GTR-Ben

Check resistances etc for the AAC and Bypass valves and make sure they are actually working correctly. Does anyone know if the Air Bypass Valves are the same across models or do they have different ranges??

Has a look yesterday while replacing my heater hose which decided to blow.. (thankfully after the dyno run and at home!) I used the small holes next to the ones the RB30 knock sensors came off. There was nothing in them to stop the bolts going in.. This may not be the ideal place. But they appear to be working fine. If you are really concerned use a helicoil in the correct holes..

Could have a slightly damaged valve? only becoming a problem at peak load?

Wheel sensor plug will be on the other side. That small one is for the Air con if that loom wraps around to the front. I would be looking at the fuel pump control circuit first, something maybe earthing there when it tries to turn on.

Well thats what I recall doing.. I used a bolt and a washer on each GTR knock sensor when I mounted them to the RB30 block. Maybe I didn't use the original holes for the RB30 knock sensors but ones close. The knock sensor worked fine today on the dyno however.

Did another tune on mine. Made 467hp with a bit of time spent on the cam gears etc. Could get more, but this is more than enough in a street car. Lots of fun

Washer + bolt. Worked fine for me..

I have had a few of those... never got them to work. Just bin it and get a late model boost controller in my opinion.

Damn. This reminds me of a friend doing exactly that on his GTR.. ended up getting a police escort home due to the amount of smoke!

I have experienced the cut at 5000 rpm or so in 5th, speed cut removed but it use to always cut for a few seconds when doing a timed flying quater.. was quite annoying.

Any muffler will cause restriction.. but not like having a butterfly that turns your 3" exhaust into a 1" pee shooter The Varex atleast lets the gas flow around through a conventional muffler setup.

With the right ECU/Tune you should be able to get more out of your current AFM. I always see people talking about Z32 AFMs etc but I have seen so many high powered cars running stock AFM's.. it makes me really wonder. In fact I have seen a high powered GTR with a single AFM probe plugged in post intercooler in a 2.5" pipe.. Seems confusing at times..

Can finally get my final tune now. Can't wait

Follow the bottom radiator hose to the block. Remove the hose. There will be a thing with 3 bolts that the hose attaches to. Unbolt it and you will see the thermostat. Give it a tug and remove it. Clean up the hole it came from, install the new one. Reseal and install the flange. Refit hose, fill with water and bleed.

I would imagine things would heat up due to the restriction.. but other than that it just wouldn't not be able to make the required boost..

Update: Seems to work a treat. Problem is now that my internal GTR pump running with no pressure against it is now louder than the 044 at 7V.. The 044 kicks in to full voltage at around 2.6V and off at about 1.4V. Took it for a drive around the hills and this seems perfect.

Check out the Varex muffler. Less restriction when closed but still the noise reduction.

If you are going that hard out. Keep the RB26 or go an OS RB30 or similar.

I removed all of that on my engine. I just need to give it a little throttle when it's completely cold so it does not stall. Little annoying but not the end of the world.

Get a multimeter, set it to the 10AMP setting. Take a battery terminal off, set it to current, put the multimeter inline and check for any power draw with everything turned off. It should have a small amount or nothing at all.

The usually work.. but the only real use of a guage on your stock 02 sensor is to have yet another gauge with pretty flashing lights.. not much useful data can be taken from it.

No I have no diodes.. it is a very basic setup. I think the reason it was staying closed was because the pump was stalled.. if it runs i'm sure this will not be a problem as it does when running 12V. The current/voltage relationship depends on whether the pump is loaded/unloaded or stalled.. the current and voltage will only increase proportionately to each other in a stalled condition (IE back EMF constant). In a loaded condition the current will remain fairly constant with voltage change as the back EMF will also vary as the pump speeds up or slows down. If you had no regulator or friction in your fuel line, varying the voltage would do very little to the current draw however. Sure if you increase the voltage the current will also increase slightly when the pump is loaded but not proportionately. If the pump goes from running at a set voltage and suddenly stalls. For that same voltage you will see a large spike in current. This was the concern. With your V=IR you are not considering I=(V-E)/R where the real voltage (potential difference) across the windings is important. (E = Back EMF) The pump resistance may be fixed, but the back EMF changes. If this back EMF hits 0 (Stalled pump) the current seen at the pump will then become input voltage x coil resistance = huge current and a burnt out pump... A voltage divider is a standard way of reducing a voltage. They use two resistors with different values and the voltage output is determined by the ratio of resistance values of these two. They are in series but the output is taken out between these. The GTR module is not as simple as a resistor voltage divider as it drives a fairly large load. Usually resistor voltage dividers are used for signal currents only. (IE milliamps) I have looked at the method you described of adding a bypass around the 044, but it seems silly to add yet another pump when this one will do 800HP on it's own. Why add more when you can slow the pump.. a PWM motor speed controller will do this perfectly.. without reducing voltage supply to the pump. So I don't think it's all as simple as people are adding here.. and I am fairly confident my setup will work fine with a few tweaks

I prefer to have the rail returning to the surge tank at present. I only run braided lines from surge tank to rail. If I ran it from rail to tank I would need to weld more fittings etc. Not hard but no need. Conservation of power is probably the wrong way of wording it.. and not a "technical" term. The pressure in the fuel system is governed by the regulator, so we can consider this fixed. So for a certain flow the pump motor needs to output a certain amount of power. For this power to remain constant with a drop in voltage (keeping the flow the same, as I was incorrectly thinking) the current would have to go up. Obviously as there is no feedback system to keep the pump operating at a constant RPM, it naturally slows down so the current ofcourse does not increase. The parts missing from that diagram are just the earths for the relays, the source of power to the voltage switch and control module. What would you like to see? The voltage is dropped by a voltage divider so not as simple as an inline resistor. Yes I don't think at 7V it has enough current to turn the 044 trying to push against 50psi rail pressure. Thats with the car off.. I didn't try and start it.. so maybe when the rail pressure goes to 40 or so and the voltage gets a little higher it would work. It did some strange things though when it was at 7V. A. It held the rail at 50 psi, but the pump was only making small sounds.. not a running noise. B. When I turned the key off it continued to make these sounds until i unplugged the power to the relay (I guess it was holding the relay closed somehow) The External pump was wired to a ignition switched power also, so it would not turn off after a few seconds like the stock pump.

Damn felixy69 thats one amazing looking setup!

Thanks, that why I was asking. A lot of people say "oh no but the voltage will increase a LOT!" but no one explains why.. And I am no electrical expert.. just people pretend to be on the internet and misguide you. With a closed loop system thats keeping the motor at a constant RPM, a decrease in supply voltage will cause an increase in current by the laws of power conservation. I had originally though just that, as the pumps voltage is lowered, the current draw would also be less because the pump is now going slower.. Surly if there was a current problem they would not use it with factory systems. About the noise.. driving it today with it mounted under the car (pump is rubber mounted and so is the tank) I can not hear it at 12V while the car is running. There is a hum from outside the car but it's not a lot. It just seemed simple and it was something I wanted to wire up... Not only for noise but also to lessen the amount of fuel I was heating up was a reason for doing this. I have the whole system ready to go, the pump just doesn't like lower voltage.. So leaving my setup how it is.. I guess the 044 just can't push the fuel with only the current 7v supply.