Sydneykid

Hi Jeremy, there are a number of torque split controllers out there, HKS make one for example and Grid Dancer also comes to mind. On the UK GTR forum there is a guy selling his own brand if I remember rightly. Do a search and shop around, I haven't used one in an R34GTR but I am sure they will be available.

On the race R32 GTST, we run 27 mm adjustable on the front and 24 mm adjustable on the rear in the dry and 22 mm adjustable on the rear in the wet. Easily the best and most cost effective handling improvement you can make. We run no more than 8 kgmm front spings and 4.5 kgmm rear springs, and it will lift the inside front wheel on corner exit using "R" compound tyres. Note that most of the roll you can feel is the outside tyres compressing under the load. As a few of the guys have said, you can easily have suspension that is too stiff and won't absorb the track irregularities. Plus a fast time sometimes requires use of the ripple strips, and you can't do that if the suspension is too stiff to absorb the impact. Remember the object is to go fast, not rattle your teeth out:cheers:

Rear stabiliser bar won't do anything for launches, pineaplles would be my first suggestion. If that doens't fix it then you have a spring rate versus shock rebound damping problem. For going round corners, a front and rear stabiliser bar upgrade is THE single most cost effective handling improvement you can make.

I used the DFA for those exact reasons, lean it out for more power, better fuel economy and keep the auto gearbox logic working as intended by Nissan. My power target is 200 4wkw, if it was higher than that I would have gone full computer. No reason why the SAFC can't do the same, I have seen many R33 GTST's make 200+ rwkw with an SAFC. The Stagea ECU has plenty of smarts, so I hope it isn't too clever. With all AFM voltage benders it is a bit of a tuning juggle, you are constantly fighting with trying to lean it out, but not advance the ignition timing too far at the same time. I have already hit that issue, but I believe the exhaust upgrade will overcome that very shortly.

I think we will be racing at the V8 round there this year. The plane schedules (Sydney / Darwin / Sydney) are so infrequent I will probably have a couple of days to kill afterwards. The Jack Daniels is on you:cheers:

Add it all up........ RB26 used "brand name" cams are much cheaper and easier to get than RB25 used cams RB26 already has solid lifters RB26 already has a good plenum and throttle bodies (Theo does 9's with them) RB26 has better valves, standard RB26 "brand name" exhaust manifolds are easier and cheaper to buy used RB26 has 12 mm head bolts standard RB26 doesn't have VVT, so no mucking around blocking it off or adding external feeds if you want it to work like an RB25 RB26 has superior water jacket around the exhaust ports, whic his important for high power applications I could go on, but I think you get the drift...... If you add up the cost of the above, you will find even paying $2K more for an RB26 head is still cheaper. I bought a complete RB26 with a blown head gasket for $3K, sold the bottom end for $1500, sold the RB25 head for $600, sold the turbos for $400, used the std cams in an RB20 $300. So the RB26 head cost $200. It took me 3 months to find what I wanted so shop around, it's out there, have your money ready and move quickly the good ones go fast:cheers:

The 120 degree bend at the throttle body design is better. There are plenty of posts on why, do a search:cheers:

If that is a standard turbo you may well be running out of airflow, insufficient airlfow to hold the boost. If that is the case, it doesn't mastter what boost controller you fit.

If you are running just a simple bleed valve then the IBC will make a big difference in how fast boost builds. This is because the bleed vlave still lets some air pressure get to the wastegate actuator, the closer it gets to its bleed off pressure the more it lets work. The IBC ensures that absolutely zero air pressure gets to the wastegate actuator until it opens the solenoid. This means you get the fastest possible boost build for that turbo on that engine. No other boost controller I have seen can give that absolute control. Absolutely, it will do it easily. When connected to the DFA, the Controller shows the AFM load point and the amount of correction you have applied. When connected to the IBC, the Controller shows the injector load point and the amount of correction you have applied. I don't have mine connected all the time, the Controller itself isn't that big and it looks OK, but the plug is damn ugly. Hope that helps guys:cheers:

The lastest SAFC I have used had a joy stick instead of the 4 buttons on the front. Nengun have them on special at the moment for ~$420 delivered, that's less than some people want for used ones.

If you can read, interpret instructions and solder OK then the Jaycar Intelligent Boost Controller works very well and has some quite unique advantages. Have a read in the Stagea section for the results. I have a throttle pedal on my car for that purpose.

Go the RB26 top end, it WILL work out cheaper in the long run.

That's a tough one, obviosuly with the SAFC you don't have to build it yourself, from a bag full of components. The wiring to the ECU is pretty much the same, so no advantage there. The later SAFC's are very good in that they have 2 "maps" one for full throttle and one for less than full throttle, usually around 70% switch over, using the TPS as a reference. That's a good feature as you can tune the WOT for max power and trim the less than 70% for economy. The SAFC only has a handfull of load points (based on rpm) and good extrapolation between them. So its is quick and easy to set up and gives a good result. The Jaycar DFA, has 128 load points and very good interpolation between them (not that it needs it) with that many. The load points themselves are solely based on AFM voltage, so you don't need the 2 TPS based maps. You can tune power and economy based on the AFM load. You don't have to input all 128 load points one by one. For example, at idle, the Stagea was up to load point 40 already. Plus the A/F ratios were OK from 40 up to around 95, then it needed leaning out. So I only had 30 or so load points to tune, not many more than the SAFC with 2 maps. I don't think there would be 1 rwkw difference in the power obtained using the 2 units. They both have enough tuning resolution and smarts to optimise the A/F ratios as much as the standard ecu will let you. Having driven cars fitted with both (now that I have the Jaycar in the Stagea) there appears to be no difference in how "nice" the car drives. They both drive "nicer" than when they were standard with just the boost turned up. The gearchange quality is not affected at all with either. Bottom line, if you can read, follow instructions and solder OK then there is simply no comparison. The ~$80 price for the DFA is hard to argue with, compared to ~$500 for the SAFC. I can think of a whole pile of go faster stuff I could buy for ~$420, the only thing is you don't get a blue screen.

Let's start with the Tomei spes, what Tomei are recommending to me is to set the VCT switch point at 4,500 rpm on the ECR33 RB25DET using their camshafts. There is always a no switching point at low rpm as zero overlap is best for emmissions. That's is usually just above idle, but it isn't adjustable, well not on any PFC or chipped std computer I have seen. There is also the question of sufficicent oil pressure at idle (to rotate the camshaft), so switching is best left till above the fastest idle rpm. So Tomei say 1050 which should be above the a/c or other load compensation (fast) idle point. OK max boost, they confirm two timing positons 0 and 20 degrees only. They say 1500 rpm for the lower limit, it may be a typo (1050 rpm). Or they are simply wrong. Either way a 1500 rpm lower limit wouild have it switching on/off/on/off at strange times for no good reason. They indicate 4,200 rpm as the switching point. Lastly V6 performance, they indicate (on the graph) a single switch over point at ~4,900 rpm on the VE30DE from the 92-94 Maxima SE. But the words directly below say 6,100 rpm, so I assume that must be for the VG30DETT. Bit confusing. Note that the graph starts at 1200 rpm, just enough above fast idle with the VCT already switched. Bottom line, I don't think we dissagree at all. The only issue I can see is the use of the words "on" and "off". Most people say "4500 rpm switch "on" vct". Whereas the more corrrect terminology would in fact be "4,500 rpm switch "off" vct".

GCG carry them in stock and will ship interstate overnight www.gcg.com.au

Let's kill 2 birds with stone stone here. I have the Datalogit plugged into an R33 RB25DET and on screen "Settings 1" it has the VCT set at 4,700 rpm. I have not changed it on this engine, so that is the default RPM as selected by Apexi. It doesn't have different "on" or "off", or "in between" or "load" or any other selection. Just RPM and just ONE RPM, so it turns on at 4,700 rpm on the way up and off at 4,700 rpm on the way down. That's it, no more complicated than that. So tango, yes the PFC does have VCT control and it is adjustable, ie; pick an RPM. How do I pick an RPM? Well I do a power run with the VCT off until 8,000 rpm (ie; past the rev limit, so it never turns on). I graph that. Then I do a power run with the VCT on at 800 rpm (ie; at idle, so it is on all the time). I graph that. Then I overlay the 2 graphs, where the power curves cross is the best VCT change over point. Nissan's 4,700 rpm is pretty close every time, regardless of the engine mods. So it appears to me to be rpm dependant ie, the speed of combustion cycle. Load, throttle opening, power etc all seem to be irrelevant in a simple "on" or "off" scenario. BTW, the power curves only ever cross at one point, so it makes no sense to have multiple "on's" and "off's" In an R34GTT, with its more sophisticated VCT control via the more powerful and faster ECU, there are obviously other parameters taken into account. Logically to allow appropriate selection of the amount of inlet camshaft timing changes and the circumstances as to when they are required. Hope that clarifies:cheers:

So you guys just bolted the GTRS straight on, you didn't have to modify anything, buy anything extra or fabricate stuff? The GTRS fitted up exactly the same as the standard turbo? And it took you half a day to remove and replace, no special knowledge or tools required? Then it made more power EVERYWHERE than when the engine was standard? Then you took it out ot the drags in a full weight R34 GTT and it did an 11.9 at 120 mph? There is more to a turbo than how much it costs on its own and the maximum power it makes at one RPM point. Personally, I take it all into consideration, look at what I expect from the car and then make a choice. I have seen 240 rwkw at 1.2 bar, but remember boost is irrelevant, it is simply a measure of resistance to airflow. An example, the R34 GTT has cams and headwork. It makes 15 rwkw more at similar boost because the cams and headwork have removed the restriction, so it flows more air (to make more power) but the resistance (boost) is lower. I am sure the GCG ball bearing hi flow would make more than 1.5 bar if you stuck it on a restrictive/choked engine. Guys, don't get me wrong, I am not picking on anybody or saying you have done it badly. There are more ways than one to skin this cat, I simply post up my way. That way readers can make their own choices. PS; I don't place any importance in having a certain "name" brand product on my cars, I only care about how nice they drive and how fast they go. I can understand that some people want to have a "name" brand to impress people, but it's just not my thing.

Hi guys, I need to clarify a few things here; GCG ball bearing hi flow, no problems for 250 rwkw, best I have seen is 265 rwkw at 1.5 bar. Upping the fuel pressure at the rail increases the fuel flow through the injector, but is isn't one for one. For a 10% increase in flow you need around a 25% increase in pressure. That's a lot more pressure (48 psi compared to 38 psi) so you need to make sure your fuel fittings, hoses, filter and clamps are capable. Personally I would never aim for more than a 10% increase in flow, so 410 cc's is about the limit. Using the rule of thumb for a 6 cylinder, that's 410 bhp (306 kw) or ~ 240 rwkw. Best I have seen was 235 rwkw. That's using cleaned injectors with the highest flowing one in #6, the next in #5 etc. In a GTST this is due to #6 being at the rear, furthest from the radiator, not much air flow, radiated heat etc. Nothing to do with differential flow in the inlet system (like a GTR). So you need to do the numbers, 1.5 bar = 22 psi + rail pressure 48 psi = 70 psi. Minimum you need a fuel pump that can supply 410 cc X 6 X 60 = 148 litres per hour at 70 psi. An R32 GTR fuel pump (used for the 265 rwkw) will do 190 litres per hour easily, as will a Z32, at that pressure. With reference to the attached tests on the Supra pump (make sure the part number actually agrees with yours) you can see that they are extremely voltage sensitive....... At 12 volts they are below what I would consider a safe margin (155 litres per hour at 70 psi rail pressure). So if you haven't already done it, I would strongly suggest you run a dedicated supply to the pump from the battery via a relay. Use the standard wiring to switch the relay. That will get the voltage at the pump up to 13.8 volts (alternator output) and give you around 210 litres per hour, which should be more than enough. OK on the Z32 AFM, although you might just get away with the standard R33 GTST AFM at ~240 rwkw. The Nismo "bolt on to the fuel rail" style of fuel pressure regulator will do the job for 70 psi ($149 from Nengun). Bottom line GunMetalR33, the injectors will be the limiting factor in your plan, with around 240 rwkw being the most likely limit. Hope that was of some help:cheers:

Looking forward to seeing the comparison dyno charts.

I vote for 30 psi cold.

Ah well, another peed off neighbour, the Forrester just can't keep up anymore! I waited for him this morning at the end of the usual run through the corners. The first thing he said was, "even the farken exhaust is still farken standard". Thinking about the difference it made to his Forrester.... "What's it going to be farken like when you get a farken big one?" I think that means he is impressed: PS; every sentence had at least 2 profanities.

Hi J, it was getting up to 11 psi (maybe 11.5) on the boost at that rpm, so I trimmed it back to 10 psi. But I don't think that made much difference to the dip at all, comfirmed by a quick power run. I spent a few minutes around that rpm point and lowered the AFM voltage, at a few load points. That leaned it out obviously, but it also advanced the ignition. I just kept going with the adjustments until the ecu went rich and retard, they seem to do that because there is a missmatch between the rpm, throttle postion and afm voltage. Maybe even a little pre-ignition from the knock sensor. I think the ecu then believes that there is an issue (dud afm for example) and tries to protect the engine, hence the rich and retard. So I backed it off from that, very slightly until the ecu stopped going rich and retard. I figured that was going to be the best I could get. A quick power run, bingo no dip. In summary, a juggle between fuel and ignition and make sure the boost doesn't overshoot on the climb, which is very rapid at that point. BTW, the ecu behaves very much like an R34GTT one, the rich and retard intervention is very quick and quite savage. Much more so than the earlier ecu vintages.

Hi guys, it seems to me that there are two techniques being discussed here... #1 blip thottle on down change without lifting clutch. #2 blip throttle on downchange while lifting clutch #1 matches the engine RPM to the road speed and lets the synchros match the gearbox input shaft rpm to the engine rpm. #2 matches the engine rpm to the the road speed and also raises the gearbox input shaft rpm. #1 stops rear wheel lock up (compression lock) when you lift the clutch with zero throttle on, but doesn't save the load (rpm differences) on the synchros or the gearbox input shaft. So it is OK if you have a gearbox with good (single or double) synchros. #2 also stops rear wheel lock up (compression lock) when you lift the clutch with zero throttle on, but it also saves the load (rpm differences) on the synchros and the gearbox input shaft. So it is necessary if you have a gearbox with dud synchros or a dog box (no synchros). The bigger the gearbox, the more inertia in the input shaft and the more important it is to use technique #2. This also aplies to standard/wide ratio gearboxes, where the rpm differences are large. Not so much to close ratio gearsets where the rpm differences are small. Bottom line, neither technique is wrong, it is simply a matter of horses for courses.

Hi guys, I have removed hundreds of springs from all sorts of cars and never used spring compressors to get the shock and spring unit out of the car. I use spring compressors to take the tension off the top spring mount before I undo the shock top nut. But that is on the bench out of the car as per the following picture of a Stagea front strut. If you have tension on the spring in the car it is because the stabiliser bar is still connected or you haven't jacked the car up far enough. But you have to jack the car up "far enough" to get the wheel off anyway. You only have to disconnect the stabiliser bar link (only one) if you jack up one wheel only. If you jack up both wheels (on the same axle) then you can leave the stabiliser bar connected. Hope that helps:cheers: