Sydneykid

Lots of boost and very high airflow required, I haven't seen the problem until well over 2 bar and 60 lbs of air per minute (700bhp). The problem exists in all log style plenums with an entry at one end and outlets along the log. It is due to air wave pressure build up at the end of the log (the end opposite the inlet). The rear cylinders (5 and 6) get too much air, so honing (enlarging) makes it worse. That's why Nissan tapered the plenum around #5 and #6, this works quite well until the boost gets way outside the design parameters. The simplest way to over come any minor issue is (when you get your injectors flow tested) to simply put the highest flowing one in #6, the next highest flowing in #5 etc. The 1-2% variation in flow is usually more than enough. You can also adjust the individual injector trim with most aftermarket ECUs (Power FC, Motec, Autronic etc). If you have trim adjustments over 3% then its time to think about changing to a large volume plenum, at least double the capacity of the engine (5.2 litres+). Hope that helps:cheers:

Hi Matt, the only difference between an RB20 and an RB25 is the PCV valve is screwed into the plenum chamber on the RB20. So it makes it easier, you don't have to remove it from the cam cover.

Simple, there is a hose (the small diameter black one in the picture) that goes from the compressor cover to the wastegate actuator. The bleed valve goes in that hose.

If you take the velocity out of the air flow (use a big enough can and large diameter hoses) and fill the can with stainless steel wool, then you should clean up the air pretty well. You could also put a filter inline with the hose, one of those cheap plastic fuel filters with right size fittings. That will trap any oil that escapes the can and stop it going into the inlet. Keep an eye on the filter and when it gets black change it, they only cost a couple bucks. We use them on the gearbox and diff breathers on the race cars, so only the air escapes, no oil.

HP = High Performance, 10.775 @134.35 mph yep that fits. I = Import, well it wasn't made here, so that fits too. That isn't rice you smell cooking, more like Zwiebelwurst. :wassup:

Sorry, been a bit busy... Being a one way valve, the PCV valve stops any boost (pressure) getting into the hoses and the catch can. The only "pressure" is blow by, and the volume of the can and hoses can accomodate this. The small amount of contained pressure is rapidly relieved every time you back off (eg; change gear). I would not suggest this option for cars with lots of blow by or automatics or cars that spend a lot of their time under boost (eg; circuit work). As I said in the original post it is not my system of choice, it's a compromise to keep oil out of the turbo, intercooler and pipework and still be sealed to atmosphere (legal). I have set this system up on a number of cars and it works OK Monday to Friday. On weekends the guys stick a filter on the can (to replace the flow that goes to the plenum). The "filter" can be a simple plastic fuel filter like you see on non fuel injected cars, it just plugs in to the can outlet hose. Hope that clarifies:cheers:

I have a 24 mm front stabiliser bar on the Stagea and it came with 24 mm bushes.

Hi, ask yourself three questions; Can I read and understand instructions? Can I operate a multimeter or can I teach myself to operate a multimeter? Can I solder or can I teach myself to solder? If yes to those questions, then pop into your local Jaycar and buy a copy of the book Performance Electronics for Cars (by Silicone Chip). It costs ~$20 and if nothing else, the introduction chapters will teach you a lot about how the electronics in a modern car operate. It has FULL instructions with great pictures and diagrams, the best I have seen for kits. The only additional thing you will have to do on an RB20 (over the example Stagea RB25) is to buy a boost control solenoid. Plenty of RB25 owners are not using their standard solenoids as many have EBC's with their own solenoids. So you should be able to pick up an RB25 solenoid pretty cheaply. Hope that was of some help:cheers:

I have been doing a little bit of fine tuning on the boost controller, it holds 0.7 bar rock solid from 2,500 rpm to redline. I can get 0.6 bar for launch, it is so quietly quick, very stealth, no rev, rev, dump no wheelspin. Just see ya........................ That's a good result for the Boost Controller. I am verrrrrrrrrrry busy this week, we have a new control tyre in Production Cars, Yoko's after many years of Dunlops. Maybe get on the dyno next week to set up the Fuel Adjuster and confirm the power outputs.

Well here's the challenge, produce a set (6, that's one for each cylinder) of lambda readings from idle to red line that shows all 6 cylinders are receiving the same airflow. That's without injector compensation of course. I don't want my car producing 5% less power from cylinder #1. Because that is exactly what happens when you reduce the fuel to compensate for less air. Air plus fuel = power, so less air and less fuel in 1 or 2 cylinders means they produce less power. If I have a 600 bhp engine, I want 100 bhp from each cylinder, not 95 bhp from #1 and 97 bhp from #2 and 103bhp from # 5 and 105bhp from #6. Imagine what that does to the twisting forces and then add the imbalance of combustion pressures on a long straight 6 crankshaft. Should I discuss the uneven heat loading on the cylinder head? Or the differential block stresses? Nuh, my work is done here I think.

Same response I give to all inlet manifold modifiers, while trying not to be brutal. Personally I would have spent the "plenty" on something that actually makes the car go faster. Cams maybe, or adj pulley, a better turbo, a superior exhaust manifold, split dump, Power FC, good tune (or 5), valve springs, clutch, LSD, sticky tyres, springs, decent shocks, good brake pads, stabiliser bars, radius rod bsuhes etc etc As you can see it might be "on my list", but it is sure as hell a long way down that list. Hope that wasn't too brutal:cheers:

That's about double what it should cost. Shop around some more:cheers:

Hi Paul, don't stress over the max values, they are a flash reading at a single point in time. What you are looking for is ongoing readings. The individual items; 1. Knock shouldn't go over 40, so 18 is OK. 2. Injector duty could be as a result of acceleration enrichment, don't stress until you see 90%+ holding constant speed. (ie; not accelerating). 3. AFM readings, ditto, don't stress until you see 5.1 volts when holding constant speed. (ie; not during rapid boost build).

Zeni Tani RB20 powered R32 GTST, registered road car, no nitrous, standard RB manual gearbox (synchro, H pattern) on road radials did 9.9 at the HKS drag meeting last year. Stick some nitrous in it, take off 300 kgs, add drag slicks, whack in an auto and it would do 8's on its ear...... :wassup: Not everyone cares about 8 miserably short seconds, personally I prefer several minutes of the RB20DET powered Gibson R31 GTSR in the rain with Glen Seton driving. Now that's throttle control, only made possible by the RB20's superior power band.

This is NOT a critism in any way, I am only interested in WHY you have done things, the reasoning behind the decisions. You have chosen GTSS's for their response, a very worthwhile aim for a road car. But there are a few things that you have done (intend to do) that appear to me to be the exact reverse of that strategy; 1. From you posts it sounds like you have used combined dumps, it is pretty well accepted that split dumps give better response. What is the reason for going for combined dumps, am I wrong in going for split dumps? 2. It is also accepted that a larger plenum reduces response (more air in the inlet system, more inertia etc). Help me out here, why are you are going for a Jun inlet plenum which has larger internal volume than the standard plenum? 3. Again it is generally accepted that the standard GTR throttle bodies, located close to the inlet valves, give better response than a big single throttle body located at the other end of a large plenum. Why are you going to a single Q45 throttle body, I don't understand? 4. I noticed in your posts that you have HKS PODS, but I have not seen any mention of heat shielding or ambient air feed. The ingestion of hot air from under the bonnet is well known to lower response. If it is it right that you have left the POD's "open", if so can you please tell me why? 5. From you posts you have gone for upgraded head (ARP) an main (Jun) bolts. I always lean towards studs rather than bolts, can you please explain the logic behind using bolts? 6. You refer to Tomei camshafts, but not the lift or the duration, can you please let me know what timing and lift you have chosen and why? 7. I haven't seen any mention of upgraded AFM's in you posts, are you still using the standard GTR 65mm AFM's? I repeat, no critisim, I am simply trying to seek out the different thinking that you have employed. In the above areas it is somewhat different to mine, not WRONG or RIGHT, just different. If I don't ask, I won't learn.

Wow, I do get quoted a lot....... I have seen terrible air flow patterns from relocated throttle bodies. I wouldn't do it. There is verey little difference in the amount of air in the pipes from a relocated throttle body and the 120 degree bend system. There is no risk in the 120 degree bend system. I have flow bench tested the standard inlet manifold and it shows no discernable restrirction at airflows equivalent to 450 bhp. At that point you are looking at internal upgrades to the engine. Just because the pipe is hot doesn't mean the air inside the pipe is the same temperature. I have recorded pipe temperatures over 80 degrees with the air inside the pipe at 1 or 2 degrees higher that the intercooler outlet temp (38 degrees). This is because the air flows through the pipe so fast it doesn't have time to heat up. Plus the contact area (air to pipe) is so small it wouldn't make any difference. Compare the short pipe to the size of an intercooler, which also has fins on the inside and the outside, so the contact area is many hundereds of times greater than a round aluminium pipe. I always use aluminium pipe because it cools down faster than steel, weighs less than stainless steel and doesn't rust like mild steel.

The tyre is the limiting factor, I have yet to find a road tyre that can handle the standard R32GTR callipers, DBA slotted rotors and decent brake pads (we use Bendix Ultimates). Even on the race cars with "R" tyres, a simple upgrade to Hawke carbotics in the blue compound and we can still lock up the tyres even after a 20 minute race. The secret is good brake fluid, braided lines and regularly overhauled callipers and master cylinder. Most brake problems have very little to do with the hardware itself, it is the maintenance or lack thereof that causes the problems.

The RB20 Power FC wasn't really designed for use with the Boost Control Kit, but you can use it. The RB20 (R32 GTST) PFC is basically the same as the R32 GTR PFC, but AP Enginnering modified it to work on the RB20. That is why it still has inlet temperature correction (like an R32 GTR) even though RB20 's don't have an inlet temp sensor. Enough history, how do you connect it.... RB20's have a standard map sensor, so you don't have to connect up the one that comes with the Boost Control Kit. If you look at the pin outs on the standard R32 GTR ECU, you can see the wires for the standard boost control solenoid. The pin out is basically the same on the R32 GTST, there is just no wires for the boost control solenoid becuase R32 GTST's don't have them. That is where the Boost Control Kit is wired into the Power FC. Hope that is of some help.

Correct, just put an 8 psi stronger spring into a standard RB26 oil pump. Bingo it's an N1:cheers:

New coil springs with more static height will fix it. Your local Whiteline agent (www.whiteline.com.au) should be able to help:cheers:

I have the Jaycar Boost Controller working perfectly now, just needed a bit of fine tuning as per the instructions. It uses injector duty cycle as the reference, and has 64 load points with 100 settings (0 to 100%) for each load point. So it has no need for a map sensor. I am not going to get too deep into the theory, there is a full description on how it works in the instructions and in the book from Jaycar called Performance Electronics for Cars. Simply put, the injector duty cycle is very linear with the engine's airflow and thus its boost level. Since the solenoid is plumbed in series with the wastegate actuator, absolutely no pressure can get to the wastegate until the Boost Controller pulses (opens) the solenoid. This results in the fastest possible boost build. In the case of the Stagea this means I can hold it against the torque converter and get 0.6 bar at 2,600 rpm. With standard boost, the torque converter used to hold at 2,250 rpm, obviously the extra boost (and therefore power) pushes the rpm a bit higher. It obsolutely rockets off the line and quickly gets to 0.7 bar (10 psi) which I will be using as my boost limit until I put the ball bearing hi flow on it. I have kept the Stagea wastegate closed until load point ~20, for this purpose. As the airflow rises, so does the injector duty cycle, it is quite simple to set the solenod duty cycle (between 0 and 100%) to allow the required pressure to act on the wategate actuator and hold the 0.7 bar at that injector opening. I repeated that for load sites from ~20 to 64. It is 100% from ~30 to 64, if I find the boost dropping off up high (rpm and therefore injector duty cycle) I can close the wasegate a bit to make sure it holds 0.7 bar. It took me about 25 minutes of passengering and setting up the boost curve. I may have to fine tune it a bit over the next few days as I encounter more widespread conditions. But at the moment the boost just sits there at 0.7 bar, totally stable. It works and it works well, for ~$80 and half a day of my time I reckon the Jaycar Independant Electronic Boost Controller is a good thing. This the vacuum hose plumbing now; Here are the two Jaycar units installed in the glovebox, I used velcro to hold them as I have to get to the rear to plug in the hand controller. This picture shows the connections at the ECU plug, they were soldered and taped. The Jaycar wires are the red, green and black. Unfortunately both units have the same coloured wires. If I ever do this again, I will buy some different coloured wire so I don't have to keep checking that I have used the right one. The R34 ECU plug diagram is accurate so the connections are as I previously posted. The Digital Fuel adjuster is connected up ready to go, I have not loaded any corrections. I need to know the A/F readings as I make changes, so I will do that on the dyno with the fast and wide lambda sensor up the pipe. Should be good to see the results from simple electronics only, no mechanical changes. Hope you all enjoyed reading this as much as I did making them. I will post up the dyno sheets as soon as it has a run.

This is the 10 minute no cost boost to 0.5 bar rerouting of the vacuum hoses. Disconnect the two vaccum hoses from the solenoid. Then connect the boost feed (from the cross over pipe on the left of the picture) to a the standard T piece. Connect one side of the T piece directly to the wastegate actuator (on the right of the picture). The remaing connection on the T piece goes back into the inlet via the BOV return pipe (on the standard fitting). Make sure to put the the standard brass restrictor in that vacuum hose to bypass the desired amount back into the turbo inlet. The standard bypass hole of 1.25 mm bypasses enough air flow for 0.5 bar.

No they don't. High impedance, standard open close:cheers:

If you run the car so low that you need shorter shocks, then the suspension geomety will have to altered. You will have too much negative camber, too much bump steer, to little ground clearance, insufficient travel to soak up bumps (cracked suspension mounts), not enough anti squat under acceleration, not enough front weight transfer under brakes etc etc. Jumbos are made at Milperra in Sydney. PS; lowered springs need to have higher spring rates as they have less travel to hold up the weight of the car and soak up the bumps. So they are almost always outside the ability of the standard shocks to control them. Even new ones, used ones don't cut it. You get uncontrolled oscilliation of the spring (think pogo stick).

Sorry Reedy, but I need to kill this quickly............ A 200 lbs per inch linear rate spring takes 200 lbs to move it one inch, or if you prefer.... A 3.5kg/mm spring takes 3.5 kgs to move it one mm. It doesn't matter whether that is the first inch (mm) or the 10th inch (mm) it still takes 200 lbs (3.5kgs) to move it one inch (one mm). The amount of preload is determined by the weight of the car. If that corner of the car weighs 400 lbs (182 kgs) then the spring will need to compress 2 inches (51mm) to hold it up. But it still takes 200 lbs (3.5kgs) to move it the next inch (25.4mm). Progressive spring rates USUALLY compress all of the softer rate just in holding the car up. ie; they are progressive to make sure the spring doesn't go loose at full droop. They are not progessive to make the ride softer initially. This is not ALL progressive sapring just Most of them. Hope that makes sense