daisu

I was of the impression that RB26 and RB25 bellhousings were able to be swapped without implications. Both bellhousings fit RB series motors and both will fit RB25/26 gearboxes. Use the slave cylinder, clutch fork and pivot to suit the bellhousing. I found an RB25 box and clutch for cheap, only catch was it had a custom bellhousing (to suit a VQ motor). So I bought it, found an early (push type) RB26 bellhousing and swapped them over. So RB26 bellhousing on an RB25 gearbox. Fitted the gearbox into my car only to find that the shifter is now about 50mm further towards the rear of the car, I'd have to cut into the shifter hole to make it fit. Plenty of people have fitted RB25 gearboxes without shifter position issues. So makes me think that the RB26 bellhousing is longer than the RB25. Can anyone confirm this, or can anyone take a measurement of their bellhousing (early RB26 or RB25)

One of them should be ground, one should be 12V supply (should be able to measure this with the AFM disconnected) and the other should be a 0-5V signal from the AFM. Definitely sounds like either a grounding issue or the loom has been pinched and the wires are shorting.

While we are on the subject of BOV's I'd like to ask about location of them. I was under the impression the best place was as close to the throttle body as possible. That way, when the throttle closes and the BOV opens the majority of the charge air continues flowing in the same direction. The other day I was looking on the turbobygarrett website and it stated the best place for the BOV was as close to the compressor outlet as practical. To me this doesn't make sense as all the charge air in the pipes/intercooler has to reverse flow to exit the BOV. On RB's the standard BOV is pretty close to the thottle. And from what I can recall, on SR20's the BOV is located near the throttle and the return pipe crosses back over to the other side of the engine to get back to the compressor inlet. In both cases (and you see this alot in aftermarket piping kits) the BOV is usually located on the hot pipe, next to the compressor inlet in order to shorten the return pipe.

Mate, based on your description, I had the exact same problem. You tried to accelerate quickly and it bogs, hesitates and jerks. Difference with mine was it wouldn't push through unless you lifted off the throttle some. I unplugged my O2 sensor and the symptoms would ease up/disappear but then, without the O2 sensor I got shit fuel economy. Tried a new O2 sensor but that didn't fix it. I did heaps of things, cleaned the AFM, resoldered connections, new copper plugs, changed the gap to 0.7mm, swapped all of my coilpacks/loom/ignitor with known working items from a mates car. The problem remained until one day I removed my front mount/pipes and replaced it with a large sidemount. My deduction is that there was an air leak on the inlet piping (which isn't surprising considering I had welded my own pipes and I didn't pressure test them). Makes sense that the more boost you run the worse it gets. Get a PVC pipe end cap, screw a tyre valve into it, install it in place of your AFM and pressurise your inlet piping, this should identify any leaks pretty quickly.

Use soapy water to identify where leaks are coming from. Put some decent pressure in through the tyre valve cap. You're right that air will go out through the exhaust (that's possibly the sound you heard near the turbo) An air compressor is a good idea because you will get good pressure in your inlet piping.

Sorry, I just reread the first post. I thought you had bought a replacement head and put it on your existing block. Just to clarify, You originally had an RB20E (fuel injected) and you bought a replacement motor which was carburettor. Then you swapped all of your EFI stuff onto the replacement motor. As far as I understand, RB24S and RB30S were the only carburettor RB engines. So I'm guessing that maybe you were sold an RB24S. Although, you also said that the block has an RB20 engine number..... can you double check that?

Pretty sure the 25SE and the gts-25 use the smaller gearboxes (same as rb20).

An RB24S uses the same head as the RB30 (they have the same 86mm bore) the RB20 has a smaller bore (something like 79mm?)

According to commodore forums, all you need is the speed sensor gear from a VL turbo. It is the correct size to fit in an RB25 box and it fits the speedo cable (VL, R32, C33, A31 all use the same cable).

I was not aware of any RB20 heads with carbuerettor. Are you sure it's not an RB30 head?

Instructions are in the link in the first post, I just wired it up as per the diagrams on the scanned pages.

Lum is correct, the speedometer converts the cable speed to an electrical signal and sends it to the ECU. I would suspect that in the vehicles with speed sensors on the gearbox, that it goes directly to the ECU. Items like the speed checker and defi VSD plug into the consult connector, which uses a serial connection to communicate and retrieve data from the ECU, so it is highly unlikely that you would beable to connect the speed sensor directly to any of these.

Yeah pete, I'd say they'll be 15mm as 9mm is a bit small for breather hoses. Block the hole, or plumb the BOV in. I would suggest plumbing it in as it's going to be the first thing a cop sees when they open the bonnet (your atmospheric BOV). Do you know what spark plug gap you are running at the moment? I'm pretty sure the standard gap is 0.8mm There's nothing wrong with a larger gap unless you are having problems with it misfiring underboost. If so, gap them down a bit. You shouldn't have to go below 0.8mm at this boost level. If you have platinums I wouldn't try gapping them. P.S how'd you go with the tyres.

If it fits should be okay, I wouldn't be using 2nd hand idlers/tensioners though

Negative, ABS brake master is used with ABS, Regular brake master is used without ABS. The ABS brake master only has 2 outputs. Whereas the regular brake master has 3 outputs.

If it was my car I would've just bought a fuel pump and installed it. No need for FPR, injectors or PFC. Regardless of anything, you should install the pump and upgrade your fuel pump wiring. If the FPR has a gauge built in it will be a handy diagnosis tool, might aswell install it, search the forum for adjusting aftermarket FPR (set it to stock pressures). If there is no gauge on it then there is no real point to installing it as the standard FPR is fine. Either keep it as a spare or sell it. The larger injectors are not really needed unless you are going to get it tuned and plan to reach figures higher than the stock injectors will allow. Again, same with the powerFC. Unless you have decent mods (or plan on them) it's not really needed. If you really want to put them in the car, find out how to reset the powerFC to standard maps, install it and the injectors, adjust K factor to suit the size of the injectors.

I prefer to swap pins at the loom as it is reversible. I'm using a manual TT ECU

I am well aware that the stock pump is feeding into the surge tank, and the 044 from the surge tank to the motor.I agree that with a 2L buffer it would be highly unlikely for the surge tank to empty under normal conditions. But anytime the engine is under decent load (may not even be WOT) the level in the surge tank will be dropping. Without knowing injector sizes, duty cycles, flow rate of the standard fuel pump it would be hard to say how long it would take for the 2L buffer to run out. The original poster states that R31's are known to have fuel surge problems and that he doesn't like having more than half a tank of fuel. Imagine on a racetrack, during the corners the standard pump will be starved so there will be no supply to the surge tank. On the straights the standard fuel pump will be supplying the surge tank but the engine will be consuming more fuel than is supplied, so again the level in the surge tank is dropping. Again, without knowing HP figures, injector sizes etc we can't say how long it would take but you can definitely see that during spirited driving the surge tank level will be dropping. Then imagine skidpans or drifting where WOT and cornering is happening at the same time. If there is no supply to the surge tank it won't take long for the engine to consume 2L doing skids. The original poster states that the fuel pump is wrapped in foam insulation, and from the picture looks like it's mounted on a block of wood? Once the pump heats up all the heat energy will be transferred into the fuel. Running the pump at higher temps is going to shorten it's life. As the fuel heats up it is more likely to cavitate which will cause more damage to the pump internals and cause fuel pressure problems.

I will never forget that bed *shudder* We'll have to talk numbers on the cars. I'll talk to you on msn or something.

Generally speaking, oil has a specific gravity of approx 0.8 So 800 grams. Viscosity does not necessarily change the density of the product.

The stock pump wasn't keeping up with the engine before hand. How is it going to keep up now? Even with the surge tank and 044, all the fuel has to flow through the standard fuel pump. Why don't you like to drive around with more than half a tank? I know that if I have anything less than half a tank I get surge issues. The fuel in the tank is supposed to cool the fuel pump. If the level is dropping below the fuel pump then you will damage the pump internals pretty quickly. I would be doing the following things, regardless of whether they are the cause of your problems. Remove the standard pump, check inside the fuel tank to make sure it has not rusted and that any baffles have not come loose. Purchase and install a high volume, low pressure lift pump. It should flow more fuel than you are going to require at full noise. Make sure it is mounted as close to the bottom of the tank as possible. A surge tank with greater volume will provide greater surge protection. G-forces and fuel surge can still affect the surge tank itself so you want something as tall and narrow as possible. Look into a swirl pot. They are designed with the fittings positioned in such a way so that the fuel swirls around the surge tank. Supposed to help in removing air pockets and cooling the fuel. You may be able to keep the 044 if it is still working properly. Install a fuel pressure gauge to monitor the rail pressure, if it's still faltering then replace the 044 with a new pump. Make sure the wiring is up to scratch. It is very common for the standard wiring to deteriorate in cars of this age. Run a new wire of decent gauge directly from the positive terminal on the battery (install a fuse at the battery end of the cable). Put a relay in the boot and use the factory pump wiring to switch the relay. Run the new cable to both pumps through the relay. Make sure the negative side of the pumps are wiring is also adequate, connections should not be on painted surfaces. Not sure if the 044 generates much heat, but wrapping it in foam will only make it run hotter and ensure that the heat is getting into the fuel. Who cares about a bit of fuel pump noise anyway.

Remove the following, Brake master, ABS unit, brake lines. Replace above items with those from a non ABS model. I would assume that S13 lines would fit the cefiro. You can use S13 brake master (or use an R32 brake master if you have skyline brakes). Alternatively, getting lines made between the brake master and wheel wells won't set you back much.

Adam, you remember me telling you how I was going to buy this car off you before you even picked it up Is that my bed I can see next to the GTR rims? What is that bracing stuff on the castor rods?

Drive up to Brisbane? hahaha Are you looking for series 2 tail lights or headlights.

Find someone selling a damaged RB25 turbo (blown seals, compressor/turbine blades failed, seized bearings) Pay $50 or whatever for it and strip it for the housing.