djr81

Hmm, well without knowing where those number come from - I reckon they are hopelessly wrong. There is no way an R31's cd figure is that low.

Eh? Sierra Costworth 1240kg. Nissan tractor R32 GTR 1430kg. So, approx 190kg. Which is about 420lb.

Well yeah. I guess not tearing up money by wrecking stuff would be the start point? So you look at the motor, the brakes, the tyres. The motor is pretty obvious. The brakes are harder. Brake fade, cracked/worn rotors & stuffed pads will be your lot until you upgrade them. If your suspension isn't half way decent you will continually butcher tyres. At $500 a corner you don't want to do too much of that. But you also need to learn to drive a car on a track. Which isn't easy. Then you have to ask the question is the journey the fun bit or the destination. Take the front suspension as an example. I have been through more iterations that I've had hot dinners lately. So what advice do you give? Go to a set up that can provide all the caster/camber & grip you will eventually want. Or a lesser option that won't scare the pants off people on cold tyres but that works on the road?

The problem in all our advice is, well, really, where do you start? You can't go near a track without the brakes being sorted. You can't go round a corner without the tyres/suspension being sorted. You can leave the corner without the Attessa & diffs being sorted. You can't do anything much without the motor being sorted (for reliability anyway). All that & the bloke still wants to drive it on the road. It s a problem given the GT-R's that work on the track are laughable on the road. How does four or five degrees neg camber on the front end go over when plod pulls you up for a 'random' breath test?

Well said. To be honest even with a rebuilt ATTESSA system I still find that making changes to the way the ATTESSA functions via the Ruzik controller is a worthwhile exercise. Some circuits like more front bias to the torque distribution, some less. Alot of GT-R's doing good lap times are heavilly reliant on their 4WD system & mega horsepower. Not everyone can have or even wants the latter but to get the old dears to punch out of the corners you have to have the former working well.

Rebuilding the transfer case is expensive. But it wont necessarilly need rebuilding. The case has a series of clutch plates in it. Like all clutches (wet or dry) the are subject to wear. If you look at the manual you will see that Nissan offer a list of end plates/shims of different thicknesses. These make sure the clutch packs are in a range that allows the ATTESSA system to function as it should. What happens is they get old, the gaps open up & then the system is slow to react. Hence you get oversteer. So yeah, a new end plate may be all you need to make it work properly. Hell it may still be ok. So find that out first. The problem is that until you take the thing apart & measure it you don't know which shim size you need so the job takes a while. The other thing to do is find a Ruzik ATTESSA controller. If they are still available. These are an important tuning aid for corner exit behaviour. If the motor is ex an R33 then the oil pump should be ok as it is of the better type. Check you harmonic balancer to make sure it is still in good order though.

He did the Busso round of the Speed Event Series in it and belted everyone.

For my 10 cents worth I would get a Quaiffe front & a 1.5 way rear. I have a Nismo rear LSD - the Pro model. The most common adjective used to describe it is "nasty". Frankly the TT or whatever Nismo call it (the version with a lesser ramp angle) would have been fine. Basically I don't beleive that a GTR needs much in the way of rear LSD & certainly nothing in the way of diff locking on the over run. You have to drive them square like teh Baron says. For me that involves trail braking hence the front LSD comment. The focus of your set up (in my opinion anyway) is finding as much front end grip as possible (a hard thing to do in a GTR) & making sure the ATTESSA system reacts the way you want it to. It is common to see GT-R's on the track that understeer on the way into a corner (because of no front end grip) then oversteer on the way our (because their 4WD system is not working well). The adjective used to describe these cars is usually "slow".

Hmm, when I went to school they were hydraulic.

Has anyone used these and how do they stack up against the Ferodo DS2500. http://www.project-mu.com.au/en/

Um, it shouldn't be hard at all. Find the HICAS units under the parcel shelf. Grab the plug & match up pin 18. hicas_pins.pdf

Yes cheers. The have some good systems. I think (from memory) that getting them to go through the sheets for your car was well priced & that getting the dampers dynoed was equally good value. Just out of interest did you get them to produce a set of sheets for your car? As for the second paragraph that is exactly what frustrates me in trying to modify a car. I don't reckon the questions are actually very hard but it doesn't mean they get answered.

Does anyone want to make comment on the PFC prediliction to randomly "sneeze" because (AFAIK) of the way it reads the signal from the AFM's without much in the way of damping? Does the Nistune do this better?

This is the chassis number & parts listing for the Australian delivered GTR's. Having sat my import next to a local delivered example I can confidently say that the seats are the same. Also the aerial was at the front of the roof, not the back. It replaced the one in the windscreen - hence the different part number for that. Wierd, random stuff they changed included the sun visors, adjustng the speed limiter and for some reason there is a listing for a jack. index3.pdf

No there isn't a direct correlation, sorry. There are too many variables to work it out - to list just some - ignition advance, engine speed, combustion efficiency, pumping losses etc etc etc. A better guide is the AFR, but even that is not very good.

Adaptor brackets to fit my F40 callipers to a 345mm rotor on a GTR.

As much info I have at the moment is as follows. The numbers are based on the sprung weight of my car & hence will be different for others, obviously. Stock R32 GTR info: Front spring rate 2.4kg/mm & damper rate based on 0.3m/sec - assumed to be linear Front bump damping ratio 0.25 (500N) Front rebound damping ratio 0.89 (1746N) Rear spring rate 2.7kg/mm & damper rate based on 0.3m/sec - assumed to be linear Front bump damping ratio 0.24 (402N) Front rebound damping ratio 0.66 (1108N) Nismo R32 GTR info: S tune damper set to the middle of 5 settings. Front spring rate 5.5kg/mm & damper rate based on 0.3m/sec - assumed to be linear Front bump damping ratio 0.36 (1079N) Front rebound damping ratio 0.64 (1912N) Rear spring rate 4.5kg/mm & damper rate based on 0.3m/sec - assumed to be linear Front bump damping ratio 0.32 (686N) Front rebound damping ratio 0.63 (1373) Notes: A reduction in srpung weight gives you an increase in damper ratio. An increase in spring rate gives you a lower damper ratio. What is deemed acceptable for bump & rebound ratios for the front & the rear is arguable. I am presently chasing some info from some of the damper manufacturers but who knows if they will come good.

The point is that once you have calculated the damper rate for bump & rebound and worked out the acceptable range on what you want for both ends of the car it would be nice to be able to tell by a means other than the usual salesman blandishments that the shocks are, infact, what you are after. The information is not unknown or even unavailable. It is not a case of being so scientific, simply a case of being able to select a shock using some basic information. The suspension shops match springs to cars & to dampers. But htey do so in such a broad range that makes me less than 100% comfortable with the selection. Anyway, love to all, etc.

Does anyone have any force velocity graphs of dampers installed on their Skylines? I am trying to work out what damper rates would be suitable for a spring change & am having trouble getting any decent information out of the suppliers. If you could make mention of the spring rates they go with that would be great.

Depends what size etc you want. Try this lot http://www.robertcameron.com.au/contact.html

Hmmm, can't find the bracket on their web pages. Plenty of other stuff, just no bracketry.

Yep.

The problem I have (well, one of many) is that for hillclimbs & driving on the road I need something that works from cold. So 3000's are no good. Where abouts in the US do you source the 2500's? I am sick of paying $400+ for the damn things.

Believe your mechanic. You won't find Dot 3 fluid anywhere. Dot 4 is the replacement so use that. Dot 5 is a mutant offspring and should not be used. If you want track biased fluid get dot 4-600 which is a high temp dot 4 fluid.

Why is it a surprise to anyone? If you think about the 92 race the "winner" had three wheels left on it & the third placed car (Crompton & his sadly departed co driver - go look it up) were closing down the # 17 Sierra hand over fist. Basically had the race not been red flagged he would have won. Coulda woulda shoulda...........