Those two Classes mix well on CTRA in public racing I don't think there will be much of a problem.
I would prefer a series of shorter races for the TBO cars. To me that suits the cars better, having shorter sprints rather than longer races and just run multiple races in an evening. Much more fun than one single long race IMO.
Street car classes are meant to have close grids with drivers always having to worry about the person behind them. After about 15-20 minutes the grids tend to spread out and the finishing position is more or less already decided. That's my opinion anyways.
The other bit is that street car classes are meant to be a stepping stone into the higher classed races and only through close racing and defending positions can you have great racers later on in the higher tiered leagues. The other bit of this is that people need to 'train' their mind to be able to focus to the level they need to be able to race without incident every lap and longer races will be much harder for a newer person to finish than sprint races incident free. The goal for the street classes is to teach drivers the rules of leagues and bring their pick-up racing skills to the required level needed for racing larger, longer races.
Having multiple races allows for drivers to start fresh if they had a spin and will give them another chance to do it properly which will make their learning curve quicker giving you better racers, sooner =)
This is just concerning the TBO cars and it's totally different for the larger cars.
I look at it this way, which do you want drivers to learn better? Racecraft or Pace? You put a driver into a series of short sprints (maybe as long as 15 laps) they will have say 6 cars to pass or be passed in a race. Extend this race to 30 you may gain 1 or two more. So their pass per lap ratio is much higher than the longer races so that in a given time with short races they are passing many more people which is what the TBO's are all about IMO.
Close racing, bumpers connecting and side panels bashing. There are rules to be followed but TBO's to me have always been about being able to scrap with the person next to you at a level that cannot be done in a faster car safely. A nudge here, a tap there =) Not saying that other divisions should have this aswell, but thats what TBO's should have, not a 2 hour race which quickly becomes boring because of the slowish pace provided by the cars.
The other bit is track selection, selecting big large tracks are great for the GTR's to a degree but when you have to sit on a strait for 1520seconds in a TBO makes for a boring race indeed, but thats a different issue and one I am sure you have already looked at.
I personaly like longer events, but only in the GTR Class. For TBO or LRF i prefer shorter races. God knows why, but shorter races suck in the GTR Class and longer ones do that in LRF/TBO imho. Dunno why...
