? ANYBODY EVER THINK OF THIS ONE- I do not care how flat the ground is or how flat you have all your jack stands sitting under the axle and a-arms-
a) what if your chassis is already tweaked and the springs have sagged uneven to compensate and correct a tweaked chassis?
b)You have a blown gas charged shock in one corner, etc. Anything weak can load unanted crossweight into the chassis when loaded and MOST LIKELY DOES.

I am willing to bet 99% of cars with subframes added are tweaked even if welded on a lift. How many of you repeatedly say "my right rear is lower than my left rear...Why? Well, chassis is tweaked. That tweaking could be temorary or it could be perminant...
....so how do we tell?
...what is the real way to set the chassis prior to weleding on SFC's?

ITS ALL ABOUT THE HIEGHT OF THE SUSPENSION MOUNT POINTS! period!

How did I do mine?

I happen to have some trick laser level equipment I have owned for years in construction that I also use in chassis setup- kind of a transit device, a hand held transit laser that is self leveling. Without one? you are pretty much screwed. You would have to do alot of percision grinding or level scaling of the lift you are on for tape references in each corner etc.

I simply jacked up my car in my garage floor- where I already happen to know is level when I put my #'ed jack stand on each square marked on the floor that were laser leveled and shim welded the plateforms of each stand individually- Its what I do for the racecars in the shop today even. I have multiple jack stands each numbered for my old camaro, my Vette, my truck, and the supertrucks I setup(Mason, DerekD, KennyS and a few other here and there.)

Back to the Camaro in MY garage (house I just sold though) I had the jack stands under/near the SUSPENSION MOUNT POINTS of the car. What are these? They are the LCA bolts on the rear of the chassis and the A-arm bolts on the front. I place the jacks right near these bolts (On the front the jack sy=tand set under the rear ear of the A-arm bushing section of the arm itself. I then laser measure each bolt height till I get the two fronts equal height AND the two rears equal height.

Now to start, my chassis was a little tweaked and would not set on all the stands equal. I missed the right rear by about 3/16" where the chasis would rock on the RF and LR suspension points. I then stuck a big jack up under the rear of the car on the left side of the fuel tank (the subframe there) and I jack it up till I got the car of the stands on the rear equal spacing and I let it back down slowly to rst them both touching equal (just touching, no wieght on the rear stands yet. I then measured the distance from the stand framerail to the ground and made a stand that height with steel scrap metal plates under it to get the height. I pulled the floorjack ou and jacke dup the car by the left rear jackstand enough to get the 5th and higher jack stand under the same spot as wher I firsdt had the fllorjack. I then let the car back down on the two fronts and the LR larger stand next to the fueltank ane the car also settled evenly on the other two main rear affixed to the suspension points of the rear LCA's. WaaLaa- The chassis is now squared on the floor stands and not tweaked for SFC installation.

NEXT- How many of you are stitch welding your perimeter SFC's to the outside chassis joint along the span? I assume not many of you because my chassis was this siff with just Spohn round tube SFC's welded in properly. My car was TOO low to be able to install Alsons or Mac SFC's, they would definately scrap. That exhaust I-pipe and cat hanging down under the driveshaft ion the original posters pics would have also scraped on my car. That stuff hangs down low.

If you span weld the SFC's it helps prevent sag of the center chassis when jacked- Its the same principle as shear facing a wall.

Dean

To make a long story short , you want all 4 corners to sit at the same height suspension-wise...correct.

Right now my car sits level left to right just not front to back, which is off by 1/4" (Front is 1/4" lower than rear (27.5" front, 27.75" rear), but both front and rear left to right are equal). So I would want to set it so my front sits at the same height as my rear, correct.

I wish I had a guy like you around when I need to do mine.

I have a 91 Trans Am convertible and have the Alistons on mine. It does make a lot of difference but I would like to add the BMRs to it also. But, the 91-92 Trans ams have that built in boxed section on the sill area that prevents me doing that. I had a 84 Z28 and had the old style Competition Engineering ones on that. They were like the BMRs and made more of a difference. I was actually thinking about removing the boxed sections and using the BMRs but hate to ruin the integrity of the car and dont know what I may get into. I may end up getting Spohns to add to the sill areas.

Nope. You are giving me fender heights, I do not care about them. I want suspension points.

I will draw a picture for you.

4 red small rectangles = jack stands
Green lines = 2 rear A-arm bolts (Front of car) ,and two front LCA bolts (Rear of the car){THESE ARE THE SUSPENSION POINTS}

1 large brighter red rectagule represents an example of where to place a jack stand leveraging the chassis to bend the twist out of it.

Note the LF,RF,LR, & RR = left front, right front, etc.

The LF and RF jack stands need to be LEVEL (NOTE: Not off the ground level, they need to be plumb level.)

The LR and RR jack stands need to be level.

HOWEVER, the jack stands front to rear do not necessarily need to be level.

Now if there is a gap and it is sitting on only three jackstands, it will be one of the rears that is gapped because the fronts carry more chassis weight from the engine.
If the RR is gapped, then jack up the left rear slightly with a large jack stand leverage (LARGE RED RECTANGLE)bending the chassis till the gap disappears. if its the LR gapped, then visa versa. once the car is solid on all "5" jackstands (5 only if the car only rests on 3 of 4 first try) then clamp up SFC's and begin to weld.

Its really that simple. It just takes time to level the jack stands on the floor of the garage and gradually shimming underneath of them with thin gauge steel plating until they are level side to side.

Dean

Um, nobody gets it? That's what I said, then you say it's incorrect, then proceed to put into detail how to install them based on a leveled floor with leveled jacks. Isn't that what i said?
I didn't say put the lifts under the a-arms or wheels, that would reference my first statement that I feel its better than an uneven frame lift, but not as good as a leveled lift on the frame.
Of course you could still do this on an uneven surface, by e.g finding the level points you want to reference on the chassis, and use a jack under the low corner to bring it up. That would put it plenty close enough for a street car.
ah, I'm sure this is incorrect also. whatever.

Are you that ignorant? I said put the leveled jack stands UNDER THE SUSPENSION MOUNT POINTS...


But I forgot, I should have read your mind because you certainly did not type that.

then you mental giant, I even took the time to make you a detailed picture and also explain in detail that you still can be wrong even on level lifts or jacks because the chassis can be tweaked like the 3 legged chair- So what then partner? I told you how to fix it with a 5th jack point. You can't do that on an overhead frame lift unless you have a death wish of a car slipping off from 6 feet up.

When people talk about a suspension loaded on a lift, they mean a flat drive on lift. That is also what I am trying to tell everyone can still be wrong and I even explained why.

Turbosbox gets the Darwin award this month- and on the last day of it also- go figure.

Its a wonder I even spend time helping out on here, Snotty little sh*ts like this rip the joy out of it so I feel the urge to rexlaim some joy in belittling yo' arse

Thank you very much for that explanation. I am on here to learn this stuff....I am not going to argue with you. I too hate when i am trying to make a thread with some good knowledge in it for everyone to benefit from and people start chiming in with their smart *** remarks.

I have a Dewalt laser transit that I have been trying to figure out how to use on the car to make it square. My garage floor may not be perfectly level from side to side either, but my car is sitting on jack stands and is not touching on all 4 corners. I know the floor is not level front to back because when I built it I sloped it so that water would run out the front. I will level my stands from side to side and put them at the points that you are showing and see what it looks like. I think its going to be hard to twist mine back though because the engine is out and there is no weight on the car. Maybe I could anchor it to the floor? Thanks again.

Okay, understand fully now. I will have to relay this to the shop I choose to do mine.

to vetruck: Yeah, nobody knows anything but yourself. Even the manufacturers and everyone else is a "so called expert". And any reply by someone else on how to do it is a smart *** remark. Then you proceed to put their comments into your own post on how to do it.
Like I reread your post, saying I have no clue, and it can't be done with a jack either to untweak it, and in your long winded post, you use a jack?! You really aren't smart enough to be calling everyone else ignorant. Please post your credentials so we can see what grounds you have to call the rest of us idiots. All I found on your bio could be construed as a waterboy to a nascar team, anything else?

I have a different way to do this without laser leveling complications. But since I'm pre-human, no sense in posting it.

BTW IH8WWD it's too bad you are not near cali as I'd love to see you walk in a shop with those instructions in had pointing to where on the floor you want them to paint the numbers and what lifts and jack stands they must weld up to work on your car. It would be funny as he77, and worthy of a utube posting !

Try jacks back here at different heights side to side seing if the LCA bolts (Green arrow distance lines pointing to the rear suspension mount points) will equal out to creative laser leveled points below them.

Be creative, just be careful also. This is the kind of backyard mechanic stuff typical to do it yourselfers. A good alignment rack/lift can chain things down and jack other things up etc. like when we chack bumpsteer etc. These hoist and pulling tools can be used for minor chassis work like this too.

Stop hijacking this informative thread with infantile squabbling. Take it to PM or something.

Lets keep this thread on track please!!! No need to be disrespectful to each other while posting.

Got around to checking my car today...it seems to be perfect. I put the jack stands where you said and all 4 were touching with everything perfectly level. No need to twist the car. I have my alston SFC's and i am going to tack them on then put it on the rotisserie. I will be going to get the rotisserie tomorrow. Thanks

A good alignment rack/lift can chain things down and jack other things up etc. like when we chack bumpsteer etc. These hoist and pulling tools can be used for minor chassis work like this too.

so a body shop that has a lift as eluded to above may be the best place to have sfc's installed? because they could make sure the chassis is straight prior to welding them on? im i correct in this assumption? and also they should really have no problems or qualms doing this type of welding as it is what they do everyday correct? thanks in advance.

also how well do the bmr sfc's with factory exhaust work? does not seem like they would work as well because there is no direct connection to the subframe on the passenger side. anyone with any experience in this area?

not trying to take anything away from the post.. that setup loos awesome.. i almost did the same thing.

however i went with another option:
http://www.thirdgen.org/techboard/su...rame-into.html (S&W subframe into 1987 iroc)

I know I'm a bit late here, but Vetruck, once the chassis is well leveled, would one weld the SCF's in with the suspension loaded, or could one weld them up on the four jackstands?

If the chassis is leveled and supported on all four suspension mount points then weld away.(there is actuall 6 mount points that come into play. two on each side up front with the a-arm mounts- just use the rear two of these)

Ahh, gotcha. Makes perfect sense. Thanks for the most valuable info, Dean.

My 89 RS is a convertible, will dual SFCs install the same on my car?

no i think the alstons only fit because the convertible car has rivets where the bmr and others weld up to.... someone else can chime in tho...

Spohn makes a set of SFC's for convertibles.
Click Here

wow..nice job!

Have Alston's on mine- great ride but they hang down too far. I may cut them off and go another route when I lower it...

Nice pic's, Just ordered some Alston SFC from Doug Herbert Racing $190 shipped.

I love how beefy it looks with both kinds on there.
problem I got is I use that side valley for my exhaust on the right.
[Dosn't work in the middle.]

But I like the looks of BMR's n Alston's together.

A matched made in 3rd gen heaven.

If you scroll down the page on this link and click on one of the photos it will show the UMI subframe connectors installed. This and a "Wonder bar" are what I'm considering.
http://www.umiperformance.com/catalo...roducts_id=127

I am looking at getting the same BMR/Alston setup as pictured in the beginning of this post. Are the pictured SFCs bolt in ones that are welded in? I can't find a picture of the weld in Alstons that look like the one's pictured.