Sydneykid

Good memory ADM and spot on as well, I don't like sphericals in road cars. But I was thinking of trying these in a race car.

Hi Guys, when the engine is cold the ecu supplies extra fuel (rich) to keep the engine running and running smoothly. It sounds like you have a lean engine when it warms up. This is usually a good sign of an air leak. This leans out the mixture at normal running but the richness when cold covers this up. Well, until it warms up anyway. My first suggestion would be to have a very good close look for leaking vacuum hoses and fittings. There are lots, so take your time, a small split in the underside of a hose is hard to see if you rush. Hope that helps

Hi USRB25S13 , "Over boost protection" is what it is know as, but it is really "excessive airflow protection". The ecu makes this decision based on what the AFM is telling it. So boost really has nothing to do with it. The fix is an SAFC, voltage clamp, Boost Cut Defeater or better still replace the std ecu with a Power FC. Full fuel cut is the next step in engine protection programming in the ECU, but you get "retard" and "rich" first. Here is a post I prepared earlier that may help ................................................................................ ...................... Hi guys, a quick, simplistic explanation of how an SAFC works might help... As the airflow into the engine increase, the AFM records this as increased voltage that the ECU sees. What an SAFC does is sit in between the AFM and the ECU and take the voltages from the AFM and either increase or decrease them depending on what you have programmed the SAFC to do. By increasing the voltage, this tricks the ecu into pumping in more fuel, you do this when the engine is running lean. By decreasing the voltage, this tricks the ecu into pumping in less fuel, you do this when the engine is running rich. The next bit is hard to understand unless you remember that the standard ecu does not supply fuel in direct proportion to the afm voltage ie; 4 volts is not twice as much fuel as 2 volts. Engine rpm, boost and throttle position also help the ecu determine how much fuel to add. It has been my experience that RB25's run a little lean down low in the rpm range (Nissan do this for fuel economy and emissions) and a lot rich up high (Nissan do this to protect the engine). So I have to increase the voltage (using the SAFC) up to around 3,000 rpm and decrease the voltage over 5,000 rpm. The real problem is in the 3,000 to 5,000 rpm range as the engine comes on boost. They really need lots of fuel very quickly in this area. This can mean that you need to increase the voltage (that the ecu sees) over 5.1 volts to get the right A/F ratios. The ecu then goes into engine protection mode, rich and retarded (sounds like a girl I knew once). Past that rpm you can start leaning it out as it runs too rich, so the voltage needs to be turned down under 5.1 volts. The ecu sees this as the engine not needing protection mode any more, no more rich and retarded. So you get good performance up to 3,000 rpm, then sluggish from 3,000 rpm to 5,000 rpm and then good performance from 5,000 rpm and over. The SAFC may not help this, in fact as explained above, it can in fact make it worse if the tuner is not switched on to this stuff. With bent afm voltages, the ecu (tricked by the SAFC) also fires the ignition to suite the airflow it THINKS the engine is getting. This is not a good thing as you generally end up with ignition that is too far advanced in some rpm ranges. The poor tuner has to juggle the SAFC settings, so that the A/F ratios are OK, the ecu doesn't get into rich and retard (engine protection) mode and the ignition timing is not too far advanced so as to cause detonation. My experience (I am not a good tuner) has been that this is full of compromises, sometimes you just can't win and have to reduce the boost level a bit to get even a reasonable compromise. Keep in mind that this explanation is very simplified to make it fit in a reasonable space, the rpm's used are rough guides only and every car is different. Hope it helps (and makes some sense).

Thanks for the well thought out response Matt. I only have one question, if the Microtech had not been "cheap" when you bought it (ie; more expensive than a Power FC is now) would you have still bought it?

Ooooooo, roll the dice :chop:

I use the throttle to control the wheelspin :thankyou:

I thought that might be the case, Scooby. I suspect Nissan would have specified the turbos with the right amount of oil flow. This can be achieved with a restrictor or simply by machining the ports smaller in the first place.

Give me a brake, you ran a vaccuum line from the plenum through the engine bay, found or drilled a hole in the firewall, plumbed it up to the Microtech in the standard ecu mounting position. Then you mounted an air temp sensor (it needs an earth and an active) and ran the wire from the front of the engine bay, found or drilled a hole in the firewall, terminated it and then plugged it into the Microtech in the standard ecu mounting position. If you did that in 5 minutes, :headspin: I have a job for you any time.

Mmmmmmmmm, I will have to measure the pulleys, I know the R33 GTST pump has lower flow rates, so maybe that's why the pulley is smaller. It was one of the fuel economy and low speed emissions measures, reduce the load from the power steering pump. It would be logical that to reduce the load they increased the rpm of the pump and reduced the torque loading on the impeller. Since the R33 pump (compared to the R32 pump) has less flow at the same rpm, I don't think you will have a problem.

Did you use an R33 GTST pump or an R33 GTR pump? Did you use the R32 pump mounting bracket (to the block) or the R33 pump mounting bracket?

Is that because you couldn't find a decent PFC tuner? Or is there some advantage that a Microtech has over a PFC? Don't you need to install pipe work and/or additonal wiring harness for the Microtech MAP sensor? Yes, but that doesn't mean you have to run you can still You just buy the right impedance, there is no difference in price between high and low impedance injectors. The price difference occurs when you have commonly available top feed or the more rare side feed. :cooldance This is the killer for me Why would I ever run open loop on a road car when I don't have to? :headspin: So far I have done a bit of dissagreeing, but I absolutely agree with That doesn't mean I have to find a dedicated XYZ brand ECU expert, a GOOD tuner should be able to tune any ECU as long as it is capable. Easy question maximajim, not so easy answer HUH? :wavey:

My guess is you have 2 separate problems; #1. The missfire is usually plugs or fuel, since you have changed plugs, my first suggestion would be to check the fuel filter. If the fuel flow is OK, then pull the spark plugs and look for which cylinder is missfiring. Swap plugs and coils and see if the miss is still in that cylinder. Next I would be doing a leak down test just to make sure all is well internally. #2. The 4K to 6K rpm flattening is always a problem on RB25s' when you run 10psi with the standard ECU. Here is a post I prepared earlier :cooldance ................................................................................ ...................... Hi guys, a quick, simplistic explanation of how an SAFC works might help... As the airflow into the engine increase, the AFM records this as increased voltage that the ECU sees. What an SAFC does is sit in between the AFM and the ECU and take the voltages from the AFM and either increase or decrease them depending on what you have programmed the SAFC to do. By increasing the voltage, this tricks the ecu into pumping in more fuel, you do this when the engine is running lean. By decreasing the voltage, this tricks the ecu into pumping in less fuel, you do this when the engine is running rich. The next bit is hard to understand unless you remember that the standard ecu does not supply fuel in direct proportion to the afm voltage ie; 4 volts is not twice as much fuel as 2 volts. Engine rpm, boost and throttle position also help the ecu determine how much fuel to add. It has been my experience that RB25's run a little lean down low in the rpm range (Nissan do this for fuel economy and emissions) and a lot rich up high (Nissan do this to protect the engine). So I have to increase the voltage (using the SAFC) up to around 3,000 rpm and decrease the voltage over 5,000 rpm. The real problem is in the 3,000 to 5,000 rpm range as the engine comes on boost. They really need lots of fuel very quickly in this area. This can mean that you need to increase the voltage (that the ecu sees) over 5.1 volts to get the right A/F ratios. The ecu then goes into engine protection mode, rich and retarded (sounds like a girl I knew once). Past that rpm you can start leaning it out as it runs too rich, so the voltage needs to be turned down under 5.1 volts. The ecu sees this as the engine not needing protection mode any more, no more rich and retarded. So you get good performance up to 3,000 rpm, then sluggish from 3,000 rpm to 5,000 rpm and then good performance from 5,000 rpm and over. The SAFC may not help this, in fact as explained above, it can in fact make it worse if the tuner is not switched on to this stuff. With bent afm voltages, the ecu (tricked by the SAFC) also fires the ignition to suite the airflow it THINKS the engine is getting. This is not a good thing as you generally end up with ignition that is too far advanced in some rpm ranges. The poor tuner has to juggle the SAFC settings, so that the A/F ratios are OK, the ecu doesn't get into rich and retard (engine protection) mode and the ignition timing is not too far advanced so as to cause detonation. My experience (I am not a good tuner) has been that this is full of compromises, sometimes you just can't win and have to reduce the boost level a bit to get even a reasonable compromise. Keep in mind that this explanation is very simplified to make it fit in a reasonable space, the rpm's used are rough guides only and every car is different. Hope it helps (and makes some sense). ................................................................................ ............................

Hi Scooby, the oil flow control issue is for ball bearing, water cooled turbos. :idea:

But it doesn't have to be that way, you can have a nice ride. :aroused: Just choose the right components in the first place. It doesn't cost more either. Sidewaymambo posted the right suggestion, Whiteline springs and Bilstein shocks.

Hi R32_GTS4, Try the local Commodoor parts outlet, lots of RB30 parts fit. We use sintered bronze valve guides (better lubrication), $9 each plus a few minutes in the lathe. Oil surge is never far away in a standard GTR sump, so we always upgrade the sump (wings, doors and baffles) when we have a GTR engine out. Hope that helps

Yep, for me that's the problem with Microtech, they don't work with AFM's. They use there own MAP sensor which reads air pressure to guess what the air flow is. Whereas an AFM actually measures the air flow. The PFC uses ALL of the standard Skyline wiring and sensors, it simply plugs in. I can fit a Power FC in under 5 minutes and drive the car away, try that with a Microtech. Some people look at the PFC Commander as only a tuning tool and a compromised one at that. I find it invaluable as a set of gauges, it tells me boost, inlet air temperature (on the GTR), engine water temperature, AFM voltage, idle rpm, road speed, ignition timing, injector duration, throttle position etc etc. Gauges to do this sort of stuff would cost far more than the Commander. Plus, as a diagnostic tool it is invaluable when fault finding. Moving on to the Datalogit system, it is a better tuning interface than the Commander. More user friendly and it opens up some of the hidden tuning parameters. It also has a couple of selectable output channnels for things like intercooler spray etc. But I find its real forte is collecting and analysing data, all of the PFC collectibles plus a few more external inputs can be added. We have oil temperature and ambient air temperature for example. So before you make a decision you need to be sure you are comparing apples with apples.

Hi guys, I feel the need to put up a question; Car 1 is a Fowlcan that revs to 4,000 rpm and has 50 psi oil pressure. Car 2 is a GTR that revs to 8,000 rpm and has 80 psi oil pressure. Surely it would illogical to have the same sized oil orifices in a turbo on both engines. The oil flow from the GTR oil pump into the turbo would be almost double. So if the turbo is designed for the Fowlcan, then it will have excessive oil flow and pressure on its seals when used on the GTR. On the other hand, if the turbo is designed for the GTR, then it will have insufficient oil flow and pressure when used on the Fowlcan. So it would seem logical to me to have all turbos designed for "low" oil pressure engines and use a restrictor if they are to be used on "high" oil presure engines. This would be particularly relevant on Roticeries that have up to 100 psi oil pressure. What do you think?

Hi SS8_Gohan, I like to drive a car around a bit before I do anything. Plus I have seen guys buy stuff for their car before they actually see it and then find it already has it when it finally arrives. I can't be too smart on this as I did it, I bought a front and rear strut brace only to find the car had a front one on it when it arrived. Took the gloss of the cheap price I got the pair for. As well, I like to feel the difference each part makes as you add it. If you do the whole lot at once and you don't like it, where do you start to fix it? So I would do it bit by bit, trying to avoid duplication of labour along the way. Don't do expensive stuff that has to be redone later on. As for the order, I would do it this way; 1. Suspension geometry, every Skyline I have worked on has had some problems (worn components, broken links, poor alignment). If you leave this to last you may make some wrong decisions along the way. An example, it understeers a lot, so you choose the larger rear bar only to find the understeer was caused by poor front wheel alignment and worn front inner upper control arm bushes. This includes caster bushes, camber adjusters and rear sub frame bushes (AKA pineapples, rear traction kit, ). I know the usual excuse for puting this off, "I will have to adjust the camber again when I lower it". Realisically it take a few minutes to adjust the camber (since you already have the camber adjusters fitted) so I wouldn't worry about duplicating labour on this one. 2. Stabiliser bars, I do this second because it is the best value for money suspension upgrade (bang for your buck). Plus many people find the handling is so good (after 1 & 2) that they don't need do the springs and shocks. They like the ride comfort / handling compromise. 3. Springs and shocks, you know what the car feels like with all of the above done, so you know how much to upgrade the spring rates (if at all) and how much you want it lowered. This then determines the shock rates (and maybe even brand) that you need to control these spring rates. If you decide to do HICAS, then it is best done at Stage 1 as it affects the choices for all of the above. Ditto strut braces. Some of your questions; Whiteline make springs, bushes, strut braces and stabiliser bars. They revalve shocks to suite the application, the spring rates and the stabiliser bar rates. Sometimes they use Bilsteins (if their characterstics suite the car), sometimes Konis, sometimes their own shocks made in Europe. Personally for the R34, I prefer Bilsteins, although the Stagea will be getting Konis as it will carry/tow different loads and I like to be able to adjust the damper rates. I would only buy adjustable stabiliser bars if I was actually going to adjust them. If you like to fine tune the handling, then they are definitely the go. If you are a "put them on and forget about it person" then save your money and buy the fixed rate bars. This applies equally to height adjustable springs and adjustable dampers, if you want to "fit and forget" then save yourself some money and go fixed. Hope that helps

Hi d3lir10u5t, this is what I do for my Skylines. Measure the thickness of the rotors, if they are undersize then I replace them. If not, I get them machined and then put new pads in together with them. If the car has done over 100,000 k's I get the callipers serviced with new seals. At the same time I replace the rubber hoses with braided ones. Value for money pads are Bendix Ultimate, if I want better performance then I use Hawke blue compound or Performance Friction Carbon Metallics in the 97 compound. If the car is seeing any circuit work I use DBA slotted rotors. The braking limit of my Skylines is the tyres, they let go long before the brakes do. Hope that helps

Hi guys, I always start at the uper control arm bushes on Skylines (all models). They wear out, it is as simple as that. Adding some positive caster (as much as you can) really helps with the tramlining, a small amount (not too much) of negative camber helps as well. If it pulls to the left, I add a little positive caster to the left hand front wheel, about 0.5 degrees more than the right usually works a charm. Don't ignore the rear wheel alignment, if it is out, it can have a similar effect. I would never suggest going to your local tyre service for a suspension check/alignment on a Skyline, it's a waste of time and money. A suspension specialist is the go.

I'll take the gauge, how much?

Hi SS8_Gohan, I suggest you have a read of the R33 GTST suspension article on www.whiteline.com.au Everything applies to R34 GTT equally as well.

As Troy said Centreline are good, alternative is Traction Tyres and Suspension, talk to Andrew.

No, rear shocks are different length.

Sorry, I don't understand the question?