Advanced GT-R Notes 5-18-02 - From - Mr . GT-R . Mostly relating to R32 GT-R's.

ENGINE

Camshaft lobe centers in 106 and ex 108 is best starting place
264 or 272 up to 600ps
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
Modified stock 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 seperate oil drainback form the rear of the head to the pan
Use Trust style oil pan modification kit
Use late style crankshaft with wider oil pump drive
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 edged 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
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 volume
Oil cooler is required
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 hold 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
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
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
Use a different ECU map for each gear , determined by rpm and mph inputs
Used 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
25-50wt Redline synthetic oil or Pure 10-60 synthetic oil.

CHASSIS

OS Giken clutches
R34 Trans with 3.7 :1 gears in front and rear
Nismo slave cylinder
Use OS Giken crossmission to replace weak factory gears
R32 does not need rear diffuser
R32 needs front diffuser
Do not use chassis foam to siffen 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 N1 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 toe out front and 0 toe rear for all circuits.
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 front wheel drive car
He has different attesa EPROMs for different types of circuits , suggested Field ETS controller as simple alternative
Attesa system reiles 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 capactity front differential cover
He recommends rear diff cooler for heavy cirucit 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

BRAKES

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