GT-R is a homologated race car
 

winning over selling:

homolagation occurs when an auto maker creates a specific number (which varies with the different class requirements) of "identical" cars and records that "event" with the FIA (a large sanctioning entity) in order to legally compete in a given class (like Group A).

typically, a car must exist as a "normal" production car, for sale to the public, before it may be eligible for competition; all of the cars are then inspected, and must be fully functional.

there are exceptions to this, as in the case of LMP1, LMP2 (le mans purpose-built one-off classes may only require one or two prototypes be built), but often 500-5000 units of a car must be homologated for GT types. this requirement intentionally poses challenges to any given auto maker as to the cost-effectiveness of homologation, and to the extent of modifications these special cars may feature.

often, homologated cars for production will offer unique features, some of which that cannot be legally sold or "benchmarked," but can be attained with very minor tweaks that a racing entity will allow for the track. a classic example of this is the GT-R: in japan exists/existed a rule that a car cannot exceed "280ps," despite the fact that the GT-R is cabable of far more than that.

most racing regulations allow for some minimal changes to the cars for competition. so with some simple actions taken (like adding a modified downpipe, porting and/or upgrading the turbo, reprogramming the ecu, etc), the GT-R is capable of 400-500ps --barely modified from stock; ready for LM GT1 or Group A. :D

Formula Nippon to F1 and back
 

known as "F3000" (after the engine displacement limit of 3000cc) until 1995, in 1996 Formula Nippon became the only version of Formula car racing in japan. but unlike F1, Formula Nippon exists only in japan. and owing to it's intensity, many japanese Formula Nippon/F3000 drivers have advanced to F1.

ironically, Ralf Schumacher, a german, became the first Formula Nippon champion.:uppydown3

JGTC was Group A, sort of
 

japan:

the R32 GT-R emerges, homologated for japanese Group A racing. it races. it races 29 times in Group A. it wins every race. it is abolished. Group A is abolished.

in 1993, JGTC is created: it offers a variety of car classes, similar to le mans, within one race. the GT-R wins the first two seasons of that. :D

N2 in tires
 

N2 has almost no water vapor. as water vapor is heated, it expands, and tire pressure increases. therefore, most race teams use nitrogen to fill their tires.

tires inflated with regular air may see a 10-25 psi of pressure rise under racing conditions. this can greatly alter tire performance, as even slight changes in tire shape can throw off a dialed-in car.

with N2, inflation changes only 2-5 PSI throughout a race.

rear wing/ spoiler invented by americans, GM
 

remote desert, the 1960s --Rattlesnake Raceway, Texas:

2 men, Jim Hall and Hap Sharp, legendary developers of the Chaparral cars, began winning over and over again in FIA, Can Am, and USRRC competitions. as timing would have it, Frank Winchell, chief of engineering r&d at GM, noticed this, and made a deal:

Frank at GM said to Jim in 1963: "test our Corvairs at Rattlesnake Raceway to prove the worthiness of Corvair handling --we're being sued."

Jim and Hap said: "ok. but what do we get?"

Frank said: "i'll engineer your idea of the rear deck spoiler and make it actually work."

the results: Jim and Hap proved that ANY production car, not just the Corvair, could be made "unsafe" enough to flip over. Chaparral Cars then received preferential treatment from Chevrolet until 1970; the rear wing became perfected, setting a standard for performance car aerodynamics that we take for granted today.:smilie_th

Mr. K and the merits of non-conformity:
 

you cannot hold back genius:

Yutaka Katayama, “Mr. K,” founded nissan motor’s U.S. subsidiary in 1960. he is considered the “father” of the z-car.

Katayama could afford to not give a sh!t: he was rich, politically incorrect, raced in rallies, was pulled over by the cops regularly, and worshiped American culture.

with his worldliness, and because of his acute awareness of american car culture, he knew the moniker "fairlady z" would not fly with stars-and-stripes consumers. soon, widespread disagreement among his stiff corporate japanese peers, insisting "fairlady" remain, spread like wild fire.

so, then, not to be swayed, Katayama, and a few of his loyalists, removed the "fairlady" badges from the first U.S.-bound z-cars, replacing them all with "240 Z," the cars' internal code name.

by the mid-1970s, nissan retired Katayama. then, finally, on October 13, 1998, he was inducted into the Automotive Hall of Fame. :D

math fun with spring rates
 

how to rate coil springs mathematically:

Spring Rate = GD^4/8ND^3

G = Torsional Modulus for Steel = 11.25 x 10^6 (ie, 10 raised to the "6th power")
D = Wire Diameter in Inches
N = Number of Active Coils
D = Mean Coil Diameter in Inches.
(Mean Diameter is:
I.D. = 1 Wire plus inside Diameter
O.D. = 1 Wire minus outside Diameter)
8 = A Constant for all Coil Springs

*the constant "G" is the same for all coils made of steel: 11.25 x 10^6
is the same as 11,250,000.

example: 10 active coils and a mean coil diameter of 5.0", wire
size of .625" (see equation below):

11,250,000 x .625 x .625 x .625 x .625 = 171,661,370/10,000
------------------------------------------------
8 x 10 x 5.0 x 5.0 x 5.0

where in the denominator, "8" is the constant, "10" is the number of active coils,
"5.0" is the mean diameter.

therefore: spring rate = 171,661,370 or 171.66 lbs./inch

_________________________________
How to determine active coils in a coil spring:

Count total number of coils, subtract a coil for each coil that touches, these are dead coils. Ground flat ends are a dead coil. Start count with cut-off end facing you directly above would be one and so on. Not all coil springs are even coiled. You can have 1/4, 3/8, 1/2, 5/8, 3/4 or 1/8 of a coil (Example 10 1/8 coils).

1. If you cut one coil from a spring, the rate will increase.
2. Increasing wire diameter, will cause a great increase in rate.
3. Nothing in spring rate calculation indicates that a coil spring ever changes rate. The rate is determined by material and dimension of the spring. Coil springs don't wear out or lose their rate.
4. Spring load determines how much load a spring can support at a given height. The rate only tells how much height will change as load is changed. A spring can lose its load height over time if steel is not heat treated properly. When a spring sags, its rate is still the same as when it was new.

Lotus Suspension Analysis (LSA)
 

a PC-based application, Lotus Engineering incorporates its Suspension Analysis (LSA) software to keep current with trends in suspension setups, design approaches and trouble-shooting.

Lotus' ride-and-handling team played a pivotal role in the creation of the LSA software, using the package for in-house use, as well as for the r & d of other companies' projects (Nissan's '07 GT-R --to name one of many clients).

Nurburgring
 

-in 1991, at the Nurburgring 24-hour endurance race in Germany, the Skyline GT-R won the Group N class.

-at the Spa Francorchamps 24-hour endurance race, 1991, the GT-R won overall --beating Group A, and Group N1 cars.

-from 1991 to 1997, the Skyline was undefeated in N1 endurance racing in Japan, winning 50 times.

Nurburgring Nordschleife lap times:

Japanese cars:

7:59 --- 154.822 kph -- Nissan Skyline R33 GT-R, Dirk Schoymans (Autocar magazine 1997)
8:09 --- 151.656 kph -- Honda NSX-R, 320 hp/1467 kg (sport auto 08/2002)
8:24 --- 147.143 kph -- Subaru Impreza WRX STi (company test driver in 2004)
8:25 --- 146.851 kph – Mitsubishi Carisma GT Evo VI, 300 hp/1466 kg (sport auto 11/1999)
8:25 --- 146.851 kph – Mitsubishi Carisma GT Evo VII (11/2002)
8:26 --- 146.561 kph -- Nissan 350Z, 280 hp/1526 kg (sport auto 10/2003)
8:28 --- 145.984 kph -- Nissan Skyline GTR, 277hp
8:33.80 144.336 kph -- Honda NSX (6-speed) Coupe, 276hp (Top Gear magazine)
8:37 --- 143.443 kph -- Nissan Skyline GTR V-Spec, 350 PS
8:37 --- 143.443 kph -- Subaru Impreza GT Turbo, 218 hp/1290 kg (sport auto 03/2000)
8:37 --- 143.443 kph -- Honda NSX 3.0 (sport auto 07/1991)
8:37.10 143.415 kph -- Nissan GTR V, 350hp (Top Gear maagzine)
8:39 --- 142.890 kph -- Honda S2000, 240 hp/1275 kg (sport auto 01/2000)
8:43 --- 141.797 kph -- Honda Integra Type R (sport auto 12/2000)
8:47 --- 140.721 kph -- Honda Civic Type-R, 200 hp/1246 kg (sport auto 11/2001)

American cars:

8:10 --- 151.114 kph -- Chrysler Viper GTS, 411 hp/1567 kg (sport auto 10/1997)
8:18 --- 149.916 kph -- Chevrolet Corvette Z05 Commemorative Edition, 344hp (sport auto 09/2003)

SR20DET generations
 

SR20DET profiles:

listed in order are:
source
stock output
stock turbo
features
identification

here we go:

1991-1993
202 hp@6000 rpm
Garrett T25, 0.64A/R exhaust
high-port head, 370cc/min injectors
red valve cover

S13 Silvia & 180SX
203 lb-ft@4000rpm
0.80A/R Compressor
--------------------------

1994-1998 S13 180SX
202 hp@6000 rpm
Garrett T25, 0.64A/R exhaust
high-port head, 370cc/min injectors
black valve cover, flat on top


203 lb-ft@4000 rpm
0.80A/R Compressor
---------------------------

1994-1998 S14 Silvia
217 hp@6000 rpm
Garrett T28, ball bearing 0.64A/R
low-port head, VTC variable intake
black valve cover with a hump


203 lb-ft@4800 rpm
exhaust 0.60A/R, T04B compressor
cam timing 370cc/min injectors
(that peaks at cylinder No. 3)
----------------------------

1999-2001 S15 Silvia
247 hp@6400 rpm
Garrett T28 ball bearing, 0.64A/R
low-port head, VTC variable intake
black valve cover with a hump

(manual trans only)
202 lb-ft@4800 rpm
exhaust 0.60A/R, T04B compressor
cam timing 444cc/min injectors; better materials in turbo,
and better wastegate flow design (that peaks at cylinder No. 3)
:)