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Old 01-24-2010, 01:57 PM   #624 (permalink)
travisjb
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Discussion needed... I need to set an objective for weight and whp, and it hinges on my decision to keep this car NA or add SC. Currently, I am in the TTS time trial class and NASA requires that I maintain a lbs/hp ratio of 8.7 or higher. NASA also give me the option to run larger tires or limit to 275 series tires or less, in which case I get a 0.4 bonus - so ratio becomes 8.3. Make sense? So, given all that - which one of these should I target ?

1. 3,175 lbs SC 380 rwhp little tires (275 series all around)
2. 3,300 lbs SC 380 rwhp big tires (285/315)
3. 3,050 lbs NA 345 rwhp big tires (285/315)
4. 2,975 lbs NA 335 rwhp big tires (285/315)

Right now, the goal is #3. I think the weight target is achievable, and once tuning software for this engine matures, I'm hopeful the hp target will work out. Alternatively, if I SC this car, I may have to ballast some weight to stay above the ratio. That may turn out to be a good thing, b/c I can load the weight low and to the rear and get on/near 50-50 weight distribution. I can see scenario #2 working out for that reason. And then a third choice would be to take a bit of weight off scenario #2 and limit myself to smaller tires. Picking between #1 and #2 is trivial - and something that I could figure out down the road if I decide to SC. I realize the hp estimate for this car with a SC is probably low, but I'm going to have to run it that way to stay in my current class, otherwise I'll be carrying too much weight, I believe. One factor favoring the SC route... Adding the SC will give me the opportunity to run RTA in the 'modified' class and have a better shot at being competitive. So, I'm looking for thoughtful input from those with a bit of TT experience or track experience with an aftermarket SC... for my NASA TTS class limits, what will turn better times, #1, #2, or #3 ??? Let's assume we are primarily talking about my 1.6 mile home track that is about half nascar oval and half infield. Thanks!

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