70 chevelle vs 79 t/a [Archive] - Chevelle Tech

: 70 chevelle vs 79 t/a


the walrus
Jul 31st, 03, 1:57 PM
A good friend of mine has a 79 trans-am which makes for a constant source of good humored ribbing and friendly competetion between the two of us what with me and my 70 chevelle. And whatever his car lacks in character IMHO I must admit it makes it makes up for in performace. The t/a has also (thus far) benifitted from a larger bank role than my chevelle.
It's faster than mine; he has fairly stout 455 vs my humble 350. But I know how to fix that :D
It stoppes better than mine; even though he is only running stock disks, they still work alot better than my drums. But again I know how to fix that :D
What I am not sure about is the cornering and gereral handling characteristics. Why does his go around corners seeminly so much better than mine and is there any chance than I can ever beat him in this game too???
Why are they so different when they seem so similar.
They both use the same front end set-up, I mean even the sway bars are interchangable. Is he benifitting from the tall spindle style??? Is pumpsteer an issue on these cars??? (i'm assuming not to both of those last two questions)
I know that the weights are comparable and that his cg is lower than mine, but does anyone know how much???
What the advantages/disadvanteges to rear leafs vs rear coils?? I've always thought that one was better for straight line and one was better for corners???
I know of all the fixes that are available to me; bigger sway bars, better control arms, tall spindles, drop springs, bushings... but I guess that my real question is to know just how much better it is that those cars handle(corner) and just as importantly why? and if I will ever be able to beat him at this game, given that he may make some upgrades along the way too.
thanks guys

Cam
Aug 1st, 03, 1:03 AM
Well, the T/A was conceived as a handler from the beginning. A ’79, if it is a WS6, uses 15x8 wheels and has a well-tuned stabilizer / shock / spring rate balance. They also have a nice constant-ratio firm feel power steering box. Also weren’t the WS6 Firebirds in ’79 the first to use 4-wheel disk brakes (other than parts counter stuff developed for the old Trans-Am series that was dominated by Z/28s & Boss 302s)
I always thought that coil springs made for a better, quieter ride. Certain leaf springs, if properly designed, can work really well for straight-line acceleration due to the storing & release of torque energy (Chrysler Super Stock springs come to mind).
The F-body Trans-Am is a unibody with detachable subframes. The Chevelle on the other hand uses a full perimeter frame. A certain amount of flex is normal and desired in both designs. If you are serious about combining big power and great handling into a Chevelle, you are going to have to brace the frame. Even the Trans-Am would need subframe connectors if the door gaps are to be maintained if he gets his foot into that 455 while pulling some G’s in a corner.

At least you have a Chevy and can get horsepower more economically than with just about anything else. Maybe a budget big block...

MalibuMike70
Aug 1st, 03, 10:41 AM
car craft, about two years ago built a chevelle that out handled a new porche 911. You have the right idea of the mods you want to make. the best thing you have going for ya, is your car. luckly for all of us, there are alot companys out there that make modifing our cars a snap. your only limited by your budget and your imagination.

chevl71
Aug 3rd, 03, 8:45 AM
I've had T/A's before and numerous Chevelles, in fact I'm building a T/A for my daughter in the next year.
I have been through the Chevelle suspension thing; poly bushings, T/A front sway and F41 rear sway. Larger meats and gas shocks and you will keep up with him on the curves. We put this same set-up in my sons' '71 and it's a blast. Just keep the car down where the suspension can work (you even try to slide under a T/A with out using a jack??).
I haven't put the two back to back, but with the common Chevelle suspension upgrades you'll have nothing to be embarassed about.