Video of Paddle Shifted S2000
 

I thought this was interesting:


These two articles explain some of the complexities. They assume a dog-gear, sequential transmission in contrast with the dual-clutch synchronized or planetary-gear transmissions used in current production car paddle shift systems.

Exploding the myths about shift times: http://www.geartronics.co.uk/shift_times.htm​

The reality of clutchless auto-blip downshifts: http://www.geartronics.co.uk/blippers.htm

I'm going to assume this is on the quaife seqential

It is.

Geartronics stuff doesn't work on H-pattern shifters.

There are quite a few sequentials that use the Geartronics: Sadev, Samsonas, Albins, Hewland, etc. in addition to Quaife. Quaife does sell a ready to go set up for the S2000 including input shaft and bellhousing. Hewland sells their own paddle shift control, Motec has version of their ECU that support paddles, but the paddles, air pump, air tank, and actuator are separate. Geartronics also has a version for rally cars that mounts on the side of the steering column and shifts with either forward or back pushes.

oooff $11,000 for the trans.

I think it is a bit over $14k for the transmission, plus $4k for the Geartronic paddle shifters. The Motec GPRP firmware and the paddle shifter kit would be closer to $5k, in addition to the M130 ECU itself. Add the time to wire and plumb the setup including fabricating brackets. When the dust settles, a paddle shifted, sequential, dog gear, straight cut transmission is probably $20k. Someone did sell a complete used one for £7000, about $10k...undoubtedly plus shipping.

https://cimg1.ibsrv.net/gimg/www.s2k...2c05cbcb2a.jpg

at $20+k, sell the car, buy a used Cayman with a PDK for the same amount of money. 7950 converted to USD was about $11k. Need the british pound to drop a bit more.... like half, before I'd consider. I'd love to stick one in the K motor car, Did the math on all the gearing yesterday. But I'm done sinking 5 figure mods in this car. 3 figure only from here on out.

PDK is a dual-clutch manual...a different type of transmission. This is a dog gear transmission with straight cut gears; the DCT is a synchro transmission with helical gears. For example, the AMG GT/S/C/R models in all the road tests have a DCT transmission. No one would use straight cut gears and few would use dog gears (there is only one Fiat not available in the US) for a production street vehicle. However, the AMG GT GT3/GT4 models, sold as complete racing cars, have a sequential, spur gear, dog gear engagement transmission with paddle shifters. Ditto the Porsche track GT3R, etc.

For street use, the Porsche would be better for a lot of reasons. As a dedicated race car, it's probably less expensive to run an S2000...just the F-series/K-series motor costs vs. a Porsche-anything would be a huge difference.

You'd get an extended warranty on the porsche lol.

This. you can get a gen-1 Cayman for less than $20k, have them pull the motor and do the IMS upgrade and still have spare cash on the side to buy some JRZs and have yourself an awesome track car with paddle shifters from the factory.

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

The wear point on dog gears is their square edges become rounded. Easy to see why...they have between 1/8th and 1/4th a revolution to engage. If enough of the dog isn't engaged, they will push apart rounding the cornered. If more than 1/4 the height of the gear is rounded, they need to be reground or replaced. Expensive either way. This is a rounded dog gear:

https://cimg7.ibsrv.net/gimg/www.s2k...b5aa957cdc.jpg

It's been a very long time since I've been on a motorcycle. The only hands-on with a dog box in a car was when I had a Formula Ford in the 1970s. However, if the box has dog gears it is the same, bike or car. Upshifts require a lift and a pull. Flat out shifts are done electronically by sensing the tension on the shifter and cut the engine with fuel interruption, ignition retardation, or blipping the throttle itself. Paddles replace detecting the tension with an actual electric signal. Flat out shifting done with a fuel cut is very popular for turbos because the turbo stays spooled.

Downshifts are tricker in a car or bike. The throttle needs to be blipped to release the dogs and then further to match revs, all while not interfering with the car's balance. The paddle shifters, or rather the controller connected to pneumatic shift operation and the engine, executes that dance far better, similar to the way traction control or abs controls the car in ways and at speeds the driver can't match. The motorcycle articles are mixed on it. There are instructional videos, and videos advising against it. It has to be very tricky on a bike since the rider is operating the front brake and throttle with the same hand.

Because of the need to match revs in a very short time and for the engine to provide minimum disturbance to the rear wheels on a downshift, lightweight engine internals and clutch is virtually a necessity.

This is a motorcycle video on it:


This became an active issue for me when someone with an SCCA GTA car (a converted super late model stock car) said he used a Jerico transmission and was able to clutchless downshift. I was examining the possibility of converting my super late model for road racing. The transmissions used in road racing stock cars, from Jerico, Andrews, G-Force, Roltek, are all straight cut dog gear transmission with H-pattern shifters. If using a sequential shifter instead of an H-pattern, it would be similar to the selection for the S2000.

Numbers are off a fair bit.

$9700 shipped: quaife box - https://shop.quaife.co.uk/honda-s200...elical-gearbox
$4500 shipped: paddle shifter - Geartronics - Sequential gearbox electronic systems - Professional paddle shift system
$400 shipped: gear indicator
$15,000 for everything..

Or KISS and just get the gearbox from quaife, then the gear indicator and GCU from geartronics and you're out $11,000ish.


You don't need an engine management system to control upshifts, since this is handled by the geartronics GCU.
I'm pretty sure the gearbox will fit the OEM mounts and prop shaft (not sure if AP1 or AP2 though).
Also, the gear selection seems to be only for helical gears and not spur / straight cut -- so quieter for street use, weaker for abuse.

Quaife in the US gave me the price. Not sure if the UK can ship around them. The price difference with Geartronics is rounding error. Geartronics isn't the only provider (e.g. https://www.proshift.com/proshift_ps35_paddleshift). Someone sold the Quaife trans and Geartronic here a year ago for £7000, which would have been less still.

Quaife offers helical and straight cut gear version. Others are usually straight cut only. However, any dog gear transmission other than a paddle shift where the ECU or GCU controls everything is going to be a bit of a challenge on the street. People have done it and PPG has a video of it being driven on the street. Porsche and MB sell GT3 and GT4 race cars, all with paddle-shifted sequential straight cut dog gear transmissions. On the street versions both use dual clutch transmissions.

Ordering from Quaife North America means you're paying 10%-20% more.
I ordered mine from Momentum in the UK. They shipped direct to me in Vegas. I also ordered when the GBP:USD was at 1:1.24 vs. the 1:1.39 it is right now.

Yep, for a used kit, you would have saved yourself a few thousand.
And yes, geartronics isn't the only game in town, but that is what the above S2000 is reportedly have used.

Just not for the S2000's QBE60G box, although I'm sure you could probably piece it together with other gears -- it just appears to only come as one set of gears with the kit. See quaife's website, with the link I posted above.

It's not a challenge --- it's the accelerated wear that's the issue. As you mentioned above, the dogs will eventually wear.
Other than the accelerated wear, the inability to go from 5th to neutral in an instant can be bothersome. In your standard H-pattern, you just move the lever into neutral. Sequential, you push the clutch in and just row thru them.
There is also a greater chance of shift-locking a sequential...

The real benefit of the sequential, at least for my use, is staying in boost between shifts.

DCT is a completely different animal from what this thread is about...

It is great to have someone who actually owns one to chime in. Do you have the Geatronics paddles on yours?

Quaife lists a lot S2000 gearboxes, most with straight cut gears: https://shop.quaife.co.uk/gearboxes?...r=66&model=339

They rate the QBE60Q to 375hp, the QBE69Q to 750hp. They list helical and spur gears for both.

I thought it would be a challenge because of the need to always make quick shifts to protect the dogs; I may have been thinking more of an H-pattern dog gear transmission. Drag racers use a straight cut dog gear transmission with a shifter that gives sequential like upshifts, but not downshifts. The paddle shifters probably make that easier, but tuning the GCU for the wide range of street driving conditions has to be difficult.

Do you use yours primarily on the street? Do you have paddle shifters? If not, do you do clutchless shifts up and down? Do you have an aftermarket dash or a gear indicator to indicate the current gear? Do you have shift lights? Did you make any other modifications, such as a lightweight flywheel and clutch?

To clarify, I have a QKE8J attached to a K24 in a Noble. Different, but similar.

Quaife underrates their boxes, and doesn't provide peak torque -- which is the important number. I have 630bhp / 450tq thru mine and haven't had an issue with it yet, other than accelerated dog gear wear. There are Kswapped Lotus with the 8J running similar power without issues, as well as a handful of big hp drag cars (ie. 800whp+) running them without failure.

You just have to make sure you are deliberate and forceful with your shifts. H-patterns want buttery smooth shifts, dog engagement want anger filled shifts.
Just to make sure everyone is on the same page, dog-engagement and sequential aren't synonymous. You can have an H-pattern gearbox and dog engagement -- you could also have a synchromesh sequential gearbox.

Mine is mixed use between track, autocross, drag, and street.
I don't have the paddle shifters (adds too much weight for my application), but have researched geartronics setup -- I do use their GCU, gear indicator, load cell, and potentiometer to handle the flat shifts and gear display.
The engine setup is built to handle +900hp, so lightweight flywheel and other stuff has been beefed up.

Not a fan of how the padels are mounted to the wheel and not the column.

The rally system has one paddle on the column that is pull for upshift and push for downshift. They also retain the level. As far as I can tell, all the racing systems mount the paddles to the wheel.