Sydneykid

Somethings to think about; You would need to use twice the spring rate to achieve the same anti roll as a stabiliser bar. Why? Because the inside wheel goes down the same amount that the outside wheel goes up. So a stabiliser bar has twice the movement for the same amount of roll as a spring, hence twice the amount of resistence to roll. Only the outside spring resists the roll, the inside spring does nothing. When you are not going around a corner, the stabiliser bar does nothing, so you get more traction from the softer spring rate. Stabiliser bars are easily adjustable, spring rates are not. If, on any given day, you need more or less front or rear anti roll you can't easily, quickly or cheaply adjust it with springs. That's why (when the regs allow) race cars have driver adjustable stabiliser bars. Diagonal weight transfer is best resisted with anti roll, not spring rate. Under corner exit acceleration the outside rear tyres take a large amount of weight transfer, this manifests itself as lift to the inside front tyre. Reducing inside front tyre grip means that the outsdie front tyre is carrying more of the cornering load than would eb the case if the diagonal weight transfer was a resisted by a stabiliser bar. Excessive outside tyre wear and inability to maintain consistent lap speed due to overheating are all systems. Too little anti roll has side effects. One of which is the need to run excessive amounts of camber, front and/or rear. This reduces the contact patch of the tyre for straight line acceleration and braking. Running an excessively high spring rate becuase of a lack of antir roll has a few more side effects. One of which is the need to run excessively high rebound damping in the shock absorber to control that higher spring rate. This means the shocks resists (slows down) the downwards movement of the suspension and makes it more difficult to keep the tyre in contact with the road surface. Skipping from small bump to small bump is not good for traction. I have several more pages in me if necessary, if anyone remains unconvinced. Cheers Gary

But you chose heavy spring rates, seems like the wrong trade off. Why? Because you can easily adjust the bar (antiroll) rates but you can't adjust the spring rates. Cheers Gary

The discolouration is due to electrical discharge, quite normal. Wipe it off and put the plugs back in the engine. Cheers Gary

An RB25 high flow (a GCG ball bearing high flow anyway) is not at all laggy on an RB20 once you tune it properly. Cheers Gary

My R34GTT ran 11.9 at 120 mph with 265 rwkw (GCG High Flow) and 11.6 at 125 mph with 305 rwkw (GT30). I could do the 11.9's fairly consistently, say 6 out of 10 runs. But the 11.6 was very tricky and despite many years of experience, I could only get it right about 3 out of 10 runs. That was because of the small window the 2.5L provided at 305 rwkw, get the launch wrong and it was either bog or wheelspin city. Not time the upshifts (1 to 2, 2 to 3, 3 to 4) perfectlyand it would drop off boost during the run. And that was on a prepared track, with set up suspension using drag radials, on the street it was even harder. Eventually, in frustration, I went back to the 265 rwkw spec and it was a much better/easier/nicer car to drive that was faster 3 times out of 10. All of the above was with the standard diff and gearbox and an OS Giken twin plate clutch. I only broke one driveshaft, twisted a tailshaft twice and ripped the clutch centre out once. it's tough on the drivetrain, but you get nothing for nothing in motorsport. Cheers Gary

An adjustable exhaust camshaft pulley helps, as does the adjustable fuel pressure regulator. Add a little fuel presure then reduce the AFM voltage, end up back at the same A/F ratios but further away from R&R in the ECU mapping. As I said, it is fiddly and time consuming. Too true. Cheers Gary

What's "quite a lot"? Have you done your research on what is required for whatever "quite a lot" is? What sized (offest/width) wheels are you going to use at the "quite a lot" height? Have you considered flared guards, rolled lips, removal of the plastic inner guards, drive shaft angles, bump steer, tyre clearance to the lower spring seats on the rear, Ackerman angle changes on the front, exhaust system size in relation to ground clearance etc etc. Do you know how much camber you need to remove at the "quite a lot" height so that the wheels, whatever offset/width they are, still clear whatever it is that you have done to the guards? Camber correction is the easiest to solve of your problems, once you know how much you need. I would be very surprised if 2 camber correction kits (Whiteline or Noltec) don't do the job just fine. Cheers Gary

You don't have one, well not for the engine anyway. There is one for the air con, it is in front of the radiator. Cheers Gary

This thread will tell you how to measure the coils so that I can work out the springs rates for you http://www.skylinesaustralia.com/forums/Sp...Are-t79157.html This is the problem, you don't have any adjustment, it sounds like the spring rates are so stiff that there is no such thing as "grip". My guess is it will make diddly squat difference. All you are doing is adjusting the rebound damping, which is going to have next to zero effect on the amount of grip you have or don't have. What size bars are you using? My guess is the off the shelf 24 mm front and 22 mm rear, which is too narrow an adjusment range for the track work you are doing, grip or drift. You should really be looking at 26 or 27 mm front and 24 or 26 mm rear. I don't recall what model it is, if it's an R32 then you need 4 adjustment settings on the front and 3 on the rear, standard (off the shelf) is 3 front and 2 rear. If it's an R33/34 then you need 6 adjustment settings on the front and 3 on the rear, standard (off the shelf) is 5 front and 2 rear. You should also be using spherical bearing links on the bars to give you the instantaneous effect, plus increase the feel as you need as little dampening of the response for track work. They will need regular replacement, even the Whiteline greasable and dust covered ones. Just like brake pads they will wear out, they are a consumable after all. To give some adjustment for the usage patterns that you have, you can't run spring rates that high, anything much over 5 kg/mm front and 4 kg/mm rear will negate the effect of any adjustment (bars, shocks or geometry) that you do. Use the bars to control the roll, that's their job after all and then adjust the rear subframe geometry to suite the traction requirements. At the moment you have nothing to adjust that will help with your problems. Cheers Gary

The problem as I see it is that you have bought a bunch of parts without really having a plan to buy them for. You don't really have a target power output, I haven't seen anything about what you are going to use the car for, is it 100% a street car, a drag car, a track day car, a dyno queen, or all of the above? This is all important stuff, because what suites one power target may not suite the usage pattern that you have in mind. Let me give you a couple of quick examples; If it's a 100% road car, then a GT35 is far too big for a 2.5 litre with a standard internals' rev limit. You will get your ass handed to you by every taxi in town. It will be virtually impossible to launch fast on the crap road surfaces we have to put up with, when it rains you are totally screwed. It will dop off boost on every gear change as the power band will be too narrow. To make 300 rwkw the GT35 will be operating well outside of its efficiency range, creating unnecessary lag for no good reason. Have you ever looked at a compressor map for a GT35? It's not a bad place to start. With the standard internals you can't simply rev it more to get a wider power band. Keep in mind that every 500 rpm increase = double the load on the up and down bits (pistons, rods etc). You can't tune it lean and advanced to improved the efficiency, as the pistons and rings simply won't tolerate the occasional detonation that will occur. Hot days, traffic, slightly off batch of fuel etc etc are all killers when you are on the limit. Tune it safe and it will have lousy throttle response and even more lag. Your mate with the EVO will be onto his second beer before you even make it into the parking lot. Briefly, as a track day car it will be a dissaster, the piss poor throttle response will make it virtually impossible to drive on the throttle, corner speed will suffer markedly. You won't be able to do more than a handfull of laps before the frightening thought of heat soak induced detonation will have you heading for the pits. As a drag car you beter ditch the manual and get an auto as that's about the only thing that will give you decent times/speeds with standard 2.5l internals and a GT35. You could always add a squirt of nitrous to get that inefficiently operating turbo up to speed, but that's just a tad risky with standard internals. In summary, think about what it is that you are trying to achieve and only use and/or buy those parts that match that goal. You can't really ask us for advice on what to do when we don't know where you want to go. Cheers Gary

I have been trying to find the full spec of the engine, this is what I found with a quick search, please ad anything I have left out. cams are jun. 264/in 272/ex 9.7mm lift tomei 1mm oversized buckets 2.17 bar 652bhp@the fly 660lbs torque @ 5500rpm shell v - power 98ron bottom end i built all forged just the crank that’s std... datalogit Since you mentioned Datalogit assume it has a Power FC, must be a D-Jetro as I can’t see any AFM’s. I would start by checking the diagnostics screen on the Datalogit (Power FC), it shows all of the sensor readings. Just look for one that looks strange, different or inconsistent. If I had to guess the problem I would say map sensors. But there are a number of other possibilities including temp sensors. As for the power versus boost, the cam lift is a bit low for the power target, which I assume is ~750 bhp as that is the size of the turbo you have chosen. I have not seen any mention of head porting, I may have simply missed that post. But for that sort of power target it is pretty much a necessity. I didn’t see any mention of exhaust manifold or intercooler either. All of these items are restrictions, which simply increase the boost required to make less power. Remove the restrictions and the boost will go down and the power will go up. As for the torque and horsepower being the same keep in mind the mathematics that; BHP = Torque (in ft lbs ) at 5,250 rpm Cheers Gary

The one that goes forward at around 45 degrees from the rear upright /hub. Bolts on to the upright/hub just in front of the camber arm. Cheers Gary

They're in the Group Buy. Cheers Gary

You just need more/better tuning. It is not a simple tune, I have never been able to get 12 to 1 AF ratios consistently through the rpm range and get rid of R&R. You have to compromise and try multiple solutions, with the SAFC, the FPR, the SITC and the exhaust cam timing. It's fiddly and time consuming. No it won't help, for the reasons explained above. Cheers Gary

When adjusting camber on the rear you should not only adjust the length of the upper arm but also the length of traction rod to match. If you don't you will end up with noticeable bump steer as the steering arm and the traction rod will fight the length of the upper control arm as the suspension goes up and down, causing toe changes. That's why the Whiteline rear camber kit comes with 4 offset bushes (2 each side) so that you can adjust both the upper control arm AND the traction rod. In case you haven't read it, this thread explains why using spherical bearings in road cars is not a very good idea. http://www.skylinesaustralia.com/forums/Wr...mp;hl=spherical Cheers Gary

I only used the fuse when checking, didn't want to blow stuff up. Cheers Gary

The only issue with R32/33/34 style ATTESA was rolling diameter, wheel offset, track and tyre width were all irrellevant. The R35 has similar requirements; 255/40ZRF20 fronts = 255 * 40% = 102 285/35ZRF20 rears = 285 * 35% = 100 A 2% difference is well within the ATTESA's ability to handle. Keep in mind that new tyres versus almost worn out tyres (of the same size) is more than 3%. Cheers Gary

The white smoke was most likely burnt oil in the tubines due to lack of oil control caused by the detonation damaged pistons and rings. Unfortunately it's engine out and rebuild time. Who did the tune? Don't answer that, just make sure that they don't tune it again. Cheers Gary

I had a 2002 model Stagea (VQ25DET) on the hoist on Friday, working out the suspension kit for it. It is pretty much Q35 especially at the rear. But the front is different, the 4wd means shorter shocks and different shaped front stabiliser bar. Some work required there, but I am on the case. Back on subject, they already have the first cat mounted right at the turbo and what looks like a second cat in the more usual position about 500 mm down stream from the turbo. The first cat is quite big and the second cat is normal size, maybe even smaller. The centre muffler is HUGE, shaped like a half scale stainless steel coffin. So simply moving the cat closer to the turbo, to fix the cold start and run emmisons, has already been done by Nissan. No joy there for late 2003 cars.

GCG (Condell Park) will roll the edges in the alloy pipework. Not open weekends though. Cheers Gary

Let's clear up the fuel cut and lean thing first. If the ecu turns off the injectors, there is no fuel, no fuel means the engine is not running. That is not LEAN combustion, it is NO combustion. The standard ECU also does this on overrunn ALL THE TIME, to save fuel. If it turned off the ignition you would have raw fuel/air in the exhaust system. When the spark was returned you would get backfiring in the exhaust system which is somewhat bad for the cat. So not something Nissan would do. Hence no ignition cut, but a lot retarding of igniton timing is OK. What causes the standard ecu to move to R&R mapping and eventually fuel cut, is sensors operating outside their normal range. Simply put, at a certain rpm and throttle position there is a range of voltage that the AFM should be reporting. But you have jacked up the boost, hence increased the airflow. So the ecu is seeing higher AFM voltages than the rpm and throttle position would suggest that it shoudl eb seeing. A Boost Cut Defencer (in Janglish) is a simple voltage clamp. You set it at a certain voltage maximum and no matter where the AFM voltage goes above that it doesn't get sent to the ecu. The idea being that you work out at what AFM voltage the ecu triggers R&R and/or fuel cut and used the BCD to clamp the voltage at that maximum. The ecu doesn't see too high a voltage and doesn't go R&R and/or fuel cut. The problem is that the voltage for R&R and/or fuel cut is variable by rpm. For example, 4 volts might trigger it at 5,000 rpm but it might only need 3.8 volts at 3,500 rpm. Where do you set the BCD? If you set it at 4 volts then you are still going to get RR and/or fuel cut at 3,500 rpm. If you set it 3.8 volts then the engine is going to be mightly lean and advanced (in ignition timing) by the time it gets to 5,000 rpm. Think detonation and lots of it. An SAFC (or DFC or equivalent) is simply a variable BCD, you get to choose the voltage clamp at various rpms. Hence it is a far more suitable solution.

That's what I did The head unit turns on the Soundstream amp and the aerial amp when it is on. When the head unit is off, no 12 volts, so no amps, neither of them. Cheers Gary

I am working through this with him, we will find out what is wrong and fix it. There is some reason why his is different from all the others, once we find it I will fix it. As I said to him, I am here, I am not going anywhere, whatever it takes to solve this one I am on the case and I don't give up until it is fixed. Cheers Gary

You would be much better off with adjustable stabiliser bars than such stiff spring rates. You can adjust bars in a few minutes while you are changing tyres. What are you going to do with too hard springs? You would have to have 4 sets and that still would not give you the adjustability you would get with bars. Cheers Gary

Well, after 3 years I finally got jack of the poor radio reception and went back inside the dash/console, the place I most hate to go, it's a real pain in the ass. Hence why I have been puting it off for so long. This thread is a life savour as I had forgotten a couple of the tricks of removing the console. I got the trusty multimeter out and went searching, I traced the antenna lead back into the dash until I found another wire attached to it that and then followed it as far as I could find. On the dash end it had a plug and a black with yellow stripe (BY) wire going into it, the BY wire was connected into the wiring harnes that dissapeared up into the main dashboard harness. I unplugged it and checked the radio reception, no difference. So I checked the voltage, none. I checked for earth, some resistence in the direction of the antenna, none in the direction of the dash. Some resistence usually = electronic components, so I figured I would try some voltage in that direction. Using a fused 12 volts, to avoid damaging anything, I applied it to the plug, BINGO, improved radio reception. Even inside the factory I could pick up the weakest AM radio statio signal that I usually can't get, even outside. I made up a small wiring harness and split the 12V turn on signal for the amplifier from the head unit. Put the dash/console back together after a bit of vacuuming, boy lots of crap suree sneaks in under the console. Now for a couple of days of testing to see if my 2 hours of pain was worth it. Cheers Gary