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Yeah as i said earlier - the problem will be because of the Tomei pump.

Go back to a lower volume pump (realistically you don't need the Tomei one on a stock motor) and be the much better for it.

That makes no sense to me. The overall volume of oil pumped is going to be set by the pressure relief valve is it not?

e.g. if an N1 pump has a relief valve set to 80psi, and so does the Tomei, then on the same motor the volume pumped through the bearings/restrictors and what not will be the same..

Since the Tomei's pressure is externally adjustable - simply set it to be a realistic pressure, anything 'flow' beyond that is returned to the sump.

Or have I missed something?

Yep. I Don't disagree with that.

Just making the point that the Tomei extra flow is not likely the 'problem' since flow is all to do with restriction as you pointed out. Hence i dont think theTomei is pumping more oil to the head if all variables including pressure relief valve are the same. I

One advantage to extra flow is getting oil pressure quicker at startup.

Yep. I Don't disagree with that.

Just making the point that the Tomei extra flow is not likely the 'problem' since flow is all to do with restriction as you pointed out. Hence i dont think theTomei is pumping more oil to the head if all variables including pressure relief valve are the same. I

One advantage to extra flow is getting oil pressure quicker at startup.

To my (limited) understanding there are two different things going on here.

Firstly the Tomei pump is physically much larger than the N1/stock unit. Being a positive displacement pump (ie not at all like a turbo) its output is proportional to its speed. So you get more flow - but this, in terms of what goes through the motor & the head is not the important point. Pressure is a function of flow, not of the pump and the pressure relief valve on the pump acts in such a way as to divert the oil away from where it would otherwise go (Through the engine).

The important point is that the pressures on the Tomei pump are high - about 4 bar at idle and more at higher engine speeds because of the hgher volume flow. An approximate number would be that the pressures are approx 2 bar higher than for an N1 pump across the rev range. As you can see from the attachment adding/deleting shims does not have a big influence on the pump pressure. It has some to be sure but maybe not what people may otherwise think.

So our start point as far as oil supply to the head is concerned is that the pressure seen at the oil restriction orifice is higher for a Tomei pump than an N1.

Consequently you will get more oil into the head with a Tomei pump - but again probably not as much as you would think. For a flow restriction orifice four times the pressure will only give you twice the flow. We dont have quite that much extra pressure but we do have some & to grab a rough number (Ie one pretty much out of the air) a 50% increase in pressure (which is not wholely unreasonable for the change in pressure) will give you a a 22% increase in oil flow. You counter this by running a smaller restrictor - 22% smaller in this example or about 1.3mm as opposed to a 1.5mm orifice if that was your default choice.

I think that makes sense - it is still early.

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Edited by djr81

I've got a rb25 with a n1 pump that liked to flood the head.

1.1mm restrictor in the back and block the middle one almost fixed it. Then rb26 cam covers with mines style baffles eliminated the problem.

Oil pressure under brakes is a minor concern now so I'm getting a new sump which should solve that.

Ok so with all the responses so far it seems to be the best cost/benefit will be to;

1. Fit oil restirctors

2. Fit a large sump

3. Oil cooler

4. Really well thought out and designed catch can/sump breather setup

5. Leave the stock pump (can anyone confirm that the NEO does come with an N1 pump factory)?

6. Stock harmonic balancer

7 Drop it in :)

I would like to retain VCT, So i'll need to pick the sweet size restrictor. It seems to that 1 - 1.3mm is the around about size to go. But which size will be ideal. The car will get the very rare street drive. Obviously you dont want to starve the head of oil at these low rpm conditions.

The Neo definitely comes with a standard, non N1 oil pump.

Ok so with all the responses so far it seems to be the best cost/benefit will be to;

1. Fit oil restirctors

2. Fit a large sump

3. Oil cooler

4. Really well thought out and designed catch can/sump breather setup

5. Leave the stock pump (can anyone confirm that the NEO does come with an N1 pump factory)?

6. Stock harmonic balancer

7 Drop it in :)

I would like to retain VCT, So i'll need to pick the sweet size restrictor. It seems to that 1 - 1.3mm is the around about size to go. But which size will be ideal. The car will get the very rare street drive. Obviously you dont want to starve the head of oil at these low rpm conditions.

What turbo are you going to run and what power, boost and revs do you think you will have?

If this is a temp engine, then I personally would just throw the std motor in, run a good oil cooler and filter. (pressures on my engine are all over the place depending on the oil filter I am running, Std Nissan seems to work well) and enjoy the thing.

Run Castrol 10W60 Edge, make sure your volume is a tad over filled and just enjoy the car. Unless you have slicks and running amazing times the engine will be fine.

All this money spent on your oil system, it would be cheaper to just buy another NEO IF the engine has a problem. In which case you woudl be able to sell the old head to the RB30 deviants, bottom end could be of use to somebody.

Seems waaaay too much hard work and money when rwd RBs last perfectly fine if you just keep good quality oil up to them.

The Neo definitely comes with a standard, non N1 oil pump.

How sure are you of this, i have hear a few conflicting reports.

What turbo are you going to run and what power, boost and revs do you think you will have?

If this is a temp engine, then I personally would just throw the std motor in, run a good oil cooler and filter. (pressures on my engine are all over the place depending on the oil filter I am running, Std Nissan seems to work well) and enjoy the thing.

Run Castrol 10W60 Edge, make sure your volume is a tad over filled and just enjoy the car. Unless you have slicks and running amazing times the engine will be fine.

All this money spent on your oil system, it would be cheaper to just buy another NEO IF the engine has a problem. In which case you woudl be able to sell the old head to the RB30 deviants, bottom end could be of use to somebody.

Seems waaaay too much hard work and money when rwd RBs last perfectly fine if you just keep good quality oil up to them.

I'll be using a high flowed RB25 turbo with a 2871 cartridge. Power, hmm i would like to think it will make 250-260kW with injectors, AFM and a Nistune.

What will i rev it to? Hmm hard question, i do love revs, however, theres no point in revving it much past the engines peak power. Maybe a shift light might come in handy here to get those smooth shifts :P I'd expect peak power to be under 7,000 with stock cams.

Yes i see your point of just throw it in. However, a sump is just so appealing to me, it will have a decent resale value and help keep the oil where it is needed - near the pickup!

I'll be using semi slicks yes, when the car was last raced it did a 1.21 around Mallala on $120 Toyo RA1's that i bought from U pull It lol. I did manage to do a better time than several GTR drivers with relatively good setups through the day. How is this so, i dont know. But it felt awesome :P

Thats me, a little rough in many areas haha, but not too bad for a 2nd day out doing a sprint. That was skyline nationals last year.

Nice vid and great work getting out there and punting it.

I will add, though and I am not trying to be overly critical as me... I am a 100% armco eater at the track...but do waaay more braking before downshifting! Your car control looks great, just work on the braking way harder and longer before down shifting. You will kill bottom ends like a CHAMPION if you forever engine brake and pin high revs on the downshifts. (my opinion only :whistling: )

Nice vid and great work getting out there and punting it. I will add, though and I am not trying to be overly critical as I am a 100% armco eater at the track...but do waaay more braking before downshifting! Your car control looks great, just work on the braking as you will kill bottom ends like a CHAMPION if you forever engine brake and pin high revs on the downshifts. (my opinion only )

Yes, i'm aware of this one for sure.

Main reason i wasn't braking harder was because my tyres simply couldn't take any more braking. They would just lock up. The brakes were fantastic, not one bit of fade and have a lot more in them. Much much more. But the tyres were old and were locking with any more pedal effort put in.

After i looked at the video, i realised how much i was over revving on down shift. This is all to be worked out the next time im back out there.

But the main idea is getting the oil control sorted and to a point where i'm happy with it and i know its going to be a happy engine.

If an oil cooler is going on, you might want to do a accusump while your at it to help keep the stocker alive.

This was something i was certainly thinking of, Seeing as i want to use one on the RB26 i might get one.

However i dont know everything there is to know about them. nor where the best place is to source one? Any Ideas?

They are very simple to setup and you can buy them direct from canton. http://www.accusump.com/

Quite a cost effective solution to keep oiling issues under control when you start getting serious without going to the expense of a dry sump.

Yeah i'm going to do an accusump, It has been on my mind for months.

The only issue i see is that when the engines oil pressure gets below the preset value, Lets say 30PSI, then the valve will open, allowing oil to flow. Now this is good. But when about when your coming to a stop and coming into the pits? Is this ideally what you want?

I assume thats just a fact of the operation of an accusump.

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