andrewmp6

Norm we both know some rules do get bent a lot in scca.Why not be different and use a 71-73 mustang they are bigger and heavier but handle ok stock but like anything else you can upgrade parts.

Sxynerd

That was my original plan but I've already built a 71 once and I'm going for a different type of handling now. I want a smaller car to enjoy and not trow into a corner and hope it sticks, lol. My last 71 was bored and stroked to 357 with massive compression, too much in fact. I took it to willow springs once and it wouldn't keep a safe temp, lol. IDK if Darkhorse racing is still doing their thing but they helped me tremendously with the suspension parts and had gotten me a great deal on my Mach1 Dominator hood for it.

67mustang302

Willow Springs is brutal. The desert out here gets hot in the summer, and ANY car that's well built can have cooling issues out there, especially since the Big Track at Willow is a very sustained high rpm/speed track. Think of Big Willow as more of an endurance issue and less of a performance issue. Really in pretty much ANY time of road racing you're better off with a car that you can control more easily that's more reliable.

And one thing you need to consider is whether or not you can actually control a car of that magnitude. My guess is no. If you have to ask what kind of things to do to get weight balance, then it's highly improbable you have the driving skill to actually run a Trans Am type car anywhere near it's limit. Start off with a modified street car with a good oiling and cooling system, and good suspension/steering. Once you've learned to drive that to it's limits, then start moving up. Otherwise you'll just end up wasting a ton of money on something that ends up getting beat by people with slower cars.

Sxynerd

While I agree that I don't have the skill to push a car to it's limit in the twisties, I can't build a car half way. 400hp isn't that much and so long as I take it slow and steady it wont be a problem. It also doesn't matter if I get beat by slower cars since this is all for fun. I'd rather build a car that has the tools than to do it than not and I could understand your logic more if I was taking my 600rw 96 to the track and being wanting to be competitive but for restoring and building a car like this it doesn't really apply.

I also didn't ask what kind of things do I do to get the weight transferred, I asked, has anyone did it and if they have a prefab firewalls.

67mustang302

Again, why? It's going to be easier and more fun to drive a lower powered car than to try and handle a higher powered car. The more power, the easier to go off track, and if you lack the skill you'll just spend most of your time sliding around and scaring yourself and ripping up tires, or worst case, totaling the car completely. It is NOT fun driving a car that's too powerful for you to handle.

400hp in a light car like a Classic Mustang is a LOT of power for a road racing car. Keep in mind that most Grand Am cars are only around 400-450hp, and those are professional race cars. A 350-400hp Mustang with good suspension and brakes will be more fun to drive, you'll enjoy it more since you will actually spend more time going around the track and having fun, rather than spending more time trying not to die going into the front straight. And as you build skill, you'll actually find that a 350-400hp Mustang that's easier to drive around the track, once you get good, will actually be a very, VERY fast car(to the point that you'll be outpacing average rich guys in Z06's and Vipers by a wide margin). Brakes, suspension and tires matter far more on a road course than power or weight distribution or aerodynamics etc.

Keep in mind that the more you modify a car, the stricter the rules may get as well. Modifying stock firewalls brings a whole new array of problems, since some race sanctioning disallows it, others would require a full 12pnt cage with fire suppression systems etc. So now in order to move the CG rearward to get a 50/50 balance, you end up having to add 200+lbs to the car in roll cage and other safety equipment, and you're back where you started. Trying to make what seems a simple modification like that, can get VERY expensive and complicated. Plus as you start moving the engine back you're changing transmission tailshaft location too, which will impact driveline angles and so on, creating other issues that you then have to spend more money on to resolve. Weight balance helps, but it's not as critical as you think, there are many cars that are not balanced that handle VERY well. And it's far easier to remove a bit of weight over the front(fiberglass panels, aluminum block etc) and add a bit in the rear(something that would happen if you run a 9" rear end let's say), than it is to try and relocate the powertrain in the car, move the firewall or modify the stock chassis.

Remember, the goal is a better performing car, so make the modifications that give it better performance. Lowering the engine(where allowed) often has a MUCH larger impact than moving it front to rear for weight balance. The center of gravity over the front(as well as the rear) determines the roll centers, and overall vehicle roll couple percentage, as well as tire loading, and can result in much better handling than simply moving the general vehicle CG rearwards.

I'm Not trying to discourage you, I'm just trying to point out that the goal is total vehicle performance, which doesn't necessarily mean you HAVE to make certain wild modifications. There are different ways to achieve the performance, so the goal should be to use whatever ways are the most effective for the least investment. There's no sense in spending $50,000 in modifications to achieve the same performance that you can for $15,000.

And one thing to note regarding engine power, is of all the main performance areas, brakes, suspension and powertrain, it's probably the least of those 3 in terms of effectiveness getting around a road course. And the more power you try to build RELIABLY for road racing, the exponentially more expensive it becomes. There reaches a point of diminishing returns, and as you start to build a lot of power reliably you get into expensive valvetrains, lightweight components, dry sump lubrication....next thing you know you have a $25,000 engine that you can't get around a track any faster with than you could with a $10,000 engine, and the maintenance gets expensive. You don't want an engine that blows up 5x every year that you have to keep rebuilding. That kind of racing gets retardedly expensive.

Remember, KEEP THE GOAL IN SIGHT. The goal is to build a car that you can have fun driving around a track with, that's reliable and that you can control and is easy to drive. That doesn't mean you have to build a wild fire breathing monstrosity that tries to kill you every time you go into a turn. You'll actually find that you can build a car that exceeds your driving skill for years to come, for FAR less money and modification than you think.

And I'm not the only one who will say this, but when it comes to road racing, the single best investment you can make for a return on performance is ALWAYS driving lessons, or just more track time to gain experience. That's why I'm saying you should just build a solid, RELIABLE and easy to drive car and race it. Race it until you've reached a point that your skill outpaces the car's capability, and then if you still want to go faster(and most people find out they don't), THEN build something bigger and badder. And by that point you'll know what kind if driving style you have and what kind of performance you want in a car, and have a good idea where to best invest your money.

As far as your original point on weight balance, I'd avoid moving or touching the firewall in any way, since it generates a ton of problems in the process. Composite panels along with aluminum top end on the engine will put a classic Mustang close to 50/50 anyway, since they're actually not horribly weight biased towards the front. If you can afford an aluminum block then you'll have more weight off the front end than you need. That combined with modified suspension and a lowered engine will result in exceptional handling.

andrewmp6

If you want the car to handle and money is not a problem look at http://www.griggsracing.com/ they sell kits that weld in but will make it handle amazing.Or for a full frame http://www.gmachinechassis.com/ but a rolling frame is like 10k.But that guys frame under a 60s gto pulled over a g on the skid pad which is nuts.

Sxynerd

Yeah, Griggs has already gotten several thousands of dollars from me over the years, lol. I never knew someone made new chassis though, that's just sick. IDK how much I'll ever spend at any one time on this project but if the buying something like that means saving more money in the end, I'll have to consider it.

67mustang302

Having a full chassis like that won't matter for a road race car. Remember most road race cars today are unibody(BMW, Porsche, Audi, Mustang, Corvette....all of them). And since you'll have to have a cage anyway(full or partial) You'll get a ton of chassis rigidity from that alone. The chassis won't save you money in the long run, and you also have to get back to the rules. Some rules are very strict on allowed chassis modifications, and if you're not careful you end up building a car you're not allowed to take on track.

Everyone always thinks you have to spend a ton of money on way out there fantastical parts to get performance, and you don't. Modified and boxed stock suspension with tires, good steering, decent trans(even a T5) with a 400hp 302 is more than enough to outrun most modern sports cars on a road course if you have the driving skill.

Look at what the guys who do historic racing use....none of that stuff. It's all a basically modified stock car, with money in the suspension(still stock type though) with a high power 302/347 and a 4spd trans, and a lot of those are 600+hp road race cars.

Sxynerd

Do you know of any resources that will break down all the different classes and from noob to advance racing requirements?

Norm Peterson

I assume that you're looking at doing a cage for this car, in which case the best advice that I can give you is to seek out Alan Blaine's advice (blainefabrication.com sp???). He's also a solid participant in a couple of cage-related threads over on corner-carvers, and has a much better idea than I do regarding what various sanctioning bodies require and how to actually get it done. It might be one thing to risk protest from another competitor over some picky little detail, but it's something else entirely if the car can't pass tech/scrutineering.


Norm