GT-R Advanced Information

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Advanced GT-R notes. RB26

 

Its been a few years since I wrote up some GT-R basics. Since then , a few more cars in the country , a few more races. A few more Ultimate Street Car Challenges. A few more passes down the dragstrip. These items are things we have actually tried unless otherwise noted. Proven combinations , proven things.

 

Road Racing

            There are different requirements for a car that is road raced than drag raced

 

Drag Racing

            Go fast , straight line.

 

Oiling

            This gets its own section. Oil is the blood of the motor . Without oil you have a dead motor. And when it dies , it normally spits parts out the side of the block. Heed this warning.

 

            Oil pump drive

                        R32 Crank
                                        The drive on a stock early R32 crank is about 1/2 the width of the late R32 /R33/R34 crank. It can be modified with a crank collar to   increase the width.

                        R32 late , R33 , R34

 

Oil pumps .

                        Stock

                                    Stock is Ok up to 8,000 rpm as long as you have an wide drive crank

                        N1

                                    It’s a stock pump with an upgraded spring to increase oil pressure

                        Jun

                                    The mostly highly recommended pump

                        Nismo

                                    Good up to 8400 rpm and 500 hp

                        Tomei

                                    New oil pump still not released. Larger drive gears

                        Reinik

 

            Oil Pans
                        Stock
                                  Stock the front differential is built into the oilpan. The stock pan is baffled , but the capacity is fairly low. About 4.5 quarts.

                        Tomei

                                    Sump extension

                        Trust

                                    Sump extension , hangs lower than the crossmember . It’s a bit low for a street driven vehicle that may encounter a speed bump.

                        Custom

                                    The point is to add capacity. At high RPMS , lots of oil ends up at the top of the motor . The oil pump sucks air , feeds air to the bearings. The motor spins a bearing , lots of                                                     bad things happen very fast.

 

            Oil Baffle plates

                        Tomei

                                    Baffle plate – replaces stock plate – has rubber trap doors

                        Nismo

                                    Baffle plate – replaces stock plate – has metal trap doors

 

            Oil Restrictors

                        Stock

                                    2.0 mm restrictor to the head.

                        N1

                                    1.2 mm restrictor – in N1 blocks

                        Tomei

                                    1.5 mm restrictor – installed on top of stock 2.0 mm

               

                Oil Coolers
                         The more and bigger you can fit , the better. The RB26 has oil cooled pistons. Oil squirters. 7 Main caps . 2 cams. 6 rods. The RB26 puts a lot of heat into the oil at 8,000                                   rpm. If you road race , it will not take long to get the oil temp up into the 130C range.  Nismo recommends keeping oil temp to a max of 110 C during an endurance race.                                       They will replace the bearings every race if they get the oil temp to 110 C

 

Head Studs

            ARP

 

Main Studs

            ARP

                        One of the main studs needs to be ground to clear the axle tube.

 

Rod Bolts

            ARP

                       

 

Rods

            Stock

            N1

            HKS

            Greddy

            Tomei

            Carrillo

            Crower

 

 

 

Pistons

            Stock

            N1

            JE

            Greddy

            HKS

           

 

Crankshafts

            Stock

            Full counter

            2.7

            2.8

            2.9

 

Blocks

            Stock

            N1

            RB30

 

Headgaskets

 

 

 

Camshafts

            Stock

                        R32

                        R34

            Tomei

            HKS

            Greddy

            JUN

           

 

Turbos

            Stock

 

            Twins

 

            Single

 

Plenum

 

            Stock

                        The problem with the stock plenum is that #6 cylinder gets the most air , and the overall distribution of air is not balanced.

               

 

                Nismo

                        Nismo has a new plenum that helps to balance flow in the plenum. #1-#5 are bell mouthed , but #6 is not. It’s a little larger to increase plenum volume.

 

            Greddy

 

            JUN /

 

            Tomei

 

           

Throttle bodies

 

            Stock

 

            Upgrade

 

            Single conversion

 

 

Head Porting

            Quench pad

 

Crank damper

           

            Stock

 

            HKS/ATI

 

            ATI bolt on

 

Front differential

            If you send 50% of the torque to the front diff – say in the area of 250-300 hp – you will break the front diff. When it breaks – it spits parts out of the front diff case. Which is also the oil pan. So when you break the front diff you break the oil pan. Which means now you must remove the engine to change the oil pan. People have broken front diffs around stock HP with a hard launch off the rev limiter. Use caution , or use a torque split controller to limit torque to the front wheels.

 

Transmission

            Stock R32 /R33
                   There were several upgrades to the R32/R33 transmission.  They all break 3rd gear.

                      Early R32
                            Push style clutch

                      Late R32/R33 
                            Pull style clutch          

            Stock R34 – Getrag

           

 

Clutch

            Stock

             Single plate

             Multi Plate
               

                    Carbon

                          ATS
                          Tilton
                          Exedy
                  


           

 

Spark Plugs

            Stock

            NGK

            Denso

            Apex

            HKS

            Greddy

             Nismo