Belly_up

JNR24, hopefully i can explain a few of the things you've mentioned: ACCEL PUMP means acceleration enrichment, and gets it's name from carbies, which have a small pump connected to the throttle. It allows you to tune how much extra fuel to add when you step on it. STEPPER MOTOR is another way of controling the idle air valve (using a stepper motor obviously), as opposed to a solenoid. Many modern engines use a stepper motor, but not all aftermarket ECU's can run them. CLOSED LOOP means that the ECU can do closed loop fuel control at low loads (ie cruise and idle), it uses the oxy sensor in the exhaust to constantly adjust the mixtures to try and maintain an stoich air/fuel ratio. Ecu's without this, such as the Microtech mentioned above, will perform fine under high load, but will have poor economy when cruising or idling, which is especially bad if you do lots of long distance trips. TEMP COMP, means temperature compensation, whereby the ECU can vary the fuel mixtures based on a given temperature, most commonly intake air temp, but some, like the Motec that SydneyKid mentioned, can also do engine temp compensation, and exhaust gas temp compensation. Standard ecu's don't need intake air compensation if they run off the AFM, as it automatically adjusts for air temp, but MAP based ECU's need a seperate sensor and compensation map to do this. LAMBDA i'm not too sure, but it would be related in some way to closed loop? it may be related to the ability to utilise a wide band O2 sensor. Hope that helps Belly_Up

yeah i guess i wouldn't want to risk a 900+hp motor cause i skimped on a fuel pump. The price just gave me a bit of a shock at first. And the $750ish isn't the alcohol compatible one, you have to pay another $100 for that. Oh well, i guess if the situation warrants it...

Has anyone used or have experience with these pumps? The CAPA site lists them as being good for 750hp, at a comparable price to bosch 044. I'm thinking that the bosch is a safer bet, and will provide more than enough fuel for what i need. But if anyone had exceptional experience of advice about the Paxton, then i'd consider it. On that topic, how many fuel pumps do SX expect to sell at twice the price of an 044? The original Bosch 944 pump in the BMW sounds a bit sick (after being dry for 2 years, and being 26 years old now), and i figure i should replace it before i get the car on the road.

I'm not sure how much detail you have to go into to actually get the mods approved (i shall find out in a few months i guess), but i think it is mainly at the discretion of the inspecting engineer. Basically if they deem the mods to be safe, ie structurally sound, and not impeding any of the safety systems of the car, then there shouldn't be too many problems.

Yeah, it's a pretty silly law, and impossible to police, which is why i think they don't bother. As if you could reasonably expect anyone to do an engine conversion for a 10% power gain... maybe thats the idea, to stop people doing conversions...

I was told the same about motor size in qld, that it is based off the largest engine fitted to the vehicle, thus an R32 came with a 2.6l, so you should be fine. I *think* that you can have a 50% increase in capacity (it's been a while since i checked it out) thus a R32 could go up to 3.9L. However you would need to have the brakes and suspension of that larger engined model (ie, a 32 GTS-T would need 32 GTR brakes and suspension *or* something deemed equivalent or greater by an engineer. However, apparently the strict letter of the law (in QLD) is that any engine conversion is only allowed to have 10% more power than the original engine in that vehicle. I was also told however that as the dept of transport / inspecting engineer doesn't actually do before and after engine dyno runs, there is really no way of them knowing if you meet this requirement, and as long as the conversion is properly engineered (once again deemed by an engineer), then the modification will most likely be approved.

also check Autospeed's online shop , as they seem to have a decent range and prices as well.

Yeah i'd hope it is, i know i'd hate to goto the dentist and have to breath in something that smelt like LPG i was just saying that they *could* give it odour if they thought it was a safety concern.

i'd love to see it too, as long as there was large concrete barrier between me, my car, and anything else i valued : ) But you're right, it would be piss funny to watch in a controlled environment.

LPG, as used in cars and bbq's, is also odourless, colourless and tasteless, when it is in it's natural state. The distinctive odour is added afterwards by the refineries for the same safety reasons you alluded to above. So there is no reason the same couldn't be done for nitrous, if that was the main safety concern. I think the main reason that it is banned on the street, is that it's only possible use, is for drag racing, which is also illegal. Personally i shudder at the thought of inexperienced drivers cruising the streets in their lowered excel's, with the ability to gain 100hp at the push of a button (through their stiff suspension and 185 tyres :eek:). Sure it might be ok in a straight line in the dry, but what about around corners, or in the rain, or both. I think N20 is too on/off in it's power delivery to be safe on the street, and if i was the authorities, i'd make it illegal too. Belly_up

how can a hydraulic piston possibly screw in? Unless you've got cable operated rear brakes?

yeah, about 6 months after i started my RB20 conversion, i found out that if i'd looked in the right place, i could have done the BMW motor for much cheaper than what i originally thought. Although if you want to go the turbo route, you're up for a turbo, custom exhaust manifold, intercooler, possibly injectors, possibly decompression of the engine, and definately aftermarket ecu, all straight away, whereas the RB25 already comes with most, if not all of that stuff.

the other thing to look out for is that the BMW motors are intake on the the passenger side, exhaust on the drivers side, whereas the nissans are the other way around. So you'll have manifolding in different places from normal. for me this was a good thing, as it gave me more clearance for exhaust manifolding (my beamer has a huge steering gbox on the drivers side, i think the e30 i saw was much better in that respect), but it might be different for you.

I've seen a RB25 in an E30, it was being done by Rollins Imports on the Gold Coast (ads in zoom if you want a no.), the actual engine fitted ok (remebering that the BMW engine bay is already designed for a straight 6 engine, but they did have issues fitting in a radiator and intercooler, so you might want to see if you can ask them about that. I've just put and RB20DET (which is the same dimensions as the 25) into my '77 520i, and it fits beautifully, looks like it was factory, but i've probably got a bit bigger engine bay. I also have no room for a FMIC, i'm running a top mount water-to-air jobbie. Thats more related to the front bar design on my car though, so you might be ok. I notice you're in toowoomba, if you want to come and check my car out sometime (not that it's verry impressive atm), even just to compare the size of the engine bay, let me know and we can arrange something. Hope that helps in some small way, Cheers Belly_up Hope that helps in some way

and i'm assuming also that the hose that goes from box to pump via the reservoir, is the return line, and not the pressure one? And on that topic, can anyone tell me which fitting on the pump (the front one or the rear one) is the outlet (ie Pressure line)? Thanks again.

my GTS-4 front cut had mechanical speedo cable, but my gearbox (which i got seperate) had an electronic sender unit on it. I'll check it out next time i'm under the car and see if has any identifying marks or part numbers on it for ya.

Hi guys, would someone be able to have a look at their power steering system and tell me what hoses go where? There are 3 fittings on the pump (that i can see, 1 large, 2 smaller), 3 fittings on the reservoir (1 large, 2 smaller), and 2 fittings on the steering box. Obviously the large fitting on the res connects to the large fitting on the pump, but i'm not exactly sure how the other hoses run, having been 8 months since i pulled them off. I've attached a picture showing how i think it might go, but i don't really know for sure. if someone could let me know that would be great. Thanks guys, Belly_up

Either of them can have the *air* outlet plumbed back, and thats what the EPA would be worried about. The advantage of the oil / air seperator is that you keep your oil in the sump rather than collecting it in the catch can. As i said above, it's really only going to be a issue for prolonged high RPM use, not so much on the street. And when shopping, the two names are used interchangeably by most people (and rightly so, because a "catch can" is acting as an oil/air seperator), so check for whether the particular item has an oil drain fitting, to determine whether it is what you want or not.

The difference between a catch can, and an oil/air seperator is that a catch can simply collects the crankcase fumes, grabs the oil out of it, and lets the air go. It would theoretically fill up with oil eventually and need to be emptied. An oil/air seperator is the same thing, except that it has an oil drain back into the sump, thus reducing the maintainance level, and ensuring that you don't run low on oil in situation where the crankcase may be breathing heavily ie. track use. For both devices, the vented air can be routed back into the intake (where it originally went anyway) as it should now be free of oil, and this will eliminate any possible legal issues with emissions etc. At minimum a filter should be fitted because a) the catch can/seperator won't be 100% efficient, so there will still be *some* oil vapour in the air, and B) the crankcase can breathe both ways, and you don't want to be drawing unfiltered air into the crankcase. Hope that clears it up a bit.

Cool thanks for that dominik, they did look like a press fit to me, i just wasn't sure how tight...but if you reckon they come out, then i'll have to give it a shot. Will try during the week if i get time, and report back on how i go.

it's ok, i don't have the stock intake plumbing anymore, so i don't need the feed back into the intake. Thus why i'd like to modify the breathers to suit my purposes a bit more.

Ok guys, has anyone removed the breathers from the top of the RB cam covers? They look to be a press fit, is this the case? and how did you remove them if you did. i've seen some pics of engines with different arrangements to suit catch cans etc, and was wondering how hard it is to do, without screwing up the covers. Any help appreciated, Adam PS. Does anyone have a spare one of those plaquards that goes on the plug cover? the one that says "Nissan Twin Cam 24v", cause i kinda bent mine trying to pry it off ...

On the RB20's (25's are probably the same), you have to unplug and remove the CAS (mark it first so you can put it back in the same place), and then just undo the 4 or 5 allen head bolts that secure the timing cover to the engine. There is basically a bolt at each corner of the cover, and one in the middle(?). That gets the top half of the cover off. you can't get the lower half off without removing the crank pulley, which whill require a puller, and may be awkward with the engine in the car. But the top half should be enough to inspect the belt, you might need to turn the engine over a bit to check the whole thing. Hope that helps, Adam

Yeah, i guess that true, there are a lot of very nice, very smooth V8s around the place, namely anything jap or euro (ie not american : ) I'm thinking Lexus, BMW, Merc, Ferrari, Maserati etc all have pretty nice 8's...

also on JimX,s point, why is it that the more cylinders you have, the smoother the engine (or exhaust note) gets, except for V8's. For example, a 12 sounds smoother than a 10, which sounds smoother than a 8 which DOESN't sound smoother than a 6 or a 4. It's a bit hard to compare i guess, cause most people, when they think V8, think of GM/Ford V8's, whereas most 10's and 12's are made by prestige marques. I guess we need to compare a Ferrari V8 to a Ferrari V12 to check properly...anyone care to indulge me?