rob82

Still reckoning its the injectors leaking - get them ultrasonicly cleaned and flowed. But in saying that I havn't seen the tune which may play a major part in the saga.

Leaking injectors?? How does the car hot start if you leave it for say 30 min.

What your tuner is describing is reversion. On very light throttle you get some back flow (reversion pulse) off the compressor wheel. The only way to fix it is to increase the distance between the AFM and the turbo or introduce a 90deg bend. With the right software it can actually be seen as you back of the MAF voltage gets larger for a second. The majority of AFM's - RX8, any Subaru, some large yank lightening MAFs will NOT run without a bend or a large distance from throttles or turbo chargers etc etc.

Dont suppose you've ever seen an s15 PFC not relearn closed TPS - and hence try to implement an idle strategy at low throttle angles? Problem was that the low throttle driving rpm was higher then the desired idle rpm and it would pull all the timing out and drive like a pig. Also too much coolant ignition retard and you just going to casue more heat to the head and overall coolant system. I prefer to heavily enrichen the mixtures if the temps is way outside operating temps.

I had an RB26 in an r32 GTST making 240rwkw with the rb20 box - it will cope with that power easily. Very quick car, should be even quicker once I finish my rb30 bottom end with GT2560r's - then we'll really see how much torque the rb20 box an handle - hopefully 1 full power dyno ramp.

If you've got more timing up your sleeve then I would be playing with exhaust cam timing to bring the turbo on even sooner and then try to get the timing back in the top end so you end up with the same power but even better response. Or you could just increase the compression - have found that this usually helps if you have an unreactive chamber - as you have. Dont know about bending rods, as has been said - they are only short little f**kers. But I would definately be monitoring exhaust gas temps will leaning out the mixtures. I'm attemping a WI install at the moment with an xede - semi closed loop ie feedback from a EGT sensor to determine final water injection amount.

Surely it would have sealing issues under higher boost. Also whats the good of a phenolic spacer to stop heat from the head when the intake manifold runs coolant through it anyway?

When running an inline external pump - we always run a bypass around the big pump along with a check vavlve and switch it on when required - either a hobbs or an output of the ECU can be used. This helps by not flowing lots of fuel to front of the car where it is heated.

Its spitting litters of oil into a catch can not burning or leaking it. The problem is not apparent on the dyno but perhaps not enough sustained high rpm loading is seen during a dyno ramp to fill the head. Which brings us back to the restrictor sizing as had been mention by sydney kid.

Putting larger duration camshafts in will reduce the dynamic compression. The reason people use thicker head gaskets is to reduce static comp which will lower dynamic comp. Lower dynamic compression gernerally means more timing can be run and more power to be made. If your putting cams in I wouldn't bother about doing the head gasket at all. If you do though you may as well do head studs for extra clamping force for very minimal extra cost.

My thinking is that there is a scaler of "base dwell time" that is not accessable via datalogit or the hand controller. Then there is a mutiplier "IGN vs BatV" which should read "Ignition Dwell mutiplier vs BatV". Then the "IGN dwell vs RPM" is another mutilpier based on RPM. Also it cant be duty cycle based as all nissan's use dumb ignitors.

Forget the GM MAF's as they are frequency based. The lightning MAF of the SVT Mustangs will flow alot more than 350rwkw but they are a little shitty to tune down low and I say this becuase I had a little trouble with a 5.4L 310rwkw NA mustang and it would have alot more cubes to aid airflow at low speeds then any skyline. Your best bet though would be using a little voltage divider circuit using say two 2k resistors. Just solder one end of the resistor to ground then solder the other end to the input to the PFC and the other resistor togeter then the other end of the other resistor goes to AFM signal.

Just check the signal pin of the map sensor at ignition on - if its 2.34 volts then it only two bar which means it wont read over 15psi. I wouldn't think its over two bar though.

I hear what your saying but spark energy is "usually" a function of dwell vs batery voltage not dwell vs rpm - as it is within the datalogit software. Dont get me wrong this table may affect dwell but it may just be worded incorrectly and the scaling from hexidecimal to actual engineering numbers may be wrong. Its one of those things I would test if I only had a free second at work!!!

I always worried about editing this feature in the PFC because I believe Datalogit have their description incorrect. How can coil dwell be dependant upon rpm? Secondary coil voltage is dependant upon input power so with a fixed impeadance only voltage and dwell will affect the final spark engergy. Most of the jap stuff I have seen - including tuning of factory ECU's, coil dwell is allways based upon amount dwell vs battery voltage not rpm unless of course its duty clyle based - but then the numbers dont make sense. Has anybody had time to scope the dwell after editing this table? And yes there is a point that more dwell will result in less secondary coil voltage.

Pressure differentials across intercooler cores is based on airflow more so than boost pressure. Its just that higher boost pressure usually means more airflow. So your figures are a little ambiguous.

Yes this test is fine for measureing fuel flow. Just remove the return line from the rail and put it into a meausrable container and run the car for 60 seconds - that will give you Liters per min. For 200rwkw you want around 2.5l/min of fuel flow at 50psi pressure. As for the "anti reversion" valve it will most likely not be needed. We usually only run check vavles around inline switched pumps.

They are just a three bar system so around 43Psi with no vacumm to the reg or 38 wiht vacumm.

How do they latence test them? Are their results based on pressure drop across the injector and also differing battery voltage?? I would definately have them cleaned - just for peace of mind - dont be cheap.

IMO the best ecu for almost any skyline is the factory ECU with an emulated tune. It has all the features allready their and usually with small mods only light tuning is required. The factory ECU has more tunability for an experience tuner than a PFC with any of the locally made software or hand controller. A major differnce between the factory GTR ECU and the GTR PFC is individual group sequentail firing of the front and rear three cylinders whereas the PFC averages the two MAF inputs and delivers a single injector pulse(depending upon injector flow rate per cylinder within the software). Both systems have quite good closed loop control and good timing control. Wolf: Lots of features however many of them dont work - may be later version 4 and above they may have ironed out some issues. Looks good on paper but lack firness. Poor closed loop operation from what I've seen. However available in plugin and is realatively cheap. We actually pulled a wolf V3 from an S14 and retuned the factory ROM using an emulator - the customer couldn't believe how much better the car drove even with his level of mods. Motec: Expensive - must pay for upgrades for each extra option. However good ignition and injector control, average PI cam control shithouse PI boost and closed loop lambda control. Can input many maps for everything to get around bad PI and PID loops. Autronic: Very good ignition and injector control, very good closed loop PI based boost and lambda. Best ECU capable of returning OEM quality. However lots of setup involed with various inputs and little help from manufacturer. Should be only setup and tuned by reputable autronic installers or tuners. Microtech: Average injector and ignition control - great easy of install and hardly ever issues with installation. Great value for money and quick tuning.

The wider the duration the lower the dynamic compression is. So if th DE cams are smaller it will increase dynamic compression.

Sounds more like a clogged injector.

Its a heat exchanger.

From what I've seen of those controllers they are quite shit!! If an EBC has no PI or PID based boost control then you may as well just use a bleed valve. From memory you set the boost from a base duty cycle not an actual desired boost pressure so there is probably no brains behind it anyway. You could try setting the gain to a higher value but it probably wont work anyway. If it is possible which I dont think it is you could check the duty cycle on the valve to see if its attempting to control the boost. As has allready been said it may be a mechanical restriction.

The stock reg is 1:1 so is nismo, sard, and SX. The stock reg has a steel diaphram unlike any aftermarket reg that I know of so it should be the most stable. And yes tuning for 1.7:1 or 6:1 or 12:1 rising rate regs is shit. If you like the fancy shit and want a to put a nismo or sard sticker on your car then I would recommend these two otherwise use the stock item.