Sydneykid

Yes It's a bit smaller and obviously has no transfer case for the 4wd. Same as RB25, around $300 for the valve body, plus fluid and filter, add labour if you are not doing it yourself. Forget worthwhile, it's essential to handle that power level.

Before we start, I need to clarify a couple of things. I have NEVER tried RB26 cams in an RB25. However I have used RB26 cams in 3 X RB20's. One was at high k's (170,000) and had slow to pump up hydraulic followers. This one definitely received R32GTR standard camshafts, they came out a of Production Race car engine and the camshafts had been scrutineered a few times and were definitely STANDARD. That engine had stronger than standard valve spring seat pressure. The RB26 cams that went into the other 2 X RB20's were not as certain to be STANDARD. Ok Luke, let's examine the facts ....... The max follower (solid) to cam clearance in a GTR is 0.50mm (as per the R32GTR Nissan workshop manual) The maximum slump on an RB20 hydraulic follower is 1.0mm (as per the R32GTST Nissan workshop manual). They don't quote the standard slump. I have measured a low K's RB25 engine and the slump was 0.6mm, which seems reasonable. What's "slump"? It is the amount a hydraulic lifter can be depressed when the engine isn't running, but measured immediatley afer it has been running for 10 minutes at ~4,000 rpm. It is a measure of how good the seals are in the hydrailic follower (ie; how much oil "leaks" past them). The amount of air in the oil is also a very minor factor, as the minute air bubbles can be compessed. So, if I have an "average" RB20 with its hydraulic followers, it will have MORE clearance (0.10mm) between the camshaft and the follower than a GTR set at its recommended clearance of 0.50mm. That's when the engine isn't running, of course. The real question here is how much slump does the hydrailic lifter have when the engine is idling? That's not an easy question to answer, as it depends on the seal of the followers, the valve spring tension, how much airation there is of the oil and finallly the engine's oil pressure. This is maybe the reaon why some times it works and others times it doesn't. It would seem logical that an RB20 with poor slump (over 1mm), low oil pressure at idle and strong valve springs would have a good chance of using the RB26 cams successfully. Certainly a better chance than a low k's, minimal slump, good oil pump (low airation), standard valve springs RB25. This is not a simple "yes it will" or "no it won't" discussion:cheers: PS, you can't compare this with say a Chevy pushrod V8, as they have a rocker ratio which amplifies the slump (1.5 or 1.7 times). A Chevy with hydrailic lifters and a solid cam idles quite OK, but doesn't produce much power. This is because the max lift is lowered by the slump times the rocker ratio.

OK, I think I understand what he is saying. The RB25 valves are shorter to allow for the extra thickness of the hydraulic follower. But this isn't a problem as you use the RB26 valves. The valve seats in the combustion chamber are in exactly ythe same piston, as you would expect. The camshafts are also in exactly the same position, again as you would expect. So if you change everything in between (followers, retainers, collets, valve springs, valves, and guides) then it fits up perfectly. The only issue is the valve spring seat in the head which needs machining very slightly. As per usual practise, the valve spring seat tension is adjusted by the use of spacers under the vlave springs (between the vlave spring and the cylinder head). I have had a couple of people get confused and try to use RB26 followers (solid) with the rest being RB25 parts. You can't do that, for the reason you described, they are not thick enough and you would need HUGE shims. You have to change the lot as described above.

This worries me, because I am far from the only one who has done this. It is not a simply throw them in, it'll be right job. You need to do a LITTLE machining, but nothing a "head specialist" couldn't do in his sleep. Did he tell you why he thought it couldn't be done?

Hi luke, I have been running wet sumps with oil coolers of all kinds for many, many years and never had a hose fail. I use good quality hoses and fittings of course. Mazda rotories have had standard oil coolers for 35 years with engine oil pressure running through the hoses. They don't have problems either, so I don't see why you should. This is a diagram of a Peterson 5 Stage Dry Sump system, you will notice that the feed to the cooler (from the pump) is under engine oil pressure; So even going dry sump will not save you from having engine oil pressure in your oil cooler and its lines.

The constant rebuilding of plain bearing turbos wore pretty thin with me many years ago. If it hasn't got balls, I simply don't use it. I don't care what Trust compressor and turbine I come up with, I will always achieve faster boost build and more reliable operation from a ball bearing core. It is then a matter of matching the compressor and the turbine with what it is that you are trying to achieve (max power, driveablility, times etc). I have read all of your posts in this thread shonen and I am still not sure what it is exactly that you want from your car. It's an auto isn't it? And I can't remember what other mods you have already done. Without that information, suggesting a turbo would be a waste of time from my perspective.

The short shifter itself can not cause harm to the gearbox. It simply changes the ratio between how far your hand moves (on the gear knob) and how far the linkage moves. Obviously, it also increases the amount of effort you have to exert to move the gear lever (there is less leverage after all). It is worth pointing out at this point that the selector forks do not move any more or any less with a short shifter installed. They still go just as far "in to" and "out of" gear. This is controlled by the detents and the synchro hubs. The gear lever is irrelevant. As ylwgtr2 pointed out, you can over extend the synchro hubs by pushing on the gearlever with your hand while a gear is engaged. But that is again the same for short and standard shifters. The only way you can get damage to the gearbox is if you stuff up the gearchanges. If you try and shift faster than the synchros will allow, then you most certainly will damage them. But that is no different whether you have a short shifter or a long shifter. It might be a bit easier to "beat the synchros", but that is still driver error. Although some would argue it is in fact harder to stuff up as you need to exert more effort to move the lever and you get better feed back. So you can better feel the synchros engaging. I had a few minutes spare this morning (while the guys were loading up the race cars) to measure the short shifter. It has a 16 mm spacer ring which moves the pivot point up by 16 mm. Since the gearshift linkage rod is in the same place, this means the shifter is 16mm longer from the pivot point to the point of engagement with the linkage. It is ~58 mm so the standard shifter would have been ~42mm. If the gearlever is the same length from the pivot point to the knob (as the standard lever) this would mean a ~20% reduction in gearknob movement for the same amount of shift linkage movement. This is using a common length (for both short and standard shifters) from the pivot point to the gearknob of 200 mm. If I remember rightly that was what was advertised, a 20% reduction in shift movement. Hope that makes some sense. PS; if anyone has a standard RB25DET shifter they want to lend for measurement, it would be greatly appreciated.

I haven't been paying much attention to this thread but then this post popped up...... Oh no, I have one of those.....and I haven't installed it yet. So here I am.... The first thing is how does a short shifter work? The concept is to change the movement ratio between the gear knob and the gear linkage. So that the gear linkage moves the same amount, but the gearknob moves less. The idea beeing that if you move your hand a shorter distance then the shift will be quicker, for the same hand speed. But if the gear linkage is already moving as fast as the synchros will allow engagement, then you get no increase in shft speed. You just move your hand less. Changing the movement ratio is achieved by having a longer portion of the lever below the pivot point and a shorter portion above it. The reduction in gearknob movement is directly proportional to the change in this ratio. For example, a 10% increase in the length of the lever below the pivot point and a 10% shorter portion above it will result in ~10% reduction in the gear knob movement. It is obviously easy to shorten the lever above the pivot. The gearlinkage (selector shaft) can't be moved however, so in order to get a longer distance below the pivot, you have to move the pivot up to make space. That's why the short sifter kits come with a spacer to move the pivot upwards. Some time ago I bought an RB25 gearbox for the R32GTST which didn't come with a shifter, so I bought one of the ones gR33ddy described above. It doesn't come with the plastic tip and spacer, you are supposed to use the ones in your gearbox. But my gearbox didn't have them. The shifter was missing the lock nut that enables you to orientate the gear knob, I found one that fitted. You are supposed to use the standard rubber boot, that's what the cable ties are for. Without the plastic tip and spacer I can't tell if it is an RB25 one or an RB20/SR20. It looks to to be the right diameter, but if it is too small (as in SR/RB size) then it will surely rattle like gR33ddy described. It's the last bit that worries me "- absolutely no reduction in shift!!!". Having looked at the lever itself and the spacer that lifts the pivot point, I can't see how it won't reduce the shift. But until I compare it with a standard shifter I can't tell by how much. So would anybody be willing to loan or sell me a genuine standard RB25 gear lever (I will need the plastic tip and spacer anyway)?. I will then do the measurements and post up the dimensions. That way, in future, everyone will be able to tell how much "shorter" their short shifter is going to be. I don't want it for nothing and I will pay for the postage. Post it up here or PM

Similar experience......ours started playing up a bit after the long run (400 k's straight). It would miss occasionally under load and drop a cylinder at idle sometimes. As usual, first guess would be plugs. It was my undertanding that it had new plugs put in during the compliance process, but I figured I might as well check them anyway. The plugs sure looked new but they were Autolites, APP 3924-11's. Now I have never had much luck with Autolites, and 1.1 mm is way too big a gap. So in went a set of the usual NGK BCPR6ES's gapped to 0.8 mm. Bingo no miss, runs perfectly and I am sure makes more power. I don't know whether anyone else has checked their plugs since compliance, but it might be worthwhile as both burkey22 and I have had similar problems.

Hi Luke, 30 degrees, that's a lot! So why don't GTR's idle low and rough? I know it's not valve clearance (solid versus hydraulic) as I have run a GTR with virtually zero clearance to try and get as much lift as possible. It still idled fine. My guess is ignition timing and fuel tuning, the low rpm maps on a GTR are quite different to the maps on an RB20/25. So with adjustments via the ECU you should be able to get it to idle and run fine. This is a quite interesting subject as some people have got it to work and others have had no luck, despite lots of effort.

A simple question, what timing belt did you use on your RB25DET and how much did it cost? Was it a genuine Nissan one? Or an aftermarket? What brand? Part number?

Hi guys, I have had an ever increasing number of people ask me about tuning their car without going to a dyno. They may live too far away, not have the budget or they simply may want to do it themselves. I have accumulated a few A/F ratio meters over time. I thought to help guys out, I might rent a couple of them out. They are not too expensive to buy, but the maintenance can be relatively high, you have to clean the lambda sensor and perform calibration regularly. So...... How many would be interested in renting one for a week for say $100? That would cover maintenance and repairs etc. What you would get is; *a wide band lambda sensor *long lead to reach to the tail pipe *a clamp for holding the lambda sensor in the tail pipe *a meter and controller with sensor preheating for accuracy *a mount and vacuum cup for attaching the display to the windscreen *a cigarette lighter power plug & supply *a full set of intructions *a laptop interface and logging software to load (not necessary for tuning) *all mailed out to you in an aluminium case What you don't get; *you are doing the tuning, if you damage your engine it's your problem *if you get busted breaking the road rules, it's your problem *I don't have time for dial up support, maybe email would be OK though *insurance, if you break it or loose it, you pay for it *a lap top, you supply your own, if you want to do logging *credit, you pay up front and there will be a deposit (not sure how much yet) *freight, you have to pay both ways, it's light, so $10 should cover almost anywhere in Oz *instant supply, I only have 2 suitable units and I don't want to buy more. So you may have to wait until one becomes available *to use leaded fuel, it must be unleaded * to send it back dirty and greasy, clean it please *your deposit refunded until it is received in good condition This is a survey for me to judge the response, so post away. If I get enough interest I will be ready to go in about 3 weeks, as I would have to clean, service and calibrate the 2 units.

If it is an electronically injected diesel it will work. If it is mechanical injection it won't. How do you tell? If the injectors have wires hanging out of the them, then they are electronic. If there is only fuel connections to the injectors, then they are mechanical. No big deal, diesels work quite well with bleeed valves.

What engine are you runing in the HR31? If it is an RB20DET then use an R32 GTST Power FC with an R32GTST engine harness If it is an RB26DETT then use an R32 GTR Power FC with an R32GTR engine harness If it is an RB25DET then use an R32 GTST Power FC with an R33GTST engine harness That's the method that I have found to be the simplest. There are so many half cuts around, getting an engine harness hasn't proven to be a problem. The only other trick is making sure you use ALL of the right sensors for the Power FC model. As for the Link question, I am not sure what else I should have done. If only people with Links respond to his question, he is only ever going to get half the story. And I don't think that is why he asked the question. The other problem is I might be very happy with my ECU, until I drive a a similar car with another brand ECU and find out that mine is not as good as I thought. Lastly, people are sometime reluctant to say that they made a mistake and bought the wrong thing. (Not in any way suggesting that this is the situation in your case.) After all they have to sell their car one day and it won't help if they rubbish it along the way. My 20 cents worth

I would add that HKS turbos (being Garrett) are also water cooled. Trust (being Mitsubishi) are not.

"Put it in the car" is easy, unplug standard ECU and plug in PFC, all you need is a 10mm spanner and 5 minutes. I have yet to find a car that doesn't start and run first turn of the key. As for tuning, with the PFC 90% of the work is done. It already has all of the tricky stuff loaded, cold start and run, hot start, over run, afm calibration, idle speeds, lambda calibration, air con, power steer and electrical load compensation etc . All the tuning that takes hours and sometimes days to get right is done out of the box. So it is a simply a matter of tuning for power (fuel and ignition) and the PFC is no different to any other ECU in that regard, it has load points and settings. The first time our dyno guy tuned a car with a PFC he sat and read the Commander manual (yes the RX7 one and he was tuning a Skyline) for about 20 minutes. He then put the car on the dyno and started tuning with the Commander. Result, 45 minutes later a perfectly tuned car. In the last 12 months or so we have been using a Datalogit on the laptops and he can tune most Skylines in ~20 minutes. I taught a guy in the US over the phone how to tune a PFC, he had the RX7 Commander Manual and we went through it. He picked it up without much help from me, 'cause I am not a good tuner. His comment to me was "you mean I don't have to set it it up?" Nope, just start tuning. "Shoot man, what a snap". There are some great tuners in WA, I simply don't believe that they couldn't work with a PFC, because it isn't really any different to any other ECU. Just easier than most, as it is very well set up for the model of car it is designed for. Let's face it there are more and more PFC's arriving everyday, so the tuner that does the best job will get lots of work. PS; doesn't Lumpy do PFC's?

The better BOV's have two air supply inlets. One for vacuum and one for pressure. Use the pressure inlet (under the diaphram) and it will open the valve when air flows. Leave the vacuum inlet open to atmosphere. Then use a boost controller to open a solenoid and allow air flow (boost pressure) to the BOV when the target boost is reached. You can of course by supercharger blow off valves, they come with a box of springs, so you can adjust to your boost target. But I like the idea of of eletronically controlling the boost.

Hint ..... yellow Stagea does not = sleeper.

This particular design (of electronic) has several advantages, the best one for me is the ability to have ZERO boost pressure at the wastegate actuator. This means (unlike beled valves or other designs of electronic controllers) the wastegate is absolutely closed until you program it to be open. The result is the FASTEST possible boost build that your engine and turbo combination can deliver. Your Turbosmart is simply a bleed valve, it lets some boost preessure escape so that the wastegate actuator sees a lower pressure. This means you get higher boost. BUT it alllows SOME boost pressure to get to the wastegate actuator, this means the wastegate starts opening long before your target boost pressure. So you get slower boost build. There are many other advantages (they are in my previous posts) but for me that is the one I personally like the best:cheers:

For $10K that's a bargain, there is easy triple that in parts alone.

I asked this a while ago, maybe do a search for the exact details. From memory, the guys suggested going in through the main wiring grommet which is outboard from the accelerator cable:cheers:

Nope, as the exhaust get colder it shrinks, so it takes up less space and there is no back pressure:cheers:

I think a BOV would be more applicable than a wastegate, too slow and way over engineered for inlet air. Use a positive boost controller (like the Jaycar IEBC) to control the BOV opening.

Adj cam gears on both inlet and exhaust, so no VVT. I will be watching for the results.

I would add that that rating (500 cc's) is at the manufacturers pressure ratiing. If you are running lower rail pressure then they will flow less. Higher and they will flow more.