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Tomei poncam 256 duration 8.5mm lift

HKS inlet 256 duration 8.8mm lift exhaust 264 duration 9mm lift

Been researching a good drop in cam for my rb25det that has a 3litre bottom end with a gt3582R, i know most people recommend the tomei poncams as the best drop in cam, which from what i gather means they are the easiest to just drop in line up and drive away with no dialling in required.. but from the specifications it appears that the HKS camshaft would be a bit better match up for what im after, with it having more lift and a bit more duration on the exhaust than the intake.

How does the hks cam compare to the poncams in terms of added performance? and ease of installation? Mid range torque? do they need much adjustment/dialling in from the factory positions? Adjusting the exhaust cam is easy enough on the dyno with some adjsutable cam gears.. but the intake cam looks to be a bit harder to adjust, even with the vct adjsutable cam gear.. it looks like the cam gear would have to be removed to be adjusted? Is there a way to set up the inlet cam gear so it can be adjusted without removing it?

Is it really worth the added hassle of setting up the hks camshafts?? Would running a tomei poncam for the inlet with the larger duration hks exhaust cam gear be a better match up??

Feel free to add any personal experiences with either of the cams, differences experienced in the mid range in terms of response and power etc

Cheers for any input

Jarrod

I have not used those HKS cams but the relevant Tomei Poncams are hard to beat from a drop in and work well perspective . I have read accounts of the HKS longer period exhaust cam set and no one I remember really liked them very much .

The theory I think is that the longer period exhaust cam is supposed to make up for the RB heads slightly smallish exhaust valves but in order for this type of exhaust cam to work you can't have any significant pressure downstream of the exhaust valves . If you do you get enhanced reversion effects because the longer cam reduces the cylinders trapping efficiency giving you a lower dynamic or effective compression ratio .

I think cams of about equal duration are a better bet in RB road engines and if you are willing to remove the head and have the exhaust valve seats machined for slightly larger valves they go in easily too .

R33 Poncams just work , easy to fit and no real loss anywhere .

A .

Ive been wondering for a while if there worthwhile dropping in, ive read mixed about some guys saying they benifeted then others saying theve ended up going back to stock cams im around the 280kw mark with bolt on mods and going to clean the lifters so may aswel drop some in, if there worth it. What gains could I expect.

So yous reckon just go the poncams? Greenline have them on special at the moment, which is making them look very attractive :laugh:.

What size exhaust valves would you recommend disco?? Crap it may be a little hard to with them all being ceramic coated =/

Jarrod

Ah i found the ones you were talking about on ebay, i had been searching for rb25det poncams so they werent coming up, they are at greenline for 900 including shipping, i may aswell wait for now and get them later on ebay

Jarrod

if you havent heard of jeese streeter you havent been in the import scene long enough haha.

he's an aussie living in japan and sells parts for a living. 100% reliable and trustworthy and cheaper then any store since he doesnt charge much commission.

http://jessestreeter.com/

send an email to him and ask for a price.

ive bought stuff through him for years now.

  • 6 years later...

Hey guys,

Im pretty new to this but have done some reading. I have an r33gtr vspec & just chasing approximately 450-500hp and dont want to touch bottom end. Do i need to upgrade my camshafts? or anything else along the way for the power im chasing. If so what is recommended that wont send me broke as i have already purchased a few items already, atm i have purchased a single turbo kit setup; (6boost manifold, 6262 precision turbo 0.84 rear, twin scroll t4 with the turbosmart prolite50mm waste gate.)  Also purchased 1150cc (e85) injectors & 460LPH walbro pump. 

Just purchased a timing belt kit also, with water pump inlcuded (hence why im asking about camshaft before replacing. )

Already have Power fc that was installed and tuned with old setup which was the N1 twins. 

Would be greatly appreciated with all the help i can get with info. 

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