Not unlike the author of Rome Sweet Rome, I’ve often wondered if one could show up to a vintage TransAm race with a showroom stock 2015 Mustang and win the whole thing. Aside from actually doing an Old Vs New comparison–the logistics of which well exceed our meager resources–it’s nearly impossible to find old race lap-time data from a track configuration that’s the same as today. Even when we have that, we don’t have a collection of lap times from new cars on the same track.
Fortuitously, Motor Trend has used Mazda Raceway Laguna Seca to benchmark a number of sports cars. Meanwhile, we’ve got this year’s Rolex Monterey Motorsports Reunion results to go through and compare.
Spoiler: The New Boss is better than the Old Boss. Some interesting comparisons and further analysis after the jump.

For the Monterey results go here for Saturday and here for Sunday. Go here for Motor Trend‘s Laguna Lap.
Old Formula Cars are still incredibly fast: the open-wheel Cosworth DFV era F1 cars and Formula 5000 cars were posting times in the mid-to-high 1:20s, which is faster than everything shy of a fully charged Porsche 918. You could not win an F1 race from the last 45 years with the best of today’s street cars.

TransAm cars weren’t faster than mid-60s GTs: The GT350s of the Featured Marque race posted 1:45ish top times, while the beefier TransAm cars trailed by a few seconds from 1:46 out to 1:50.

A new Boss 302 beats an old Boss 302: MT tested the 2012 Boss 302 Laguna Seca (duh) and it ran 1:41, a full 5 seconds ahead of the best Boss at this year’s event. Keep in mind that’s the more track-focused, tuned-up version of the track-focused, tuned-up version of the Mustang. Ahead of the Boss is a 2013 GT500 that managed to brute force its way to a 1:38. It’d be interesting to know where a more reasonable GT Track Pack falls.

The 1973-1981 FIA, IMSA GT-GTX, AAGT, GTU Cars are surprisingly fast: This is the group that includes the earliest, angriest turbo Porsches, a few beastly C3 Corvettes and the fastest of the BMW CSLs. The top 10 have fastest laps from 1:33 to 1:40, which puts them in line with the top versions of today’s sports cars (e.g. ZR1 Vette, GTR, 911 GT3, etc). I guess the other way to look at it is to say a new 911 GT3 could run toe-to-toe with a race-prepped 935 that’s turboed within an inch of its life and running two foot wide rear tires.

Everything from the early 60s and before is really slow: The ’55-62 GT cars, a field containing the Belle of the Ball, the Ferrari 250GTO, topped out with a 1:51 best lap from the homely Alfa TZ1. This means almost every car in the Laguna Lap database stomps all over the Golden Age of GT Racing’s stars. It only gets worse as you move back through the ’50s and pre-war fields. Obviously people aren’t paying megabucks for these cars for their ability to Win Track Day. Still, given the money and pretentiousness associated with “this calibre of car”, it’s refreshing to know some Texan’s hot rod re-bodied Falcon could show ’em its tail lights.
Are these comparisons perfect? No. Before you skin me alive in the comments, I’ll point out a few ways this comparison breaks down:

Race Prepped Vs Showroom Stock

The classics are gutted, caged, tuned and rolling on slicks while the new ones are coming straight off the factory line. Slap some track-ready pads, brake fluid and slicks on a new car and its performance envelope opens way up. (Though it’s worth pointing out the very premise was being able to take a showroom stock new car against a fleet of classic racers.) Anyway: (big) Advantage: Classics

Rich Guys in Classics are not Randy Pobst

MT has a wonderfully calibrated instrument in pro driver Randy Pobst. While there’s no shortage of skilled wheelmen in attendance at the Historics, few are on Pobst’s level. Advantage: New Cars

Vintage Racing is not a Magazine Best Lap Test

The statement is true. Surely with adequate time to prep, warm up and re-do on an empty track, Pobst’s approaching an ideal best possible lap time. However, we’re comparing the fastest laps of the classics (not average), and by the middle of a 20 minute race most of the field’s opened up to the extent that traffic’s not an issue. Are these guys pushing it to 11/10ths in near-priceless classics? Probably not, though the red mist is known to descend mid-race. While MT could put the occasional car on its lid without major consequence, at the very least doing so at Laguna Seca would end their testing day prematurely. Pobst’s probably not driving ’em like he stole ’em. (small) Advantage: New Cars
I suppose the interesting thought to conclude on is that (with a few prancing-horse-shaped exceptions), a lot of the classic racers and the cars they tie for lap times are actually priced in the same ball park (used F1 car Vs McLaren P1, GT350 Vs Boss 302 LS, 935 Vs GT2 etc)…for your money, which would you rather have?