Unveiling the BMW Z4 GTE – ALMS – Out With The Old, In With The New

Unveiling the BMW Z4 GTE – ALMS – Out With The Old, In With The New

 

copy from http://www.stanceworks.com/2013/02/bmw-z4-gte/

-February 14, 2013-

Unveiling the BMW Z4 GTE – ALMS – Out With The Old, In With The New

Mike Burroughs

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4:00 AM came earlier than expected. We were 2500 miles away from home, en route to the Daytona International Speedway for the grand unveiling of the all new BMW Z4 GTE, long before the sun had even considered making an appearance. The track sat silent and empty, and BMW's crew had yet to arrive. Tucked away in the paddock bays sat BMW's lineage of race cars, ranging from the Donohue E34 M5 to last year's ALMS E92 twins. In the furthest bay sat the BMW Z4 GTE, tucked under an opaque black cover, waiting to see the light of day. 2013 has marked the end of the E92 M3 GT's ALMS campaign; with the E92 M3 at the end of its production cycle, and its race car counterpart burdened by restrictions that have killed its competitive edge, BMW has been hard at work on its replacement for the upcoming season. Despite its great victories, every hero's tale must come to and end, and with every end marks a new beginning.
For those keen to BMW's current racing lineup, it will come as no surprise that BMW is replacing the M3s with it's more recent racing platform, the E89 Z4 Coupe. The Z4 GT3 chassis has held its own on more than just a few laps on countless foreign circuits, including a win at the 24 Hours of Dubai in 2011. However, America's BMW Z4 GTE is a ground-up redesign of its GT3 counterpart. Little remains the same, as regulations and standards set by IMSA, ACO, and others require more than just a set of intake restriction plates. Extensive windtunnel testing  has brought about an entirely new body, molded from carbon fiber and glossed with bright white and the renowned Motorsport stripes.The wide arches, front and rear, hang over the faintly visible factory lines in a display of immense width and true racing pedigree.
The front is reminiscent of the outgoing M3 GT; the arches roll off the front bumper and then angle in to meet the body after the arch closes, butting up against the ALMS position lights that reside on each fender. The true departure is at the tail of the car: the capacious flares widen the car almost a full eight inches. Following the redesign from the GT3, the lines are all-new, and more radical than ever, with the shape of the tail lamps being held out to the edge of the car, and a tail width that makes the GT3 seem rather scrawny. Tucked under the tail end is a massive diffuser, spanning the full width of the car, paired with a massive spoiler up top to create as much downforce as possible. In a sport as fast as this, aerodynamics play a crucial role in shaving those vital seconds off of the total race time.
Under the carbon fiber heavily-ducted bonnet rests a newly-designed 4.4-liter variant of its GT3 counterpart. The 32-valve aluminum V8 pushes out a restricted yet visceral 473 horsepower and 354lb-ft of torque, thanks to a pair of 29.4mm restrictors tucked behind the kidneys. The power is delivered to the rear wheels through a six-speed sequential manual gearbox, and delivered to the tarmac through a pair of 18x13 forged BBS monolug wheels. Up front, 18x11s hug the ground, shod in  300-680-18s. 310-710-18s wrap the rears, proudly displaying the new tire sponsor for team RLL. Dunlop has pulled from ALMS to focus on its European racing, and in its place, Michelin has moved in. However, the new tires come with a warm welcome.
To keep the tires planted, the Z4 GTE's suspension is once again all-new. McPherson struts up front and wishbones front and rear provide the handling BMW is known for. AP Racing provides the stopping power once again, utilizing  monobloc multi-piston light alloy brake calipers, inner-vented steel brake discs, and brake-balance adjustment available to the driver at any time, front and rear. Unlike the GT3, however, the GTE is not allowed any electronic driving aids, such as antilock brakes, stability, or traction control - a pivotal reason for much of the redesign. So how does the GTE stack up to the production model?  At 4 inches lower, 6 inches longer, and as mentioned before, 8 inches wider thanks to the gargantuan fenders, the GTE  fits more into the category of "muscular cousin" instead of "sister" to the road-going Z4 3.5iS. It's also, staggeringly, 700lbs lighter, totaling 2744lbs, thanks to ACO stipulations.
To pilot the cars to victory, much of last year's team is back. Bill Auberlen heads the list, embarking on his 17th year with BMW. Having driven BMWs in more races than any other driver in the world, Auberlen is as synonymous with BMW's racing success as history's greatest -  Paired with Auberlen is newcomer Maxime Martin from Belgium. While young, Maxime's success is nothing to balk at - and the pairing of the two is sure to bring trouble to BMW's competitors. For the sister car, Dirk Müller is back, along with America's own Joey Hand and the new team youngster, John Edwards. At just 21 years old, John already has several championship wins under his belt and is sure to be a solid addition to Team RLL. It will be interesting to watch as the newcomers and team veterans work together in their pairings to navigate the Z4 GTE duo around the ALMS courses.
With their new car in front of them, the drivers took some time to familiarize themselves with the cockpit where they’ll be spending countless hours in the coming months. Stories of lessons learned in the M3s were traded as they all looked over the Z4 in anticipation. Over the course of our trip, it was clear that an enthusiastic energy existed throughout the BMW Motorsport and Team RLL camps. It’s nearly time for them to get behind the wheel for another season of racing and they all hold high hopes for the races that lie ahead. In a team meeting, Auberlen expressed his enthusiasm for the coming season, “Every time a new car comes out, it renews hope. I didn’t need much more hope after the M3 because it seemed like it was ready to win everything, but whenever it comes to BMW and a new car, I think you’re going to see it on the victory podium and I’m very excited.”
After unveiling the car, Joey Hand took to the track for a quick, albeit short pair of laps for a brief demonstration, as the team was imited to just two laps at a time to avoid any penalties for "testing" the car. Dirk Müller is the only driver with serious seat time thus far - the Z4 GTE began as a mere blueprint only seven months ago. Developed in just six short weeks, the car was disassembled and shipped to Ohio where the Team RLL Headquarters resides. While car #55 was unveiled to the press, #56 is busy with testing in Spain. To add to the stress of preparing, the cars premiere at their first race in just a month.
The race? The 12 Hours of Sebring; one of racing's most prestigious races and one of the three legs of the "Triple Crown of Endurance Racing" alongside the 24 Hours of Le Mans and the 24 Hours of Daytona. The Z4 GTE will go head-to-head with last year's champions, Corvette, as well as the likes of Ferrari, Aston Martin, Porsche, and SRT's Viper, and the grueling race will truly push the newborn GTE to its limit. With just one month to prepare, there's no telling how the pint-sized BMW may fare. Rahal considers this season a "developmental" one, as it's unlikely that the car won't have some kinks to work out. However, after BMW's 20-year hiatus from DTM, Bruno Spengler won the 2012 DTM Driver's championship, allowing BMW to take home the Driver's, Team, and Manufacturers Championship titles in the inaugural year of the M3 DTM. Perhaps similar early success isn't too unrealistic; after all, while the GTE is all-new, the BMW has extensive practice and research under their belt regarding the Z4 has a whole.
With the M3 GTs sent off to to be little more than museum pieces, brought out for track days on rare occasions, it's now time for the Z4 GTE to shine. It's a mere 30 days until the pair of GTEs take on the 61st 12 Hours of Sebring, and with a bit of luck, perhaps we'll see BMW take home yet another victory. Until then, we wish Team RLL the best in preparation and testing for the big day, and we hope to see some StanceWorks fans there as well.

Sneak Peek: Daigo Saito's Achilles Tire SC430

copy from http://www.motoiq.com/magazine_articles/id/2698/sneak-peek-daigo-saitos-achilles-tire-sc430.aspx

 

Sneak Peek: Daigo Saito's Achilles Tire SC430

By Mike Kojima

After two years of rumors and plenty of gossip, it finally happened, Daigo Saito, reportedly the best drift driver in the world arrived on our shores with not just a splash but a bang.  Daigo, 2008 D1GP champ and 2011 Formula D Asia Champ came out of the gates hard at the Long Beach season opener with a third place.  Daigo has fought hard on foreign soil maintaining a solid second place in Formula D standings for much of the year.
There are many rumors surrounding Daigo's car which has been reported as having as much as 1300 hp.  The fact that Daigo and his crew don't speak English and that they are somewhat secretive about their car, has kept many fans wondering about what makes it tick.  We don't directly know all of the car's specs either, but we have photos and I will attempt to give you a technical tour around the car.  It is an interesting blend of both Japanese and American Technology.

Daigo took the old guard of US drifting by storm with surprisingly strong performances.

Daigo sometimes runs the SC430 with the hard top on if it is raining or to shield him from smoke.

Perhaps the best follow driver in the world, Daigo's aggressive, super close proximity, in your face driving style has angered some drivers like Luke Lonberger and Justin Pawlak.  A lot of Daigo's controversial driving tricks are probably due to the differences between what is acceptable in D1 vs FD in part and the fact that he is a rookie and just getting to learn some of the courses that many other drivers have been driving for years.

2011 FD champ Dai Yoshihara has been able to defeat Daigo with each encounter in the 2012 season so far.

Conrad Grunewald has had more battles with Daigo than any other driver, fighting numerous one more time bouts from road Atlanta to New Jersey.  The battles have been controversial and have resulted in some motions by FD to more clearly define scoring and DQ criteria for the season.

 

This is the most powerful engine on the Formula Drift Circuit by far. The engine that strikes fear in the hearts of LS swapped drift cars everywhere.  Daigo's SC430 is powered by a 2JZ rumored to have as much as 1300 hp.  Personally we think 900-1000 hp is much more realistic but there is no doubt that Daigo's car is very powerful.  Daigo's engine uses a Brian Crower 3.4 liter stroker kit which has a billet 94mm stroke crank and 87mm JE pistons using a 2618 alloy asymmetrical forging with a contoured undercrown, hung on BC 5.59 center to center H beam rods.
The engine uses a 2JZGE cylinder head, presumably to take advantage of the VVT-i variable cam timing system on the intake cam.  This can give needed faster spool and a wider powerband, we think as much as 100 lb/ft in some parts of the powerband.  Daigo uses Brian Crower cams and HKS timing gears with all the related valve springs by Brian Crower as well.  A heavy duty HKS timing belt is also used.  The heads are probably mildly ported with a good valve job.
The engine has a rear mounted radiator so the layout of the plumbing for the engine's front mounted Greddy core tube and fin intercooler can be very simple and straightforward for minimal volume while still being large diameter for good flow.  All couplers and hoses are burst resistant 4-ply HPS silicone parts.  HPS also supplied all of the postive locking stainless T-Bolt clamps as well.
The secret behind Daigo's awesome power is a Garrett GTX4294R turbo.  It uses a billet compressor wheel with better aero and maximum compressor efficiency with a ball bearing CHRA for faster spool.  It has an exhaust A/R of 1.2 with a divided housing to speed spool time with a pulse converter exhaust manifold.  The turbo can provide enough airflow for over 1100 hp.
A fabricated intake manifold with a large surge tank is used to feed the big stroker engine.  An enlarged throttle body feeds the big plenum.
An HKS GT50 wastegate is used to regulate boost pressure.  The exhaust manifold is an HKS tubular stainless piece designed for pulse conversion with a  twin scroll exhaust housing on the turbo.  This speeds spool by over 500 rpm. The unusual stainless mesh air filter is made by Blitz.  It filters better than you might think and has very low restriction. A Greddy RZ 40mm blow off valve helps reduce turbo compressor surge. Greddy also supplied the oil cooler adaptor.  The adaptor has ports for oil pressure and temperature sending units for the Racepak dash. The exhaust is a large 4" in diameter stainless part.  To flow enough gasses for mega power you need a big exhaust! Yes, Daigo's car has nitrous.  It's probably the reason why the rumors of 1300 hp started.  The 10 lb bottle has a heater and one bottle lasts a FD weekend.  We think that the nitrous is only used to spool the turbo quickly and shuts off once a certain boost pressure is reached.  Daigo typically does not use the nitrous in an event's early practice sessions and you can really hear the difference in exhaust note and how fast his engine responds when he turns it on in later sessions once he learns the basics of each track.  The nitrous is the key factor in levelling the playing field against the V8's.  With nitrous, you can have the low end power of a big V8 with the tremendous top end power of a turbo.  Daigo's power is one of the key factors in his success this year. Under the dash, Daigo's car has typical Japanese style engine management which is a somewhat confusing bundle of magic tuning boxes.  The basic fuel, spark and cam control maps are controlled by the large gold box which is an HKS V-Pro stand alone ECU. The next box is an HKS part that converts the stock waste spark ignition system to an individual coil direct fire system and  the final box is a Greddy Profec boost controller.  There is another box we think it's a Racepak multiplexor for data logging.  Bulkhead terminations for the wiring and plumbing would be safer as well. The rear of Daigo's car is almost more interesting than the engine!  In the interest of having as much weight rearward as possible, nearly every moveable component is relocated to the rear of the car.  This offsets the forward weight bias of the long 2JZ. The back of the car contains the heat exchangers for coolant, and oil as well as their attendant surge tanks.  The fuel cell, nitrous bottle, rear wing supports, battery and reservoir for the interooler and radiator sprayer are also located back here. The whole back of the car is supported by a delicate, super light bird cage arrangement of small diameter aluminum tubes bolted to the frame rails.  Although the construction is exquisite, we feel that this is much too fragile for the rough and tumble world of pro drifting and it leaves many critical components exposed to potentially crippling damage.  Most typical FD cars use larger diameter seamless or chromoly tubing for the front and rear fabricated subframes. The critical heat exchangers are also the most rear mounted components and prone to damage.  A good hit can cause the car to be taken out of action.  Koyo makes the radiator and oil cooler and you can see the electric Davies Craig water pump back here as well.  Don't get us wrong, this is beautifully made, super trick stuff but it makes the car less robust in a semi contact motorsport. The cooling fans are located under the car.  The screen was added after Long Beach as it was found that debris could easily fly up and hole the radiator. An Odyssey dry cell battery provides power for the car's systems in a safe lightweight package. This fabricated aluminum tank is the water reservoir for the intercooler and radiator sprayer.  A high pressure AEM water injection pump is used for spraying the radiator and intercooler. Water is added every round to the rear mounted tank to help keep things cool. Daigo's car runs on VP C16 fuel.  C16 is really good turbo and nitrous fuel.  The fuel is transferred from the fuel cell to the engine via twin Bosch 044 fuel pumps. Like the rear of the car, the front has a beautifully fabricated aluminum sub structure.  We feel that this is easy to damage.  Fortunately since the radiator is in the back, it can crush quite a bit before it gets into critical components.  On most drift cars this structure is made of seamless mild steel or 4130 chrommoly for better impact resistance.  This lightness of construction probably contributed to the car's heavy damage suffered in the Las Vegas round. The roll cage is Formula D compliant and is sort of minimalistic.  Many Japanese drift teams feel that the cage should be flexible to help the car find traction.  This is the opposite of what many of the better American teams feel who build stiffer cages with more triangulation. The cage is minimalistic lacking the triangulation seen in many of the top US cars.  This is an area where a lot of US built cars are triangulated. The pedal system is very simple as it is just using modified stock Toyota components.  This is very different from most US drift car that use racing pedal boxes with dual brake master cylinders and balance bars to adjust brake proportioning fully.  Daigo's car uses a stock master cylinder and power brake booster.  The lightweight clutch pedal operates a Spec twin disc clutch using metal discs and a lightweight flywheel. Daigo can adjust his brake bias to some degree with this hydraulic proportioning valve.  Unlike dual master cylinders and a balance bar where you have full control of the brake bias, the valve can only adjust the slope of the rear brake pressure curve after the knee point. Daigo uses a driver controlled drift brake operated by this lever attached to a Willwood master cylinder.  The shifter goes to an exotic sequentially shifted Holinger dog type, close ratio, six speed transmission from a GT300 JGTC car.  The close ratio six speed reduces the need for a quick change rear end like many US drift cars run. US thinking is to use a strong and light 4 speed NASCAR style gearbox with fine tuning of the final drive ratio via a quick change rear end. The rear brakes and the drift brake are Wilwood Dynapro 4 piston calipers.  We were looking at the offset in the rear brake rotor hat and are pretty surprised that the cars track was widened so far by spacers.  This puts a lot of strain on suspension components and wheel bearings.  A wave type, solid sprint car rotor is used.  On a sprint car this helps clear dirt from the brakes but we suspect that Daigo uses these rotors for lighter weight and looks. The front brakes use a 6 piston Wilwood Dynapro caliper with a solid wave rotor.  When using the stock master cylinder, careful attention has to be spent on caliper fluid capacity and the ratio of caliper piston sizes.  It is interesting that this works out Ok. Daigo's office is very straightforward, all RHD using the stock Toyota dash shell and carbon panels.  Note how the cage does not extend past the dash. This is not good for stiffness or footwell intrusion protection but is consistent with the JDM chassis flexibility line of thought. The switch panel contains the master cut off switch, ignition kill, start button, dash, lights, nitrous system and fuel pump switches. it also has a nitrous bottle pressure gauge and a Blitz boost controller.  The Blitz boost controller is the primary boost control and the Greddy Profec under the dash is a back up boost control.  We are uncertain as to why the team feels that two boost controllers are needed. A PLX Devices M-300 wide band a/f ratio gage is used. This is the arming switch and sprayer button for the intercooler and radiator water spray. A deeply dished Prodrive steering wheel is mounted to he stock steering column.  A Racepak digital dash and data logger is also used.  The red T-handle is the activation lever for the Safecraft fire system. The Safecraft fire system employs FE36 extinguishing agent.  FE36 is the replacement for Halon 1211.  It does not damage the ozone layer like Halon and is less toxic while still extinguishing better. A Seibon dry carbon hood saves a bunch of weight and has functional vents that help keep the 2JZ cool.  The hood has survived some pretty decent impacts without breaking!  The front fascia, rear bumper, fenders and side skirts are also Seibon dry carbon.   Daigo sometimes runs the gutted out stock top.  On some occasions this is for rain and on others to reduce the amount of smoke in the cabin.  The doors are lightweight and strong Seibon dry carbon fiber parts that save about 80 lbs off the total weight of the car.   A huge rear wing is run, presumably to help contain the massive power the engine produces.  Sturdy mounts for the wing attach directly to the rear support structure not the trunk.  The trunk lid is a Seibon superlight dry carbon part.  Seibon parts take around 150 plus lbs off of the SC430.   The stock configuration diff is run, not a quick change like US drift cars typically use.  An OS Giken LSD splits the power.  Daigo runs a 3.7 final drive.  An oval section exhaust flows enough for all the power while maintaining ground clearance.   Ikeya Formula adjustable links are used in the rear suspension.  These links are fully adjustable and replace the squishy rubber bushings with bearings.  The rubber bushings in the uprights are pressed out and replaced with spherical bearings as well.  Stock Supra axles are run and they hold up well.   DG 5 adjustable coilovers are used with Swift Springs.  The stock rear antisway bar is run.  The rear crossmember bushings are locked in place with aluminum top inserts.  Note that the motion ratio of the coilovers can be adjusted as can the position of the swaybar end links.  Also note the full seam welding treatment that has been performed on the unibody.   Look at the extreme wheel spacing used to fill out the widebody.  This puts a lot of stress on the wheel bearings and suspension.  The Ikeya Formula lower arm is adjustable for length on the inboard end and has an additional eccentric on the outboard end for adjusting camber.  Cool stuff! Currently Daigo's car runs super sticky and super smoky Achilles 123S tires in 265/35-18 in the front with the Achilles ATR Sport 2 also in 265/35-18 in the rear.  The Achilles 123S is a really grippy tire and we are looking forward to evaluating it on some of our project cars. The front suspension also runs adjustable Ikeya Formula arms.  A Cusco non adjustable front sway bar is used.  The stock Lexus electric over hydraulic power steering is used. To get more steering angle, the lower part of the spindle is replaced with a shorter piece to increase the steering ratio.  What's cool is that this part unbolts from the upright part of the spindle making getting more angle a simple job. A DG-5 front coilover is used with a Swift spring.  The front hub uses a thick spacer to space the wheel out to fill the widebody.  Unfortunately this really increases the scrub radius which affects turn in.  From the look of things, the rear steer rack position is set up for minimal Ackerman. Increasing the track can increase rear grip while sliding sideways by reducing weight transfer to the outside wheel.  When the tires sizes are restricted like they are in Formula D, this is a trick that helps.  The Achilles 123 is currently only available in a 265 width but we think the car can probably run a 275 or wider under the FD tire width to weight rule.  When wider sizes of the 123S come out, the car will get faster! Lightweight Prodrive forged wheels are used. Currently Daigo is in second place in Formula D points heading into the last event at Irwindale.  Daigo's performance this year has been amazing.  Just wait until next year now that he has experience with the US circuit and knows the tracks. We have shown that Daigo's Achilles Tire SC430 is an interesting mix of JDM and US technology.  The car's stellar performance is the result of tremendous power provided by the Garrett boosted, Brian Crower large displacement, nitroused 2JZ and grip of the Achilles 123S tire.  Combined with Daigos suburb driving skill, the Achilles team has been very competitive in their inaugural season and we expect that to increase as the team becomes more experienced with US tracks and driving protocol. We can't wait to see what Daigo has in store next year, especially now that he is more familiar with the Formula D circuit Sources Achilles Tire Design Craft Fabrication Bridges Racing