Custom subfram question

[Doubt_Incarnate]

i did a search, all that came up from "subframe" was a fiero topic, 3 posts long. it didnt help.

I was wondering if anyone has made, or attempted to make, tubular steel subframes, or any other chassis or suspension related component. Just want to know what all is involved, if anyone has done this, what the results were.

Like about everyone else on here i want to get a bit of power out of my motor, but my car being a ragtop has a bit of flex in it. its in great shape, but still, when you open the doors and put the top down, you almost wonder how its holdin up. add a bunch of power to it and i'd probably get nervous. I'd like to eventually make a subframe for the front and rear, and a pair of subframe conectors to stiffen it up end to end, eliminate the flex. an independent setup in the rear, and a full subframe cradle up front that incorperates the engine/tranny mounts, some nice suspension arms too.

[Lyle's GTP]

RE: Custom subfram question

Wow. Sounds pretty crazy to me. If you are worried about frame deflection from engine torque. I don't think you need to worry. Because the engine is transversly mounted. Therefore any torque is applied front-to-back not side-to-side. I haven't heard too many compaints of peoples cars folding in half.

A buddy of mine new this guy who swapped a GM 350 into his 1983 Hyundai Pony (conventionaly mounted). It twisted the unibody so bad that it would teader back and fourth on two wheels. The DOT eventually pulled his registration and forced him off the road, because his car was so fucked up.

But good luck finding the info you need.

Lyle

[Doubt_Incarnate]

whoah! thats a lot of torque. i'm never going to mount a motor longitudinaly, i just want the car to stay stright as possible. i know if the front or rear is jacked up the doors dont like to close, but ive seen sedans like that as well. more or les just dont want the suspension or unibody geometry to change under the twistin' turnin' of the roads i drive.

[vsop4me3.1]

did you try a strut tower brace? I put one on the front and it helped my cornering. maybe put a rear one on

[Doubt_Incarnate]

yeah, tower bars are things i'll eventually get around to. right now i'm just playing around with the motor combo, eventually id like to squeeze the biggest 60degree in there i can get my hands on. i figure once i get that motor i want in i can make the strut tower bar to fit, instead of making one that fits now, but not later. i will get one together for the rear soon, or try to, i dont recall off hand if the top is in the way when its down. i just figure i'd do everything as cool, neatly, and profesionaly as possible in the end. strip the unibody, blast it, paint it up, and put it on the frames that everything else is rigidly attached to.i also want to remove the spare tire well and put in an slp loudmouth copycat type of exhaust system, so i need to relocate my spare. At my pace i'll be done and happy with it when i've got 1 foot in the grave.

i dunno how your rear susp is setup, but my swaybar is connected to the same peice of metal, from end to end. i cant figure out what its actually doing. thats one reason for wanting to do up a rear frame with independant, i think it would make a world of difference.

[hamondale]

Re: Custom subfram question

I was wondering if anyone has made, or attempted to make, tubular steel subframes, or any other chassis or suspension related component. Just want to know what all is involved, if anyone has done this, what the results were.

DI, I have a subframe under my Austin. The car has a very simple flat underside, unibody construction. This was a 1400lb car with a 950cc motor in it, now has a 3.4L crate motor and T5. The subframe is made of rectangular 1" x 3" 12 ga tubing. I needed someting flat because of ground clearance issues, and I had to keep my exhaust up really tight to the floors. I'd say the results were good, probably overkill actually, I think the frame could carry a V8.
The subframe runs along the unibody rails in front, and angles out to the width of the spring mounts in the rear. Cross member for the tranny mount. Welded to the unibody at various points along the length. To make it, I just bought the tubing and trimmed up all of the pieces and had somebody good with good equipment weld it together. Set up my motor mounts too while we were at it.
Maybe none of this is relevant since our cars are so different, but FWIW if interested see http://tinyurl.com/5a92d and scroll down a ways.
Chow

[Doubt_Incarnate]

thanks for the info, i wouldnt think there is such a thing as overkill in this dept. but i guess there can be in any application. i'd have to get the car up in the air and check it out some more, it isnt an easy task for me to get a good view of the bottom side safely.