Notching the rear frame - concerns?

[BA.]

I was just curious about others thoughts about the notching of the rear frame rails.
I've seen a couple of members using extra plates welded in for support in the cut area. Seems to me like this should be mandatory.

Is it enough though? The rail is so damn narrow at that point, a friend was concerned about it.

Do you think a 4 link rollbar would be recommended??

[Camaro Zach]

how much are you notching it and what are the dimensions on the existing frame rail. 4 point bar might not be manditory but will almost always stiffen a car trumendously.

[BA.]

notching it per the vendor spec's which unfortunately I don't have in front of me right now.

It's part of a tub-kit, and I didn't want to mention vendor names, but I was hoping for some experienced feedback about it since it's way out of my field. I have nothing against the vendor at all, just checking from others on my friends concerns.

[Serpa69]

Like this? They tell you it's Ok once you box it in but if you don't like it change it. As you can see I wasn't to OK with It.

[Serpa69]

Here's some pics





Attachment 10360

Attachment 10361

[bretcopsey]

I've wondered about this myself. Some of those frame notches leave what looks to be about 1/2" of the original frame.

Serpa69-aree those frame rails from a kit, or did you fab them yourself?

[jeffandre]

I notched my 2nd Gen rails a lot, left 1/2" max of the stock frame, backed it up with some C channel, and then created a trunk 'subframe' that I welded directly over the stock frame to help out. I will also be installing another roll cage to help everything as well. I just didn't like the idea of having a scrawny looking frame...

I would post pics again, but I cannot remember my Yahoo password. I have posted before, try a search and you may come up with photos of my setup.

[Serpa69]

I bought the rails from 21st century but they come straight with only the hard bends in them. I don't have anyone who could do the hard bends for me. The rest I fabricated.

[Leadfoot1]

Serpa69,

Not to hi-jack the thread here, but if i may ask; How did you like the 21st century rails? I'm going to order a set + their mini tub kit probably by the end of the week (was gonna do it tonight...but i'm still reading posts tonight looking for more info/ feedback) I see you cut them to conform to original contours, nice job! I need space to clear 345-25-20's and my floor was gone anyway sooooo. I like the 21st rails because of their (seem's to) good fit and rigidity. I'll have to cut the new 1 piece floor to fit 'em, but with the mini tub kit it should be awesome.

Was the lenght adequate? (before you cut them) overall fit?
Quality of the bends?

The more i think of it the more i'm leaning on an air ride suspension. (Maybe an Art-M kit or A-R technologies)

Any other pics would be great,

Thanks for your input!

Lead.

[Serpa69]

Their rails were a pretty close fit. You may have to trim some and they won't fit the contour perfect. I did follow the contour in front of the DSE tubs then brought them out straight along the side of them. This is so they meet up with the subframe conectors.

[hotdog]

How much are the 21 st century frame rails? can you by just the rails and not the tubs?

[Leadfoot1]

'September '05, they we're going for 298$ for the pair. (rails only)

'Better check with Ed, as steel price has gone up since then and i'd bet the parts followed the way...

Lead.

[hotdog]

What kind of rear suspension are you planning on running? I was thinking about going with DSE quad with the 21st frame rails.

[Leadfoot1]

Thats the big question for me....I really like the Art Morrisson tri 4 bar rear clip, but i like the adjustability of air bags....the Quadra link is awesome...but won't fit my aftermarket rails withiout modifications and i can't come to convince myself of paying top $ to cut and fit everything still (the originals rails are already out with the whole car floor and the car is on a jig) I'm currently talking with (highwayman) about his Art M G-Max full frame conversion and evaluating the possibilities...I have a friend with a '69 as well that would be ready to buy all my new floor parts, but thats a MAJOR direction change for the project and i need to research this whole deal further)

Otherwise, i think the AM tri 4 bar clip is gonna be it, i love the exhaust cut outs, the suspension is awesome and from what i read, quality is top notch. Only thing i need to verify is clearance as the frame has a measure of 40" outside to outside and with my 345-25-20's under the car (empty) it looks kinda close to the 1/4's for my taste....

Thats about it...I tought about fabbing a rear with the 21st Cent rails at some point (they look real nice) and have not turned my back on that idea either...I would put a crossmember in front (AM probably) and will use custom tubs in any scenario i guess as i'll need MONDO space to get the car as low as i want it.

The big assle for me right now is finding a few hours to work on the thing! I have parts coming in regularly, but i only get to stack them up one on the other....

Any pics of your project?

Here is mine.......... http://www.racingjunkrides.com/view_ride/319/
(Gotta click under the main pic "view images to flip thru the album)

Lead.

[hotdog]

I dont have any pics as of now, going to buy a digitial camera tonight. I am taking a pro-street and turning back to a non - back half car. From why i have learned the only change to the dse set up with 21 st frame rails would be the panhard bar and the brace between the frame rails. I just recently pick up the one piece floor pan to put in, but i been on hold. The past owner took out the inner rocker panels and added some 2x3 box rails. so i am debating on what to do there because the box rails are out a 1/4 inch compared to the factory panels. Beeb thinking about building some rocker panels out of .080 sheets to replace. I was planning on buying the 1 piece trunk, but i been on hold since i would have to cut it up to fit the 21 st frame. maybe i will look into the 4 bar like you. just need to make sure i keep the back set.

[Leadfoot1]

The back seat is of major concern for me too. It stays in with the AM kit. (well it does too with anything that's not 4 link related)

If the fabbed inner rockers are solid like thatand nicely done (at 1/4" thick they must be solid!!!) I'd keep them if they're installed properly, and you could graft your rails to a front crossmember like i wanted to do, it would save you some work since it must almost be ready to receive the rails then.

Yeah, the AM kit is very nice and is in the same fashion their G-Max full chassis...Go to lateral-g.net and search the user "Highwayman" to see his car (Mindblowing project!) I'tll give you an idea why i love this set up!

Or pm me your e-mail and i'll send you pics.

Lead.

[Leadfoot1]

Here is the anwser i had gotten from Frank at DSE...Probably what you got too...

Mario,

If you use aftermarket frame rails, you will have to shorten the panhard rod since it locates off the stock rail. The upper shock crossmember is also notched to fit between the stock rails so it will have to be narrowed slightly. Otherwise, it should work. With our tubs and QUADRA Link you can fit the 345’s in the back, but I’m not sure about 355’s. You’ll have to measure, but let me know.

As far as IRS’s go, they have their advantages and disadvantages. They are more forgiving on rougher surfaces since each wheel reacts independently, but can be prone to wheel hop due to the additional pivot points. They also have more moving parts that can fail and are usually not as strong as a live axle. When buying an aftermarket IRS, be careful. Just because it uses Corvette parts doesn’t mean it will handle like a Corvette unless the geometry is designed correctly to work with track width of your car. The QUADRA Link handles extremely well and should perform as well or better than any comparable IRS on the market. Good luck!

Thanks,

Frank Halcarz III

A friend of mine is building a '69 And has already all his vette stuff...

[LSRS7]

Hotdog, Here's pic's of mine. DSE Q-Link and modified 21st frame rails (way to expensive IMO). If you keep the inner rail dimensions the same up to the DSE crossmember everything elese works. The crossmember, panhard mount and bar fit. The subframe connectors will go right in same place and mount to the WD sub with little mod. Once the rails exit past the crossmember run them straight out, youll have to fab some perches outboard to pickup the bumper mount. A Rock Valley narrowed tank from DSE will fit perfect in between the frame rails. Had to section 2" out of the trunk pan to fit between rails. Interior of car stays the same.

Jason

Attachment 11510Attachment 11511

[Leadfoot1]

Wow LSRS7,

Thats a neat job. Love the trunk. Thats what i want it to look like, stock to the onlookers.

Have you had the car on the ground? What size wheels tires are you running?

why do you mention you think the rails are too expensive? Thats the price almost everyone sells them for....They not worth it?

Any build pics?

Lead.

[LSRS7]

I hope to have it on the ground by next weekend, got to finish up some welding and put it in dp this weekend.
Running 275/35/18's on a 18x10 on front
335/30/18's on a 18x12 on rear
I guess it's just me but it's hard to spend that on tube and then cut it up. That's what I wanted was a stock as possible looking trunk when finished. the only thing that gives it away is the 3" filler I made between the inner and outer trunk extension.