72 skylark chassis reinforcement

im wanting to reinforce the chassis on my 72 buick skylark and cant find any info or how to go about it. im planning to push for 300 or more HP and want to play it safe.

 

With that amount of horsepower, a stock chassis will be fine. If you want to do something, start with rear lower trailing arms. Install a set of boxed arms. Some adjustable uppers would be a good addition but not needed in your situation. Braces that connect the front lower trailing arm to the upper control arm are great too.

An airbag in the passenger rear spring will help preload that side to assist in removing chassis twist on launch. Better yet is an anti-roll bar from HRpartsnstuff or similar.

The list can go on and on, but with 300 or so horsepower, a stock chassis is just fine.

 

I concur with covertolds above.

There are a lot of tricks to get the chassis to work the best, but as far as holding up, the boxed rear control arms might be all that is needed for strength. We still had stock rear control arms with about 550 hp.

 

X3 you'll be fine

 

Ok thanks yall. i appreciate the help. I plan to take my car on the GT tracks so i thought id need a lil reinforcement on the chassis for the turns.:3gears:

 

By GT tracks do you mean road courses? If so, having 300 rwhp is very different than having 300 flywheel hp. Either way the production frame is fully capable of handling the power.

Make sure the frame is straight, square and plum. Next verify all the suspension bushings are in good shape start with the rear control arms and associated reinforcement brackets. Add the radiator cross braces from a GS. Then a set of appropriate shocks and springs. Then a very careful alignment. You will then have a base platform to work from.

Then you can really start tuning the setup. There are several good books on the subject. :Smarty: And don't forget about the brakes. They are vitally important on a road course.

 

I have seen stock lower unboxed arms get so loose, the car swayed down the road. Upon removal of the arms, a bushing literally fell out of the wallered out hole in the arm. Seen this on two occasions.
Known of a few cars suffering severe damage to the cross member where the upper arms attatch. Can cause a crash. My friends LeMans was simply and safely TOTALED at the starting line. Get braces.

Two Top Priorites:
* Controll arm braces - http://www.v8buick.com/showthread.php?t=73629
* Boxed original, or aftermarket, lower arms.

 

hmmm well its an SC car and it never saw road salt. should i still check the cross member?

 

ah road track. btw where can i get GS radiator cross braces? Also how can i check my chassis is true? also what are some manufacturers for parts and books u recommend? lol sorry to ask so much im a new guy to this

 

ABOUT THOSE BRACES:
Here is what "DAWARD" said
...I managed to rip my upper support with the baby 300 motor in my '66 Skylark. At the time I only had a TH350, 2200 stall and a HEAVY foot...

If your serious about performance, you should already know if your pinion angle is set properly, but still, that sucker could be pointing to the sky when you hammer the throttle. You need braces to keep it rock steady under power.
If you can't make that flimsey crossmember flex at least a little, you don't have any power at all.

As for rust....
On a soggy day go raise your hood and put a kleenex against the metal parts.
Your car is dry only in a garage seviced by hvac.

 

Adon214,

So let me clarify my understanding of your reply. Yes, you are writing about going road racing on a closed course; somewhere like Cherry Point, Cape Fear, Virginia International Raceway, etc. Next, join the local chapter or either the SCCA or NASA and go to their meetings and events just to watch what goes on and learn.:Smarty: Also fill your library with books about chassis design and driving technique. Then take a weekend at get some seat time at a driving school. That way you know if you really want to take on a huge project of making a 4000 lb Musclecar handle on a road course. I must admit that having a Pro Touring Buick is a future project of mine.

If the answer is yes to all the above then you will want to take your car to a collision repair facility that has a three dimentional frame machine that is capable of making a frame straight, square and true. By contrast a racing shop (you are in NASCAR country) uses a surface plate as a starting point to build a car car chassis. You can find the frame dimensional details in section 20 of the factory service manual. You can get a rough idea if your frame is straight, square and true by referring to the table and using a tape measure and plumb bob. To this point it a lot of time and labor but few if any parts.

If all checks out ok than you can proceed with all the replacement suspension parts and the alignment or the various chassis, suspension and and drivetrain componants.

Lastly, I'll give you the bibliography info on a book from my library that I used when I was on the crew of NASCAR Sportsman team in the early 1990's before I decided that restoring a car is more rewarding than wrecking them for sport.

Alexander, Don, Performance Handling, Osceola,WI, Motorbooks International, 1991. ISBN 0-87938-418-2

I hope that didn't give you information overload.

 

check out www.lumpydogmotorsports.com for a list of road courses by state.

 

Thanks friend i will def check out all you mentioned. im just starting out so i am very grateful for your help.