Sydneykid

Does this happen when it is idling or when you are driving? What rpm does it happen at? Is it at all rpm's? Things to check; Spark plug gap, if is is misfiring it will cause the turbos to surge. Camshaft timing, if it is too retarded on the inlet or too far advanced on the exhaust you will get surge Ignition timing, similar to camshaft timing. Valve clearances, if the inlet valves are not closing you will get combustion pulses back through the inlet. If the exhaust valves are not closing you will get combustion based pulsing of the turbines. Hope that is of some help:cheers:

Low is slow:cheers:

Yep, wall thickness is relevant and the Whiteline stabiliser bars for Skylines are most definitely solid, spring steel bar from BHP.

TOE IN!!!!!!!!!!!!! :confused: That's the first thing I change, zero or a little toe out will make a noticeable difference to the steering response. Toe in also wears the outside of the tyres. What is the front spring rate? If it is over 400lbs per inch (7kgmm) then it is too high.

With an R33GTST wastegate actuator 7 psi, with an R32GTST wastegate actuator 10 psi. PS; I don't know about you but I don't drive around with my bonnet open. So I like my cars to be tuned as I would drive them.

Standard GTR bars are hollow:cheers:

Based on what I have seen, Lumpy has no need to give out false readings.

OK some real world examples, on the R32 GTST, if we increase the anti roll to max from min (via the adjustable stabiliser bars) we can remove up to 2 degrees of negatve camber. We can reduce the roll so much that it lifts the inside front tyre off the ground on corner exit. You don't excessively wear the outside of the tyres then. We run 8 degrees of caster, MINIMUM. Note the inside tyre lift on full acceleration away from the apex at Murray Corner. At your rate, 1 tyre saved = one adjustable stabiliser bar paid for. Sounds like an easy decision to me.

Thanks for the invite, I may not be going up though. We have a new ECU package and I think I will have to send the engine tuner up instead. There are no spare seats on the plane, so it's him or me. Will know for sure later this week.

That is simply not true, the PFC has as much engine protection as you want to tune into the fuel and ignition maps. Uncontrolled boost = excessive airflow. So tune the fuel to go rich when excessive arirflow is achieved. Ditto ignition, retard the crap out of it when excessive arirflow is achieved. As much (or as little) protection as you want. Asa back up, if you get excessive knock (whatever you decide is excessive), then the PFC will flash the dash warning light at you. The Jaycar DFA is demonstably superior for 1/4 the price, as long as you can solder and read intructions. That said, I have the DFA because the Stagea is an auto, if it was a manual it would have a PFC. It is that easy a decision. That's what I call no protection, even the standard ECU won't save you then. Compromise is the right word, you end up in a tuning circle. It needs to be leaner, but then it is too advanced. It needs more retard but it is already too rich. It is so easy to end up chasing your tail, striving for the best compromise. There is no compromise with a PFC, tune it exactly how you want, safe and powerful. And when you don't want the PFC anymore, you can sell it for not much less than you paid for it.

Why do you think it is the fuel pump? Have you monitored the fuel pressure on the dyno? If the pressure drops that means the pump is running out of flow capacity. With 13.8 volts via a relay and direct to battery connection the single 044 should have more than enough capacity to handle that sort of power.

I though I covered this, with this post; The engine is accelerating (rpm increasing) but the G Forces don't correspond to that amount of engine accelleration (in that gear). Fast engine acceleration and low chassis acceleration = wheelspin. Hope that made sense:cheers: PS; with a 2 axis G force meter I could draw a map of wherever you went, that's how a data logger works in a race car. Acceleration over time = distance, so not only do I know how fast you have travelled, but I also know what direction you travelled in and for how long, hence I know how far you went.

While on the subject of XForce, has anyone got a titanium exhaust from them?

I have already expressed my feelings directly to TK, but others may be interested; We have 2 X RX7's in the race team and they are up to engine #5 this season. The 2 X GTR's are BOTH on engine number #1. The rotaries are built by a well know rotary engine builder, are well tuned, religously serviced and make great power. They have to, just to be competitive. But we still get high engine maintenance, it's a fact with rotaries. Hot days, following other cars, high humidity, minor fuel differences, altitude changes etc all give us problems. The RB's on the other hand just keep on handling it, without problems. Same conditions, same atmosphere, same races. Pull them down at the end of the season, new rings and bearings and away they go for another year. The last point, RX7's are 2wd and GTR's are 4wd, there is no way an RX7 will keep up with a GTR when the going is anything but dry and smooth. Targa Tas (on public roads with weather conditions) proves that every year, when was the last time a 2wd car won? The only times Jim hasn't won, he was driving a 2wd. I know which one I would much rather own.

If they show no signs of wear (are within factory tolerance), then one new piston with 5 current ones would be OK. Just make sure they balance up the same. PS; buying a set of forged ACL Race Series pistons wouldn't cost much more than a set of new standard RB25DET Neo pistons from Nissan.

The surface affects the G forces, obviously slippery or loose surfaces generate lower G forces for both cornering and accelleration. The G force sensors measure this and tell the ATTESSA controller.

Post up a picture of what you have got and we can tell you what is missing.

The ambient temp was 28 degrees, in a Perth dyno room, sounds reasonable. Note the car has POD, no CAI or heat shielding mentioned. So +17 degrees (28 to 45) due to hot air through the radiator and into the POD is not unusual.

Mine does, but I haven't tried using the BKC MAP sensor, might have a go at it one day to see if there is any difference. Do you notice any difference between what your standard boost gauge says and the PFC Commander display?

Remove cylinder head, remove valve, replace valve, replace cylinder head, that's about 8 to 10 hours depending on experience. Say $600 to $800 plus parts, total around $1,000 to $1200 depending on the hourly rate.

Ok, so you have done exactly the same as what I have done, except you are using the BKC map sensor and I am using the standard R32GTST map sensor. I suspect that the BKC map sensor may be a 2/2.5 bar one, which may be necessary for people running boost that high. We run less than 1.5 bar, so I have never had a problem.

Yep the good old R33GTST standard ECU rich and retard strategy. If it's a manual then Power FC is the go, if it's an auto then SAFC, DFA or equivalent. PS; I wouldn't be running the standard turbo at 12 psi.

Sorry Adam, there are not "two lines coming out of it, that go to the rear for the two hydraulic rams". Have a closer look and you will find that the front half of the power steering pump supplies pressure to the front steering rack and the rear half of the power steering pump supplies hydraulic pressure to the rear steering rack. There is no hydraulic pressure interconnection between the front and rear steering racks. Read my previous posts on HICAS, it explains how to disconnect and remove the rear stearing with out changing anything else (other than those items directly associated with the rear steering itself)

Several years ago we were given an engine that made 680 bhp on the engine dyno, the task was to convert it to fuel injection from carby. It made 360 bhp average from 4,000 rpm to 7,000 rpm. After we converted it to fuel injection, it made 685 bhp, 5 bhp gain, big deal, waste of money did I hear you say? But the average power went up to 420 bhp from 4,000 rpm to 7,000 rpm. That's a 17% increase in average power. The reality is a max power figure at one RPM point is waste of time, what is important is the average power available over the rpm range that is used. That's what determines how fast a car accelerates. Then there is the how it drives, responds to driver inputs, there was daylight in that comparison as well. PS; we also did ignition control (via the Motec) at the same time, so the full effect can not be just attributed to better fuel supply control.

Nissan designed the vacuum hose for the fuel pressure regulator supply to be nice and short for very good reasons. That is response, the short hose means the fuel pressure regulator responds to changes in the plenum pressure (vacuum or boost) very quickly. Plus reliability, the hose is nice and short therefore less chance of it cracking or being broken. Firstly, by sticking a long vacuum hose (to the boost gauge in the cabin) you are introducing a dampening effect of the boost/vacuum changes on the fuel pressure regulator. This means it responds slower to changes. Not a good idea. Secondly, you are introducing a huge increase in potential for failure. Loosing the boost supply to the fuel pressure regulator can be catastrophic. Let's do some numbers; The fuel pressure regulator is set for 38 psi above boost (that's ~standard for an RB) You are running 20 psi of boost. That means 58 psi in the fuel rail. The hose to the boost gauge splits You loose 20 psi of fuel pressure The fuel rail pressure drops to 38 psi less the 20 psi of boost = (effectively) 18 psi at the injector outlet The fuel flow drops (38 psi versus 18 psi) by ~35% What was a nice safe 11.5 to 1 air fuel ratio drops to 15.5 to 1 You now have 6 pistons with holes in them after less than 10 seconds of full power running Personally I see no good reason to take that sort of risk. This is not the same as the vacuum supply to the boost gauge splitting when it is connected to the plenum (not in line with the fuel pressure regulator). It that happens then some boost will escape, not much as its small hose. But the injectors will continue to squirt the same amount of fuel. This means you will have slightly rich running, which as everyone knows is much, much safer than huge lean running. As for Blitz/HKS/Apex etc not telling you the wrong thing, give me a break. They have only one diagram for all engines! And its been the same one for 10 years. If they told you the best plumbing for all engines they would have to have hundreds of drawings and they would have to be updated every time a new engine/vacuum system was introduced. They are simply not going to do that, so they rely on the simplest and most common. Every turbo car has a vacuum line to the fuel pressure regulator, plumb it in there it’s the same for all cars. One drawing will do then, thank you very much. But we on SAU know better than that and we can share that detailed knowledge on Skylines with you. Take advantage of it or not, I don't really care, it's your engine after all.