GT-R historie og teknisk info.

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Ole-M
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GT-R historie og teknisk info.

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Stjålet fra GGON

THE ENGINE

Background
Engine power was the GTX's Achilles heel in Group A competition.
The car needed more power to be competitive on the high-speed
stages. Although the fundamental design strengths of the GTX's
1.8 litre 16-valve DOCH engine, its low weight and compact const-
ruction, helped the 323 to win many a rally, cars with more muscle
took the overall championship.


Development aim
Mazda wanted the benefit of the technological advances that raised
the GT-R's engine performance for Group A competition to be built
into the production model for success in Group N rallies. The Motor
Sports Engineering Group design team developed certain GT-R parts with
Group N rally teams in mind, knowing that those parts would be modified
under Group A rules. The designers wanted to maintain the GTX's balance
between engine and chassis so they chose turbo-charging rather than
a greater engine displacement for the GT-R. Turbo-charging offered
improved torque response and flexibility at the top end, while main-
taining the original weight distribution of the light, compact engine.


Outcome
The engine, fully tuned to Group A specifications, has met all perfor-
mance parameters during bench testing. Maximum output is some 20%
greater than the existing engine: on a par with or better than its
gtr-17 2.0 litre turbo-charged rivals. The intercooler's performance has been
dramatically improved, reducing intake air temperature problems and
increasing the potential to tune the engine with different air-fuel
ratios. The GT-R engine in its original specification produces less
torque than the GTX engine below 3.500 rpm, about the same as for a non
turbo-charged engine of equivalent displacement (this is of little concern
during everyday driving or when racing). The GT-R revs freely through to
the redline with greater response than motors in the 2.0 litre turbo-charged
class. With in Mazda, the GT-R's acceleration is figuratively described as
rocket like. Turbo-lag time was reduced by changing the rotor bearings
in the larger turbo-charger from floating-metal to low-friction ball
bearings. The designers tested the GT-R engine with all petrol grades on
sale in Europe, in consideration for everyday driving. No problems exist.



Technical Information

Basic design inherited from the GTX
The GT-R's transverse in-line four-cylinder engine's displacement is 1.840 cc
with a bore and stroke of 83 x 85 mm and compression ratio of 8.2:1.

The cylinder head is an aluminium alloy cross-flow type. Intake and
exhaust efficiency is very high in this 16-valve engine. There are two
intake valves per cylinder (33 mm diameter, 8 mm lift) together with two
exhaust valves (28 mm diameter, 8.5 mm lift). The larger valve diameter
and the thinner valve steams (intake/exhaust) enhance gas exchange efficiency.
The pentroof combustion chamber has a centrally mounted spark plug. The valve
angle is 50º.

Double overhead camshafts directly actuate the intake and exhaust valves.
Intake/exhaust overlap is large (intake open 2º, intake closed 51º/exhaust open
59º, exhaust closed 8º).

Hydraulic Lash Adjusters (HLA) maintain zero valve clearance between the cams
and the valve stems.

The cast-iron cylinder block has thin walls of uniform thickness for weight
reduction. The half-skirt design further cuts weight. Efficient rib positioning
and shape, together with the oval cross-section of the outer wall increases
rigidity.

The fully balanced forged steel crankshaft with eight counterweights runs on
five bearings.

Lubrication oil is pressure fed to various parts of the engine by a trochoidal
oil pump mounted at the end of the crankshaft. The unitized oil cooler is water
cooled.

An integrated engine management system employs a single-chip 8-bit microcomputer
to oversee a number of important tasks: fuel injection (timing and volume),
spark advance, the electric radiator cooling fan, and several other functions.

A knock sensor sends feedback to the microcomputer which in turn retards the ignition
to prevent engine knock.

The microcomputer-controlled injection system delivers fuel via a single jet at
each cylinder. Injectors 1 and 3 are grouped together, as are the injectors
for cylinder 2 and 4.

The exhaust manifold is cast in lightweight, heat resistant ferried steel, using
the latest in casting technology: lost-foam casting. The manifold has a
port-partitioning wall between cylinder 1 and 4, and 2 and 3, reducing gas flow
interference, thus raising combustion efficiency.


Group A competition regulations prohibit modification of certain engine
components. The GT-R design team have included the following performance boosting
parts and modifications in the stock engine.

The GT-R's turbo-charger exhaust and compressor rotors have been increased from
52.5 mm to 62 mm and the A/R ratio have been increased from 15 to 16. The design
team selected these specifications after through testing, in line with basic
engineering policy of maximizing boost pressure at the top end, while minimizing
turbo-lag.

Low-friction ball bearings replaced the GTX's floating metal in the water-cooled
turbo-charger journal. Components are made from new heat-resistant materials to
withstand rigorous rally conditions.

A new large-diameter duty valve at the waste gate is under microcomputer control.
The same microcomputer regulates the intercept point and maximum boost pressure
settings.

The intercooler core size is 70% larger, up from 125 x 247 mm in the GTX, to
225 x 234.6 mm for the GT-R. Performance has soared 37% from 4.500 kcal/h
to 6.150 kcal/h. the cooling fins are arranged in a zigzag pattern which
increases cooling efficiency. The intercooler is mounted in front of the
radiator to catch the cool air stream, lowering the intake gas temperature to
prevent engine knocking. the intercooler's square shape and tube layout minimizes
pressure loss.

The surge tank wall baffles equalize intake air pressure, reducing cylinder over-
load and improving performance and reliability. This design was pioneered by Mazda
engineers and developed following extensive testing. The technology is a world
first and Mazda holds the patent.

The exhaust manifold is made of lightweight, heat resistant ferrite steel. Lost-
foam casting gives a smooth inner surface which reduces gas flow resistance.

The con-rods are made of a tougher alloy and their ' I '-shaped cross-section are
wider for increased rigidity and strength.


The stock GT-R engine contains numerous modified parts over the gtr-16
GTX that increase the car's potential for Group N competition

The capacity of the air flow meter, fuel pump and fuel injection system have
increased for higher power output.

The exhaust valve steams are hollow and partially filled with sodium. As the
valves heat up, the sodium melts and is agitated violently as the valves move.
Heat is absorbed from the valve neck by the liquid metal and conducted to the
valve steam where it dissipates. The cooler exhaust valve prevent pre detonation,
increasing engine reliability.

The forged aluminium pistons with cooling channels, resemble Formula One engine
pistons. The piston crowns are tin plated. There are two compression rings and
one oil ring. Nickel cermet is fuse-boded to the groove area of the top ring
to enhance wear resistance.

The well-lubricated kelmet metal con-rod big-end bearings are the same as those
fitted in Group A competition motors.

The new five stage water-cooled oil cooler has a greater capacity over the GTX's
old two stage unit. Oil jets spray oil up into the cooling channels in the under-
side of the piston crowns.

Exhaust temperature and pressure is reduced by minimizing the number of cells in
the catalytic converter and by straightening the silencer's internal construction.


GT-R TRANSMISSION

Background
The GT-R Was built to capture overall victory in Group A of the World Rally
Championship. Compared to the GTX, the GT-R has greater engine power so it was neces-
sary to redesign the transmission to correspond to the upgraded engine performance.


Development aim
The transmission was designed for Group N racing (Group A competitors are given
considerable freedom to modify their cars) with strengthened gears to bear the
high stress and wear of rally competition.


Outcome
The torque split and gearing ratio inherited from the old GTX, together with the
greater torque spread, gives the car its rocket-like acceleration. following
stress simulations, based on data provided by Group N rally teams, the design
team strengthened second, third and fourth gears, and the front hypoid by shot
peening them to handle the GT-R's increased engine torque.


Technical information
The compact, light weight, planetary-geared centre differential has an uneven
front/rear torque split ratio set at 43:57 following extensive testing.

By distributing more power to the rear wheels, the fine handling characteristics
of rear-wheel drive vehicles are combined with the advantages of four-wheel drive.
If torque distribution was 50:50, then the front wheel cornering force would
decrease with increasing drive power, resulting in understeer as lateral accele-
ration increases above 0.3g, reaching an 0.8g limit. With greater torque to the rear
wheels, understeer is comparatively mild, giving the driver greater control. Lateral
acceleration can rise as high as 0.9g. These characteristics allow the driver to put
the car into a controlled tail slide, the so-called "throttle oversteer", a basic
RWD technique.

The centre differential is fitted with a viscous LSD (limited slip differential)
which gives the GT-R an automatic variable front/rear torque split. The viscous
LSD coupling has 29 thin overlapping steel plates inside its housing. The hub and
the inside of the housing are splinted. Half the plates rotate with the hub and the
rest are fixed to the housing. Each plate has holes and grooves and the plates
sit in a pool of viscous silicon oil. The centre differential's sun gear is connected
to the viscous coupling's housing. The pinion gear is attached to the coupling's
hub. When a wheel begins to slip, a large rotational difference occurs between the
29 plates which spin against each other, heating up the silicon oil which in turn
expands. This forces the plates together, locking the coupling which eliminates the
rotational difference. This action switches the GT-R's front/rear torque distribution
ratio from 43:57 to a maximum of 60:40 which matches the GT-R's front/rear weight
distribution. The advantage of fitting a viscous LSD to the centre differential is
increased traction and stability. If one wheel floats, for example on rough road
surfaces or during hard cornering, or if a tyre loses grip, the viscous LSD re-
allocates torque to the other wheels without reducing drive power to that wheel.
On gravel or snow-covered roads, more torque to the front wheels lets the car adopt
FWD characteristics, enhancing vehicle stability. The rear differential is also fitted
with a viscous LSD to further enhance stability should a rear wheel lose its grip.
The GT-R has a perfect drivetrain for a WRC Group N rally car.



GT-R SUSPENSION

Background
Mazda believes that the 323 GT-R will be driven like a rally car and raced in rallies.
Compared to the GTX, the GT-R's suspension is more compatible with sports driving.


Development aim
The GT-R stock suspension was designed with Group N drivers in mind, as Group A teams
are given considerable freedom to modify their cars. Mazda has prepared a separate
competition kit for Group N competitors, as change are permitted to springs and shock
absorbers in this class.


Outcome
The GT-R's suspension system is more rigid to improve steering, handling response and
stability. The cornering limits is now higher with superior controllability near the
limit. The GT-R's stock suspension is satisfactory for everyday driving.


Technical information
Basic technology inherited from the GTX.
The highly praised basic suspension layout of the GTX has been passed on unchanged
to the GT-R, along with the same wheel-base (2450mm) and front and rear track (1430
and 1435).

The front strut-type suspension employs lower A-arms with the frontal attachment
point beside the wheel centre for greater lateral rigidity. Wheel alignment: front
toe-in (2mm), camber (-0º40'), and caster (2º40').

The rear strut-type suspension has twin lateral links and a single trailing link
arranged in a trapezoid. Wheel alignment: rear toe-in (2mm), camber (-0º20').


New technology developed for the GT-R
The bushes are harder in the front and rear suspension units. In the front suspension
units, the bush hardness for the front side of the lower arm is 63º, increased from 58º,
the rear side bushes are up to 65º from 52º. Harder front strut mounts are fitted,
up from 67º on the GTX to 74º on the GT-R. These measures improve handling response.
The front stabilizer bar diameter was increased to 23mm from 22mm. Front roll rigidity
has benefited from greater damping.

In the rear suspension units, the harder bushes and altered coil spring ratings have
helped to improve the GT-R's steering response. Bush hardness at the front lateral links
is 70º, up from 55º. The GT-R's rear coil spring ratings are higher than those of the
GTX. The attachment points for the trailing link bushes are harder, up from 70º to 73º,
the rear strut mount hardness is up from 72º to 75º.

Rear roll rigidity was reduced by replacing the 20mm diameter solid rear stabilizer bar
with a 19mm diameter pipe with 3mm thick walls. Toe-in caused by roll was increased
by raising the axle-side attachment point of the front lateral link by 3mm. This
increases rear tyre grip.

By increasing front roll rigidity and reducing rear roll rigidity, the GT-R's basic
characteristic is to understeer. However, through higher rated rear springs and raised
attachment points, the cornering limit is greater.

Larger wheels with wider tyres increases wheel grip. The GT-R wheels are 15x5.5JJ, up
from 14x5.5JJ wheels on the GTX, and are fitted with 195/50R15 tyres (195/60R14 for
the older model).

The gearing ratio of the rack-and-pinion steering has been reduced from 15.0 to 14.0,
with a lock to lock of 2.6, down from 2.7 on the GTX. These changes make the steering
more responsive.

To improve acceleration on/off response, the No. 1 engine mount hardness was increased
from 43º to 60º, the No. 3 mount was similarly upgraded from a hardness of 51º to 60º
and the No. 4 mount hardness was altered from 70º from 55º.



GT-R BRAKES

Background
Many private teams will compete in Group N where the only modifications permitted to
braking system are changes in brake pads. The GT-R has a new braking system to make
the car more competitive in this popular class.

Development aim
Shortening the braking time dramatically improves a car's competitiveness, especially
in the special stages. The GT-R's shorter brake pedal stroke, together with a balanced
pedal feel, allow exact control at the point of entry to a corner, giving the new braking
system greater stopping power and better feel to allow late braking.

Outcome
The larger 15" wheels give an increased effective radius to the brake discs for greater
stopping power, letting the driver accelerate longer between corners and leave braking
to the very last moment. Although pressure on the brake pedal for both the GTX and the
GT-R, with ABS fitted, is about 11 kg, the GT-R's pedal stroke is 40mm, 10mm shorter
than the GTX's. This remarkably short brake pedal stroke, together with the rigid calipers
and lower hydraulic pressure allow a better braking feel. Larger asbestos-free Kevlar/aramid
fibre brake pads have increased fade resistance, even under continuous, rigorous use.


Technical information
Basic technology inherited from the GTX.
metal gtr-10 Less hydraulic pressure is required to generate an equivalent breaking force
in the GT-R's breaking system due to an increase in brake disc effective radius
from 109 mm to 122 mm for the front discs and from 105mm to 111 mm for the rear.

The brakes have a very firm feel thanks to lower hydraulic pressure preventing
brake hose swelling.

Highly rigid calipers contribute to the shorter GT-R brake pedal stroke.

The firmer feeling is made possible through reduced hydraulic pressure due to
changes in the master cylinder and wheel cylinder diameters. The design team
increased the master cylinder diameter from 22.2 mm to 23.8 mm on cars fitted
with ABS. Both the front and the rear wheel cylinders were increased from 54 mm
to 57.2 mm at the front, and from 30.2 mm to 34.9 at the rear. For cars without
ABS, the design team made the same changes to the front and the rear wheel cyl-
inner diameter: they increased the master cylinder diameter from 23.8 mm to
25.4 mm and reduced the master vac servo ratio from 5.0 to 4.5.

Larger, asbestos-free Kevlar/aramid fibre brake pads are more resistant to fading.
The brake discs are thicker to correspond with their greater diameter. The GT-R
has 24mm thick, ventilated front discs (GTX:22mm) and 10mm thick, solid rear discs
(GTX:9mm).

The optional four-wheel ABS has a hydraulic pressure modulator with three control
channels and a sensor at each wheel. Both front wheels have their own control channel
and are monitored and controlled independently. The rear wheels are governed by an
integrated management system. The "select low" logic of the ABS precisely controls
brake fluid pressure to the rear wheels the instant either wheel begins to lock. This
system uses a return flow control device to control hydraulic pressure via a solenoid
valve to prevent wheel lock. The 4W-ABS ensures optimum braking performance,
even under adverse weather conditions of rain or snow, and is of great benefit in
maintaining directional stability under braking.
-'91 323 GTX aka Banehora aka Støvsamler'n
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WireD
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Post by WireD »

Veldig interessant det de sier om girkassa og drevene, at de er forsterket i GTR-kassa. Det er jo blitt diskutert siden tidenes morgen. :)
----------------------

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Beating a Honda is like banging a fat chick. Everyone can do it but who wants to brag about it?
"I don't wanna look up from an engine and see a nipple...I quit, man..."
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ochagenes
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Post by ochagenes »

Og visst de var det, korfor har ikkje de eget delenummer da? Og det står ingenting om det i GT-R verkstedsmanualen.
GT-R, apexi, whiteline, compbrake, D2, walbro
Darkstar
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Post by Darkstar »

Ligger mye bra info her også: http://www.mazdafun.com/the_story.htm
07' Audi A3 Sportback 2,0TDI
X - 96' Audi S6, X - 92' Mazda 323 GT-R, X - 99' Passat 1,8T
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Mazdaråner
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Post by Mazdaråner »

Virker som mazdafun er uoppdatert? :?
Har prøvd å sende mail flere ganger ditt men går ikke!!
Råne sjef =)
Mazda MX5
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Ole-M
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Post by Ole-M »

Mazdaråner wrote:Virker som mazdafun er uoppdatert? :?
Har prøvd å sende mail flere ganger ditt men går ikke!!
Trur ikke han oppdaterer den siden lenger.
Du får heller prøve å sende han en PM her.
-'91 323 GTX aka Banehora aka Støvsamler'n
mazdafun
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Post by mazdafun »

Mazdaråner wrote:Virker som mazdafun er uoppdatert? :?
Har prøvd å sende mail flere ganger ditt men går ikke!!
Hei.

Mailadressen er ikke rett på den siden. Bruk : mazdafun@gmail.com

Oppdateringer er vel ikke det som har slitt ned den siden nei... :roll: Blir bare så altfor korte kvelder med alt mulig annet. Men en dag.... * _ håper 8)

mvh
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low and slow
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Re:

Post by low and slow »

ochagenes wrote:Og visst de var det, korfor har ikkje de eget delenummer da? Og det står ingenting om det i GT-R verkstedsmanualen.
sikkert for dem kutta ut og produsere di dreva om satt i gt-x når gt-r kom med nye drev, dermed et delenr
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RaceKing
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Joined: 01 Nov 2009, 17:16

Re: GT-R historie og teknisk info.

Post by RaceKing »

Hvordan finner man ut hvilket produksjons nummer min Mazda GTR er? Av de 2500 som ble laget!
93 Mazda 323 GTR (Bilen selges) http://www.mazda-ogn.org/phpBB3/viewtop ... 13&t=19049
99 Saab 9-3 Cab
05 Suzuki GSX-R 600(Solgt)
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ninja
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Re: GT-R historie og teknisk info.

Post by ninja »

Ja hvordan finner man ut d egentlig?
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WireD
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Re: GT-R historie og teknisk info.

Post by WireD »

ninja wrote:Ja hvordan finner man ut d egentlig?
u ifra rammenr ditt mener jeg?
----------------------

Image

Beating a Honda is like banging a fat chick. Everyone can do it but who wants to brag about it?
"I don't wanna look up from an engine and see a nipple...I quit, man..."
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ninja
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Re: GT-R historie og teknisk info.

Post by ninja »

sikkert nok :)
hvor står det og hvilket nr i nummeret er prod nr?viss du skjønner :)
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