Quote: Originally Posted by Twin_Turbo sizes are metric (mm): ya the umi design dose look prety weak!

Knows what? 8 pages of posts & no indication of who your asking or what your talking about.....

This is what he wants to know...

The box around the LCA mount is probably just there to make installation easier, so you can bolt it on before you weld it.

Stephen,

Don't mean to state the obvious but I asked a direct question about 3 posts up...

To clairfy...the boxing and bracing made on the subframe connectors where they connect to the LCA/LTA...are they necessary? Or can you just weld directly to the LCA/LTA mounting block instead of bolting on the brace...

Greg,

Thanks!! That's exactly what I was looking for.

That and you want a nice 360* weld in which having these sort of box in the LCA mount for a nice solid connection.

Can't wait to see these installed.

*Stephen, your hilarious.

Very good point! Thanks again!

to answer it simply... yes it would sacrifice some integrety. if you notice the stock LCA mount on the body is 1/16" steel, but since the LCAs only apply pushing and pulling forces to the mounts the 1/16" stock steel is sufficent for street driving. the reason the aftermarket bolts into the LCA mount is for convience, its something that is universal(allows for perfect fitment where they want it) on all 3rd gens and 4thgensm not to mention its the only real place that allows you to bolt on a pair of SFC on the back of the car without drilling new holes, it also allows u to reuse the stock LCA bolt hardware as well as reinforces the LCA bracket at the same time. since the LCAs dont twist really or see much if any side forces to compromise the weak stock design they work fine for the pushing/pulling forces of the LCAs. i would think tho with enough power and enough traction that the stock LCA bracket would "bow". adding the aftermarket SFC with the LCA reinforcment would prob eliminate/lessen this.

as far as im concerned the only thing on these cars that dnt need to be reinforced are the front Kmembers... otherwise id reinforce everything.


on a side note... fueledsoul. ive kind of copied your design and made myself some perimeter SFC to weld onto the inner thru floor SFC that ive installed on my car already. the arent as creative as yours but they should do. i ended up using 1"x2"x.120" rectangle tubing and 2"x 3/16" flat stock. the SFC tuck up so well u cant see them from the side of the car even if your laying down on the ground lol. dnt mind the messy garage

You guys are awesome! Thanks again...I'll be doing my fab this weekend so I will put some pics up...Hope nobody minds me borrowing ideas here and there...

If i ever do more then my cage and spohn mammoth frame ties. The main goal will be to be able to run duals, larger then 3". Pretty much channeling. This looks to be very structual and nicely done. I just want to know why you didn't heat up and bent some of the parts.

Very nice and I am glad you are doing this stuff yourself, I do the same thing. I am just handing out more idea's for others.

I am not picking on ya....

who was that in reference too? also FYI bending tube by heating it is not as easy as you would think. i tried to bend some 1.5x.095" HREW tubing and i got it red and tried to bend it and it didnt go anything. i will eventually get a tubing bender.... once i decide i have like 300$ to throw at it

torches acetylene/oxygen work just fine and I have bent some serious stuff what way, with a good heavy work area. Like a thick steal table to weld up a jig or weld the part to, while you heat a certain area to bent. I just take my time. It just makes all the parts look pro or factory made.

if you had all that then maybe you would be able to bend some tubing. doesnt heating the tubing cherry red weaken it/change the properties of the metal...

Yes and no. If it is white metal, there is more of a tendency for the weakening of the steel as the heating of the metal and rapid cooling causes the crystal like molecules of the steel to rearrange and become more susceptible to weakening/cracking. Done properly, all metal (including white metal) can be heated without structural concerns as along as it is done in a controlled manner (controlled heating and controlled cooling). The worst thing you can do to metal is dip it in water after super heating (ever done this to a glass haha). However, you can quench (type of tempering) metal by this process, but you better know what your doing or it can be dangerous (i've seen flat bar shatter by someone doing this improperly)

This would HAVE to be one the most useful threads on this forum. Thanks Fueledsoul, I will be making some SFCs for myself very soon as it is too expensive for me to import some, and so I will be borrowing (stealing?) your design for the outer SFCs, and I may make a set of inners later.

I have the round tube Alstons on my RS- do the job great(sound tube is stronger than square) but they hang too low and scrape on EVERYTHING. And I haven't lowered it YET!!
Are you going to market your design, because they look killer!

Finally i got these fully welded! I will probably clean them up media blast and powder coat them but not till after im done mocking up and install my exhaust...


Here is a shot of of converter clearance,
Since i think someone assumed there would be interference...

amazing work as always

Thanks

Unfortunately 2 years ago when you started this project I decided to cut my homemade SFCs out and at least go for some better mounting like yours. Just wanted to say thanks for a bit of motivation.

Now I just need to find the time to get started.

Your welcome

thanks from eastern canada...

me and another fbody owner are doing your design. Well done!!

You can put my order on your build list, k thanx........
Those came out awsome, keep us posted.

I know this is kind of old but do you have measurements for these? What kind of changes would have to be made for dual exhaust that may be in the future?

This is disturbing to read....I ordered mine & they just came in this morning. My 'bird is LOW.

I hope they don't hang down off the floor, but stay tucked up against the floor.

Sweet! post some pics when your done!

Iv thought about producing these and iv already drawn up better plans but im undecided at this point to many factors to consider.

As far as updates go, I have some small tweaks to do to get them to fit like they did when i built them on the car since the welding warped a few spots. They are temporary back on the car since im currently working on fabricating a y-pipe and hooking up the rest of the exhaust so i needed these in place. It looks like i might have to modify one of the lags that connect to the front drivers side frame rail, its not necessary but im tucking my exhaust up as close as possible to the chassis. after that im double checking the frame measurements i will also get these cleaned up, powder coated then i will fully weld them in. The underside of this car is going to be ridiculous! Just for fun Here is teaser pic of the exhaust...

I don't have any measurements other then what i posted in this thread.
Since i'm in the mites of doing exhaust now, i contemplated doing dual exhaust i would still have the same clearance with dual 2.5 as what i will have now with a single 3"

I say go with duals it sounds better & go with an x-pipe. What kind of mufflers are you gonna use?

That's what i thought about doing, however i already bought this cat-back brand new about 5 years ago

I like the overall design and this inspires me to see if I can make something myself instead of just buying it off the shelf. However I will say up front yours are in a league by them selves and mine would not compare. I just need to get the car in my shop drivable.

I too will probably use your design. I was going to buy a pair but now I have a fun project in store for the near future. Great job... Really great job.

Thanks! i guess since this is still a semi active thread i will give an update if that's what you wanna call it so...

UPDATE:

I still haven't got around to getting the sub frames blasted and coated but im thinking i will do that with in the next few months so i can get them on in the spring and be done with them and by done i mean
(by permanently welding them in place) I had used a trim gauge to trim out my car and everything seems to be good but im going to run some more measurements before these become a permanent fixture of my car.

The exhaust turned out great and hopefully it will inspire more people to try there hand at fabrication i will post a link below in this post.

I will share what had to be modified on the drivers side sub frame like i said earlier in one of the above posts i want my exhaust really tucked up...






Link to the exhaust fab:

http://www.thirdgen.org/techboard/ex...-fab-long.html (My exhaust fab! - Long tube headers and lots of ground clearance!)