kyboxster06 Posted September 21, 2011 Share Posted September 21, 2011 All, I would like to tap the knowledge base of this discussion forum to inquire about how to set up a 2006 Porsche Boxster S (3.2L 280hp, 2965lbs) for optimum performance in a GTS series. I'm not sure if this is where I would end up, but it looks like a logical progression, if there is one. First, a little about my track experience/car history. I have 13 track days in HPDE in a combination of Porsche club and NASA events. The only modifications to the car today are lowering springs and pagid brake pads. I do use OZ wheels and Nitto tires on the track. My last trip to Mid-Ohio in July yielded a lap time of 1:45.80. Second, I wouldn't mind getting an opinion or two on whether or not this is a worthwhile project. Should I sell this car or keep it for the street and get something else for a track project that would yield better results for the dollars spent? I enjoy driving the car on the street, so even if I decide to turn it into a track dedicated car, it will likely take me 3 years or so to make the complete transition. Third, what is the general consensus on the following modifications (meaning are they worth it and if so what flavor)? PSS9 coilovers (are the spring rates that come with the coilovers good?) gt3 front control arms rear toe links engine re-maps exhaust mods limited slip diff aero racing (or some other kind of performance) clutch, I have a factory short throw that came on the car when I bought it. With regard to safety equipment, please give recommendations there are well. Any and all ideas/experiences are appreciated! Quote Link to comment Share on other sites More sharing options...
JSG1901 Posted September 22, 2011 Share Posted September 22, 2011 Hi, and welcome to GTS (or nearly so). The Boxster S would be a fantastic GTS car but you probably need to think about a lot more modifications to make it competitive. To figure out what class you might fit into, we need to work out a power-to-weight ratio. 2,965 lbs is the factory weight of the car. You'll want to strip it, which will get rid of several hundred pounds of weight but then you have to add your own weight back in. Let's call the racing weight 2900 lbs but I'm sure you could get lower. The 280 hp is the factory horsepower from the flywheel but we use rear wheel horsepower. If you do nothing to the motor, that's probably 10-15% less, let's call it 250hp at the wheels. 2900 lbs with 250 hp = 11.6 lbs/hp which puts you nicely in GTS3 where 11.0 lb/hp is the lightest you can be on DOT race tires. To give you a sense of your goal, depending on whether your 1:45 Mid-Ohio lap was on the Club or the Pro course, you'll need to find 8 to 10 seconds to run near the front of the GTS3 field, which is not a trivial number. How to do that? Well, some of it may be skills development, which is relatively cheap. After that you need to go through the car starting with bushings, shocks, wheels and tires. While the PSS9s are nice (I used to have a set on a Boxster S street car), you'll want better and more adjustable shocks for the track. To have a chance, you'll need aerodynamics in the form of a wing and splitter (at least). You'll need a roll cage and fire system, harness, seat, etc. I'm not trying to discourage you here (although I probably am). It's just that this is a pretty well developed series and it takes a pretty complete equipment package if your goal is to run up front. On the other hand, if you just want to race and don't need to be at the front, obviously you can save on some of these items (and add them later when you decide you want them). It is one of the truisms of racing that the cheapest way to build a great racing car is to buy one somebody else already built. When you're the one doing the conversion, it's going to be expensive. It would be fun as heck to do but expensive nonetheless. If you have the budget and the stomach for it, dig in! If not, find a car that's already been built--or even mostly built--and take advantage of the HUGE discount by buying it that way. So, I didn't really answer your questions. In GTS, keep in mind that every horsepower has a weight penalty associated with it. In GTS3, that penalty is 11 lbs. So, if you remap your engine and find another 20 hp, you'll also have to raise your minimum weight by 220 lbs. In racing, lighter is faster. So, my recommendation would be to get the car as light as you can reasonably get it and then evaluate where you are in relation to the amount of horsepower needed to make you legal at that weight. If you need to add horsepower to get there, great, but most of us find we have too much horsepower and need to carry ballast. If it were me, I'd do the horsepower things last and try to minimize the weight. Good luck! I'll be interested to see what other advice you collect here. Quote Link to comment Share on other sites More sharing options...
kyboxster06 Posted September 24, 2011 Author Share Posted September 24, 2011 Scott, Thanks for your reply and you did help answer some of my questions! My 1:45.80 was on the pro course at Mid-Ohio. I have only had 4 track days there and two of those were in 45 degrees and wet conditions. So I am sure the largest decreases in lap times in the near future will be in skill development. I was at the NASA event in July at Mid-Ohio and I did not see (or at least remember seeing any) boxsters in GTS. That is why I asked this question on this forum. I know a couple of guys involved in the time trial program. But, I don't know anyone in a race series with NASA. I wanted to know if there was a reason that there were no boxsters there or was it just coincidence that there were none at that event. I am not set on the equipment list mentioned in my previous post. These just seemed to be the most popular among Porsche owners that take their car to the track. I just wanted to do a little homework before spending more money than I already have! You gave me some guidance on how to start this project, if I decide to. I "graduated" to HPDE4 in July, so I've got some more track time ahead of me before I start making decisions on what to do. Thanks, Scott! Quote Link to comment Share on other sites More sharing options...
Brad Waite Posted September 24, 2011 Share Posted September 24, 2011 I think Scott's advice is right on target. I've developed two 944 S2 GTS 2 race cars and my experience is that is costs about $50-60k including the cost of the car to build one. Now admittedly that number can be dramatically reduced if you have the time and skill to do much of the work yourself, something I didn't have. So even if you do the work yourself, if you intend to fully develop the car with top notch suspension, minimized weight, fire suppression, data acquisition, aero etc., I think you're still going to spend $25k+. You can find a fully developed race car ready to go for $20-25k. So if you like your Boxster as a street car, another way to go is buy the race car and leave the Boxster alone. My guess is you'll spend the same amount of money and have 2 cars instead of one. fwiw. Brad Quote Link to comment Share on other sites More sharing options...
pmilli319 Posted September 24, 2011 Share Posted September 24, 2011 Brad is spot on with his numbers. I bought my car as a street car for $2500 about 5 years ago. I have tons more in it now and I'm selling it for pennies compared to what I have in it. I've had a Boxster S as a street car and I understand how beautifully they handle. As an added sales pitch, I'll say that this BMW would drive circles around my Boxster S! You should really just buy my car as a great starter race car! viewtopic.php?f=31&t=47575 Quote Link to comment Share on other sites More sharing options...
JSG1901 Posted September 25, 2011 Share Posted September 25, 2011 Brad is spot on with his numbers. I bought my car as a street car for $2500 about 5 years ago. I have tons more in it now and I'm selling it for pennies compared to what I have in it. I've had a Boxster S as a street car and I understand how beautifully they handle. As an added sales pitch, I'll say that this BMW would drive circles around my Boxster S! You should really just buy my car as a great starter race car! viewtopic.php?f=31&t=47575 ...or mine as a finished race car... http://www.nasaforums.com/viewtopic.php?f=31&t=37514 Quote Link to comment Share on other sites More sharing options...
Brad Waite Posted September 26, 2011 Share Posted September 26, 2011 There are a handful of Boxsters running in NASA, including a pretty fast one on the west coast running in GTS2. I know this because he won the Nationals at Miller in Utah last year and I took second to him. If I recall, his was a Boxster, not an S, and was very nicely developed. I think he may have been out of Denver, and you could probably track him down through the results etc. Brad Quote Link to comment Share on other sites More sharing options...
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