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May 4, 2010

Nissan Skyline GT-R Advanced Notes

The following is some old Nissan Skyline GT-R notes that Steve Mitchell took one day while hounding a certain “Mr. GT-R” May 18, 2002. Most of the notes relate to R32 GT-R’s, as that is what is Mr. GT-R’s personal trial car.

Camshaft lobe centers in 106 and ex 108 is best starting place
264 or 272 up to 600ps (Advancing the intake cam a little +4 degrees really helps low end response)
Prefers 10.1 mm lift

Minimum 3" exhaust from each turbo
Must have flex joint in downpipes to prevent cracking of #6 cylinder exhaust manifold. 4" minimum to equal 3" pipe flow

Prefers 720cc injectors (I like 1000 cc, do it once will be enough to cover about 1000 hp, and idles fine)
Modified stock fuel rail (N1 race car had a -6 entry onto a modified stock style fuel rail)
2 stock fuel pumps up to 600ps. 2 Nismo pumps for 600+ in parallel in tank
Use fuel cell foam in R32 tank due to fuel slosh problems

Add a separate oil drainback from the rear of the head to the pan Use Trust style oil pan modification kit (the trust hangs so low, I am not a fan of it on a street car)
Use late style crankshaft with wider oil pump drive
Late oil pump drive RB
Stock crank good to 600ps if balanced
Prepped crank and rods good to 700ps max, (deburr ,polish , shot peen , balance)

Use metal headgasket after 450ps for circuit racing 1.2 mm or 0.9 mm
Use aftermarket rod bolts , Isky in the UK ??

Only minor head porting is required , cleanup and bowl work
Push intake splitter back and knife edge
Unshroud intake valves and remove all sharp edges to combat detonation , leave exhaust quench pad alone for under 800ps. He sometimes removes the intake quench pad as well.
For 800 +ps remove both quench pads like Porsche 996 turbo combustion chamber

Use forged pistons Tomei or Renik , he likes oil gallery pistons (OEM are oil cooling channel)
Use Nismo timing belt - much stronger
Re-check cam timing after 1000 miles due to belt stretch
N1 oil pump is only higher pressure , volume is same

Nismo oil pump is higher pressure.
Oil cooler is required (two more more for a serious car)
Center main journal clearance is very critical
#6 cylinder runs leanest . Flow test injectors and put largest in rear and smallest in front.

Fully divorced wastegate is not good . Should only be divided for 30mm to prevent cracking and warping issues on stock type turbos
Add bracing to wastegate actuator or extra springs .
Wastegate hole in turbo housing should be made smaller diameter and the puck arm modified to open further by shortening arm length. This helps spool up by preventing the exhaust flow from sucking the puck slightly open.

Stock inlet hose to rear turbo collapes due to vacuum , replace with steel
Rear turbo always runs much hotter and fails first .
It also produces a different pressure than the front turbo and this contributes to turbo surge (divided twin turbo pipe helps calm surge)

R34 Vspec II has NACA duct to help with rear turbo cooling
Replace intercooler piping with silicone or hard pipes

Add hole to stock airbox though fender well (if you run the stock airbox, gangster if you do)

Change resolution of ECU map to have more data points at high rpm
Use Z32 AFM's or Apex'i D-Jetro for best response (R35 MAF, and a NISTUNE works for up to about 600 hp)
Use a different ECU map for each gear , determined by rpm and mph inputs

Use NGK 5400-10 plugs for racing and 5400-9 for street , Alternate is Denso 32R for race and 31R for street

He uses custom made coils with 60kV output . Stock is 45 kV.

Stock N1 exhaust manifolds are cast molded stainless. Port to 50mm , but weld up outside first with stainless rod
Stock manifold on left, Modified N1 on the right

25-50wt Redline synthetic oil or Pure 10-60 synthetic oil.
OS Giken clutches (I like NISMO/Exedy twin plates for a street car)
R34 Trans with 3.7 :1 gears in front and rear
Nismo slave cylinder (makes pedal effort lighter)
Use OS Giken crossmission (close ratio transmission) to replace weak factory gears

R32 does not need rear diffuser
R32 needs front diffuser

Do not use chassis foam to stiffen chassis. Breaks after heavy circuit use and can not be removed

R32 front chassis is weak in bending and torsion. Add as much bracing as possible , such as Do-luck sub frame connectors and HKS Kansai Kit

R32 NISMO lip rear lip adds a lot of drag for minimal downforce increase use only on short circuits.

Front wheel bearings and CV boots wear out quickly when using extreme camber. Cool bearing with nitrogen vapor prior to installing into spindle
Recommends up to 4.5 degrees negative front camber and 1.5 negative rear camber.
For short circuits use up to 5mm (13/64) toe out front and 0 toe rear for all circuits. (I like an 1/8th out for track, 0 in the back)

For street use he recommends 10kg front and 8 kg rear spring.
Track use he recommends to reverse them or 10 kg front and rear.
When using 15-18 kg front - use 2 kg softer rear

Set up car like a front wheel drive car

He has different attesa EPROMs for different types of circuits , suggested Field ETS controller as simple alternative
Attesa system relies on the factory ECU to sense engine load and when you change the engine load mapping , it affects the attesa system response
He uses LSD type front diff for some short circuits
He used Trust type large capacity front differential cover
He recommends rear diff cooler for heavy circuit use
He likes 245 tire on a 17 x 9 20mm offset wheels for R32 . Or 17 x 9.5 with 265 tire
Disconnect Hicas for circuit use
Use Staega 260 RS master cylinder 15/16ths (46010-0V600). Gives more rear bias than Vspec.
Not good for wet circuits , too much rear brake bias

Use F40 front brakes , 332 mm and R34 Vspec 322mm rear rotors
ABS actuator is the same for all R32's . Control unit is different between models

1 comment:

Anonymous said...

is there anyway to tell the difference between the stock r34 exhaust manifold and n1? is there any writing on the top or sides? also is there a size difference between the stock r32 to r34 manifold or just the same? thanks.