Hopefully moving up to our race group this year whose classes are generally hp/weight. Currently building out my car and, while trying to stay out of the arms-race classes, have a few decisions on how light do I go. Generally, staying on the light side of the class means you run less racy tires, heavier you can run slicks. Cost aside, where do I want to end up?

 

If you're building a car, you generally want to make it as light as you can afford. Then, when you look at how points are allocated in your particular classification rules, you can add weight back -- but low down and in the center of the car.

 

Weight requires HP. HP requires money.

Realize that racing IS an arms race.

Want to minimize the arms race? GTS1, for starters...

Just my .02.

 

Sobering words. Everyone who gets into this should be required to sign papers understanding this. Even in the so called "spec" classes, there are cars that are "more spec" than others....

 

Lighter is always better.

 

Which series? GTS? ST?

A lot depends on what you are starting with. Another consideration is where the competition is.

Chassis
Current Weight
Current HP/TQ
Current Brakes

 

thanks guys...just confirms what i think i already knew. Already in trouble minimizing any arms race wanting to stay in my 997, but wanted a modern car. Trying to stay in the POC GT4 category...we'll see how she weighs when she's back from all the fixin, but my guess is about 2950/3000 dry without a whole lot of real weight reducing. That plus gas and me says that I'm driving on NT01s and running unrestricted. Probably will keep it there until i can log significantly more seat time and then we'll see.

 

Light you pay for once.

Heavy you'll be paying for it all the time.
Compensation, consumables, etc.

Mike

 

"Light you pay for once.

Heavy you'll be paying for it all the time.
Compensation, consumables, etc "


^^^ Well stated

 

hi guys. I'd agree with the 'light is much less expensive in the long run'. BUT ---- (big but here!): you have to take into account the type of track you are running on to really decide (is the track very tight and twisty? or is it long and fast?). for example, we have the GTS classes in NASA, and lately in GTS2 and GTS3 expecially, I've seen some real movement towards 'make it heavier, but add horsepower, so that you don't exceed the power to weight limits'. by this, I mean that if you have a power to weight limit of say 10:1, then you are better off with a 3000 lbs car making 300 hp vs a 2000 lb car making 200 hp, most especially on a 'fast' track. the reasoning I think is that you can have a much higher top speed on the long straights, and in the GTS classes, aero is pretty much free, so you can have more aero, and still have enough power to push it at a high speed. yes, certainly the lighter lower power cars will be better in the braking zones and in the real tight twisties, but if you are killing them on the straights and high speed corners, then it makes it almost impossible for them to win the race (I'm talking exclusively sprint races right now; under an hour races).

currently I'm seeing almost all E36 M3s running lots of ballast and pretty strong engines in GTS2. and GTS3 is pretty much E46 M3s at a high weight with lots of power (this at NASA MA; VIR full and Summit Point tracks).

so I don't think you can just say as a generalization that 'lighter is better'. most especially if you are in a power to weight class. I think you can definitely say 'lighter is less expensive' though!

Todd
ReidSpeed

PS in my class (NASA PTE) I am by far and away the heaviest car (Ford Probe GT weighing in at 2700 minimum weight) with the most allowed power (169 whp is my cap). when my engine was healthy (its down into the 158 whp range now), it would make that power, and it was VERY tough for the other PTE'ers to beat me at VIR and other fast tracks; I'd get a decent start, motor past all of them (if any of the had outqualified me, which was not common) and then take defensive lines in the tight sections, and fly away in the fast sections and the straights. most of the other cars were weighing in anywhere from 2250 lbs to 2400 lbs (with 125 to 150 hp typically). it was relatively easy to balk them just a touch in the tight stuff, and out power them in the fast stuff.

 

love the light you pay for one comment....SO TRUE

lighter lower powered cars will ALWAYS cost less to run than heavier more powerful cars......

Why are spec miata so popular......PRICE TO RUN........

 

Unless you run heavier, win(for the reasons Todd said 2 posts above), and get free tires.

 

The POC arms race in GT boils down to three primary factors right now:

1) Torque
2) Torque
3) Torque

Basically, build the best engine you can and restict the top end HP as much as possible to maximize the torque curve, then you have your base power with which to apply the weight ratio. Big push away from the air-cooled momentum cars and into the water-pumpers as a result (and the fact the 996 variant race cars are so much cheaper to build now). As others have mentioned, best thing to do is build the lightest car possible and ballast accordingly.

BTW, POC GT4 is a great class that is only growing....I'll be there next year!

 

in most of the GT classes the higher HP cars are winning on our tracks. Auto Club Speedway, Willow Springs, and Laguna Seca all reward HP pretty well. Any of the points races are 30 minutes or less, so good tires (slicks) can handle the weight OK.

The motor is already built and should put down about 300rwhp on 91 in a class currently dominated by strung 3.2-3.5L aircooled cars under 250. The chassis just wont run any lighter than 2800 with you in it without going really crazy. Kind of narrows it down.

So, if you want to stay in GT4, there isnt any other option than being one of the heaviest and most powerful cars in the class, even after you drop 300lbs.

 

Bingo. This has been my experience in GT so far.