Sydneykid

What part of his post didn't I answer? Low top end oil levels - covered Cooling pistons - covered Oil supply at low rpms - covered Oil flow regulator at high rpms - covered External oil pump = dry sump, I don't think that needed covering again What have I missed? cheers

Who says you're the only one? Happens all the time. Did you refit the anti siphon valve when you fitted the Walbro? It stops the fuel running back to the tank when the engine is off. Checked the fuel pressure lately? Lastly the Skyline disease, vacuum hoses and intercooler pipework leaks. When the engine is hot, it is more susceptible to lean start and run issues caused by vacuum leaks. So check all of the hoses and clamps for any CHANCE of a leak. cheers

No you haven't cheers PS; they are ball bearing

I understand what you are trying to achieve, but you are perhaps overlooking one point. Sure, using the SAFC to reduce the AFM voltage that the ECU sees, leans out the A/F ratios But it also advances the ignition at the same time. So you can only take out a limited amount of fuel before the advancing ignition causes detonation, or at the very least pre-ignition. This is the usual compromise forced on tuners by AFM voltage benders like SAFC’s. Keeping the above in mind, increasing the fuel pressure results in a linear increase in fuel flow though the injectors at all durations. But a 10% increase in pressure does not result in a 10% increase in fuel flow. Based on past experiences going from the standard 34-36 psi to 45 psi (~33% increase) results in around a 10% increase in flow. I gather from what you have said (rather NOT said) is that the tuner leaned out the A/F ratios by REDUCING the fuel pressure. But if he then had to add fuel via the SAFC, he obviously reduced the fuel pressure too far. As you have found out (and he should have known) adding fuel with the SAFC simply brings on R&R mapping earlier. Which is exactly the reverse of what should have been done to avoid triggering R&R. My suggestion is to take it back to the tuner and tell him what your problem is. This is what I would consider a “warranty” issue and he should fix it for you at no charge. Or at the very least, a small nominal cost. Hope that was of some help cheers

I use camber correction as the first measuring stick as to how much a car can be lowered. When the camber gets grossly excessive, then you know you have lowered it too far. This is what is usually needed for each height increment, note that all measurements are centre of wheel to guard; Standard (new) height is 380 mm front and 370 mm rear 360/350 mm needs only the standard rear camber adjusters 350/340 mm needs 1 front camber kit and 1 rear camber kit 340/330 mm needs I front camber kit and 2 rear camber kits Using that rule of thumb, 340 mm front and 330 mm rear is a low as I would go, keeping in mind that they handle best at around 350/340. So even at 340/330 you are sacrificing handling for looks. cheers

PM sent cheers PS, sorry for the delay, people who send PM's get answered first, questions in posts come second.

Yes, but it would stop the AFM "reading" the air flow twice, which is what is happening now. Plus it sounds like you have the AFM located in the rammed air tubulence. It may be worthwhile moving the AFM a bit further away from the filter. I understand why you have it as far from the compressor, it helps with any reversion problems. But somewhere in between might be beneficial. At least it would move the AFM out of the turbulance and it would be getting only straightened airflow. cheers

Keep in mind that the larger an intercooler the more air it holds, the more inertia this causes and hence lessens the throttle response. Personally (for what I use mine for) I would give away a couple of psi of pressure drop for an improvement in reponse. It all comes down to what you use the car for. cheers PS; the best I have seen out of a standard R33GTR intercooler was 450 rwkw.

Start up hydraulic lifter rattle is the first sign of lifter wear. It is most commonly caused by worn oil seals in the lifters. The oil leaks out over night and when you start the engine first thing in the morning it takes a little while for the oil to firstly fill up the empty lifters and then build up pressure. Replacing the lifters usually fixes this. If the lifters are not replaced, then the wear rate increase exponentially due to the lack of oil. Eventually the lifters can't hold the oil pressure at all and the rattle comes back at low to mid rpms. Replacing the lifters will fix this. Eventually the lifter get so badly worn that they rattle all the time. This can lead to damaged camshaft lobes due to the excessive clearances. So my first suggestion is to replace the lifters. I should mention that some lifter rattle is caused by too infrequent oil changes and a resulting build up of sludge. This causes blockages in the oil flow into the lifters, hence they rattle. A few oil changes usually fix this problem, not that I think it is the case for a Skyline enthusiast, we change the oil too often for that. At this point it is worth expanding on the discussion of RB25 oil supply. They have 3 oil feeds, one for the VVT which overflows into the cylinder head and has its own return to the sump located on the front LHS. The other 2 are the normal RB oil feeds to the camshaft bearings. I can’t remember what you have done regarding the VVT oil supply, but from what I have seen it should always be left in place, untouched if the VVT is being used. Then selecting from the 1.0 mm 1.25 or 1.5 mm restrictors according to the usage. Refer to the table for the exact details. Lastly oil pump, if the oil pump is not achieving maximum oil pressure (and therefore flow) by 3,000 rpm, then you have an oil pump problem. Revving the engine to higher rpms should not result in higher oil pressure. If it does, then you have an oil pump problem that needs to be fixed. Keep in mind that a swap to solid lifters will also require a swap to camshafts designed to run with solid lifters. Hope that has been of some help cheers

Piston cooling (same as main bearing and big end bearing supply) is done from below (before) the oil flow restrictors. So restricting the oil flow to the cylinder head in fact improves the piston under crown cooling. Please remember that Nissan blocks off one oil supply in RB26's standard. So there is nothing unusual or unrealistic in doing that. What we are doing (that Nissan don’t) is to restrict the oil flow further (than they do) by using a smaller orifice restrictor. Noting that Tomei, Jun, HKS and Apexi all use restrictors, so it is a well know technique. The oil pump’s flow basically increases as rpm increases, at least until the predetermined oil pressure is reached. Then the flow is constant. The pressure is controlled by the oil pressure relief valve, which bleeds off oil flow at the oil pump outlet and returns it directly to the sump. The first problem occurs when people use constantly higher rpm than Nissan ever envisaged together with a higher oil pressure relief (N1 for example). This is further exacerbated by using a larger flow oil pumps (Jun, HKS, Tomei etc). Keeping the above in mind, what I have done with the table is to give a gradual decrease in the amount of oil flowing to the cylinder head in relation to the oil pumps and rpms used. Simplistically what I have done is to give the SAME (not less) oil flow as the engine would have had when the oil pump and rpm used were standard. How do I know it works? Well, we have done over 30 engines using this technique since 1998 and not one of them has had a camshaft bearing wear problem. That’s a pretty good sample IMHO. But (as I say often) every engine is different, so use your own discretion when selecting the appropriate restrictor for your uses. cheers PS, the table also mentions the fitment of an oil cooler

OK, either you are having a dumb day or I didn't explain it very well. I will assume its my fault and have another go. What is happeing is the air is being rammed in 1. through the filter 2. into the inlet pipework 3. through the AFM 4. through some more inlet pipework 5. into the compressor 6. the compressor "rejects" what it doesn't need 7. some of this air goes back out through the AFM (ie, gets measured twice) 8. this is air that the AFM has measured (once and/or twice) but it hasn't gone into the engine 9. so the ECU is squirting in more fuel than the engine needs So what you need to do is stop that reverse airflow. You do that by sticking a one way valve in the inlet pipework (#4 above) between the AFM and the compressor. When the compressor is using all of the airflow, there is no pressure build up, so the valve stays closed. When the compressor is rejecting some air flow, there is pressure build up, which opens the one way valve. A simple PCV valve works OK. We bleed off pressure from the airbox on N/A race cars (even V8 Supercars) for exactly the same reason. Does that make sense now? cheers

1. RB26 AFM = 65 mm RB20/25 AFM = 80 mm Z32 AFM = 80 mm Q45 AFM = 90 mm 2. When the Z32 AFM has reached its maximum voltage (5.1 volts) before boost has stabilised. cheers

Simple solution, put a one way valve in between the filter and the AFM, it will "blow off" any excess air flow. Cheers

PM sent cheers

You betcha, PM sent cheers

Well, yes and no. Yes, but I thought you were talking about the difference before boost started building ie, when the wastegate should be 100% closed anyway. And no, these days with the fast acting solenoids, short actuator hoses and a correctly sized wastegate (diameter and spring rate), the opening doesn't have to be that premature. A couple of psi is all you need, and you shouldn't notice it anyway, if you have the timing right. cheers

1. On GTR's we run 2 scavenge pick ups from the sump. One in front of and one behind the front drive shaft. 2. Plus 1 scavenge pick up from each cam cover. 3. Nope, it's all frothy and foamy after its been though the turbo, so best to gravity feed it into the block. 4. The standard RB oil pump is the normal rotor style. We use Peterson dry sump pumps, they are gerotor style as you would expect. cheers

If the boost controller is allowing the wastegate to open before the boost target is reached, then it's a BAD boost controller. That's either ZERO or 100% solenoid duty, it should be fully open or, in the case of an IEBC, fully closed. Regardless of what gear it is in, it's still a BAD boost controller if that's not the case. cheers

Since you haven't posted up an A/F ratio graph it's a bit hard to be specific on what might be the problem with the power output. Equally as hard to be decisive regarding the need for an AFM upgrade without knowing what sort of voltages they are seeing at what rpms. Did you run it with a fuel pressure gauge connected? That will tell you if you have a fuel pressure fluctuation problem that could be causing the drift in A/F ratios. Where are the camshaft pulleys set at? It seems to have a very decent amount of mid range power. Maybe the lobe separation (advanced inlet and retarded exhaust) is a bit much. GTSS’s have lot’s of bottom end, quick response and fast boost build, so you don’t have to “help” them out with excessive lobe separation. Better to use their natural abilities down low and adjust the camshaft timing to help their top end. That’s about it, other than I hope you are running it on Shell V Power as that makes a noticeable difference when tuned for it. cheers

Simple answer, if I don't want as much power, I don't psuh the accelerator down as far. I don't care how smart the boost controller is, I KNOW that I am a lot smarter. cheers

1. Yep we are up to 32 engines now and not one has any sign of oil starvation of the camshaft bearings 2. It is both 3. RB26's have one of the oil supplies blocked off STANDARD, Nissan seems to think its necessary for STANDARD RB26 rpms as used on the road. 4. The pressure before the restrictors INCREASES under certain cirumstances, that means superior lubrication for the main and big end bearings. Refer to #1 regarding the camshaft bearings 5. Because sometimes it's simply not enough, depending on your usage patterns and the sustained engine rpm. The only time I don't have to limit the flow to the cylinder head is when we use a dry sump sytem running partial vacuum on scavenge. The 4 scavenge stages have considerably more flow capability than the pressure stage. We don't get excessive oil build up in the cam covers then. cheers

OK, ignore that. I just noticed you measured coil OD not ID. I will redo them tonight, sorry. cheers

Try leaving the bonnet open between runs, heat soak is a problem. cheers

Shoot, where to start............just a short list of stuf that your are risking; 1. Drive shaft breakage is possible 2. CV joints will wear very fast (they are also soaking up extra power due to the extreme angles) 3. Steering tie rods (front and rear) are under extreme loads 4. Every single bush in the front and rear suspension will wear out excessively fast 5. The strut towers will eventually crack (both front and rear) due to the lack of bump absortion 6. The rear cradle will crack around the upper and lower control arm joints also due to the lack of bump absorbtion 7. You will suffer poor traction, so it won't stop or accelerate anywhere near its potential 8. The front and rear windscreens are stressed members, so they will eventually crack as well 9. Every electronic component is being subject to higher than its design levels of NVH, so they will eventually start to fail one by one 10. Your chiropractor will make a small fortune fixing your lower back problems That's pretty much the major items, there are quite a few minor ones of course, but I think you get the drift. cheers

All PM's replied to cheers