The Cayman first had the PDK in 2009. Isn't the IMS (IMS 101 – IMS Retrofit) only needed through 2008? Are 2009 Caymans with PDK really under $20k? Ian has a dry-sumped, 4Piston 2.5L K24 in a car with extensive race preparation. Would a 2009 Cayman really be comparable without similar modifications or would that require a 310hp 2.4L Cayman S?

according to this article

https://blog.caranddriver.com/shift-...transmissions/

PDK was first introduced in 2005 with 7-gears.

As for Ian's K24... LOL! Ask him how much all of the development trial and error cost him. He could have easily had a 997 GT3 with the money spent on that car.

He could have just ordered the engine from 4Piston and a K24 conversion kit and been pretty close. But he has it working...with lots of trick stuff (e.g. dry sump, is current intake tuning, etc.). Doesn't NASA apply a penalty for the S2000 suspension over the Cayman? However, it is mid-engined, the engine larger (significantly in the S) and potentially more powerful.

It wouldn't be hard to spend $60k building a race S2000. Even the least expensive new Spec Miatas are in the $35k-$40k range by the time they are complete. Equivalently equipped a Cayman would be over $100k...Porsche stuff is expensive.

For a track day car, a new Cayman with PDK and other performance options only would be $65k...add maybe $10k to make it a workable track day car. For W2W, a used SRF3 is around $30k and a Spec Miata capable of a top 5 in an SCCA Majors is maybe $25k. The pole-sitting STU Honda S2000 was a second quicker than the pole-sitting SRF3 at the SCCA runoffs. The difference is 5 cars within 2 seconds of the pole in STU, 15 in SRF3. There was also an S2000 in E-Production. Wasn't the reason for going K24 to win in STU?

My docs say the 2008 was Tiptronic: http://press.porsche.com/vehicles/08...cs_UPDATED.pdf

All of Porsche's current race cars, except the Cayman GT4, have sequential dog gear transmissions: https://www.porsche.com/usa/eventsandracing/motorsport/

Yeah, you're right on the pdk. I did more searching, pdk first in 2009.

In any case, I'm not sure where the s2k is competitive that it's "worth" it to spend $20k to drop in paddle shifters. I feel like a lot of the character of the car is the OEM shifter, but hey, this is the R&C forum, so yeah, I get that the intended use is racing. Hardly anyone actually races the S2K at that level anymore. The vast majority in here are amateur time attack, HPDE cup, scca auto-x str, or some sort of NASA TT class. Very few of those are going for the posted application, the most i'd venture seeing someone doing is a quaife sequential along the lines of Hartanto or Hazelton's STU cars.

An S2000 was on the poll at Indy in STU and led comfortably until it had mechanical problems. The trouble with all the SCCA and NASA classes is that other than SRF/SRF3/SM and occasionally SpecE30 or SSM (at Summit Point), all of the classes have a very small turnout often with huge gaps in lap times. The SCCA runoffs are a once a year thing.

In a dedicated race car, the paddle-shifted sequential dog gear transmission makes sense. It gives seamless, quick shifts up and down and lets the driver focus on driving and helps enable consistent left-foot braking. It is expensive. The sophisticated controller of the pneumatic shifter is key to making that happen. The upshifts can be done reasonably, but the downshifts require the blip to release the dogs rather than just match revs. The controller matches revs and allows full-throttle upshifts. The articles linked at the top cover that.

While PPG has done videos showing how it can be used on the street, it is hard to imagine where that is cost effective for a dual purpose car. If the driver needs paddle shifters, there are a variety of paddle shifted dual clutch and torque converter (e.g. Corvette) automatics.

However, Ian's car would be one where this makes a little sense, budget permitting.

Talk Quaife into giving me a Price I can't refuse and we might be in business. FYI, I've been eyeing sequentials for YEARS for this car. I'd really like to do a before and after lap time diff with one. I just haven't been able to justify it. The Paddle shift is neat, but spending an extra full season of tires pricing just cause you can't reach down....... that's hard to jusify.

THIS^^^^ It's made me very jadded against modding cars and rule sets that require extensive modifications (time attack). It has really expanded my fab skills and engineering skills and for that I can't complain. But yes it's been A LOT of money and trial and error. The amount of money my trail and error has saved others though..... Note to self, next time I decide to build a car...... don't be the 1st one to do it.

Did the Math on the Quaife Sequential gearing. It would be like adding 12hp AVERAGE to my power band due to the closer ratios. Be nice if someone offered closer gears for he standard trans so you didn't take a hp to weigh hit for Nasa.

This is a less expensive sequential box for the S2000. It would still need the Geartronics paddle shifters, as the Quaife: IL300 6S EVO 2 – Inline 6 speed sequential - Elite Racing Transmissions They offer a selection of ratios and you could go to just sequential first, and add the paddles later although making sure a compatible paddle kit is available before the purchase is a good idea.

https://cimg9.ibsrv.net/gimg/www.s2k...ba1f1c5345.png

Is this for STU or a different class? Doesn't STU require the OEM intake manifold? I'm guessing the 4P 156 heads don't meet the porting restrictions and there are probably other things that are off.

The power gains from straight cut gears would be lost on NASAs dyno. NASA also allows liberal suspension (apparently any control arms and spindles and very wide track) and aero modifications (rear diffuser, cooling airflow/ducted hood) in ST3.

thanks for the great info David, sounds like the auto throttle blip is very complicated to setup correctly on your own, without it i guess you still have to use clutch and heel & toe, which kind of defeats the point imo.

why is it that motorcycle transmission can downshift without auto blip, and no clutch. What's the difference exactly