Project 996 Road Rallye: Part 6

We installed the Girodisc 2-piece rotors as the car needed new brakes.  I wanted to save some weight if possible - which we have.  But I want to do down to 17" rims.  We bought a wheel measurement tool to better estimate what offset/width and diameter could possibly work.

GiroDisc weights: 

• Front: 17.95 lb each 
• Rear: 15.25 lb each 

Our stock rotors were worn so I searched for better weights.

OEM-equivalent weights (ours): 

• Stock front: ≈ 23.1 lb each (18.7lb)
• Stock rear: ≈ 14.6 lb each (12.55lb)

Weight deltas (per rotor → per axle → total) 

• Front: 23.1 − 17.95 = 5.15 lb saved per rotor → 10.30 lb per axle
• Percent change: 5.15 ÷ 23.1 ≈ 22.3% lighter per rotor 
•  Rear: 15.25 − 14.6 = 0.65 lb heavier per rotor → 1.30 lb per axle (heavier) 
•  Percent change: 0.65 ÷ 14.6 ≈ 4.5% heavier per rotor 
•  Net vehicle change (all four): −9.0 lb unsprung/rotational mass (mostly from the fronts). 

 What that means on the car The fronts deliver the big win: ~10.3 lb unsprung + rotating mass off the nose, plus larger diameter and better cooling. The rears end up roughly stock-like in weight (slightly up), which is normal for upsized rear rings on two-piece kits.  

Girodisc upsized their rotors vs the stock sizes.  Why?  The rear stock rotor houses a drum brake for the handbrake.  To clear this, Giro have to make their rotor larger.  They then enlarge the front as well to maintain the brake bias.  The benefit is larger brakes for more over heat capacity and performance.  So overall, a good tradeoff - lighter unsprung weight and more performance.

The wheel tool that we used suggests that a 17"x8" rim could work for us at the front.  This would be great as we would like to run tires with more sidewall.  Once the Elephant Racing dampers arrive, we can install and do a proper measurement.

Project 996 Road Rallye: Part 2

The car is in rough cosmetic condition.  It needs quite a bit of things inside and out.  The old window tint was bad and the windshield was cracked.  We got those sorted as we waited for additional parts that we ordered from Elephant and Girodisc.

We pulled the front and rear fascias off the car.  This gave us a peek at what we would secure tube bumpers to.  Our fabricator, Danny, came by to assess the possibilities.  We plan to create a fair discrete bumper that will allow us to hang driving lights while also providing some protection from parallel parking.

Overall the car appears to be in decent mechanical condition. There appears to be an oil leak coming from the engine that we will need to investigate. We have the car scheduled for a dry ice cleaning of the underbody.

While under the car, we noticed some opportunities for improvements.  Expect some new ideas from us soon.

The front facia was pretty bad and I managed to find a good used one along with a front DS fender.  The front headlights have washer nozzels - one of which is broken.  We are deleting these along with the pumps and associated hoses.  That'll save a bit a weight.

Wheel and tire considerations are proving to be a bigger challenge.  The suspension will sit 1" higher and ideally we would like to go with taller sidewalls.  We are working closing with Paul at Braid USA on solutions.  Two wheels I like include the Rallycross and the Dakar.

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!  ;^)

New Sector111 Race Elise Build: White Rascal

We have been searching for a crashed Elise that we could build into a Spec Elise track car since selling our Exige S.  We finally snagged one from our good friend Ryan.  This car showed up a couple weeks ago and we cleaned it up a bit and organized our build plan.  Essentially this car will be another test mule for us in addition to potentially becoming a rental car for Lotus Cup racing.  As a result, we will keep the build fairly simple.  If any of you are interested in this car, let us know.  We would be happy to build it to your spec...

The car is stock though it came missing many bits.  It had suffered a crash that damaged both clams, one side sill and a door.  We will replace the clams with our Spec Elise clams front and rear as several clients have done in Lotus Cup.  These clams are lighter and easier to repair than stock.  Plus they lack the openings for lights which is another advantage that prevents those items from popping out during a race.  Don't ask us how we know this...The chassis is straight and undamaged so we will simply clean her up and bolt on our tasty bits.

The car will run as a normally aspirated car to start.  Eventually we may install our KATANA265.  The brakes and suspension will all be upgraded.  We'll address the typical failure areas like radiator, steering rack, shift cables.  Reliability and safety are our top goals so we will avoid any drastic modifications.  Our R3cage will get installed along with harnesses a race seat and fire extinguisher.  The TrackTrilogy of Terror will be taken care of right away as well.

We've named this car the White Rascal.  You'll have to ask us why next time you call us or see us.  The car is actually silver so we may be off a bit...We are working on this car in between client's cars so it may take us until the end of the year to have her running.

Really Filthy

Less Filthy

Correct Brake Rotor Venting

We often get asked what is the correct orientation when installing directional brake rotors. The correct orientation of the vanes is a subject often debated. I wanted to take this opportunity to clarify it with help from my buddy Martin from Girodisc.

From Girodisc's website: For maximum airflow and superior cooling, the Girodisc system uses curved vanes. For a curved vane internally vented disc, the geometry of the vanes dictates the direction of rotation. A curved vane disc must be installed with the vanes running back from the inside to outside diameters in the direction of rotation. Your discs will come with labels indicating their correct placement on the vehicle. Orienting the disc in this manner creates a centrifugal pump. The rotation of the disc causes air to be pumped from the center of the disc, through the vanes, and out through the outside diameter of the disc. This greatly enhances the disc’s ability to dissipate heat. Discs installed backwards have very limited cooling.

Many clients wonder if their brakes are good enough. The truth is that most stock Lotus will run fine on track with the stock brakes. The advantage of our lightweight cars is that we don't actually generate that much heat when braking properly. We've tested brakes temps and posted about it last year: see brake temp post. Of course as drivers get faster they realize that the stock pads lack the initial bite they need to be confident when out braking those pesky GT3s. Or when they have burned through their original rotors they start looking for alternatives.

Our discNOIRs, ULTRAdiscs & CUPdiscs all come from Girodisc and therefore use curved vanes to maximize the cooling potential. Now that cars are running higher levels of power, with slicks and serious downforce, we are starting to see more heat in the brakes. Running properly vented rotors, better pads and fresh brake fluid usually is enough to keep a modified Lotus stopping on a dime - repeatedly. We use our AP Rotor paint to see how hot they are really getting - before jumping to conclusions.

But for those who need more, we have more BBK solutions coming.....we are now testing a bracket that relocates a stock front caliper to the rear - especially tasty for clients running our 308BBK or a Lotus Sport upgrade. Stay tuned as we are still mental as ever...

New Wheel Studs & SS Brake Lines

We installed a set of our new BULLETstuds onto Project Nirvana. I've used these on my previous Elise and on our last Exige. I love this kit as it makes wheel changes a snap. The quality of the kit is excellent and we have finally sourced some black nuts to keep it discrete. Another key advantage is that it eliminates the need for the Lotus wheel bolt key AND locking key. The lock key was prone to failure and worth eliminating ASAP.

We also installed some new stainless steel brakelines from Girodisc. These are a good addition to any track oriented car. New stock lines are usually adequate for most but over time they begin to deteriorate and soften causing additional softness to an already soft brake pedal.

The red lines add some additional flash to our wheel well area. They also come in a more subdued silver color. You can find them: HERE

Now we need to bleed the brakes....