Twin Hks Gt2530 - Rb26 - What Camshafts To Reach Full Potential?

[rev210]

Im pretty sure tomei poncams run best at the zero setting after what I remember reading from SK posts. The other tomei cams most likely need some timing adjustments.

Correct me if Im wrong and Ill get our 32 gtr retuned with timing adjustments on the poncams

You are wrong.

[180bfj20det]

You are wrong.

Indeed I am!!!!!!! I got confused with the rb25 which is best at 0 as per SK post below....

Great thread guys.

I just need to clear something up here, I have used the Tomei 256/260 Poncams in 2 X RB25's, one Neo in an R34GTT and one non Neo in an R33 GTST. Neither of them benefitted from having an adjustable exhaust camshaft pulley, they both made their best average power at zero degrees adjustment. The Poncams work very well with the VVT, I kept it, so no adjustable inlet camshaft pulley.

This has not been my experience with GTR's, they ALWAYS benefit from adjustable inlet and exhaust camshaft pulleys. The more extensive the mods, the more they benefit and no two engines are the same.

Hope that clarifies:cheers:

BUT, how many times do you feel happier when youre told youre wrong...time to make some timing changes and pay attention to the car.

[rev210]

now you are right, and on the way to more power

[Owgasm]

Ok, Great. I guess i'll be getting some cam pulleys.

Are there any differences in Cam Pulleys beside "adjustable" ones?

Any recommended ones? are HKS, TOMEI, JUN etc just names but all pulleys the same?

[rev210]

The HKS ones are the easiest to adjust in my opinion having only three bolts to loosen/ do up. They all do the job.

[700HP-GTR33]

Ok, Great. I guess i'll be getting some cam pulleys.

Are there any differences in Cam Pulleys beside "adjustable" ones?

Any recommended ones? are HKS, TOMEI, JUN etc just names but all pulleys the same?

Why would you not buy the set as I have indicated?

You will be saving 100's.......

[Owgasm]

Because i have decided to go big.

260 in/ex and 10.8 lift.

So looking for suitable cam pulleys.

btw. The F-Con, i'll see what happens about getting it tuned.

If not, i will change it.

[700HP-GTR33]

Because i have decided to go big.

260 in/ex and 10.8 lift.

So looking for suitable cam pulleys.

btw. The F-Con, i'll see what happens about getting it tuned.

If not, i will change it.

Ok...that is great to see.....

You have made a good choice.

Bear in mind.....

You may want to also buy these parts

http://www.nengun.com/tomei/cam-bearing-cap-studs

http://www.nengun.com/tomei/valve-springs

http://www.nengun.com/tomei/valve-lifters

http://www.nengun.com/tomei/valve-guide

This is why I choose Poncams(although I did replace the stud caps only)..the greater the revs and lift..the more money you will need.

[Owgasm]

Looks like i may have to continue with what i'm doing.

With the Valve Springs.

Which one is most suitable for the 10.8 lift?

Thanks

[The Dan]

The higher the lift generally means the Higher power at higher rpm.

Not so.

The trick to selecting a good camshaft in a turbocharged engine is to match it to the turbo.

The higher lift will increase torque and, therefore, power overall.

The duration of the camshaft will determine where the camshaft is MOST efficient.

If your turbos are starting to make most of their power from about 3.5-4K (which I would expect out of 2530's) then you would want to select a camshaft that suits that powerband. Therefore, I would not be going any higher than the 264's. This duration will be at it's most efficient at the same time the turbos are making their power.

The higher you can get your lift, the more torque you will make. The duration shifts the powerband up or down but be careful not to go too high as the longer the duration, the narrower the powerband becomes.

Also if you select anything over 9.15mm lift, you will need to change springs etc. Try to buy the springs from the same manufacturer as the camshafts as this will ensure no hickups....they are designed together.

[Owgasm]

Thank you.

What you say sounds exactly what i'm looking for and i've started to head that way already.

Currently got Tomei Procams 260 in/ex.

Now just need all the components to match it and put it all in at the same time.

So like you said, same manufaturer = tomei.

Will the Guides, Lifter, Springs... finish it off?

Are there different kinds or is there just the one type of these items?

Thanks

[700HP-GTR33]

Thank you.

What you say sounds exactly what i'm looking for and i've started to head that way already.

Currently got Tomei Procams 260 in/ex.

Now just need all the components to match it and put it all in at the same time.

So like you said, same manufaturer = tomei.

Will the Guides, Lifter, Springs... finish it off?

Are there different kinds or is there just the one type of these items?

Thanks

I am now very curious...

Why are you selling your cams when you want to install them?

Why are you looking for all these items when you don't want your cams.

Or have I missed something?

[Owgasm]

Hey,

Yeah, thats why i said i may follow through on my plans.

Though first i gota find out how much the complete set up will cost, with those other parts. If its way too much then as i've listed, i'll sell the cams.

Sorry for the confusion.

Thanks

[Owgasm]

....So like you said, same manufaturer = tomei.

Will the Guides, Lifter, Springs... finish it off?

Are there different kinds or is there just the one type of these items? ...

Thanks

[Swiper the Fox]

The power and respose of our HKS 2530 engine with Tomei 260's is well documented over 460KW at the wheels with the response of nearly a stocker...just be careful not to do too much to the ports or the response will be lost.

[Owgasm]

460KW at the wheels?

That is extreme. What was/is necessary for that to be accomplished.

I want the most response possible thats why i'm trying to do everything correctly and not over do it and produce alot of hp and less response. What is too much done though?

Thanks for the comments, greatly appreciated.

[Swiper the Fox]

460KW at the wheels?

That is extreme. What was/is necessary for that to be accomplished.

I want the most response possible thats why i'm trying to do everything correctly and not over do it and produce alot of hp and less response. What is too much done though?

Thanks for the comments, greatly appreciated.

Extreme...ITS OFF THE HOOK!!

yeah...467 actually @ Powercruise Dyno comp under full competition/shootout conditions.

you want to leave as much material in the exhaust port...so just a polish on that side. Removing the material on that side will cause the gas velocity to decrease and the "hit" on the turbine wheel to soften. A mild port on the inlet side to allow the extra air to enter the combustion chamber without restriction is a plus...just remember to have the port rough swirled NOT polished at the end of the porting (this will aid in even distribution of the air fuel mix in the cylinder).

[R31Nismoid]

460KW at the wheels?

That is extreme. What was/is necessary for that to be accomplished.

I want the most response possible thats why i'm trying to do everything correctly and not over do it and produce alot of hp and less response. What is too much done though?

Thanks for the comments, greatly appreciated.

Lots and lots of race fuel :sorcerer:

[Swiper the Fox]

Lots and lots of race fuel :sorcerer:

to be fair it was in RWD @ 35psi and yes it was race fuel but not C16 it was on VP103 unleaded at Powercruise.

it would make over 440kw everyday in 4WD @ 34psi on C16 and around 400 on pump fuel

[R31Nismoid]

Meh, i love race fuel, you love race fuel

We are all happily in love