Thursday, April 23, 2015

Project Dragon (Drakan Spyder) Update #12: More Track Testing &Improvements

We are working hard with the Drakan and a few weeks behind on our updates.  We been back to the track earlier in April for additional testing and up to Palatov/Lancair for body fitment two weeks ago.  We go back again next week to begin building the first official production car.  Keep reading to learn the latest...

More Track Testing

Joe and Dave went out to Spring Mountain once again to verify some changes that were made to the car. We had to test our new oil pan baffle, front suspension arms, and HRE wheels. 

Our previous test on SMMR's East Course 2.1 showed oil pressure dropping to 11 psi when the car was subjected to two quick successive left hand turns under hard braking. This drop in oil pressure was unacceptable to us - Dave is a pro and is driving the car hard so we know this is an extreme case. In all of our previous testing with Dave, oil pressure data was acceptable.  In fact we posted about our good performance on this blog entry.  Clearly this specific combination of left hand turns was too much for the stock pan to handle.  We got in contact with Improved Racing and had them send us an oil pan baffle and crank scraper kit. With the new baffle installed, our lowest oil pressure in the same corner was 24 psi. The Improved Racing baffle will now be standard on all Drakan Spyders with a Dailey Engineering dry sump offered as a future option.

We had a few handling related tweaks to try out as well; a new set of front wishbones and our new HRE wheels. The steering was a bit heavy on our test mule - even compared to similar cars with no power steering. Palatov redesigned the new front wishbones with different geometry that has less caster built in. These new arms are a drastic difference, the steering is now much lighter, and this should contribute to less driver fatigue both on the street and track.  Dave appreciated the reduced effort at the end of the test day!

The new HRE wheels were also slightly different. The front wheels have a bit more offset and the rears are 0.5" wider than what we were running in previous tests. Dave was pleased with the new wheels, he said the wider front track provided more grip. Admittedly, some of this improvement may have been due to fresh rubber, but the wheels definitely did not hurt the handling. 

Ultimately we turned 1:28s time on this circuit.  This compares favorably with a new Lotus V6 Cup R that is running slicks and a sequential.  This car is turning 1:27s at the hand of our good friend & Lotus Cup champ, Jack.  With slicks, we're sure we can shave a second or two off of our time.

Other updates

The new switch panel is in and operational. The backlighting looks awesome and the switch location and action is spot on. The ignition switch is locking so you can't accidentally shut off the car.  The horn and turn signals can be actuated without removing your hand from the wheel and all the rest of the switches are well within reach. The left hand panel which is home to our master kill switch and brake bias knob turned out well also.

The switch paneling is nice but the new dash from AiM has certainly stolen the show.  We posted a quick video on our Instagram page: HERE.  The MXS is now in production and it is a bolt in swap from our old MXL2. Functionally, it is almost exactly the same; visually, it is in another league. The MXS features a beautiful TFT display that not only looks gorgeous but offers more flexibility for different page displays. There is a street page with a conventional style dial tachometer, a race page with a sweeping tach, and a test page that can display 11 different parameters at once.  We are really pleased with this kit.  The Drakan will will be ready for AiM video so owners will be able to add any of AiM's cameras easily.

The other notable upgrade since our last post are the new rotors. We decided to up the braking performance of the Drakan with some 12.88" rotors from Girodisc, the same people who make our ULTRAdisc rotors for the Elise/Exige, Evora, and soon Alfa Romeo 4C (testing now). These disks are high quality, well proven pieces that add to the performance and reliability of the Drakan. Another plus of our rotor setup is that they are the same front to rear, this ultimately means that replacement rotors are going to be less expensive.  We are thinking about you guys who keep spares and are properly prepared...8^)

Thursday, April 9, 2015

Alfa 4C Update: New Race Exhaust & Brake Rotors/Pads

Our 4C has been racking up some miles and we are finding things we like and others that we don't.  The Launch Edition 4C comes with the factory 'race' exhaust - which drones like crazy.  We had to fix this.  The brakes on track, can be improved, so we started to develop some options.  We now have a couple of solutions that we have been able to test and are under development.

Race Exhaust:
The factory race system has no muffler.  It is a turbo car that does a decent job at killing dBs.  Since it has catalytic converters, it is not as loud as you might think.  It sounds great at idle and when you are really going for it.  It is loud and won't pass noise limits at Laguna Seca - as Eric@SuspensionPerformance found out.  But the real issue for me is the the drone that the car creates when cruising on the freeway.  When you are in 6th gear, anywhere from 2250-3500 rpm, the car creates a resonance that hums so loudly in the cabin that you need ear plugs.  Forget listening to the stereo.  I dreaded having to take the car anywhere that required freeway travel.  Luckily we have a great exhaust partner who knew how to fix our issue.  

We lent them our 4C for about a week so they could measure the frequencies inside our car.  They use sophisticated equipment to map out the frequencies and identify the offending range.  They then employed Helmholtz principles to kill the range that was causing the drone.  This Helmholtz Chamber is a canister that sits outside of the main flow of exhaust and does not interfere with the straight through design.  This allows this system to keep power as stock and not create any additional back pressure or power reduction.  Sophisticated exhaust suppliers are now employing these Helmholtz principles to great effect.  Learn more about this: HERE  

I brought another fellow 4C LE owner, Martin, along with me to pick up my 4C.  See his car above compared to our 4C - note the exhaust tip difference.  We took the car with the prototype system installed and were shocked at the difference!  The car has no drone when cruising.  The only thing you hear is wind and tire noise.  The difference is amazing.  Watch the video we made of the car:

We are now putting the system into production as we know there are many other 4C LE owners who share our opinion.  We believe that once standard 4Cs (with actual mufflers) start getting delivered, our system will become a great choice over the factory race exhaust option.  Now we have to decide on the size of the exhaust tips.  Unfortunately we have to send the prototype system back so they can measure it for production.  The stock system is getting reinstalled until our first production part arrives.  Where are my ear plugs...

Brake Rotors:
Finding unsprung weight savings has always been one of our goals with all of our cars.  The 4C is heavier overall than the Elise/Exige so we would like to find any savings that we can.  We have had great success with our ULTRAdiscs on the Lotus.  Our partner, Girodisc, has been a key ally in our attempts to find weights savings while delivering excellent performance.  The factory rotors are a one piece rotor but are made in a innovative manner that frankly is fairly light.  We had Martin make us some ULTRAdiscs to fit the 4C and found a 1.25lb savings on the rear and .5lb savings at the front.  This is per rotor.  We installed them onto our 4C and ran them on track.  We still had the stock pads and they performed well.  Unfortunately we discovered that the front stock pads were already at about 30% life after 3 track days.  One of our brake pad suppliers worked to get us pads but they did not arrive in time for this test.

Brake Pads:
The pad shape on the 4C are not made by anyone other than the OE supplier so we had to get them specially made.  The pads arrived a day late so we did not track test them.  We received a compound that is not a strict race pad so it should work for aggressive street use.  Stay tuned as we will report back soon.  Looks like we have to go back to the track for more testing...what a rough life!  ;^)