Shit I don’t understand… #1: SCCA Time Trials

This is the first in a series of rants about things I don’t understand about car culture, motorsports, and racing. Let’s get started with the mystery of SCCA classing rules.

SCCA Time Trials

If I was going to participate in the SCCA, it would probably be in the Time Trial series. I’m not interested in SCCA Solo (autocross) because there’s far too much standing around and far too little driving. I am also not interested in SCCA sprint racing. I prefer endurance racing because my mentality fits much better with “drive fast all day” rather than “win the next corner at all costs”. But Time Trial is somewhat attractive because I like racing against a clock in the virtual world. So let’s have a look at the Time Trials classes to figure out what kind of car I would take. Taking a quick look over the cars, I don’t see any reason for me to have a car any faster than an S2000, which is in Sport 5 (S5). So I would enter a car in either S5 or S6 (slower). Let’s have a look at a few of the cars in each class that I could imagine driving.

SPORT 6 (S6)

  • Acura Integra GSR, RSX
  • BMW Z3 1.9
  • Miata NA, NB, NC, ND1
  • Mini Cooper NA
  • Scion FRS, BRZ, 86
  • Celica GTS

SPORT 5 (S5)

  • BMW E30
  • Honda S2000
  • Miata ND2
  • Nissan Sentra SE-R 2002-2006
  • Boxster (non-S) 1996-2004

At first blush, there is an odd mixture of cars in each class. How can a dog-shit slow 4-banger Z3 be in the same class as the highly praised ND1? How can an E30 be in the same class as a Boxster? Let’s take a look at the Weight to Power ratio for a bunch of these cars (weight is curb weight + 150, power is brake hp / 1.15, source Wikipedia). I’m going to add a few cars in the S4 class also.

SPORT 4 (S4)

  • Cayman, Boxster S
  • Mazdaspeed 3, Protege
  • Lexus IS300
  • BMW E36/46 (non-M)

In the graph below, red is S6, green is S5, and blue is S4. You would think they would group red, green, blue left to right, but they don’t.

E30s and NA8 Miatas have pretty similar performances in real life (take a look at the SM and SE30 track records). Yet the E30 is classed not only above the NA8, but also above the NC and ND1. Why? Well, partly because all of the Miatas (except ND2) are classed together! The E36 gets similar treatment, and instead of competing with its natural rivals, has to compete against a Cayman. This is not an E36 M3, but a standard E36 325/328.

The Toyota Celica GTS, Nissan Sentra SE-R, and Mazdaspeed Protege are all pretty similar FWD cars. On paper, the Celica should be faster than the Nissan, which should be faster than the Mazda. But the SCCA classes them in 3 completely different classes in reverse order. Can you imagine driving an SE-R and having to compete against an S2000? Or how about a Mazdaspeed Protege vs a Porsche Cayman? Because that’s what you do in SCCA Time Trials. Bonkers.

Weight to power ratio isn’t the only deciding factor on a race track. Suspension, tires, aero, brakes, and balance are all part of the equation. So what has Porsche done so terribly wrong when designing the Cayman that it would compete on equal footing with a FWD sedan? Who makes up these rules?

5 thoughts on “Shit I don’t understand… #1: SCCA Time Trials

  1. That’s weird. Their rules also seem to ignore the realities of people building to class as well. When I got my track toy Miata I removed the carpet (because it was moldy) and didn’t bother to replace it (because racecar). I was informed by someone that that would change my SCCA classification. I didn’t worry about it, but I’ve seen many other weird comments about what seem like overly-specific rules like that. I’m sure that the intent was to encourage “street” cars to compete, but the reality seems like you just get built cars with a carpet thrown in rather than inexpensive unmodified cars.

    The NASA approach of power to weight with a few modifiers on things like FWD/RWD, aero or suspension design seems to make far more sense. That has winners and losers, for sure, but it rarely seems to produce results that are totally outlandish.


  2. I had exactly same confusion. The rules doesn’t make sense at all….I eventually decided to give it a try at NASA, their rules are simpler and more reasonable.


  3. Bummer – and odd – my modified 86 classes out as T4, which I suppose makes some sense, as mods do affect the lap time of an 86 significantly. But I suspect that puts that car at the bottom of T4. As an aside, all things being equal, the lighter car with equal power/weight will be faster as it can brake and turn faster (it will have better braking power/weight and cornering traction/weight).


    1. On really fast tracks like Watkins Glen you will hear the people with light cars complain that they can’t keep up with the high horsepower cars. On some tracks, top speed really matters.


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