History
Late in 2000, Spectrum5 Racing placed an order for a factory built Ultima GTR rolling chassis that would be used as in SCCA/NASA and Unlimited Open Road Racing events.
This particular car, intended to operate in the 245mph range in open road racing events required many special components and some engineering work from Ultima.
While Ultima was busy engineering and building the car, Spectrum5 set to work to develop a suitable engine package for the car.
Using some wind-tunnel data provided by Ultima, it was determined that 632bhp would be required at the rear wheels to achieve 230mph with the added drag of the rear wing and front splitter required to keep the car on the ground. We looked into various available engines including the NASCAR packages we often race against in such events as the Silver State Classic (http://www.silverstateclassic.com/).
At the time, a fresh NASCAR motor made
about 740bhp at the flywheel.
However, considering the altitude power loss encountered in events in the
We then decided to develop a dry-sump race twin-turbo package for this car. The objective was a reliable package with a minimum of 1000bhp on tap under any atmospheric conditions.
The base
engine, shown on the right used the best racing components available – Dart Iron
Eagle dry-sump block, GM/Chapman prepared splayed valve cylinder heads, Crower
10,000 RPM balanced reciprocating assembly, Kinsler stack injection system,
Jesel cam and valvetrain components, and Moroso dry-sump components.
In January, 2001, the rolling chassis arrived in a large box and was rolled into the shop.
To the base engine, we specified and designed the
additional turbo/intercooler components to complete the package. The photo to the right shows the results
after $65k, in parts and a year of design and fabrication prior to anodizing and
ceramic coating.
Note the sheet metal intake plenum, twin turbo's, side-pod mounted intercoolers, waste-gates and custom headers. Most of the challenge was finding a way to package all the components and plumbing within the tight constraints of the GTR chassis.
An initial 4 hours of chassis dyno testing and tune up resulted in 825bhp at the rear wheels with only 5.5lbs of boost. Later testing would produce almost 1300bhp at 14lbs of boost – two much torque for reliable operation of any transaxle we know of.
With full time effort from January to July, the car was completed in July, 2001. We raced the car 4 times at the Las Vegas Speedway at NASA (http://www.nasaracing.com/) and without fail lapped the field of race prepared Vipers,Vettes, Ferrari's and Porsches at will on street tires.
By Fall, we felt the car was sorted
enough to make a trial run in the Gold Rush open road race in
Project Build
We offer the following as an example project that we did internally at Spectrum5 Racing. Although we purchased a rolling chassis, we did the engine development, optimization, header design, turbo system design, fuel injection, electronics, aerodynamics, and a zillion bits and pieces to put it all together.
Our Porsche 911 twin-turbo weighs 3125 lbs and produces 400bhp stock. This is good for 0-60mph in 3.6 seconds and 12 second quarter miles. We've run this car in 5 of the Silver State Classic races and the car will do 187mph on 92 octane pump gas. If you run 100 octane, it will run at 195mph. Remove the windshield wipers and rear view mirrors and you pickup 7mph for 202mph. Not bad for an all wheel drive showroom stock vehicle.
Besides running the Silver State Classic at an average speed of 187.6mph a year ago in April 2001 (until the race was red-flagged), the Porsche is also a very quick GT-2 class car that we run in SCCA and NASA road racing events.
When we went looking for our next race car project, we found the Ultima, a car designed and built in the U.K. and widely used by F1/Indy teams as powerplant/drivetrain test bed. The Ultima weighs in at about 2600lbs with 3 fuel cells (210lbs of fuel) and a much more complex twin-turbo setup. The engine produces 925bhb at only 6 lbs of boost and has another 9lbs (and an additional 750bhp) on tap. The reason we designed the engine this way was to ensure that it would run reliably at roughly the torque limits of the Porsche six-speed (650 ft/lbs) as well as the chassis (about 1000 bhp).
After considerable research we purchased an Ultima GTR rolling chassis. Although Ultima offers some "kit" versions, our GTR was factory built and included many special parts including LeMans hubs, FIA roll-cage, heim racing suspension, full length alloy bottom and many strengthened suspension components designed for 245mph top speeds.
The Ultima GTR is truly the finest quality road/track car in the world with fit and finish superior to many production automobiles. With cockpit adjustable boost allows power settings from 550bhp to 1000bhp at the rear wheels.
We've seen speeds in excess of 220mph with this car in 5th gear and expect further testing and shakedown during 2002 with record runs in open road race events such as the Silver State Classic Challenge (www.silverstateclassic.com). We also ran the GTR at 4 road racing events late in the 2001 season and have found the cars handling characteristics to be superb and the performance absolutely frightening. For fun, we took the car to the drag races and even with P-Zero street tires we turned consistent 10.00 sec quarter miles at over 160mph, with most of the acceleration occuring after 100mph when the wing made enough down-force to achieve traction. We would expect mid-8 second runs at 185mph if it were possible to find 18 inch drag race slicks!
Below are pictures of the Ultima GTR upon arrival in the US. The car arrived in a very large plywood crate and the photos below show the unpacking. Click on any thumbnail for a larger picture (approx 500kbytes each).
A few photos of the engine with the beautiful Kinsler stack injection system, GM splayed valve heads prepared by Chapman Racing, and Moroso dry-sump system, but without the turbo's, air intake plenum, intercoolers, wastegates, etc. This engine was designed with a very short 3.25 inch stroke and 4.125 inch bore which works out to about 348 cubic inches and was designed to run continuously at up to 10,000 rpm using a special Crower rotating assembly.
Below are some photos when the transaxle and engine are finally in place with all the plumbing. These pictures were taken just before everything was disassembled and the aluminum parts were sent out for anodizing and the exhaust/intercooler plumbing was ceramic coated. Note the custom intercoolers, dry-sump tank, air intake plenum and all the special billet aluminum bits and pieces that were machined to mount all the parts. Also note the stainless steel headers, 3 inch turbo exhausts and aluminum intercooler plumbing -- all of which was designed using Spectrum5 Racing piping software described elsewhere. You're looking at about a year of work to design and build all these pieces, but we were very pleased with the results.
A year later, here's the results. Several photos of the car are shown alongside our 911 twin-turbo Porsche to show you how really small the GTR is.
Our Ultima GTR is currently listed as one of the fastest road cars in the United States: See the link at: http://www.ultimaclub.com/Fastest%20Production%20Sportscar.htm for more information.
The folks at K&N Filters also put together a GTR in full race trim to compete in the Rolex 24 hour race. For a complete story on the car, go to the K&N site at: http://www.knfilters.com/news2002/gaupdate.htm