It was my understanding that NASCAR race cars had to be semi-streetable.
What are the rules for the race cars relative to production cars?
Please, no “double-wide/slack-jawed” comments. Junior Johnson has agreed to personally enforce this rule. 
Peace,
mangeorge
I’m not sure I understand the question, nor am I a major NASCAR expert. But I think you may be referring to the fact that in its early history, “stock car” racing was done with actual production street cars.
However, this has not been the case for several decades. Today, NASCAR cars are purpose-built race cars that must meet very specific standards WRT size, shape, weight, power, and a thousand other specs established by the sanctioning body. Their only resemblance to the production models they are named for is some faint, non-functional styling similarities, decals that look light the production headlights, and the name plate.
ISTR a thread in which someone looked for common parts between a NASCAR car and its production namesake and came up with the brake fluid reservoir.
There are many pro and semi-pro sports car racing series that start with production vehicles (e.g. Porsches, BMWs, Corvettes, etc.) and add safety gear and performance parts, but NASCAR ain’t one of them.
As for being “streetable” in the sense of legal to drive on public roads, no real race car is, whether it’s custom-made or production-based. No license plate holders, no emissions controls, no airbags, and interestingly, no legal seat belts.
I learned this when I bought six-point harnesses for my sports car: racing harnesses are not approved as legal restraints by the U.S. Department of Transportation, even though they obviously vastly exceed the standard three-point belts in terms of safety. But apparently DOT approved belts must have a red push-to-release button, not the lever or twist quick-release that racing belts usually have. Presumably this facilitates emergency crews in getting injured or unconscious people out of the car.
If anything, NASCAR stockcars are less technologically-advanced than cars the average consumer can buy today: Overhead cam and fuel-injection are forbidden by NASCAR rules (yes, all those racecars are built with carburetors).
Yeah, I was reading about that at wikipedia.
The company I work for sponsors a NASCAR team, and they brought one of the cars to our facility to show off. I was surprised th see how ordinary it was under the hood. The driver gave a couple short rides, and it sounded just like the hot rods with cut-outs from the old days.
there’s no real reason one of those engines wouldn’t run just fine in a street car. Other than legal, anyway.
IIRC they run on leaded fuel, like most racecars.
Snippity snip snip Plus pick a nit.
I think rally(e) racecars may fit that “street legal” definition.
Previous thread: When did stock cars cease being stock?.
Modern rally cars such as those competing in the World Rally Championship do have to carry some sorry of government license because they must travel on open public roads between timed special stages on closed roads (drivers can be and are ticketed by the police for speeding/traffic violations outside of the special stages). I don’t believe they are really “street legal” in that you could legally drive one outside an outgoing competition, however.
My understanding is that rally cars are indeed street-legal. I do recall a 17 year old guy doing a British rally in a VW Bug, and another guy used a Trabant.
I think the rule is (or used to be) that there had to be a certain publically available production run of the car, though the run was pretty small; maybe just a few hundred or so.
If I were going to race, I think it would be rally. There are some ameteur events one can get into. Looks like fun.
Well that is true but misleading. The rules specify the basic engine design. But a carbureated 350 that’s turns 800+ Hp and can run for 5 hours pushing 8500 RPM is way past the days of cousin Jethro slapping something together in the barn.
The features of the engine may be old school, but the precision engineering, material science, airflow design, combustion optimization etc. are pretty advanced.
Apparently in states where vehicle inspections don’t exist folks with an older race car that no longer meets racing regs find it to be a real hoot to slap things like lights, wipers, etc. on their cars, then title them based on the engine and drive the cars around.
Nascar engines are also built to only last the 200-500 miles they put on them during a race. You’d never make it past 5000 miles on one of their engines.
I was curious if you had a cite on that, cause I’ve allways been curious. Has anyone ever tested how long one of the engines would last under normal street driving conditions( say 2500-4000RPM) vs near red-lining the whole time? I’m pretty sure my car’s engine wouldn’t last 500 miles at red-line.
It should. At least if looked after. During design and manufacture, modern car engines are bench tested at redline or close to redline for days to make sure that they will survive the real world.
I would wager a few dollars that most manufacturers pull an engine off the line every now and again and put it on the bench for a torture test.
None of the race cars have the emissions controls needed to be registered. The ones I’ve seen don’t have VINs, which would make registrations very difficult if not impossible.
It almost certainly would. As I’ve mentioned before, I drive my sports car on racetracks, and although we run on road courses, not ovals, and therefore don’t run at the redline the whole time, I spend quite a bit of time at full throttle and high in the rev range. Even after a day of this, as much as 150 miles, the engine temp never gets above the midpoint on the gauge. I’ve been running this stock 350Z this way for five years, and have put more than 6,000 track miles (and 34,000 road miles) on it, with no engine problems of any kind. The engines on modern street cars are pretty damn good.