- If 1100 wheel horsepower in your street driven R34 Nissan GTR
isn't enough to blow your hair back, don't worry, you've still got another
200 horsepower on tap when you press the nitrous button.
We're here at World Time Attack's Flying 500 competition with Anthony's
War GTR R34 and we're wanting to find out what makes this impressive
street driven GTR so fast.
The heart of the car is of course the RB32 engine.
But getting an RB26 out to 3.2 litres is no mean feat.
This actually starts by ditching the factory RB26 block and working with an RB30
block as the base.
The rest of it is all based around a Nitto 3.2 litre stroker kit.
This includes the Nitto crankshaft, the Nitto controds, and a set of pistons.
Now the bottom end of the engine is really all about achieving a certain amount
of displacement but also achieving reliability.
It's the head as well as the turbocharger that really dictates how much power
the engine can make.
In this case the head is a full Croydon Racing Developments race cylinder head.
Now we haven't got too many details on the exact specifics here but fair
to say that with the ability to rev to 9500 RPM, and support around 1300
wheel horsepower, there's not a lot that hasn't been done to the head.
Getting the air flow into that head is the Precision 7685 turbocharger.
Now for a 3.2 litre engine, that 7685 isn't actually considered to be a massive
turbocharger and that's proven by the fact that it can produce full boost by around
about 4500 RPM.
Considering the engine revs all the way to 9500, that's quite a nice wide power band.
Now that full boost point, particularly when the car is being used in competition
is 41 psi and on the quarter mile, the car's gone as fast as an 8.90
It's important to mention though that that was on an unprepped street surface.
The highest mile an hour the car's tracked at is over 164 mile an hour,
showing that it's certainly making some power considering the fairly heavy
weight of the R34 chassis.
Once that 7685 is up on boost, all of that air is forced through a Hypertune
intercooler front mounted.
And then it feeds into a Hypertune plenum chamber.
Now this is one of the areas that's a common change with highly modified RB engines.
The factory individual throttle bodies have been ditched and the Hypertune plenum
chamber consists of a single drive by wire throttle body.
Now the plenum also houses a set of six Siemens Deka 2400cc injectors,
that are essential to supply the kind of fuel flow necessary to support that
power level when the engine is running on E85 fuel.
That drive by wire throttle body is a kind of unique change for an R34 which
conventionally uses a cable throttle.
The drive by wire throttle in conjunction with the Motec
electronics package allows for some significant advantages.
One of these is the ability to provide an automatic throttle blip on the
downshift when changing down gears with the sequential transmission.
In terms of that transmission, the car is fitted with a six speed Samsonas
sequential.
Now this allows most importantly clutchless upshifting.
And when you've got a reasonably large turbocharger, this is really important to
keep that turbo on the boil when the car's going down that quarter mile.
The driver can keep his foot pinned on the throttle and when he pulls back
on the gear lever, a strain gauge in the gear lever lets the ECU controlling
the engine know that the driver's requesting an upshift, and from here
the ECU can perform an ignition cut, a fuel cut, or both,
to momentarily unload the dogs in the gear box and allow the next gear
to be selected.
This provides incredibly fast shifts that are almost imperceivable
from the driver's seat.
Now I've alluded to the electronics package a couple of times now,
we'll get into a little bit more detail about what's involved there.
And the heart of the electronics is the Motec M150 ECU.
This controls obviously all of the functions of the engine.
It controls the boost pressure, and it also enables those clutchless shifts
that we've just talked about, along with the automated blip of that drive by
wire throttle on the downshifts.
The M150 ECU is also connected to a Motec C127 dash display unit,
and this is a driver display as well as a central logging unit.
Completing the Motec suite of electronics is the Motec PDM or power distribution
module.
Now this replaces conventional fuses and relays that we may see in most cars
and all of the circuits or power distribution circuits for the
electronics on the engine as well as the chassis are controlled via essentially
solid state relays.
This allows a lot more flexibility in the fusing and CAN control of those circuits.
Now the power distribution module is controlled via a CAN based keypad
which is located on the transmission tunnel.
This allows the driver quick and easy control over all of the functions
of the ECU and the dash.
One of the challenges with getting fast consistent launches out of a heavy
four wheel drive drag car is managing clutch slip off the line.
Simply sidestepping the clutch actually isn't desired as this is likely to result
in the car either bogging or alternatively launching into
uncontrolled wheel spin.
Either of those are going to give you a fast 60 foot time.
In this time Anthony's actually used a trick that's been common in the
drag racing market for a number of years.
This consists of a Magnus clutch slipper unit.
And essentially this is a valve that's plumbed in line with the clutch line,
and what it does is it controls the release rate of the clutch pedal.
So this allows a very consistent and repeatable amount of clutch slip
when the driver sidesteps the clutch off the line.
Now the downside of this of course is because you're creating a lot of slip
through first gear it is going to wear your clutch plates quickly.
In this case the engine is backed by an OS Giken quad plate clutch,
giving plenty of clutch material for a reasonable clutch life,
even with the slip taken into account.
To date this system has netted Anthony a 60 foot time in the mid 1.4s
on a street surface that was unprepped, which is a pretty impressive result.
At this stage we've only gone through the first day in the Flying 500 competition
and unfortunately Anthony has faced a few issues.
It really didn't give him a representative mile an hour at the end of the strip.
We're hoping he can resolve those problems overnight and we're looking
forward to seeing how the car goes tomorrow.
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