Sydneykid

Honestly it is cheaper to buy an RB26 top end and sell the RB25 top end, than it is to fabricate the stuff to make it fit an RB25. Plus you get all of the RB26 advantages, solid followers, valve springs, valves, ports, combustion chamber, squish etc etc. And the other parts, cams pulleys, no VVT etc are much cheaper and easier to get second hand for an RB26 than an RB25. I have done the numbers 20+ times for people, it always works out cheaper in the long run, you get a better result and it's much easier to sell if you ever want to.

Yep Duncan, that's one of the two Primeras. There is a Mondeo as well. Fantastic technology in them, makes a V8SuperCar look like the dynosaur that they really are.

Hi James, there are plenty of Skylines on the track you just have to be there at the right time. HICAS is not your friend, get rid of it. Do a search on other stuff I have written on HICAS and why it's gotta go. We run Whiteline adjustable stabiliser bars, 27 mm on the front on a GTST and 24 mm on the rear in the dry and 22 mm in the wet. Ordere them with one extra hole per side, std is 2 you need 3. The standard diff is not a good track device, we find a 1.5 way clutch pack mechanical to be best. ATS make a good one, as does Nismo. Alignment settings are really dependant on rubber and spring rate. We use 3.5 degrees negative camber on the front, with 8 degrees positive caster. Between 1.5 and 2 degrees negative camber on the rear. I usually run the alignment on the race cars straight ahead front and rear. If you find the rear a bit fidgetty under brakes, a bit of toe in helps with stability. Decent R compound tyres are really a must, R33 GSTS's are heavy beasts so need plenty of grip. Our control tyre is a Yokohama A032R, we use 245/45/17. The Dunlop and Bridestone equivalents are arguably slightly superior in the dry. You will find as the corner speeds increase, the brakes won't be such an issue. We use Hawke carbon pads in the blue compound with DBA slotted rotors and AP 600 brake fluid. Remove the backing plates from the rotors, the fronts bolt on but you will need to cut the rears off. An air saw is a big help. For track work the Bilsteins are very effective and give good value for money. I have yet to find a Japanese damper that gives as good a result. Ohlins are also very good if you want some adjustment to play with. The Konis don't have quite the piston area for track work, great for the road though. Keep the rear spring rate low, not much over 200 lbs and control the roll with the stabiliser bar and the squat with the subframe bushes. Hope that helps

Well, lets put it this way, the "kid" in Sydneykid is for fun :wassup: I mostly worked on circuit race cars and there you learn heaps of stuff real fast. I also write articles for magazines, mostly on suspension and do a bit of driver training to go with the race team data logging and interpretation. It's all good fun.

I only looked at east coast compliers. There is one in WA that I didn't contact. I got quoted $4K from one workshop, $4.5K from another and $5K from another. The $4K workshop had no licences left, so I went with the $4.5K one. All were plus tyres.

Thanks, very impressive for a 2.6 litre.

Hi Brad, not a problem for the Autronic, if well tuned of course, they can handle multiple throttle bodies

Power FC runs AFM's so the multiple throttle bodies would be OK. You didn't really think that Nissan would make it easy to put RB26 (flagship) stuff on an RB25, did you? They simply didn't want the value of GTR's being deminished, so they made it as hard as possible. :headspin:

AAAAAHHHHH!! :Bang:

Oooops, It thought they were the same. The Blitz catalogue lists the same engine pipe part number for R33 GTST and WGN34 Stagea. Blitz Front Pipe ECR33 Stegia WGNC34 ¥15,360.00 Care to check with your exhaust guy and find out what exactly was different. It would be a great help

What bore size?

Email sent

Accept yes, match up the ports no, the RB20's are smaller. Yes, all RB25 heads are like this. I found one easily 4 years ago, haven't tried since. I use RB26 top ends on RB31DET now. Hope that answered your questions

Hi geno8r, following are some of my previous posts on HICAS; I believe that removing the HICAS is a good move for a couple of reasons........... Firstly I like to be in control of the rear end via the throttle. The HICAS computer is slow and dumb, ie; it doesn't act very quickly and only has limited inputs. So it does things too late and sometimes they are the wrong things. It tries to help the rear traction by steering the wheels and this works OK, but only for as long as the car is within the traction limits of the tyre. Secondly, rear tyres don't like to be twisted around when they are already under a lot of side load and scrambling for traction. The HICAS movement of the tyre is enough to break the contact patch on the road and the car slides. Sometimes a little, sometimes a lot. Then the HICAS tries to fix that by changing the steering angle and the whole thing starts all over again. So, to answer your question, sometimes the HICAS adds to the oversteer and sometimes it doesn't. That's the killer, with the throttle and suspension setup, I have consistency. This gives the driver more confidence and consequently you can drive the car closer to the limits (ie; faster). ---------------------------------------------------------------------------------------- we remove all of the HICAS stuff of our R32 road/race cars. We replace the rear rack with an billet alloy block, shaped and threaded to suit. This locks the rear wheels and stops them from steering. Just pulling the fuse will still allow some movement under load. We remove all of the pipes, hose fittings, mounting blocks and the rear (1) and front (2) solenoids. We then take the hose that usually goes from the power steering pump to the front solenoids and re-route it so the fluid goes straight through the oil cooler pipe. Removing all this saves almost 30 kgs (including the excess fluid) and the car handles much more predicably on the circuit and on the road. None of the GTR's circuit race cars I have seen anywhere in the world (including the Gibson ones here in Australia) ran the HICAS. Simple HICAS bypass kits are available from people like Jun, Apexi, Tomei etc. They have a couple of washers that stop the rack from moving and an electronic box that tricks the HICAS computer into thinking the rack is still working and so the dashboard warning light doesn't come on. There are other kits around that have a replacement for the rack and a small bypass hose that goes between the two standard hoses at the rear rack. This makes the HICAS computer think the rack is still working and so the dashboard warning light doesn't come on. Stillen make kits like this for Z32's. There are relatively cheap solid rear rack replacements available (eg; Japanese Motorsport) but the HICAS warning light comes on when you remove all of the other stuff. Some people remove the bulb to fix this problem. My suggestion to people when they ask about HICAS is to remove it totally cause it saves weight and the car handles better. If they don't want to go to all the trouble and expense that involves, then I tell them to use a Tomei kit. Takes under an hour to fit by an amateur with limited tools. Whatever way you do it, the car will need a wheel alignment when finished. ------------------------------------------------------------------------------------ This is the Stillen rear rack replacement in billet alloy, similar to what we use on the race R32's http://www.stillen.com/product_images/308550.jpg ------------------------------------------------------------------------------------ Hope that helps.

Nah, I'll change it in a few days anyway, at 1280 by 1024 it looks OK, doesn't it?

Just a few questions ...... What capacity is the engine? Is the gearbox standard? Transfer case? Diffs? Brakes?

What Cam said, the Power FC part number you require for an R32 is 414-N011, the applicable Commander part number is 415-X001 and the Boost Controller Kit part number is 415-A001. Hope that helps

HICAS is not your friend, every Skyline I own or have ever owned has had all evidence of HICAS removed by me. It's the first bit of suspension work I do. Thank heavens the Stagea doesn't have HICAS, so I don't have to remove it. Have a read on HICAS in the suspension section, if you want to know more.

Hi tangO, Standard GTR pump is 190 litres per hour and supports 420 bhp at standard pressure (that's ~265 rwkw) Standard GTST pump is 135 litres per hour and supports 300 bhp at standard pressure (that's ~175 rwkw) Hope that helps

An 85 mm butterfly or a 100 mm butterfly, it makes no difference in the example I have given above. It is the volume of air between the butterfly and the inlet valve that matters. Obviously if the turbo can supply more air than will flow though the buttefly, then bigger is better. But I personally have used a standard RB25 TB and inlet up to 450 bhp and it is certainly not a restriction at that power level. I have seen a Zeni Tani built 550 bhp RB25 with the standard TB and inlet and it did not seem to suffer either. Regardless of whether it is for road or circuit, as most people know, I hate cars with poor throttle response, turbo cars already have too much for me, even at their best. So I see no reason to make it worse and, if everything else is equal, a single TB WILL make it worse. Well up to a power level that I have yet to exceed anyway. If you are intending to use a MAP sensor driven ECU (not an AFM driven ECU) then go with the single TB, it makes the tuning so much easier. Multiple TB's and MAP sensors are not happy together. Hope that answered your question.

The combustion chambers are between 62 and 65 cc's. Most are 64 cc's, but they do vary. So you really need to do the calcs on your own engine. A skim of 1 mm is around 6 cc's so you can see why you need to be precise. Hope that helps

Hi Nathan either you read it wrong, or I wrote it wrong. You definitely need high impedance with the RB20DET Power FC, so if you use low impedance injectors (as in GTR) you need to increase the impedance. You can do that by using the GTR resister pack or by using individual resisters at the injectors. Hope that clarifies

Steve, I have "tried it" both with a standard RB25 throttle body and a Foulcan throttle body. I could fee lthe slowness instantly on the road, and on the track it was disasterous. With the dog box we have ~50 milliseconds for a downshift and you MUST match the engine rpm with the gearbox rpm. Otherwise you end up with twisted splines on the input shaft from the triple plate clutch and missing teeth on the gears, particularly 2nd. It is quite simple to understand why this is the case. With the multiple throttles there is very little air between the butterflies and the inlet valves. So when you close the throttle the airflow to the engine stops instantly, therefore so does its power production. Compare that to a single throttle body with a plenum in between the butterfly and the valves. The usual rule of thumb is at least double the engine capacity in the plenum, so on a 3.1 litre that's 6.2 litres. Plus that 6.2 litres is under boost just before you close the throttle, so at 1.5 bar it really has 9.3 litres of air in it. In addition, after you close the throttle, the plenum goes under vacuum, around 0.25 bar is not unusual, that's another 1.6 litres. So when you close and reopen the throttle 7.8 litres of air flow dulls the response. On a 3.1 litre engine that's almost 5 revolutions of the crankshaft, at 7,500 rpm that's 666 milliseconds. That's more than 10 times slower than the gearbox will handle. To translate that into distance, at Bathurst it would mean we would be lapped twice during the race distance Another way to look at it, Nissan designed the GTR to win races on the circuit, if they thought a single TB was better then they would have used it. Let's face it, a single TB is simpler to make, therefore cheaper, easier to tune and maintain. But Nissan went for multiple TB's, why? Because for their stated aim it was superior. Let me close off with;

How much do you want for them?

Are the brakes the single piston sliding calliper style?