G-body, Malibu chassis creative expertise needed

rapidride3

Amateur Racer
Mar 8, 2008
111
0
16
Saint Louis
Hello, I will never claim to know it all. I am gathering ideas and am in need of peoples' past experience along with some creativity.

I have a bone stock rust-free 78' Malibu that will be going into the chassis shop within the next 3-4 months. I want to do a 25.5 cage and big tire back half. This will be a 60%street/40% 1/4 mile car. The car will eventually be a pump gas, pro-charged,intercooled, possible meth injected 540-565 bbc with 14-1500h.p. with probably a Rossler th-400. High 7.70-7.80E.T. while being able to "hit" the big tire hard from the start rather than build a more expensive, higher horsepower engine only to "limp" it off the line.

So as previously stated I am looking for ideas. Both those that make perfect engineering sense and those that offer detail and creativity. Here is what i have initially planned for the car.

Tig welded moly cage and round tube back-half
Thinking about keeping the stock trunk floor cut out around wheel tubs to keep rattles down to a minimum.
Solid body mounts.
4-link with wishbone and an anti roll bar. (opinions)
running the a pillar bars down into the dash to increase room
Stock dash, stock door panels, cut sail panels, stock appearing factory black interior, roll-up windows, except a pair of kirkey seats.
Unsure on what switch panel to use as of yet.
I want to primarily be able to run Hoosier 33x22.5x15 dot quick times for the street/track but also a 10.5w for resale value.
Custom fab 9 housing with larger tube 4-link bars
Unsure whether to run strange or Mark Williams 3rd member, brakes, axles, etc. components.
TRZ upper and lower control arms that will allow a coil over shock. TRZ spindles.
POSSIBLY making a removable engine cross-member.
Boxing of factory frame before building the 25.5 floor.
Removable chute mount.
Unsure as to keep the factory style core-support.
Possibly do some floor work to accommodate larger exhaust.
Fiberglass cowl hood, possibly fiberglass bumpers and deck lid.
Larger fuel cell.
Penske coil overs for the track and probably lesser grade coil over for the street.
?????

For those who ask what class i will run??? I say none other than occasional bracket racing. I cannot keep up financially or personally with the never-ending class changes in heads up racing. So in short this car will be built for ME. I would love to drive the car 20 min. to the track, make a few subtle changes,,, make a few high 7 second passes and drive the car 20 minutes back home and maybe hit a cruise the following night.



What I am looking for is peoples past experiences in a similar build regarding parts, craftsmanship or overall ideas and advice. I too only wanna do this once.

Feel free to offer what you would do differently if you were to " do it all over again" Photos, links or websites would be greatly appreciated. I am also looking for a place that supplies some of the more unique chassis parts for these g-bodies. (I already have trz in mind)

Lastly, thanks you for your guys' time.
 

Strokin

Daily Driver
Aug 30, 2014
11
0
0
I'm in the midst of a similar build, seems to be very little experience with these builds on gbody.
I researched for months for backhalf kit, I ended up going with S&W race cars rear kit. I live in on west coast, so shipping was a little more from the east, but seems to be the only gbody specific kit.
 

10secBu

MalibuRacing Junkie
May 21, 2003
4,284
0
36
Westminster, MD
If doing a round tube back half, why in the world would you keep the stock rear floor. With all the tubes needed, the stock floor will be nothing but in the way, make a mess trying to make patches and close off the big holes and add weight.
 

rapidride3

Amateur Racer
Mar 8, 2008
111
0
16
Saint Louis
10secBu said:
If doing a round tube back half, why in the world would you keep the stock rear floor. With all the tubes needed, the stock floor will be nothing but in the way, make a mess trying to make patches and close off the big holes and add weight.
The car is totally rust-free. I 'm not sure of the weight difference between the stock floor and sheet metal panels. I was also thinking rattles would be held to a minimum with the factory rear floor vs sheetmetal rivets. The chassis guy actually suggested it, he said it would be no problem to keep the stock floor.
 

10secBu

MalibuRacing Junkie
May 21, 2003
4,284
0
36
Westminster, MD
A round tube back half consists of more than just a single pair of round frame rails out back. It's built with a ladder assembly to give the frame height which is how it's made strong compared to a 2x3 square tube frame.

Just two round rails under the stock floor will not have enough strength and has no advantage over the stock frame or a 2x3 frame.

The whole idea of a round tube is to get rid of the heavy stock floors as well as raising the tube frame as high up inside the body to allow the car to be lowered down and be able to handle not only a wide back tire, but also a tall back tire and not have the housing hit the frame above it. Aluminum and carbon fiber floor panels are just part of the round tube back half.

I do chassis work for a living and am just sharing my experience.

If your really concerned about squeeks and rattles i don't think a back half is for you. Even doing a 2x3 back half I can't say it'll be squeek freek. Your gonna hear all kinds of noises out of the suspension and tires if you have quiet exhaust. Now if you do a street 4 link with poly ends on the bars it may be quieter, guess it boils down to how you intend to use the car.

if you want tall tires and the car to sit low, then go with a round tube back half. If you want big tires and a normal ride height, just do a 2x3 back half, steel tubs and poly end 4 link bars.