Help Understand GTT Boost Setup

[MBS206]

1 hour ago, Dose Pipe Sutututu said:

I dream of a day someone buys my R33 shit box and I never see it again.

I will then buy a German shit box and post how it constantly uses tyres, fuel and how much more economical it is to operate.

Give you $100.00 for it...

[Dose Pipe Sutututu]

10 hours ago, MBS206 said:

Give you $100.00 for it...

Come on lad, missing a few zeros and * 0.6 lol

[silviaz]

On 2/14/2025 at 9:34 AM, Dose Pipe Sutututu said:

Let's be honest here @GTSBoy 250kW in a GTS-t would easily get walked by my a family SUV these days.

300kW is the sweet spot, fast enough to keep up with the modern German cars (not from a stand still), fun enough and the motor still can be stock/unopened.

Realistically, 400kW is a good number. It's enough to give you cold sweats, still be very street able in terms of the power band (provided you're not an idiot and go single scroll and delete VCT) and only needs a very basic rebuild (or stock if you have a NEO motor).

Anything more, it starts to be stupid.

When you say basic rebuild, you mean an oem rebuild?

Edited 18 hours ago by silviaz

[GTSBoy]

8 minutes ago, silviaz said:

When you say basic rebuild, you mean an oem rebuild?

That's more or less what he meant. What it really means is that you do not have to go full crazy on the build. Don't need the best oil pump, expensive rods & pistons, big cams, etc. You can upgrade whatever you want instead of using stock level items, but you don't have to.

Having said that - any time an RB is opened up, if anything is getting replaced, I think the opportunity should be taken to do all the sensible upgrades. Pistons, rods, pump, etc.

[MBS206]

3 hours ago, Dose Pipe Sutututu said:

Come on lad, missing a few zeros and * 0.6 lol

Oh man, sorry, $60.00000000... 😛

[MBS206]

1 hour ago, GTSBoy said:

That's more or less what he meant. What it really means is that you do not have to go full crazy on the build. Don't need the best oil pump, expensive rods & pistons, big cams, etc. You can upgrade whatever you want instead of using stock level items, but you don't have to.

Having said that - any time an RB is opened up, if anything is getting replaced, I think the opportunity should be taken to do all the sensible upgrades. Pistons, rods, pump, etc.

I agree on doing some better than factory pistons, rods, and oil pump.
For anyone using the vehicle on the road, I don't get why everyone wants big cams. The stock cam profile, with some more lift would be mint for road usage. Everyone going big cams and then wondering why it isn't as responsive in traffic, when they've shifted the torque curve upwards an additional 1000RPM.
Make torque, at lower RPM. Sure it's not as cool as claiming "500KW" and revving it to 8,0000RPM, but that same torque 2,000RPM earlier... Then you don't need the extremely high end pistons and rods, and blah blah blah.

[joshuaho96]

4 hours ago, GTSBoy said:

That's more or less what he meant. What it really means is that you do not have to go full crazy on the build. Don't need the best oil pump, expensive rods & pistons, big cams, etc. You can upgrade whatever you want instead of using stock level items, but you don't have to.

Having said that - any time an RB is opened up, if anything is getting replaced, I think the opportunity should be taken to do all the sensible upgrades. Pistons, rods, pump, etc.

I really don't understand the point of aftermarket oil pumps if your particular engine doesn't need more oil pressure. As far as I can make sense of it the problem seems to be cavitation from sucking air, maybe the pump gear design with how it interfaces with the OEM crank, and maybe the backing plate screws wanting to loosen themselves. How does flowing more oil fix these issues?

[MBS206]

6 minutes ago, joshuaho96 said:

I really don't understand the point of aftermarket oil pumps if your particular engine doesn't need more oil pressure. As far as I can make sense of it the problem seems to be cavitation from sucking air, maybe the pump gear design with how it interfaces with the OEM crank, and maybe the backing plate screws wanting to loosen themselves. How does flowing more oil fix these issues?

Strength.

And on the early RB26, full engagement of the pump drive.

[joshuaho96]

46 minutes ago, MBS206 said:

Strength.

And on the early RB26, full engagement of the pump drive.

Right, but if you replace the pump gears + put a spline or sine drive gear on the crank on a Nismo/OEM/N1/etc pump at that point do you really still want more flow/oil pressure? Let's say this is a the aforementioned "keep it simple" build, no more than ~400 kW at the crank.

[MBS206]

17 minutes ago, joshuaho96 said:

Right, but if you replace the pump gears + put a spline or sine drive gear on the crank on a Nismo/OEM/N1/etc pump at that point do you really still want more flow/oil pressure? Let's say this is a the aforementioned "keep it simple" build, no more than ~400 kW at the crank.

Well, can you still get an OEM pump, and by the time you're buying a Nismo/N1 etc, just buy another aftermarket pump.
It's better to have the pump able to flow more if its needed, than for your pressure to drop off.
At any point in time, you're replacing the oil pump in a rebuild. Aftermarket pumps are likely going to be a better economical choice, and they don't have any negatives, even if they can flow more.

 

Also, when you're saying "replace the pump gears" are you meaning leave a 25+ year old housing in the engine with unknown wear, and just put new gears in?
As that sounds silly to me, especially if you do have that minute amount of wear, that means your new pump gears now have a little bit more clearance beside them, which means, whelp, you may not get to build a lot of oil pressure or make a lot of flow.

[GTSBoy]

Yeah. "New pump" does not have to mean "massive pump".

[Dose Pipe Sutututu]

2 hours ago, MBS206 said:

Also, when you're saying "replace the pump gears" are you meaning leave a 25+ year old housing in the engine with unknown wear, and just put new gears in?

Don't do what I did, use a 300000km old housing with billet gears.

The old pump probably was clearanced with saw dust, Edward Lee's special engine treatment sauce and a good odo wind back.

I had oil pressure issues, then replaces pump with new housing, new billet gears and 2x track day later binned a motor due to other oil related issues due to a previous engine builder.

Long story short, buy a M2 or 3 or 4 N55/S55/S58 and enjoy life.

[joshuaho96]

24 minutes ago, MBS206 said:

Well, can you still get an OEM pump, and by the time you're buying a Nismo/N1 etc, just buy another aftermarket pump.
It's better to have the pump able to flow more if its needed, than for your pressure to drop off.
At any point in time, you're replacing the oil pump in a rebuild. Aftermarket pumps are likely going to be a better economical choice, and they don't have any negatives, even if they can flow more.

 

Also, when you're saying "replace the pump gears" are you meaning leave a 25+ year old housing in the engine with unknown wear, and just put new gears in?
As that sounds silly to me, especially if you do have that minute amount of wear, that means your new pump gears now have a little bit more clearance beside them, which means, whelp, you may not get to build a lot of oil pressure or make a lot of flow.

This would be a new pump with new gears. I'm just unclear on whether it's a good idea to run more oil pump flow if you don't actually need said flow. Oil level is set a minute or so after shutting off a warm engine so wouldn't the high RPM oil level in the sump end up lower all things equal? Plan is OEM clearances, main concern in my mind is whether the OEM pump can keep up with the flow requirements of any additional oil coolers.

[MBS206]

27 minutes ago, joshuaho96 said:

This would be a new pump with new gears. I'm just unclear on whether it's a good idea to run more oil pump flow if you don't actually need said flow. Oil level is set a minute or so after shutting off a warm engine so wouldn't the high RPM oil level in the sump end up lower all things equal? Plan is OEM clearances, main concern in my mind is whether the OEM pump can keep up with the flow requirements of any additional oil coolers.

Re read everything that has been written about this in this thread..

Let us know if you're still confused.