rb25det oem oil pump or an nismo n1 oil pump??

[supersayianjim]

so i brought this oil pump and brand new cog over 2 years ago. then only after getting it, i heard the horrors of the n1 oil pump. so in the box it sat.





so now my rb bredren just for a piece of mind(or maybe iam overdoing it). iam looking at the options of installing this on my 25. i don't have $500.00 to spend on a remaix oil gear(and there out of stock for n1 pumps). but the oem one i had for the 20 did me no wrong and i was very happy with it.

so my options are

-stick with the oem one thats on there

-chance it and put that shiny new n1 on there

-sell myself some more and buy a new oem unit for $200.00

what do you guys think???

[Daryl @ RightDrive]

The problem with N1 pumps is not the pump, it's the user.
There are 3 different pumps that Nissan makes.

1) OEM pump, geared for normal street use, with factory rev limiter. OK for racing, as long as OEM rev limits are adhered to.

2) N1 pump - made by, and branded Genuine Nissan. These are identical to the OEM pump. They are geared towards driving that is more centered around higher rpm usage, BUT WITHIN OEM REV LIMITS.

3) Nismo pump - this is made by, and branded Nismo. These pumps are rated for rpm limits higher than the OEM and N1 pumps. The Nismo pump flows more and is more durable. The Nismo pumps are comparable to Tomei, HKS, Jun, Nitto etc., however all the pumps have slightly different flow rates and rpm limits.

I've probably had to explain this over 100 times in the past 7 years of owning/managing performance shops.

AN N1 PUMP IS NOT A NISMO PUMP

One of the reasons N1 pumps have gotten a bad name is because people mistskenly think they are Nismo pumps, rev the s**t out of them and blow them up. So like I said, N1 pumps are not the problem, it's the user. The pumps are being abused and letting go.

OEM pumps are very good as long as the OEM rev limit is adhered to. I've raced my car on long, high speed circuits such as Suzuka, with extended periods of full throttle, as well as smaller circuits that are gas/brake constantly. I've never had a problem with lubrication over the years.
Hope that helps!

[supersayianjim]

thank you sir. but isn't it true that oem oil pumps have a bigger gear than nismo oil pumps???

http://www.ebay.com/itm/261108483848?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

"Reimax gears are constructed from SCM430H material- Chrome Moly

Alloying elements include chromium and molybdenum, and as a result these materials are often referred to as chromoly steel or CRMO. They have an excellent strength to weight ratio, are easily welded and are considerably stronger and harder than standard 1020 steel.

Reinik/Reimax, Nismo = SCM430H Pump Gears.

N1.............77mm x 11mm
STD...........81mm x 11mm
Nismo.........77mm x 11mm

REIMAX race pump on my other auction is 85mm x 12mm for the track or street serious racer with more than 800HP and up to 8500 RPMs"


and what is the max oem rev limits??? i don't plan on going anywhere neaR 800whp on this setup. id be happy with a modest 400whp-500 realistically.

[Skym]

Like you have mentioned there should be hp (at engine), rev limit's the oil pump is good to. Around 500hp at engine is the reliable limit for N1 engine (proven at Nurburgring 24 hour race) and from memory stock revlimit's are around 7500-8000rpm (there's more than one revlimiter, one is a soft cut revlimiter and the other a hard cut revlimiter).

Group-A oil pump (Reimax oil pump) teeth are 1mm thicker than N1 oil pump gears and is 85mm with rotor size. Same material as used on upgraded N1 oil pump gears, which is where it might be thought of as being the same.

N1 oil pump should be higher pressure than OEM oilpump (there's a good reason behind this, ask a engine builder). There are the stronger Reimax gears for N1 oil pump that as mentioned are made of a stronger material.

[supersayianjim]

so, would a higher pressure oil pump hurt or help the engine not going outside the rev limitations??

[Skym]

I read that you can shim the oil pressure relief valve, so oil pressure rises with stock oil pump. Not sure if that's a good idea (best to ask a engine builder).

Engine builder can advise what oil pressure you need for clearances based on their experience, calculations, etc (there's alot to take into account and engine builder needs to know specs of engine, etc). With stock clearances being so tight it makes sense that stock lower pressure oil pump is used and thinner 5w30 oil to suit clearances (they should mention oil that was used when measuring oil pressure and stock is with 5w30 or 7.5w30 in manual, but 5w30 is the closest off the shelf).

[supersayianjim]

i run 15w-30 in my rb

[Skym]

From what I understand, the 15 is the cold start thickness. The w30 is when oil is warm and depends on clearances of engine (cst rating / thickness of oil, as clearances take into account oil thickness), oiltemps (cst rating / thickness of oil at that oiltemp).

If you look at this -

http://www.opieoils.co.uk/pdfs/tech-articles/10w-60-oil.pdf

They mention cst rating at 100 degrees C (what they test it at) for w30, w40, w50, etc. Factory is a w30 when engine is new.

I use 10W40, as is used on a lightly modified RB engine up to 120 degrees C oiltemps for short periods (it's usually 90-100 degrees C after a drive) and has done some km, so clearances have widened. But I think I should be running 5w40 for better cold start. If on racetrack oiltemps can reach 110-120+ for long periods, so a w50 is used. But thats a stock engine and would change with a forged engine (clearances, thickness of oil), etc.