RB25DET Camshafts, Camshaft, Cams, Cam

[Brodiemans]

Alright im looking at aftermarket camshafts for an RB25DET engine, now the question is, does anyone know the specifications of the stock camshafts for this engine, im just trying to figure out if the aftermarket Poncams from Tomei are truely worth their money.


And if you are going to post about searching :gives: because I search, and find nothing anywhere on this topic, not everyone is a complete and total idiot.

Thank You

[badboy6686]

http://www.tomei-p.co.jp/_2003web-catalogue/e090_camshaft-specs.html

[drift freaq]

well you make the determination. stock cams have a 240 duration with a 7.80 lift and a lobe center of 120 degrees intake and 117 degrees exhaust.
Stage 1 Tomei Poncams are running a 256 duration i.e which means your valves are held open for that much longer allowing your turbo to force that much more charge into your engine. with a 8.50 lift , for some reason Tomei does not list their lobe centers.
These cams come in earlier than stock cams and tend to pull harder all the way up the rpm band peaking a lot quicker than stock. from the graphs I have seen they look interesting. Is it worth it?
Yes I ripped these off someones ebay sale to show you. These charts are also on Tomei's site as well.

[steve shadows]

well you make the determination. stock cams have a 240 duration with a 7.80 lift and a lobe center of 120 degrees intake and 117 degrees exhaust.
Stage 1 Tomei Poncams are running a 256 duration i.e which means your valves are held open for that much longer allowing your turbo to force that much more charge into your engine. with a 8.50 lift , for some reason Tomei does not list their lobe centers.

Tomei does that because that is the key to the design of the poncam.

The poncam (not the procam) allows you to use a much higher lift with comparably longer duration than many other companys supply while still being same for oem valve springs and the lobe center designs and specific cam profile of the poncam allows for maximum horsepower without needing to adjust cam timimng at all (although a little more power could prolly be pulled out of any aftermarket cam with said adjustmnts).

Im actually going to go with some 270 procams soon, in ex on sr, very good parts. Procam valve springs upgrade is recomended on any motor.

[drift freaq]

Tomei does that because that is the key to the design of the poncam.

The poncam (not the procam) allows you to use a much higher lift with comparably longer duration than many other companys supply while still being same for oem valve springs and the lobe center designs and specific cam profile of the poncam allows for maximum horsepower without needing to adjust cam timimng at all (although a little more power could prolly be pulled out of any aftermarket cam with said adjustmnts).

Im actually going to go with some 270 procams soon, in ex on sr, very good parts. Procam valve springs upgrade is recomended on any motor.

Interesting info Steve, I always had wondered about that. I guess you could call it their secret weapon grind.

[steve shadows]

Japanese love secrets and tomei can afford to keep it. im sure I could figure it out, ill find out once i pick up a set next millenia when i have money! lol

Definitely good pieces, funny thing though, they are almost always back-ordered on the poncams for sr, because ease of install and best grind for drop in performance.

[drift freaq]

Japanese love secrets and tomei can afford to keep it. im sure I could figure it out, ill find out once i pick up a set next millenia when i have money! lol

Definitely good pieces, funny thing though, they are almost always back-ordered on the poncams for sr, because ease of install and best grind for drop in performance.
hahahhahhahahhahahahahaha, I think this pretty much answers Brodiemans question with tech, humor and insight.

[Brodiemans]

yeah pretty much, now i have a few more questions for you ultimate Nissan guys, any idea how high the stock valve train can rev on the RB25DET? and what after market valve train parts are out there and how high can the engine be spun to with those parts?

I read with the Tomei valve springs it can be spun to an 8500 redline safely, any other companies that can take it higher then that?

[steve shadows]

I would have to agree with Tomei in terms of long term saftey

8500 sounds just right!

[eh?]

It's the lifters that will limit you first, not the valve springs. I've read the stock head will rev to 8k fine without any float. I've had mine up to 7.5k daily without any issues.
If you have an R33 motor I'd worry about the oil pump before I'd worry about the head.

[Brodiemans]

alright, so say lifters, valve springs and a different oil pump, my goal is to rev to about 9k or so, what brands would you use and everything

Ive never seen an aftermarket oil pump, whats the problem with the stock one?

[Brodiemans]

Anyone know?

[eh?]

The oil pump gear can and does crack. Tomei, HKS, grex, jun, nismo all make oil pumps.

Why the fixation on 9k rpm though? The rods and rod bolts will not take that daily. You'll run into a oil starvation problem too. Then there's the issue if you do get an aftmkt oil pump you'll need to have the crankshaft snout modified..

Just cut to the chase.. how much money do you have to spend?

[sepulchral]

9k.. is just gay :D

[Brodiemans]

honestly, while its my daily driver i dont really want to take it past 8k, but sometime in the future i think im going to tear it down and buy an RB30 block and see where i can go with that fully built, i was just curious, i would like to hit 9-10k once the engine is fully built, talking years from now